000
FXUS63 KLBF 241518 AAB
AFDLBF

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1018 AM CDT FRI MAY 24 2013

.SYNOPSIS...
ISSUED AT 334 AM CDT FRI MAY 24 2013

AT 08Z...ANALYSIS OF THE MSL DATA SHOWED LOW PRESSURE CENTERED IN
NORTHWEST COLORADO AND OVER CENTRAL WYOMING. FROM THE LOW IN
COLORADO...A WARM FRONT STRETCHED ACROSS SOUTHERN COLORADO TO
SOUTHWEST KANSAS AND THE TEXAS-OKLAHOMA PANHANDLE. SURFACE DEWPOINTS
IN THE MID 40S TO LOWER 50S HAD SPREAD INTO SOUTHWEST SOUTH DAKOTA
AND WESTERN NEBRASKA. INFRA-RED SATELLITE IMAGERY SHOWED CLOUDS
STREAMING ACROSS THE HIGH PLAINS ON A LOW LEVEL JET OF 40-50KT
INDICATED IN THE WSR-88 RADAR WIND PROFILERS. THE DODGE CITY
SOUNDING FROM YESTERDAY EVENING WOULD INDICATE PRECIPITABLE WATER OF
AN INCH OR HIGHER RIDING IN ON THE LOW LEVEL JET.

&&

.UPDATE...
ISSUED AT 1019 AM CDT FRI MAY 24 2013

WINDS EXPANDED ACROSS NORTH CENTRAL NEBRASKA AS WE BEGAN TO MIX.
SEVERAL SITES NOW ABOVE ADVISORY CRITERIA SO PUT OUT A SHORT FUSED
ADVISORY.

UPDATE ISSUED AT 955 AM CDT FRI MAY 24 2013

UPDATED FORECAST TO ACCOUNT FOR AREAS OF DRIZZLE OVER THE
SOUTHWEST. CUT BACK ON HIGHS SLIGHTLY AND INCREASED WINDS SOME.
TOOK THUNDERSTORMS OUT OF THE FORECAST THIS MORNING.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT FRI MAY 24 2013

THE WARM FRONT LIFTING NORTHWARD FROM SOUTHERN COLORADO WILL GIVE A
FOCUS FOR MOIST AIR LIFTING ACROSS NORTHEAST COLORADO AND SOUTHWEST
NEBRASKA THIS EVENING AND OVERNIGHT. WITH VERY UNSTABLE AIR (SB-CAPE
AT OR ABOVE 3000J/KG)... CONVECTION IS LIKELY TO BE STRONG.
HOWEVER...THE DEEP (0-6KM AGL) BULK SHEAR OVER NORTHEAST COLORADO
WILL NOT BE REAL STRONG (ON THE ORDER OF 35-45KT). STILL...SINCE THE
STORMS WILL MOVE SLOWLY AT 10-15KT AND LOW LEVEL WIND FAVORS
ROTATION...THAT MAY BE SUFFICIENT FOR MARGINALLY LARGE HAIL. IT
APPEARS THOUGH THAT THE GREATEST RISK IS HEAVY RAIN WITH ORGANIZED
CONVECTION DEVELOPING EARLY IN THE EVENING AND PUSHING TO THE
NORTHEAST ACROSS CENTRAL NEBRASKA.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 334 AM CDT FRI MAY 24 2013

SATURDAY CONTINUES TO LOOK ACTIVE IN TERMS OF CONVECTION. SCATTERED
EARLY MORNING SHOWERS/TSTMS WILL BE POSSIBLE...BUT ACTIVITY SHOULD
BE WANING IN WAKE OF EXPECTED FRIDAY NIGHT CONVECTIVE COMPLEX.
ATTENTION THEN TURNS TO SATURDAY AFTERNOON...WHEN ADDITIONAL TSTM
ACTIVITY IS POSSIBLE. AT THIS TIME IT IS UNCLEAR WHERE THE BEST
POTENTIAL WILL EXIST...THIS DUE TO EXPECTED FRIDAY NIGHT STORMS
LIKELY HAVING AN IMPACT ON BOUNDARIES ACROSS THE AREA. THE GEM
REGIONAL MODEL WAS PREFERRED OVER THE NAM...AS IT SEEMS TO HAVE A
BETTER HANDLE ON THE CONVECTIVE ACTIVITY FRIDAY NIGHT. BOTH MODELS
HAVE A FAIRLY DEFINED WARM FRONT SATURDAY AFTERNOON...THE NAM IS
FOCUSED MORE ACROSS NORTH CENTRAL NEBRASKA WITH THE FRONT...WHILE
THE GEM REGIONAL IS FARTHER SOUTH...MORE ACROSS SOUTHERN NEBRASKA.
FEEL THE GEM REGIONAL FARTHER SOUTH SCENARIO IS BEST...AS THE FRONT
LIKELY WILL BE PUSHED SOUTH SOME BY THE FRIDAY NIGHT COMPLEX. IF
CONVECTION IS LESS FRIDAY NIGHT...THEN THE FRONT MAY END UP SOMEWHAT
FARTHER NORTH. REGARDLESS...IT WILL BECOME VERY UNSTABLE NEAR THE
BOUNDARY BY LATE AFTERNOON...WITH BULK SHEAR INCREASING TO 40 KTS OR
GREATER DUE TO BACKED EAST/SOUTHEAST FLOW TO THE NORTH OF THE FRONT.
GFS INDICATES A SUBTLE WAVE EJECTING OUT OF THE WEST COAST UPPER
LEVEL LOW AROUND PEAK HEATING/EARLY EVENING...WILL GIVE THE NEEDED
LIFT TO GET TSTMS GOING. MODELS HAVE BEEN FAIRLY CONSISTENT THE LAST
FEW NIGHTS WITH AN MCS DEVELOPING ACROSS CENTRAL AND EASTERN
NEBRASKA...SO THIS IS WHERE THE HIGHEST POPS WILL BE MAINTAINED.
SEVERE STORMS POSSIBLE...WITH STEEP MID LEVEL LAPSE RATES AND
ADEQUATE TO FAVORABLE DEEP LAYER SHEAR. LARGE HAIL APPEARS TO BE THE
MAIN THREAT...BUT A TORNADO POTENTIAL MAY EXIST JUST NORTH OF THE
WARM FRONT. AGAIN...LATER FORECASTS WILL BETTER DETERMINE WHERE THE
FRONT WILL BE LOCATED. IF SFC BASED STORMS FAIL TO MATERIALIZE NEAR
THE FRONT...THEN CHANCES WILL EXIST FOR ELEVATED STORMS NORTH OF THE
WARM FRONT AS A HEALTHY SOUTHERLY LLJ DEVELOPS SATURDAY EVENING.

CHANCES FOR TSTMS WILL BE NEARLY DAILY SUNDAY THROUGH MUCH OF NEXT
WEEK...AS A LARGE UPPER LEVEL LOW SLOWLY MOVES EAST FROM THE
WESTERN CONUS TOWARDS THE CENTRAL PLAINS. DIFFICULT TO NAIL DOWN
WHEN AND WHERE STORMS WILL BE...BUT EVENING THROUGH THE OVERNIGHT
HOURS WILL BRING THE BEST CHANCE EACH DAY. SOME SEVERE STORMS
POSSIBLE FROM TIME TO TIME...BUT AGAIN EACH DAYS STORMS WILL
DICTATE WHERE THE BEST FOCUS FOR THE NEXT DAY WILL BE.

TEMPERATURE WISE...WARM PERIOD EXPECTED...WITH HIGHS MAINLY IN THE
70S AND 80S...AND LOWS IN THE 50S WEST TO 60S EAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI MAY 24 2013

STRATUS WILL CONTINUE SPREADING OVER WESTERN NEBRASKA AND IS LIKELY
TO BRING THE WIDESPREAD CEILINGS OF 1000-2000 FEET AGL...FIRST AT
LBF AND WEST AROUND 13Z AND THEN VTN AND WEST AROUND 15Z. LOW CLOUDS
WILL CONTINUE THROUGH THE DAY...THOUGH CEILINGS MAY GO ABOVE 2000
FEET AGL. THUNDERSTORMS THIS EVENING WILL BRING HIGHER CEILINGS TO
IML...OGA AND LBF FROM 00-03Z THEN BBW AND POSSIBLY TIF 03-06Z. HAIL
CAN BE EXPECTED WITH THUNDERSTORMS...AND WIND NEAR THE STORMS WILL
BECOME VARIABLE AND MAY GUST OVER 45KT.

LATE TONIGHT AFTER THE STORMS CLEAR THE AREA...STRATUS IS LIKELY TO
RETURN AND CONTINUE INTO SATURDAY.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ005>010-026>029-
038.

&&

$$

UPDATE...POWER
SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...TAYLOR
AVIATION...SPRINGER

000
FXUS63 KLBF 241454 AAA
AFDLBF

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NORTH PLATTE NE
954 AM CDT FRI MAY 24 2013

.SYNOPSIS...
ISSUED AT 334 AM CDT FRI MAY 24 2013

AT 08Z...ANALYSIS OF THE MSL DATA SHOWED LOW PRESSURE CENTERED IN
NORTHWEST COLORADO AND OVER CENTRAL WYOMING. FROM THE LOW IN
COLORADO...A WARM FRONT STRETCHED ACROSS SOUTHERN COLORADO TO
SOUTHWEST KANSAS AND THE TEXAS-OKLAHOMA PANHANDLE. SURFACE DEWPOINTS
IN THE MID 40S TO LOWER 50S HAD SPREAD INTO SOUTHWEST SOUTH DAKOTA
AND WESTERN NEBRASKA. INFRA-RED SATELLITE IMAGERY SHOWED CLOUDS
STREAMING ACROSS THE HIGH PLAINS ON A LOW LEVEL JET OF 40-50KT
INDICATED IN THE WSR-88 RADAR WIND PROFILERS. THE DODGE CITY
SOUNDING FROM YESTERDAY EVENING WOULD INDICATE PRECIPITABLE WATER OF
AN INCH OR HIGHER RIDING IN ON THE LOW LEVEL JET.

&&

.UPDATE...
ISSUED AT 955 AM CDT FRI MAY 24 2013

UPDATED FORECAST TO ACCOUNT FOR AREAS OF DRIZZLE OVER THE
SOUTHWEST. CUT BACK ON HIGHS SLIGHTLY AND INCREASED WINDS SOME.
TOOK THUNDERSTORMS OUT OF THE FORECAST THIS MORNING.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT FRI MAY 24 2013

THE WARM FRONT LIFTING NORTHWARD FROM SOUTHERN COLORADO WILL GIVE A
FOCUS FOR MOIST AIR LIFTING ACROSS NORTHEAST COLORADO AND SOUTHWEST
NEBRASKA THIS EVENING AND OVERNIGHT. WITH VERY UNSTABLE AIR (SB-CAPE
AT OR ABOVE 3000J/KG)... CONVECTION IS LIKELY TO BE STRONG.
HOWEVER...THE DEEP (0-6KM AGL) BULK SHEAR OVER NORTHEAST COLORADO
WILL NOT BE REAL STRONG (ON THE ORDER OF 35-45KT). STILL...SINCE THE
STORMS WILL MOVE SLOWLY AT 10-15KT AND LOW LEVEL WIND FAVORS
ROTATION...THAT MAY BE SUFFICIENT FOR MARGINALLY LARGE HAIL. IT
APPEARS THOUGH THAT THE GREATEST RISK IS HEAVY RAIN WITH ORGANIZED
CONVECTION DEVELOPING EARLY IN THE EVENING AND PUSHING TO THE
NORTHEAST ACROSS CENTRAL NEBRASKA.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 334 AM CDT FRI MAY 24 2013

SATURDAY CONTINUES TO LOOK ACTIVE IN TERMS OF CONVECTION. SCATTERED
EARLY MORNING SHOWERS/TSTMS WILL BE POSSIBLE...BUT ACTIVITY SHOULD
BE WANING IN WAKE OF EXPECTED FRIDAY NIGHT CONVECTIVE COMPLEX.
ATTENTION THEN TURNS TO SATURDAY AFTERNOON...WHEN ADDITIONAL TSTM
ACTIVITY IS POSSIBLE. AT THIS TIME IT IS UNCLEAR WHERE THE BEST
POTENTIAL WILL EXIST...THIS DUE TO EXPECTED FRIDAY NIGHT STORMS
LIKELY HAVING AN IMPACT ON BOUNDARIES ACROSS THE AREA. THE GEM
REGIONAL MODEL WAS PREFERRED OVER THE NAM...AS IT SEEMS TO HAVE A
BETTER HANDLE ON THE CONVECTIVE ACTIVITY FRIDAY NIGHT. BOTH MODELS
HAVE A FAIRLY DEFINED WARM FRONT SATURDAY AFTERNOON...THE NAM IS
FOCUSED MORE ACROSS NORTH CENTRAL NEBRASKA WITH THE FRONT...WHILE
THE GEM REGIONAL IS FARTHER SOUTH...MORE ACROSS SOUTHERN NEBRASKA.
FEEL THE GEM REGIONAL FARTHER SOUTH SCENARIO IS BEST...AS THE FRONT
LIKELY WILL BE PUSHED SOUTH SOME BY THE FRIDAY NIGHT COMPLEX. IF
CONVECTION IS LESS FRIDAY NIGHT...THEN THE FRONT MAY END UP SOMEWHAT
FARTHER NORTH. REGARDLESS...IT WILL BECOME VERY UNSTABLE NEAR THE
BOUNDARY BY LATE AFTERNOON...WITH BULK SHEAR INCREASING TO 40 KTS OR
GREATER DUE TO BACKED EAST/SOUTHEAST FLOW TO THE NORTH OF THE FRONT.
GFS INDICATES A SUBTLE WAVE EJECTING OUT OF THE WEST COAST UPPER
LEVEL LOW AROUND PEAK HEATING/EARLY EVENING...WILL GIVE THE NEEDED
LIFT TO GET TSTMS GOING. MODELS HAVE BEEN FAIRLY CONSISTENT THE LAST
FEW NIGHTS WITH AN MCS DEVELOPING ACROSS CENTRAL AND EASTERN
NEBRASKA...SO THIS IS WHERE THE HIGHEST POPS WILL BE MAINTAINED.
SEVERE STORMS POSSIBLE...WITH STEEP MID LEVEL LAPSE RATES AND
ADEQUATE TO FAVORABLE DEEP LAYER SHEAR. LARGE HAIL APPEARS TO BE THE
MAIN THREAT...BUT A TORNADO POTENTIAL MAY EXIST JUST NORTH OF THE
WARM FRONT. AGAIN...LATER FORECASTS WILL BETTER DETERMINE WHERE THE
FRONT WILL BE LOCATED. IF SFC BASED STORMS FAIL TO MATERIALIZE NEAR
THE FRONT...THEN CHANCES WILL EXIST FOR ELEVATED STORMS NORTH OF THE
WARM FRONT AS A HEALTHY SOUTHERLY LLJ DEVELOPS SATURDAY EVENING.

CHANCES FOR TSTMS WILL BE NEARLY DAILY SUNDAY THROUGH MUCH OF NEXT
WEEK...AS A LARGE UPPER LEVEL LOW SLOWLY MOVES EAST FROM THE
WESTERN CONUS TOWARDS THE CENTRAL PLAINS. DIFFICULT TO NAIL DOWN
WHEN AND WHERE STORMS WILL BE...BUT EVENING THROUGH THE OVERNIGHT
HOURS WILL BRING THE BEST CHANCE EACH DAY. SOME SEVERE STORMS
POSSIBLE FROM TIME TO TIME...BUT AGAIN EACH DAYS STORMS WILL
DICTATE WHERE THE BEST FOCUS FOR THE NEXT DAY WILL BE.

TEMPERATURE WISE...WARM PERIOD EXPECTED...WITH HIGHS MAINLY IN THE
70S AND 80S...AND LOWS IN THE 50S WEST TO 60S EAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI MAY 24 2013

STRATUS WILL CONTINUE SPREADING OVER WESTERN NEBRASKA AND IS LIKELY
TO BRING THE WIDESPREAD CEILINGS OF 1000-2000 FEET AGL...FIRST AT
LBF AND WEST AROUND 13Z AND THEN VTN AND WEST AROUND 15Z. LOW CLOUDS
WILL CONTINUE THROUGH THE DAY...THOUGH CEILINGS MAY GO ABOVE 2000
FEET AGL. THUNDERSTORMS THIS EVENING WILL BRING HIGHER CEILINGS TO
IML...OGA AND LBF FROM 00-03Z THEN BBW AND POSSIBLY TIF 03-06Z. HAIL
CAN BE EXPECTED WITH THUNDERSTORMS...AND WIND NEAR THE STORMS WILL
BECOME VARIABLE AND MAY GUST OVER 45KT.

LATE TONIGHT AFTER THE STORMS CLEAR THE AREA...STRATUS IS LIKELY TO
RETURN AND CONTINUE INTO SATURDAY.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...POWER
SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...TAYLOR
AVIATION...SPRINGER

000
FXUS63 KGID 241421
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
921 AM CDT FRI MAY 24 2013

.UPDATE...
ISSUED AT 920 AM CDT FRI MAY 24 2013

FCST TSTM ACTIVITY IS NOT EVOLVING AS EXPECTED. SO POPS WERE
SLASHED THRU NOON. 12Z LBF SOUNDING SHOWS A CAP FOR ELEVATED
PARCELS JUST BELOW 600 MB. WE ARE SEEING SHWRS DEVELOP OVER NW KS.
A SUBTLE SHRTWV TROF IS OVER ERN CO IN WV IMAGERY. TOUGH TO GET A
FEEL FOR HOW THINGS EVOLVE TODAY. OBSERVED AND FCST SOUNDINGS SHOW
A LOT OF CINH IN THE 800-700 MB LAYER. BELIEVE WE WILL HAVE TO
WATCH POTENTIAL FOR AN ISOLATED TSTM OR TWO BASED ON MULTIPLE
MODELS ATTEMPTING TO FIRE CONVECTION.

ALSO DECREASED FCST CLOUD COVER E OF HWY 281 PER VIS SATPIX.

WIND: THE PRES GRADIENT IS TIGHT. WINDS WERE INCREASED THRU 23Z.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM CDT FRI MAY 24 2013

FOCUS IS ON TSTM POTENTIAL THRU TONIGHT.

THE PATTERN ALOFT FEATURED A CLOSED UPPER LOW PRESSURE SYSTEM IN THE
PACIFIC NORTHWEST...RIDGING ACROSS THE INTERIOR CONUS...AND A TROUGH
TO THE EAST THRU THE OHIO VALLEY.  AT THE SFC...LOW PRESSURE WAS
LOCATED IN THE ROCKIES...WITH SOUTHEASTERLY LLVL IN PLACE ACROSS OUR
REGION.  SATELLITE IMAGERY INDICATES LOW CLOUD COVER INCREASING IN
COVERAGE ALONG THE HIGH PLAINS AND INTO WESTERN NEB/KS AS MOISTURE
ADVECTS NORTHWARD.

THE LOW CLOUD COVER WILL CONTINUE TO DEVELOP/EXPAND ACROSS
CENTRAL/EASTERN NEB/KS DURING THE PRE DAWN HOURS WITH CHCS FOR
SHOWERS/TSTMS INCREASING TOWARD DAYBREAK IN OUR WESTERN ZONES IN
WAA/THETA E ADVECTION...WITH THE CONVECTIVE ACTIVE SPREADING
EAST/NORTHEAST TODAY.  AN INSTABILITY AXIS OF AROUND 1000 J/KG ALONG
THE HIGH PLAINS EARLY THIS MORNING WILL MIGRATE EASTWARD...AND MAY
TOP 1000 J/KG ACROSS OUR WESTERN ZONES BY EVENING...WHILE SHEAR IS
AROUND 30KTS.  IN INCREASING INSTABILITY AND DECENT SHEAR...WE COULD
SEE A FEW STRONG STORMS.

THE SFC GRADIENT TIGHTENS BY MID DAY AND SOUTH/SOUTHEASTERLY WINDS
WILL BE ON THE INCREASE WITH CONDITIONS AT LEAST BREEZY IN THE 15 TO
25 MPH RANGE...AND POTENTIALLY HIGHER WITH GUSTS OF 30 MPH OR SO.
HAVE KEPT TEMPS RIGHT AROUND 70F FOR HIGHS TODAY WHICH IS A
COMPROMISE BETWEEN GUIDANCE WITH NAM/MET SUGGESTING TEMPS WARMER THAN
GFS/MAV.  TODAY IS NOT LOOKING LIKE A RAINOUT BUT THERE WILL BE
SCATTERED CONVECTION AROUND.

FOR TONIGHT...HAVE FOLLOWED CLOSER TO THE 3KM WRF...AND THE
GFS...GEM REGIONAL WITH CONVECTION DEVELOPING ALONG THE HIGH
PLAINS...WITH POTENTIAL FOR STORMS TO ORGANIZE AND ROLL EASTWARD AS
AN MCS OVERNIGHT.  INSTABILITY OVERNIGHT IS PROGGED AROUND 1500 J/KG
WITH SHEAR AGAIN REMAINING AROUND 30KTS...AND AGAIN STRONG TO SEVERE
STORMS ARE POSSIBLE WITH HAIL/WIND THE PRIMARY HAZARDS.
PRECIPITABLE WATER VALUES ARE JUST OVER AN INCH AND SOME DECENT
RAINFALL AMOUNTS MAY BE REALIZED IF STORMS DEVELOP AS MODELS
SUGGEST.  FOR LOWS...WE ARE LOOKING AT MILDER TEMPS DUE TO THE
INCREASE IN MOISTURE/DPS WITH READINGS EXPECTED TO BE AROUND 60F.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 455 AM CDT FRI MAY 24 2013

NEEDLESS TO SAY...THIS IS SHAPING UP TO BE A VERY ACTIVE 6-DAY
PERIOD...WITH SEVERAL...OFF-AND-ON CHANCES FOR THUNDERSTORMS...AND
LIKELY AT LEAST A FEW ROUNDS OF SEVERE STORMS AND LOCALLY HEAVY
RAINFALL...AS WE FINALLY GET INTO A PATTERN WITH CONVECTIVE
INSTABILITY CONSISTENTLY CLIMBING AT/ABOVE 1000 J/KG. ON A
POSITIVE NOTE...THIS WEATHER PATTERN SHOULD RESULT IN DECENT
CUMULATIVE RAINFALL TOTALS FOR ALL/PARTS OF THE CWA THROUGH THE
NEXT WEEK...AIDING DROUGHT RELIEF...THE DOWNSIDE FROM A FORECAST
PERSPECTIVE IS A LACK OF CONFIDENCE IN DAY-TO-DAY DETAILS...WITH
CONVECTIVE CHANCES FOR ONE PARTICULAR DAY/NIGHT LIKELY INFLUENCED
QUITE A BIT BY HOW THE PREVIOUS DAY/NIGHT CONVECTION OR LACK
THEREOF INFLUENCES SURFACE BOUNDARY POSTION...INSTABILITY...ETC.
AS A RESULT...DESPITE THE MULTIPLE PERIODS OF THUNDERSTORM CHANCES
IN THE CURRENT FORECAST...WE REALLY TAKE THIS ONE DAY AT A TIME
IN TERMS OF POSSIBLE SEVERE WEATHER TIMING/PLACEMENT. WOULD NOT BE
SURPRISED THOUGH TO SEE SEVERAL UPCOMING DAYS EVENTUALLY ASSIGNED
A SPC SLIGHT RISK FOR PARTS OF THE AREA...AND OUR LOCAL HAZARDOUS
WEATHER OUTLOOK WILL AT LEAST ATTEMPT TO GIVE SOME ENHANCED DETAIL
TO THE DAY 1-2 TIME FRAME.

LOOKING OVER THIS TIME FRAME FROM A BROAD...SYNOPTIC SCALE
PERSPECTIVE...THE LATEST ECMWF/GFS RUNS ARE IN PRETTY GOOD
AGREEMENT IN GRADUALLY TRANSITIONING MID-UPPER LEVEL FLOW OVER THE
CENTRAL PLAINS FROM QUASI-ZONAL THIS WEEKEND...TO MORE
SOUTHWESTERLY BY MID-WEEK AS A LONGWAVE TROUGH MIGRATES INTO THE
CENTRAL CONUS FROM THE WESTERN STATES. PRIOR TO THE ARRIVAL OF THE
PRIMARY TROUGH...MULTIPLE...LOW AMPLITUDE DISTURBANCES WILL TRACK
INTO THE PLAINS AND INTERACT WITH A GENERALLY EAST-WEST LOW-LEVEL
FRONT THAT WILL LIKELY BE MEANDERING NORTH-SOUTH ACROSS THE REGION
DUE IN PART TO CONVECTIVE OUTFLOW INFLUENCES. AS ALREADY ALLUDED
TO...THE DAILY DETAILS ARE GOING TO BE DIFFICULT TO DISCERN VERY
FAR IN ADVANCE. AS IS OFTEN THE CASE IN THESE PATTERNS...DETERMINISTIC
MODELS SUCH AS THE NAM/GFS SOMETIMES DEVELOP SUSPECT QPF BULLSEYES
AND STRUGGLE WITH CONVECTIVE FEEDBACK ISSUES.

ATTEMPTING TO GIVE AT LEAST A SMALL DEGREE OF GREATER DETAIL TO
SATURDAY/SATURDAY NIGHT...GENERALLY PREFER THE 00Z 4KM-WRF
SIMULATED REFLECTIVITY SOLUTION OF POTENTIAL FRIDAY NIGHT
CONVECTION GRADUALLY EXITING EASTWARD OUT OF THE CWA IN THE
MORNING...WITH A LULL THEN ENSUING FOR MUCH OF THE DAY AS CAPPING
HOLDS NEW DEVELOPMENT AT BAY. HOWEVER...BY THE MID AND ESPECIALLY
LATE AFTERNOON TIME FRAME...THERE IS A LEAST LIMITED POTENTIAL FOR
ISOLATED TO SCATTERED STORM DEVELOPMENT IN THE VICINITY OF AN
WEST-NORTHWEST TO EAST-SOUTHEAST ORIENTED WARM FRONT THAT SETS UP
SOMEWHERE ACROSS CENTRAL/NORTHERN NEBRASKA. WITH THE NAM
ADVERTISING 0-1KM MLCAPE ON THE ORDER OF 3000 J/KG IN THE PRESENCE
OF MODEST 0-6KM BULK SHEAR AROUND 30KT...FAIRLY SLOW-MOVING SEVERE
STORMS AND MAYBE EVEN A SUPERCELL OR TWO IS POSSIBLE...ESPECIALLY
WITHIN THE NORTHEAST 1/2 OF THE CWA...AND SEEMINGLY LESS LIKELY
ACROSS THE SOUTHWEST 1/2 INCLUDING KS ZONES DUE TO STRONGER
CAPPING AWAY FROM THE WARM FRONT. DEPENDING ON WHETHER OR NOT THE
WARM FRONT ACTUALLY SETS UP ACROSS THE CWA...MAY EVEN HAVE TO KEEP
AN EYE OUT FOR A LOW-END TORNADO THREAT GIVEN DECENT LOW LEVEL
SHEAR...BUT THIS RISK STILL SEEMS LOW ENOUGH TO OMIT FROM THE
HAZARDOUS WEATHER OUTLOOK. HEADING INTO THE EVENING AND OVERNIGHT
HOURS...ITS A TOUGH CALL WHETHER OR NOT CONVECTION CONTINUES
FOCUSING WITHIN THE CWA...OR INSTEAD RIDES MORE SO JUST NORTH/EAST
OF OUR AREA ON THE NOSE OF A BROAD 30-40+ KT LOW LEVEL JET. DUE
TO THESE UNCERTAINTIES...FELT IT WOULD BE BEST TO AT LEAST
TEMPORARILY REDUCE POPS SATURDAY NIGHT TO 50 PERCENT ACROSS THE
NORTHEAST CWA...WITH EVEN LOWER CHANCES SOUTHWEST. ALTHOUGH THE
PREVIOUS 60 POPS IN THE NORTHEAST WERE ONLY LOW-END LIKELIES...IT
JUST SEEMS TOO SOON...EVEN AT THIS TIME RANGE...TO ASSIGN THE
LIKELY TERMINOLOGY TO ANY GIVEN AREA. TURNING TO OTHER ELEMENTS OF
SATURDAY WEATHER...DECENT SOUTHERLY BREEZES SUSTAINED 15-20 MPH
WILL PREVAIL MOST AREAS...WITH HIGHER SPEEDS TO AROUND 25 AND
MAYBE EVEN NEARING 30 MPH FOCUSED ACROSS KS ZONES SOUTH OF THE
WARM FRONT. KEPT HIGH TEMPS SIMILAR...RANGING FROM NEAR 80 FAR
NORTHEAST TO NEAR 90 FAR SOUTHWEST...ALTHOUGH THE NAM WOULD
SUGGEST THAT MORE OF THE AREA COULD END UP IN THE UPPER 80S/NEAR
90 THAN CURRENTLY DEPICTED.

SUNDAY/SUNDAY NIGHT...ONCE AGAIN IT GOES WITHOUT SAYING THAT
CONVECTIVE POTENTIAL WILL LIKELY BE SOMEWHAT INFLUENCED ON HOW
SATURDAY NIGHT PLAYS OUT...BUT OTHERWISE ITS MUCH THE SAME STORY
ALTHOUGH POSSIBLY WITH A BIT STRONGER CAPPING INFERRED BY 700MB
TEMPS CLIMBING TO AROUND 12C IN MUCH OF THE CWA. LIKE SATURDAY
THOUGH...THE BEST STORM CHANCES SHOULD FAVOR THE EVENING/OVERNIGHT
VERSUS THE DAYTIME HOURS...AND THUS HAVE ONLY 20-30 POPS DURING
THE DAY...VERSUS 50S SUNDAY NIGHT WHEN CONVECTION COULD DEVELOP
OVERHEAD ALONG THE LOW LEVEL JET...ROLL IN FROM THE WEST IN THE
FORM OF A MESOSCALE CONVECTIVE SYSTEM...OR BOTH. AGAIN
THOUGH...MOST STORM ACTIVITY WOULD TEND TO FAVOR NEBRASKA VERSUS
KS.

IN GENERAL...THIS SAME PATTERN REPEATS ITSELF DURING THE MONDAY-
TUESDAY TIMEFRAME. THEN BY WEDNESDAY-THURSDAY...THERE MAY BE A
RISK FOR A SOMEWHAT MORE ORGANIZED SYNOPTICALLY-EVIDENT SEVERE
WEATHER THREAT AS THE LARGER SCALE TROUGH TO THE WEST APPROACHES
AND SWINGS ACROSS THE PLAINS...ENHANCING MID-UPPER LEVEL FLOW AND
RESULTANT WIND SHEAR. HOWEVER..ITS FAR TOO EARLY TO DIVE INTO ANY
MORE DETAILS AT THIS TIME RANGE.

AS FOR TEMP TRENDS THROUGH THE SUNDAY-THURSDAY TIME FRAME...MADE
LITTLE CHANGE...WITH HIGHS AVERAGING SOMEWHERE IN THE 80S...AND
LOWS MAINLY LOW-MID 60S.

ON ONE LAST NOTE...ALTHOUGH LOCALIZED FLOODING ISSUES CERTAINLY
CANNOT BE RULED OUT AT TIMES DURING THE NEXT WEEK...ESPECIALLY IF
THE SAME COUNTIES RECEIVE 1-2+ INCHES OF RAIN TWO OR MORE
DAYS/NIGHTS IN A ROW...WE ARE AT LEAST HEADING INTO THIS PATTERN
WITH A PRETTY DECENT CAPACITY TO ACCEPT WATER GIVEN BELOW NORMAL
RAINFALL ACROSS THE MAJORITY OF THE CWA SO FAR THIS MONTH. AS A
RESULT...RFC 3-HOUR FLASH FLOOD GUIDANCE IS AVERAGING AT LEAST 2-3
INCHES ACROSS THE ENTIRE CWA.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 515 AM CDT FRI MAY 24 2013

A FEW SHOWERS HAVE DEVELOPED WEST OF THE TERMINAL...AND
ADDITIONAL CONVECTIVE DEVELOPMENT IS POSSIBLE TODAY WITH HIT OR
MISS RAIN SHOWERS OR THUNDERSTORMS CARRYING INTO THE AFTERNOON.
TONIGHT...ANOTHER ROUND OF STORMS IS EXPECTED TO DEVELOP ALONG THE
HIGH PLAINS AND MOVE EASTWARD...WITH THE BETTER CHCS FOR KGRI
ARRIVING AFTER DARK. STRONG TO SEVERE STORMS ARE POSSIBLE WITH
LARGE HAIL/DAMAGING WINDS BEING THE PRIMARY HAZARDS. WINDS WILL
INCREASE FROM THE SOUTHEAST TODAY WITH GUSTS AROUND 25KTS. CIGS
HAVE BEEN SLOW TO LOWER TO MVFR...AND HAVE DELAYED ONSET ON THE
LOWER CLOUDS TIL 14Z. SOME POTENTIAL EXISTS FOR IFR CIGS TONIGHT
AND WILL NEED TO MONITOR.


&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...PFANNKUCH
AVIATION...FAY

000
FXUS63 KOAX 241138
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
638 AM CDT FRI MAY 24 2013

.AVIATION...12Z TAFS FOR KOMA...KLNK AND KOFK. MID CLOUDS WILL
PREVAIL THROUGH THE PERIOD WITH WINDS INCREASING TO ABOUT 15 KNOTS
GUSTING TO 25 KNOTS BY 15Z. MID LEVEL IMPULSE COULD TRIGGER
ISOLATED THUNDERSTORMS BY 21-02Z.

DEWALD

&&

.PREV DISCUSSION... /ISSUED 342 AM CDT FRI MAY 24 2013/

DISCUSSION...
LOOKS LIKE QUITE THE ACTIVE WEATHER PATTERN WILL DEVELOP OVER THE
MIDDLE OF THE COUNTRY TODAY AND REMAIN IN PLACE THE NEXT 7 DAYS.
UPPER LOWS/TROUGHS MOVING TOWARD THE EAST COAST AND ALONG THE WEST
COAST WILL KEEP OUR PART OF THE WORLD UNDER WEAK RIDGING AT LEAST
THROUGH SUNDAY. THEN MORE SOUTHWESTERLY FLOW TAKES OVER AS WESTERN
TROUGH MOVES A LITTLE EAST. DESPITE WEAK RIDGING ALOFT...SEVERAL
IMPULSES WILL MOVE OVERHEAD WHICH WILL TRIGGER OFF-AND-ON EPISODES
OF POTENTIAL PRECIPITATION OVER THE WEEKEND.

AT LOWER LEVELS...MOIST SOUTHERLY FLOW AT THE SURFACE THROUGH AT
LEAST 850MB IS FORECAST TO OVERSPREAD ALL OF THE PLAINS LATER TODAY
AND PERSIST THROUGH MUCH OF NEXT WEEK. 850 DEW POINTS WERE ALREADY
10-14C FROM SOUTHWEST KANSAS THROUGH THE TEXAS PANHANDLE...AND THIS
AIR SHOULD BE MOVING INTO WESTERN NEBRASKA TODAY THEN SPREAD EAST
THROUGH WESTERN IOWA TONIGHT. AT THE SURFACE...EASTERLY FLOW WAS
KEEPING DEW POINTS IN THE 40S THIS MORNING...BUT 60S DEW POINTS IN
THE SOUTHERN PLAINS WILL SURGE NORTH AND BECOME ENTRENCHED OVER OUR
CWA ON SATURDAY.

SO WITH MOISTURE BECOMING INCREASINGLY FAVORABLE FOR PRECIPITATION
AND WEAK IMPULSES MOVING OVERHEAD...REALLY CAN NOT RULE OUT AT LEAST
SMALL CHANCES FOR SHOWERS/THUNDER AT ANY TIME THROUGH THE HOLIDAY
WEEKEND. FOR TODAY...MOISTURE WILL NOT BE AS ROBUST...BUT DECENT MID
LEVEL WARM ADVECTION WILL BE SWEEPING THROUGH EASTERN NEBRASKA DURING
THE DAY WITH INITIAL SURGE OF MID LEVEL MOISTURE. ALREADY SEEING
SIGNS OF THAT WARM ADVECTION AS MID LEVEL CLOUDS HAVE EXPANDED FROM
WESTERN INTO CENTRAL NEBRASKA. ONLY PRECIPITATION NOTED SO FAR WAS IN
NORTHWEST KANSAS...BUT SHORT RANGE AND MESOSCALE MODELS ARE ALL
HINTING AT HIT-AND-MISS CONVECTION SPREADING INTO EASTERN NEBRASKA
DURING THE DAY. SO WILL MAINTAIN SMALL CHANCES IN OUR WEST THIS
MORNING...WITH BETTER CHANCES IN THE AFTERNOON AS SOUTHERLY FLOW
BECOMES MORE ROBUST.

PERHAPS THE BEST CHANCES FOR CONVECTION THROUGH THE WEEKEND WILL
COME DURING THE NIGHTTIME HOURS AS LOW LEVEL JET DYNAMICS CONTRIBUTE
TO FORCING. AFTERNOON INSTABILITY WILL CERTAINLY INCREASE EACH DAY
THROUGH MONDAY...AND ANY UPPER IMPULSE COULD RELEASE THAT
INSTABILITY. BUT NAILING DOWN THOSE IMPULSES WITH MUCH MORE THAN A
DAY OR SO LEAD TIME IS NEARLY IMPOSSIBLE. SO FORECAST WILL REFLECT
CHANCES FOR THUNDERSTORMS EACH OF THE NEXT SEVERAL DAYS...WITH
MORE LIKELY POPS COMING DURING THE EVENING AND OVERNIGHT HOURS.

HEAVY RAIN MAY OCCUR WITH ANY OF THESE CONVECTIVE EPISODES AS WELL.
PRECIPITABLE WATER VALUES ARE FORECAST TO COME CLOSE TO 1.5
INCHES...WHICH IS WELL ABOVE NORMAL LEVELS FOR THIS TIME OF YEAR.
PLUS FREEZING LEVELS APPROACHING 13000 FT SUGGEST WARM CLOUD DEPTH
COULD ENHANCE RAINFALL PRODUCTION. WILL HAVE TO WATCH HOW AND WHERE
THINGS DEVELOP OVER THE NEXT COUPLE OF DAYS TO FINE TUNE ANY
POSSIBLE FLOODING CONCERNS.

THE REST OF THE WEEK TUESDAY THROUGH THURSDAY MAY BRING BETTER
CHANCES FOR SEVERE STORMS IN THE CENTRAL PLAINS. WESTERN UPPER
TROUGH SHOULD BE PUSHING INTO THE PLAINS WITH STRONGER MID LEVEL
FLOW AND SLIGHTLY COOLER AIR ALOFT SPREADING INTO THE PLAINS.

DERGAN

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

000
FXUS63 KLBF 241133
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
633 AM CDT FRI MAY 24 2013

.SYNOPSIS...
ISSUED AT 334 AM CDT FRI MAY 24 2013

AT 08Z...ANALYSIS OF THE MSL DATA SHOWED LOW PRESSURE CENTERED IN
NORTHWEST COLORADO AND OVER CENTRAL WYOMING. FROM THE LOW IN
COLORADO...A WARM FRONT STRETCHED ACROSS SOUTHERN COLORADO TO
SOUTHWEST KANSAS AND THE TEXAS-OKLAHOMA PANHANDLE. SURFACE DEWPOINTS
IN THE MID 40S TO LOWER 50S HAD SPREAD INTO SOUTHWEST SOUTH DAKOTA
AND WESTERN NEBRASKA. INFRA-RED SATELLITE IMAGERY SHOWED CLOUDS
STREAMING ACROSS THE HIGH PLAINS ON A LOW LEVEL JET OF 40-50KT
INDICATED IN THE WSR-88 RADAR WIND PROFILERS. THE DODGE CITY
SOUNDING FROM YESTERDAY EVENING WOULD INDICATE PRECIPITABLE WATER OF
AN INCH OR HIGHER RIDING IN ON THE LOW LEVEL JET.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT FRI MAY 24 2013

THE WARM FRONT LIFTING NORTHWARD FROM SOUTHERN COLORADO WILL GIVE A
FOCUS FOR MOIST AIR LIFTING ACROSS NORTHEAST COLORADO AND SOUTHWEST
NEBRASKA THIS EVENING AND OVERNIGHT. WITH VERY UNSTABLE AIR (SB-CAPE
AT OR ABOVE 3000J/KG)... CONVECTION IS LIKELY TO BE STRONG.
HOWEVER...THE DEEP (0-6KM AGL) BULK SHEAR OVER NORTHEAST COLORADO
WILL NOT BE REAL STRONG (ON THE ORDER OF 35-45KT). STILL...SINCE THE
STORMS WILL MOVE SLOWLY AT 10-15KT AND LOW LEVEL WIND FAVORS
ROTATION...THAT MAY BE SUFFICIENT FOR MARGINALLY LARGE HAIL. IT
APPEARS THOUGH THAT THE GREATEST RISK IS HEAVY RAIN WITH ORGANIZED
CONVECTION DEVELOPING EARLY IN THE EVENING AND PUSHING TO THE
NORTHEAST ACROSS CENTRAL NEBRASKA.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 334 AM CDT FRI MAY 24 2013

SATURDAY CONTINUES TO LOOK ACTIVE IN TERMS OF CONVECTION. SCATTERED
EARLY MORNING SHOWERS/TSTMS WILL BE POSSIBLE...BUT ACTIVITY SHOULD
BE WANING IN WAKE OF EXPECTED FRIDAY NIGHT CONVECTIVE COMPLEX.
ATTENTION THEN TURNS TO SATURDAY AFTERNOON...WHEN ADDITIONAL TSTM
ACTIVITY IS POSSIBLE. AT THIS TIME IT IS UNCLEAR WHERE THE BEST
POTENTIAL WILL EXIST...THIS DUE TO EXPECTED FRIDAY NIGHT STORMS
LIKELY HAVING AN IMPACT ON BOUNDARIES ACROSS THE AREA. THE GEM
REGIONAL MODEL WAS PREFERRED OVER THE NAM...AS IT SEEMS TO HAVE A
BETTER HANDLE ON THE CONVECTIVE ACTIVITY FRIDAY NIGHT. BOTH MODELS
HAVE A FAIRLY DEFINED WARM FRONT SATURDAY AFTERNOON...THE NAM IS
FOCUSED MORE ACROSS NORTH CENTRAL NEBRASKA WITH THE FRONT...WHILE
THE GEM REGIONAL IS FARTHER SOUTH...MORE ACROSS SOUTHERN NEBRASKA.
FEEL THE GEM REGIONAL FARTHER SOUTH SCENARIO IS BEST...AS THE FRONT
LIKELY WILL BE PUSHED SOUTH SOME BY THE FRIDAY NIGHT COMPLEX. IF
CONVECTION IS LESS FRIDAY NIGHT...THEN THE FRONT MAY END UP SOMEWHAT
FARTHER NORTH. REGARDLESS...IT WILL BECOME VERY UNSTABLE NEAR THE
BOUNDARY BY LATE AFTERNOON...WITH BULK SHEAR INCREASING TO 40 KTS OR
GREATER DUE TO BACKED EAST/SOUTHEAST FLOW TO THE NORTH OF THE FRONT.
GFS INDICATES A SUBTLE WAVE EJECTING OUT OF THE WEST COAST UPPER
LEVEL LOW AROUND PEAK HEATING/EARLY EVENING...WILL GIVE THE NEEDED
LIFT TO GET TSTMS GOING. MODELS HAVE BEEN FAIRLY CONSISTENT THE LAST
FEW NIGHTS WITH AN MCS DEVELOPING ACROSS CENTRAL AND EASTERN
NEBRASKA...SO THIS IS WHERE THE HIGHEST POPS WILL BE MAINTAINED.
SEVERE STORMS POSSIBLE...WITH STEEP MID LEVEL LAPSE RATES AND
ADEQUATE TO FAVORABLE DEEP LAYER SHEAR. LARGE HAIL APPEARS TO BE THE
MAIN THREAT...BUT A TORNADO POTENTIAL MAY EXIST JUST NORTH OF THE
WARM FRONT. AGAIN...LATER FORECASTS WILL BETTER DETERMINE WHERE THE
FRONT WILL BE LOCATED. IF SFC BASED STORMS FAIL TO MATERIALIZE NEAR
THE FRONT...THEN CHANCES WILL EXIST FOR ELEVATED STORMS NORTH OF THE
WARM FRONT AS A HEALTHY SOUTHERLY LLJ DEVELOPS SATURDAY EVENING.

CHANCES FOR TSTMS WILL BE NEARLY DAILY SUNDAY THROUGH MUCH OF NEXT
WEEK...AS A LARGE UPPER LEVEL LOW SLOWLY MOVES EAST FROM THE
WESTERN CONUS TOWARDS THE CENTRAL PLAINS. DIFFICULT TO NAIL DOWN
WHEN AND WHERE STORMS WILL BE...BUT EVENING THROUGH THE OVERNIGHT
HOURS WILL BRING THE BEST CHANCE EACH DAY. SOME SEVERE STORMS
POSSIBLE FROM TIME TO TIME...BUT AGAIN EACH DAYS STORMS WILL
DICTATE WHERE THE BEST FOCUS FOR THE NEXT DAY WILL BE.

TEMPERATURE WISE...WARM PERIOD EXPECTED...WITH HIGHS MAINLY IN THE
70S AND 80S...AND LOWS IN THE 50S WEST TO 60S EAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI MAY 24 2013

STRATUS WILL CONTINUE SPREADING OVER WESTERN NEBRASKA AND IS LIKELY
TO BRING THE WIDESPREAD CEILINGS OF 1000-2000 FEET AGL...FIRST AT
LBF AND WEST AROUND 13Z AND THEN VTN AND WEST AROUND 15Z. LOW CLOUDS
WILL CONTINUE THROUGH THE DAY...THOUGH CEILINGS MAY GO ABOVE 2000
FEET AGL. THUNDERSTORMS THIS EVENING WILL BRING HIGHER CEILINGS TO
IML...OGA AND LBF FROM 00-03Z THEN BBW AND POSSIBLY TIF 03-06Z. HAIL
CAN BE EXPECTED WITH THUNDERSTORMS...AND WIND NEAR THE STORMS WILL
BECOME VARIABLE AND MAY GUST OVER 45KT.

LATE TONIGHT AFTER THE STORMS CLEAR THE AREA...STRATUS IS LIKELY TO
RETURN AND CONTINUE INTO SATURDAY.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...TAYLOR
AVIATION...SPRINGER

000
FXUS63 KGID 241023
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
523 AM CDT FRI MAY 24 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM CDT FRI MAY 24 2013

FOCUS IS ON TSTM POTENTIAL THRU TONIGHT.

THE PATTERN ALOFT FEATURED A CLOSED UPPER LOW PRESSURE SYSTEM IN THE
PACIFIC NORTHWEST...RIDGING ACROSS THE INTERIOR CONUS...AND A TROUGH
TO THE EAST THRU THE OHIO VALLEY.  AT THE SFC...LOW PRESSURE WAS
LOCATED IN THE ROCKIES...WITH SOUTHEASTERLY LLVL IN PLACE ACROSS OUR
REGION.  SATELLITE IMAGERY INDICATES LOW CLOUD COVER INCREASING IN
COVERAGE ALONG THE HIGH PLAINS AND INTO WESTERN NEB/KS AS MOISTURE
ADVECTS NORTHWARD.

THE LOW CLOUD COVER WILL CONTINUE TO DEVELOP/EXPAND ACROSS
CENTRAL/EASTERN NEB/KS DURING THE PRE DAWN HOURS WITH CHCS FOR
SHOWERS/TSTMS INCREASING TOWARD DAYBREAK IN OUR WESTERN ZONES IN
WAA/THETA E ADVECTION...WITH THE CONVECTIVE ACTIVE SPREADING
EAST/NORTHEAST TODAY.  AN INSTABILITY AXIS OF AROUND 1000 J/KG ALONG
THE HIGH PLAINS EARLY THIS MORNING WILL MIGRATE EASTWARD...AND MAY
TOP 1000 J/KG ACROSS OUR WESTERN ZONES BY EVENING...WHILE SHEAR IS
AROUND 30KTS.  IN INCREASING INSTABILITY AND DECENT SHEAR...WE COULD
SEE A FEW STRONG STORMS.

THE SFC GRADIENT TIGHTENS BY MID DAY AND SOUTH/SOUTHEASTERLY WINDS
WILL BE ON THE INCREASE WITH CONDITIONS AT LEAST BREEZY IN THE 15 TO
25 MPH RANGE...AND POTENTIALLY HIGHER WITH GUSTS OF 30 MPH OR SO.
HAVE KEPT TEMPS RIGHT AROUND 70F FOR HIGHS TODAY WHICH IS A
COMPROMISE BETWEEN GUIDANCE WITH NAM/MET SUGGESTING TEMPS WARMER THAN
GFS/MAV.  TODAY IS NOT LOOKING LIKE A RAINOUT BUT THERE WILL BE
SCATTERED CONVECTION AROUND.

FOR TONIGHT...HAVE FOLLOWED CLOSER TO THE 3KM WRF...AND THE
GFS...GEM REGIONAL WITH CONVECTION DEVELOPING ALONG THE HIGH
PLAINS...WITH POTENTIAL FOR STORMS TO ORGANIZE AND ROLL EASTWARD AS
AN MCS OVERNIGHT.  INSTABILITY OVERNIGHT IS PROGGED AROUND 1500 J/KG
WITH SHEAR AGAIN REMAINING AROUND 30KTS...AND AGAIN STRONG TO SEVERE
STORMS ARE POSSIBLE WITH HAIL/WIND THE PRIMARY HAZARDS.
PRECIPITABLE WATER VALUES ARE JUST OVER AN INCH AND SOME DECENT
RAINFALL AMOUNTS MAY BE REALIZED IF STORMS DEVELOP AS MODELS
SUGGEST.  FOR LOWS...WE ARE LOOKING AT MILDER TEMPS DUE TO THE
INCREASE IN MOISTURE/DPS WITH READINGS EXPECTED TO BE AROUND 60F.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 455 AM CDT FRI MAY 24 2013

NEEDLESS TO SAY...THIS IS SHAPING UP TO BE A VERY ACTIVE 6-DAY
PERIOD...WITH SEVERAL...OFF-AND-ON CHANCES FOR THUNDERSTORMS...AND
LIKELY AT LEAST A FEW ROUNDS OF SEVERE STORMS AND LOCALLY HEAVY
RAINFALL...AS WE FINALLY GET INTO A PATTERN WITH CONVECTIVE
INSTABILITY CONSISTENTLY CLIMBING AT/ABOVE 1000 J/KG. ON A
POSITIVE NOTE...THIS WEATHER PATTERN SHOULD RESULT IN DECENT
CUMULATIVE RAINFALL TOTALS FOR ALL/PARTS OF THE CWA THROUGH THE
NEXT WEEK...AIDING DROUGHT RELIEF...THE DOWNSIDE FROM A FORECAST
PERSPECTIVE IS A LACK OF CONFIDENCE IN DAY-TO-DAY DETAILS...WITH
CONVECTIVE CHANCES FOR ONE PARTICULAR DAY/NIGHT LIKELY INFLUENCED
QUITE A BIT BY HOW THE PREVIOUS DAY/NIGHT CONVECTION OR LACK
THEREOF INFLUENCES SURFACE BOUNDARY POSTION...INSTABILITY...ETC.
AS A RESULT...DESPITE THE MULTIPLE PERIODS OF THUNDERSTORM CHANCES
IN THE CURRENT FORECAST...WE REALLY TAKE THIS ONE DAY AT A TIME
IN TERMS OF POSSIBLE SEVERE WEATHER TIMING/PLACEMENT. WOULD NOT BE
SURPRISED THOUGH TO SEE SEVERAL UPCOMING DAYS EVENTUALLY ASSIGNED
A SPC SLIGHT RISK FOR PARTS OF THE AREA...AND OUR LOCAL HAZARDOUS
WEATHER OUTLOOK WILL AT LEAST ATTEMPT TO GIVE SOME ENHANCED DETAIL
TO THE DAY 1-2 TIME FRAME.

LOOKING OVER THIS TIME FRAME FROM A BROAD...SYNOPTIC SCALE
PERSPECTIVE...THE LATEST ECMWF/GFS RUNS ARE IN PRETTY GOOD
AGREEMENT IN GRADUALLY TRANSITIONING MID-UPPER LEVEL FLOW OVER THE
CENTRAL PLAINS FROM QUASI-ZONAL THIS WEEKEND...TO MORE
SOUTHWESTERLY BY MID-WEEK AS A LONGWAVE TROUGH MIGRATES INTO THE
CENTRAL CONUS FROM THE WESTERN STATES. PRIOR TO THE ARRIVAL OF THE
PRIMARY TROUGH...MULTIPLE...LOW AMPLITUDE DISTURBANCES WILL TRACK
INTO THE PLAINS AND INTERACT WITH A GENERALLY EAST-WEST LOW-LEVEL
FRONT THAT WILL LIKELY BE MEANDERING NORTH-SOUTH ACROSS THE REGION
DUE IN PART TO CONVECTIVE OUTFLOW INFLUENCES. AS ALREADY ALLUDED
TO...THE DAILY DETAILS ARE GOING TO BE DIFFICULT TO DISCERN VERY
FAR IN ADVANCE. AS IS OFTEN THE CASE IN THESE PATTERNS...DETERMINISTIC
MODELS SUCH AS THE NAM/GFS SOMETIMES DEVELOP SUSPECT QPF BULLSEYES
AND STRUGGLE WITH CONVECTIVE FEEDBACK ISSUES.

ATTEMPTING TO GIVE AT LEAST A SMALL DEGREE OF GREATER DETAIL TO
SATURDAY/SATURDAY NIGHT...GENERALLY PREFER THE 00Z 4KM-WRF
SIMULATED REFLECTIVITY SOLUTION OF POTENTIAL FRIDAY NIGHT
CONVECTION GRADUALLY EXITING EASTWARD OUT OF THE CWA IN THE
MORNING...WITH A LULL THEN ENSUING FOR MUCH OF THE DAY AS CAPPING
HOLDS NEW DEVELOPMENT AT BAY. HOWEVER...BY THE MID AND ESPECIALLY
LATE AFTERNOON TIME FRAME...THERE IS A LEAST LIMITED POTENTIAL FOR
ISOLATED TO SCATTERED STORM DEVELOPMENT IN THE VICINITY OF AN
WEST-NORTHWEST TO EAST-SOUTHEAST ORIENTED WARM FRONT THAT SETS UP
SOMEWHERE ACROSS CENTRAL/NORTHERN NEBRASKA. WITH THE NAM
ADVERTISING 0-1KM MLCAPE ON THE ORDER OF 3000 J/KG IN THE PRESENCE
OF MODEST 0-6KM BULK SHEAR AROUND 30KT...FAIRLY SLOW-MOVING SEVERE
STORMS AND MAYBE EVEN A SUPERCELL OR TWO IS POSSIBLE...ESPECIALLY
WITHIN THE NORTHEAST 1/2 OF THE CWA...AND SEEMINGLY LESS LIKELY
ACROSS THE SOUTHWEST 1/2 INCLUDING KS ZONES DUE TO STRONGER
CAPPING AWAY FROM THE WARM FRONT. DEPENDING ON WHETHER OR NOT THE
WARM FRONT ACTUALLY SETS UP ACROSS THE CWA...MAY EVEN HAVE TO KEEP
AN EYE OUT FOR A LOW-END TORNADO THREAT GIVEN DECENT LOW LEVEL
SHEAR...BUT THIS RISK STILL SEEMS LOW ENOUGH TO OMIT FROM THE
HAZARDOUS WEATHER OUTLOOK. HEADING INTO THE EVENING AND OVERNIGHT
HOURS...ITS A TOUGH CALL WHETHER OR NOT CONVECTION CONTINUES
FOCUSING WITHIN THE CWA...OR INSTEAD RIDES MORE SO JUST NORTH/EAST
OF OUR AREA ON THE NOSE OF A BROAD 30-40+ KT LOW LEVEL JET. DUE
TO THESE UNCERTAINTIES...FELT IT WOULD BE BEST TO AT LEAST
TEMPORARILY REDUCE POPS SATURDAY NIGHT TO 50 PERCENT ACROSS THE
NORTHEAST CWA...WITH EVEN LOWER CHANCES SOUTHWEST. ALTHOUGH THE
PREVIOUS 60 POPS IN THE NORTHEAST WERE ONLY LOW-END LIKELIES...IT
JUST SEEMS TOO SOON...EVEN AT THIS TIME RANGE...TO ASSIGN THE
LIKELY TERMINOLOGY TO ANY GIVEN AREA. TURNING TO OTHER ELEMENTS OF
SATURDAY WEATHER...DECENT SOUTHERLY BREEZES SUSTAINED 15-20 MPH
WILL PREVAIL MOST AREAS...WITH HIGHER SPEEDS TO AROUND 25 AND
MAYBE EVEN NEARING 30 MPH FOCUSED ACROSS KS ZONES SOUTH OF THE
WARM FRONT. KEPT HIGH TEMPS SIMILAR...RANGING FROM NEAR 80 FAR
NORTHEAST TO NEAR 90 FAR SOUTHWEST...ALTHOUGH THE NAM WOULD
SUGGEST THAT MORE OF THE AREA COULD END UP IN THE UPPER 80S/NEAR
90 THAN CURRENTLY DEPICTED.

SUNDAY/SUNDAY NIGHT...ONCE AGAIN IT GOES WITHOUT SAYING THAT
CONVECTIVE POTENTIAL WILL LIKELY BE SOMEWHAT INFLUENCED ON HOW
SATURDAY NIGHT PLAYS OUT...BUT OTHERWISE ITS MUCH THE SAME STORY
ALTHOUGH POSSIBLY WITH A BIT STRONGER CAPPING INFERRED BY 700MB
TEMPS CLIMBING TO AROUND 12C IN MUCH OF THE CWA. LIKE SATURDAY
THOUGH...THE BEST STORM CHANCES SHOULD FAVOR THE EVENING/OVERNIGHT
VERSUS THE DAYTIME HOURS...AND THUS HAVE ONLY 20-30 POPS DURING
THE DAY...VERSUS 50S SUNDAY NIGHT WHEN CONVECTION COULD DEVELOP
OVERHEAD ALONG THE LOW LEVEL JET...ROLL IN FROM THE WEST IN THE
FORM OF A MESOSCALE CONVECTIVE SYSTEM...OR BOTH. AGAIN
THOUGH...MOST STORM ACTIVITY WOULD TEND TO FAVOR NEBRASKA VERSUS
KS.

IN GENERAL...THIS SAME PATTERN REPEATS ITSELF DURING THE MONDAY-
TUESDAY TIMEFRAME. THEN BY WEDNESDAY-THURSDAY...THERE MAY BE A
RISK FOR A SOMEWHAT MORE ORGANIZED SYNOPTICALLY-EVIDENT SEVERE
WEATHER THREAT AS THE LARGER SCALE TROUGH TO THE WEST APPROACHES
AND SWINGS ACROSS THE PLAINS...ENHANCING MID-UPPER LEVEL FLOW AND
RESULTANT WIND SHEAR. HOWEVER..ITS FAR TOO EARLY TO DIVE INTO ANY
MORE DETAILS AT THIS TIME RANGE.

AS FOR TEMP TRENDS THROUGH THE SUNDAY-THURSDAY TIME FRAME...MADE
LITTLE CHANGE...WITH HIGHS AVERAGING SOMEWHERE IN THE 80S...AND
LOWS MAINLY LOW-MID 60S.

ON ONE LAST NOTE...ALTHOUGH LOCALIZED FLOODING ISSUES CERTAINLY
CANNOT BE RULED OUT AT TIMES DURING THE NEXT WEEK...ESPECIALLY IF
THE SAME COUNTIES RECEIVE 1-2+ INCHES OF RAIN TWO OR MORE
DAYS/NIGHTS IN A ROW...WE ARE AT LEAST HEADING INTO THIS PATTERN
WITH A PRETTY DECENT CAPACITY TO ACCEPT WATER GIVEN BELOW NORMAL
RAINFALL ACROSS THE MAJORITY OF THE CWA SO FAR THIS MONTH. AS A
RESULT...RFC 3-HOUR FLASH FLOOD GUIDANCE IS AVERAGING AT LEAST 2-3
INCHES ACROSS THE ENTIRE CWA.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 515 AM CDT FRI MAY 24 2013

A FEW SHOWERS HAVE DEVELOPED WEST OF THE TERMINAL...AND
ADDITIONAL CONVECTIVE DEVELOPMENT IS POSSIBLE TODAY WITH HIT OR
MISS RAIN SHOWERS OR THUNDERSTORMS CARRYING INTO THE AFTERNOON.
TONIGHT...ANOTHER ROUND OF STORMS IS EXPECTED TO DEVELOP ALONG THE
HIGH PLAINS AND MOVE EASTWARD...WITH THE BETTER CHCS FOR KGRI
ARRIVING AFTER DARK. STRONG TO SEVERE STORMS ARE POSSIBLE WITH
LARGE HAIL/DAMAGING WINDS BEING THE PRIMARY HAZARDS. WINDS WILL
INCREASE FROM THE SOUTHEAST TODAY WITH GUSTS AROUND 25KTS. CIGS
HAVE BEEN SLOW TO LOWER TO MVFR...AND HAVE DELAYED ONSET ON THE
LOWER CLOUDS TIL 14Z. SOME POTENTIAL EXISTS FOR IFR CIGS TONIGHT
AND WILL NEED TO MONITOR.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.

&&

$$

SHORT TERM...FAY
LONG TERM...PFANNKUCH
AVIATION...FAY

000
FXUS63 KGID 240957
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
457 AM CDT FRI MAY 24 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM CDT FRI MAY 24 2013

FOCUS IS ON TSTM POTENTIAL THRU TONIGHT.

THE PATTERN ALOFT FEATURED A CLOSED UPPER LOW PRESSURE SYSTEM IN THE
PACIFIC NORTHWEST...RIDGING ACROSS THE INTERIOR CONUS...AND A TROUGH
TO THE EAST THRU THE OHIO VALLEY.  AT THE SFC...LOW PRESSURE WAS
LOCATED IN THE ROCKIES...WITH SOUTHEASTERLY LLVL IN PLACE ACROSS OUR
REGION.  SATELLITE IMAGERY INDICATES LOW CLOUD COVER INCREASING IN
COVERAGE ALONG THE HIGH PLAINS AND INTO WESTERN NEB/KS AS MOISTURE
ADVECTS NORTHWARD.

THE LOW CLOUD COVER WILL CONTINUE TO DEVELOP/EXPAND ACROSS
CENTRAL/EASTERN NEB/KS DURING THE PRE DAWN HOURS WITH CHCS FOR
SHOWERS/TSTMS INCREASING TOWARD DAYBREAK IN OUR WESTERN ZONES IN
WAA/THETA E ADVECTION...WITH THE CONVECTIVE ACTIVE SPREADING
EAST/NORTHEAST TODAY.  AN INSTABILITY AXIS OF AROUND 1000 J/KG ALONG
THE HIGH PLAINS EARLY THIS MORNING WILL MIGRATE EASTWARD...AND MAY
TOP 1000 J/KG ACROSS OUR WESTERN ZONES BY EVENING...WHILE SHEAR IS
AROUND 30KTS.  IN INCREASING INSTABILITY AND DECENT SHEAR...WE COULD
SEE A FEW STRONG STORMS.

THE SFC GRADIENT TIGHTENS BY MID DAY AND SOUTH/SOUTHEASTERLY WINDS
WILL BE ON THE INCREASE WITH CONDITIONS AT LEAST BREEZY IN THE 15 TO
25 MPH RANGE...AND POTENTIALLY HIGHER WITH GUSTS OF 30 MPH OR SO.
HAVE KEPT TEMPS RIGHT AROUND 70F FOR HIGHS TODAY WHICH IS A
COMPROMISE BETWEEN GUIDANCE WITH NAM/MET SUGGESTING TEMPS WARMER THAN
GFS/MAV.  TODAY IS NOT LOOKING LIKE A RAINOUT BUT THERE WILL BE
SCATTERED CONVECTION AROUND.

FOR TONIGHT...HAVE FOLLOWED CLOSER TO THE 3KM WRF...AND THE
GFS...GEM REGIONAL WITH CONVECTION DEVELOPING ALONG THE HIGH
PLAINS...WITH POTENTIAL FOR STORMS TO ORGANIZE AND ROLL EASTWARD AS
AN MCS OVERNIGHT.  INSTABILITY OVERNIGHT IS PROGGED AROUND 1500 J/KG
WITH SHEAR AGAIN REMAINING AROUND 30KTS...AND AGAIN STRONG TO SEVERE
STORMS ARE POSSIBLE WITH HAIL/WIND THE PRIMARY HAZARDS.
PRECIPITABLE WATER VALUES ARE JUST OVER AN INCH AND SOME DECENT
RAINFALL AMOUNTS MAY BE REALIZED IF STORMS DEVELOP AS MODELS
SUGGEST.  FOR LOWS...WE ARE LOOKING AT MILDER TEMPS DUE TO THE
INCREASE IN MOISTURE/DPS WITH READINGS EXPECTED TO BE AROUND 60F.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 455 AM CDT FRI MAY 24 2013

NEEDLESS TO SAY...THIS IS SHAPING UP TO BE A VERY ACTIVE 6-DAY
PERIOD...WITH SEVERAL...OFF-AND-ON CHANCES FOR THUNDERSTORMS...AND
LIKELY AT LEAST A FEW ROUNDS OF SEVERE STORMS AND LOCALLY HEAVY
RAINFALL...AS WE FINALLY GET INTO A PATTERN WITH CONVECTIVE
INSTABILITY CONSISTENTLY CLIMBING AT/ABOVE 1000 J/KG. ON A
POSITIVE NOTE...THIS WEATHER PATTERN SHOULD RESULT IN DECENT
CUMULATIVE RAINFALL TOTALS FOR ALL/PARTS OF THE CWA THROUGH THE
NEXT WEEK...AIDING DROUGHT RELIEF...THE DOWNSIDE FROM A FORECAST
PERSPECTIVE IS A LACK OF CONFIDENCE IN DAY-TO-DAY DETAILS...WITH
CONVECTIVE CHANCES FOR ONE PARTICULAR DAY/NIGHT LIKELY INFLUENCED
QUITE A BIT BY HOW THE PREVIOUS DAY/NIGHT CONVECTION OR LACK
THEREOF INFLUENCES SURFACE BOUNDARY POSTION...INSTABILITY...ETC.
AS A RESULT...DESPITE THE MULTIPLE PERIODS OF THUNDERSTORM CHANCES
IN THE CURRENT FORECAST...WE REALLY TAKE THIS ONE DAY AT A TIME
IN TERMS OF POSSIBLE SEVERE WEATHER TIMING/PLACEMENT. WOULD NOT BE
SURPRISED THOUGH TO SEE SEVERAL UPCOMING DAYS EVENTUALLY ASSIGNED
A SPC SLIGHT RISK FOR PARTS OF THE AREA...AND OUR LOCAL HAZARDOUS
WEATHER OUTLOOK WILL AT LEAST ATTEMPT TO GIVE SOME ENHANCED DETAIL
TO THE DAY 1-2 TIME FRAME.

LOOKING OVER THIS TIME FRAME FROM A BROAD...SYNOPTIC SCALE
PERSPECTIVE...THE LATEST ECMWF/GFS RUNS ARE IN PRETTY GOOD
AGREEMENT IN GRADUALLY TRANSITIONING MID-UPPER LEVEL FLOW OVER THE
CENTRAL PLAINS FROM QUASI-ZONAL THIS WEEKEND...TO MORE
SOUTHWESTERLY BY MID-WEEK AS A LONGWAVE TROUGH MIGRATES INTO THE
CENTRAL CONUS FROM THE WESTERN STATES. PRIOR TO THE ARRIVAL OF THE
PRIMARY TROUGH...MULTIPLE...LOW AMPLITUDE DISTURBANCES WILL TRACK
INTO THE PLAINS AND INTERACT WITH A GENERALLY EAST-WEST LOW-LEVEL
FRONT THAT WILL LIKELY BE MEANDERING NORTH-SOUTH ACROSS THE REGION
DUE IN PART TO CONVECTIVE OUTFLOW INFLUENCES. AS ALREADY ALLUDED
TO...THE DAILY DETAILS ARE GOING TO BE DIFFICULT TO DISCERN VERY
FAR IN ADVANCE. AS IS OFTEN THE CASE IN THESE PATTERNS...DETERMINISTIC
MODELS SUCH AS THE NAM/GFS SOMETIMES DEVELOP SUSPECT QPF BULLSEYES
AND STRUGGLE WITH CONVECTIVE FEEDBACK ISSUES.

ATTEMPTING TO GIVE AT LEAST A SMALL DEGREE OF GREATER DETAIL TO
SATURDAY/SATURDAY NIGHT...GENERALLY PREFER THE 00Z 4KM-WRF
SIMULATED REFLECTIVITY SOLUTION OF POTENTIAL FRIDAY NIGHT
CONVECTION GRADUALLY EXITING EASTWARD OUT OF THE CWA IN THE
MORNING...WITH A LULL THEN ENSUING FOR MUCH OF THE DAY AS CAPPING
HOLDS NEW DEVELOPMENT AT BAY. HOWEVER...BY THE MID AND ESPECIALLY
LATE AFTERNOON TIME FRAME...THERE IS A LEAST LIMITED POTENTIAL FOR
ISOLATED TO SCATTERED STORM DEVELOPMENT IN THE VICINITY OF AN
WEST-NORTHWEST TO EAST-SOUTHEAST ORIENTED WARM FRONT THAT SETS UP
SOMEWHERE ACROSS CENTRAL/NORTHERN NEBRASKA. WITH THE NAM
ADVERTISING 0-1KM MLCAPE ON THE ORDER OF 3000 J/KG IN THE PRESENCE
OF MODEST 0-6KM BULK SHEAR AROUND 30KT...FAIRLY SLOW-MOVING SEVERE
STORMS AND MAYBE EVEN A SUPERCELL OR TWO IS POSSIBLE...ESPECIALLY
WITHIN THE NORTHEAST 1/2 OF THE CWA...AND SEEMINGLY LESS LIKELY
ACROSS THE SOUTHWEST 1/2 INCLUDING KS ZONES DUE TO STRONGER
CAPPING AWAY FROM THE WARM FRONT. DEPENDING ON WHETHER OR NOT THE
WARM FRONT ACTUALLY SETS UP ACROSS THE CWA...MAY EVEN HAVE TO KEEP
AN EYE OUT FOR A LOW-END TORNADO THREAT GIVEN DECENT LOW LEVEL
SHEAR...BUT THIS RISK STILL SEEMS LOW ENOUGH TO OMIT FROM THE
HAZARDOUS WEATHER OUTLOOK. HEADING INTO THE EVENING AND OVERNIGHT
HOURS...ITS A TOUGH CALL WHETHER OR NOT CONVECTION CONTINUES
FOCUSING WITHIN THE CWA...OR INSTEAD RIDES MORE SO JUST NORTH/EAST
OF OUR AREA ON THE NOSE OF A BROAD 30-40+ KT LOW LEVEL JET. DUE
TO THESE UNCERTAINTIES...FELT IT WOULD BE BEST TO AT LEAST
TEMPORARILY REDUCE POPS SATURDAY NIGHT TO 50 PERCENT ACROSS THE
NORTHEAST CWA...WITH EVEN LOWER CHANCES SOUTHWEST. ALTHOUGH THE
PREVIOUS 60 POPS IN THE NORTHEAST WERE ONLY LOW-END LIKELIES...IT
JUST SEEMS TOO SOON...EVEN AT THIS TIME RANGE...TO ASSIGN THE
LIKELY TERMINOLOGY TO ANY GIVEN AREA. TURNING TO OTHER ELEMENTS OF
SATURDAY WEATHER...DECENT SOUTHERLY BREEZES SUSTAINED 15-20 MPH
WILL PREVAIL MOST AREAS...WITH HIGHER SPEEDS TO AROUND 25 AND
MAYBE EVEN NEARING 30 MPH FOCUSED ACROSS KS ZONES SOUTH OF THE
WARM FRONT. KEPT HIGH TEMPS SIMILAR...RANGING FROM NEAR 80 FAR
NORTHEAST TO NEAR 90 FAR SOUTHWEST...ALTHOUGH THE NAM WOULD
SUGGEST THAT MORE OF THE AREA COULD END UP IN THE UPPER 80S/NEAR
90 THAN CURRENTLY DEPICTED.

SUNDAY/SUNDAY NIGHT...ONCE AGAIN IT GOES WITHOUT SAYING THAT
CONVECTIVE POTENTIAL WILL LIKELY BE SOMEWHAT INFLUENCED ON HOW
SATURDAY NIGHT PLAYS OUT...BUT OTHERWISE ITS MUCH THE SAME STORY
ALTHOUGH POSSIBLY WITH A BIT STRONGER CAPPING INFERRED BY 700MB
TEMPS CLIMBING TO AROUND 12C IN MUCH OF THE CWA. LIKE SATURDAY
THOUGH...THE BEST STORM CHANCES SHOULD FAVOR THE EVENING/OVERNIGHT
VERSUS THE DAYTIME HOURS...AND THUS HAVE ONLY 20-30 POPS DURING
THE DAY...VERSUS 50S SUNDAY NIGHT WHEN CONVECTION COULD DEVELOP
OVERHEAD ALONG THE LOW LEVEL JET...ROLL IN FROM THE WEST IN THE
FORM OF A MESOSCALE CONVECTIVE SYSTEM...OR BOTH. AGAIN
THOUGH...MOST STORM ACTIVITY WOULD TEND TO FAVOR NEBRASKA VERSUS
KS.

IN GENERAL...THIS SAME PATTERN REPEATS ITSELF DURING THE MONDAY-
TUESDAY TIMEFRAME. THEN BY WEDNESDAY-THURSDAY...THERE MAY BE A
RISK FOR A SOMEWHAT MORE ORGANIZED SYNOPTICALLY-EVIDENT SEVERE
WEATHER THREAT AS THE LARGER SCALE TROUGH TO THE WEST APPROACHES
AND SWINGS ACROSS THE PLAINS...ENHANCING MID-UPPER LEVEL FLOW AND
RESULTANT WIND SHEAR. HOWEVER..ITS FAR TOO EARLY TO DIVE INTO ANY
MORE DETAILS AT THIS TIME RANGE.

AS FOR TEMP TRENDS THROUGH THE SUNDAY-THURSDAY TIME FRAME...MADE
LITTLE CHANGE...WITH HIGHS AVERAGING SOMEWHERE IN THE 80S...AND
LOWS MAINLY LOW-MID 60S.

ON ONE LAST NOTE...ALTHOUGH LOCALIZED FLOODING ISSUES CERTAINLY
CANNOT BE RULED OUT AT TIMES DURING THE NEXT WEEK...ESPECIALLY IF
THE SAME COUNTIES RECEIVE 1-2+ INCHES OF RAIN TWO OR MORE
DAYS/NIGHTS IN A ROW...WE ARE AT LEAST HEADING INTO THIS PATTERN
WITH A PRETTY DECENT CAPACITY TO ACCEPT WATER GIVEN BELOW NORMAL
RAINFALL ACROSS THE MAJORITY OF THE CWA SO FAR THIS MONTH. AS A
RESULT...RFC 3-HOUR FLASH FLOOD GUIDANCE IS AVERAGING AT LEAST 2-3
INCHES ACROSS THE ENTIRE CWA.

&&

.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1156 PM CDT THU MAY 23 2013

THE TAF PERIOD WILL BEGIN WITH VFR CONDITIONS AND END WITH MVFR TO
IFR CONDITIONS. AN AREA OF STRATUS ALONG THE HIGH PLAINS WILL
SPREAD NORTHEAST ACROSS THE CENTRAL PLAINS AND REACH KGRI AROUND
08Z AND CIGS WILL DROP TO THE MVFR CATEGORY. IN INCREASING LLVL
FLOW...WARMER MOIST AIR WILL BE DRAWN NORTHWARD AND SHOWER AND
TSTM DEVELOPMENT IS EXPECTED AFTER DAYBREAK WITH CONVECTIVE
POTENTIAL CARRYING INTO THE DAY. SOUTHERLY WINDS WILL BE ON THE
INCREASE TODAY WITH GUSTS NEAR 30KTS POSSIBLE. HEADING INTO FRIDAY
EVENING...CIGS MAY LOWER TO IFR CATEGORY.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...FAY
LONG TERM...PFANNKUCH
AVIATION...FAY

000
FXUS63 KOAX 240842
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
342 AM CDT FRI MAY 24 2013

.DISCUSSION...
LOOKS LIKE QUITE THE ACTIVE WEATHER PATTERN WILL DEVELOP OVER THE
MIDDLE OF THE COUNTRY TODAY AND REMAIN IN PLACE THE NEXT 7 DAYS.
UPPER LOWS/TROUGHS MOVING TOWARD THE EAST COAST AND ALONG THE WEST
COAST WILL KEEP OUR PART OF THE WORLD UNDER WEAK RIDGING AT LEAST
THROUGH SUNDAY. THEN MORE SOUTHWESTERLY FLOW TAKES OVER AS WESTERN
TROUGH MOVES A LITTLE EAST. DESPITE WEAK RIDGING ALOFT...SEVERAL
IMPULSES WILL MOVE OVERHEAD WHICH WILL TRIGGER OFF-AND-ON EPISODES
OF POTENTIAL PRECIPITATION OVER THE WEEKEND.

AT LOWER LEVELS...MOIST SOUTHERLY FLOW AT THE SURFACE THROUGH AT
LEAST 850MB IS FORECAST TO OVERSPREAD ALL OF THE PLAINS LATER TODAY
AND PERSIST THROUGH MUCH OF NEXT WEEK. 850 DEW POINTS WERE ALREADY
10-14C FROM SOUTHWEST KANSAS THROUGH THE TEXAS PANHANDLE...AND THIS
AIR SHOULD BE MOVING INTO WESTERN NEBRASKA TODAY THEN SPREAD EAST
THROUGH WESTERN IOWA TONIGHT. AT THE SURFACE...EASTERLY FLOW WAS
KEEPING DEW POINTS IN THE 40S THIS MORNING...BUT 60S DEW POINTS IN
THE SOUTHERN PLAINS WILL SURGE NORTH AND BECOME ENTRENCHED OVER OUR
CWA ON SATURDAY.

SO WITH MOISTURE BECOMING INCREASINGLY FAVORABLE FOR PRECIPITATION
AND WEAK IMPULSES MOVING OVERHEAD...REALLY CAN NOT RULE OUT AT LEAST
SMALL CHANCES FOR SHOWERS/THUNDER AT ANY TIME THROUGH THE HOLIDAY
WEEKEND. FOR TODAY...MOISTURE WILL NOT BE AS ROBUST...BUT DECENT MID
LEVEL WARM ADVECTION WILL BE SWEEPING THROUGH EASTERN NEBRASKA DURING
THE DAY WITH INITIAL SURGE OF MID LEVEL MOISTURE. ALREADY SEEING
SIGNS OF THAT WARM ADVECTION AS MID LEVEL CLOUDS HAVE EXPANDED FROM
WESTERN INTO CENTRAL NEBRASKA. ONLY PRECIPITATION NOTED SO FAR WAS IN
NORTHWEST KANSAS...BUT SHORT RANGE AND MESOSCALE MODELS ARE ALL
HINTING AT HIT-AND-MISS CONVECTION SPREADING INTO EASTERN NEBRASKA
DURING THE DAY. SO WILL MAINTAIN SMALL CHANCES IN OUR WEST THIS
MORNING...WITH BETTER CHANCES IN THE AFTERNOON AS SOUTHERLY FLOW
BECOMES MORE ROBUST.

PERHAPS THE BEST CHANCES FOR CONVECTION THROUGH THE WEEKEND WILL
COME DURING THE NIGHTTIME HOURS AS LOW LEVEL JET DYNAMICS CONTRIBUTE
TO FORCING. AFTERNOON INSTABILITY WILL CERTAINLY INCREASE EACH DAY
THROUGH MONDAY...AND ANY UPPER IMPULSE COULD RELEASE THAT
INSTABILITY. BUT NAILING DOWN THOSE IMPULSES WITH MUCH MORE THAN A
DAY OR SO LEAD TIME IS NEARLY IMPOSSIBLE. SO FORECAST WILL REFLECT
CHANCES FOR THUNDERSTORMS EACH OF THE NEXT SEVERAL DAYS...WITH
MORE LIKELY POPS COMING DURING THE EVENING AND OVERNIGHT HOURS.

HEAVY RAIN MAY OCCUR WITH ANY OF THESE CONVECTIVE EPISODES AS WELL.
PRECIPITABLE WATER VALUES ARE FORECAST TO COME CLOSE TO 1.5
INCHES...WHICH IS WELL ABOVE NORMAL LEVELS FOR THIS TIME OF YEAR.
PLUS FREEZING LEVELS APPROACHING 13000 FT SUGGEST WARM CLOUD DEPTH
COULD ENHANCE RAINFALL PRODUCTION. WILL HAVE TO WATCH HOW AND WHERE
THINGS DEVELOP OVER THE NEXT COUPLE OF DAYS TO FINE TUNE ANY
POSSIBLE FLOODING CONCERNS.

THE REST OF THE WEEK TUESDAY THROUGH THURSDAY MAY BRING BETTER
CHANCES FOR SEVERE STORMS IN THE CENTRAL PLAINS. WESTERN UPPER
TROUGH SHOULD BE PUSHING INTO THE PLAINS WITH STRONGER MID LEVEL
FLOW AND SLIGHTLY COOLER AIR ALOFT SPREADING INTO THE PLAINS.

DERGAN

&&

.AVIATION...06Z TAFS FOR KOFK...KOMA AND KLNK.

VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH BKN-OVC MID LEVEL
CIGS MOVING INTO THE AREA. FLOW BECOMES SOUTHERLY AS HIGH
PRESSURE SHIFTS EAST OF THE AREA WITH WINDS INCREASING TO 15G25KT
BY 18Z.

FOBERT

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

000
FXUS63 KLBF 240837
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
337 AM CDT FRI MAY 24 2013

.SYNOPSIS...
ISSUED AT 334 AM CDT FRI MAY 24 2013

AT 08Z...ANALYSIS OF THE MSL DATA SHOWED LOW PRESSURE CENTERED IN
NORTHWEST COLORADO AND OVER CENTRAL WYOMING. FROM THE LOW IN
COLORADO...A WARM FRONT STRETCHED ACROSS SOUTHERN COLORADO TO
SOUTHWEST KANSAS AND THE TEXAS-OKLAHOMA PANHANDLE. SURFACE DEWPOINTS
IN THE MID 40S TO LOWER 50S HAD SPREAD INTO SOUTHWEST SOUTH DAKOTA
AND WESTERN NEBRASKA. INFRA-RED SATELLITE IMAGERY SHOWED CLOUDS
STREAMING ACROSS THE HIGH PLAINS ON A LOW LEVEL JET OF 40-50KT
INDICATED IN THE WSR-88 RADAR WIND PROFILERS. THE DODGE CITY
SOUNDING FROM YESTERDAY EVENING WOULD INDICATE PRECIPITABLE WATER OF
AN INCH OR HIGHER RIDING IN ON THE LOW LEVEL JET.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT FRI MAY 24 2013

THE WARM FRONT LIFTING NORTHWARD FROM SOUTHERN COLORADO WILL GIVE A
FOCUS FOR MOIST AIR LIFTING ACROSS NORTHEAST COLORADO AND SOUTHWEST
NEBRASKA THIS EVENING AND OVERNIGHT. WITH VERY UNSTABLE AIR (SB-CAPE
AT OR ABOVE 3000J/KG)... CONVECTION IS LIKELY TO BE STRONG.
HOWEVER...THE DEEP (0-6KM AGL) BULK SHEAR OVER NORTHEAST COLORADO
WILL NOT BE REAL STRONG (ON THE ORDER OF 35-45KT). STILL...SINCE THE
STORMS WILL MOVE SLOWLY AT 10-15KT AND LOW LEVEL WIND FAVORS
ROTATION...THAT MAY BE SUFFICIENT FOR MARGINALLY LARGE HAIL. IT
APPEARS THOUGH THAT THE GREATEST RISK IS HEAVY RAIN WITH ORGANIZED
CONVECTION DEVELOPING EARLY IN THE EVENING AND PUSHING TO THE
NORTHEAST ACROSS CENTRAL NEBRASKA.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 334 AM CDT FRI MAY 24 2013

SATURDAY CONTINUES TO LOOK ACTIVE IN TERMS OF CONVECTION. SCATTERED
EARLY MORNING SHOWERS/TSTMS WILL BE POSSIBLE...BUT ACTIVITY SHOULD
BE WANING IN WAKE OF EXPECTED FRIDAY NIGHT CONVECTIVE COMPLEX.
ATTENTION THEN TURNS TO SATURDAY AFTERNOON...WHEN ADDITIONAL TSTM
ACTIVITY IS POSSIBLE. AT THIS TIME IT IS UNCLEAR WHERE THE BEST
POTENTIAL WILL EXIST...THIS DUE TO EXPECTED FRIDAY NIGHT STORMS
LIKELY HAVING AN IMPACT ON BOUNDARIES ACROSS THE AREA. THE GEM
REGIONAL MODEL WAS PREFERRED OVER THE NAM...AS IT SEEMS TO HAVE A
BETTER HANDLE ON THE CONVECTIVE ACTIVITY FRIDAY NIGHT. BOTH MODELS
HAVE A FAIRLY DEFINED WARM FRONT SATURDAY AFTERNOON...THE NAM IS
FOCUSED MORE ACROSS NORTH CENTRAL NEBRASKA WITH THE FRONT...WHILE
THE GEM REGIONAL IS FARTHER SOUTH...MORE ACROSS SOUTHERN NEBRASKA.
FEEL THE GEM REGIONAL FARTHER SOUTH SCENARIO IS BEST...AS THE FRONT
LIKELY WILL BE PUSHED SOUTH SOME BY THE FRIDAY NIGHT COMPLEX. IF
CONVECTION IS LESS FRIDAY NIGHT...THEN THE FRONT MAY END UP SOMEWHAT
FARTHER NORTH. REGARDLESS...IT WILL BECOME VERY UNSTABLE NEAR THE
BOUNDARY BY LATE AFTERNOON...WITH BULK SHEAR INCREASING TO 40 KTS OR
GREATER DUE TO BACKED EAST/SOUTHEAST FLOW TO THE NORTH OF THE FRONT.
GFS INDICATES A SUBTLE WAVE EJECTING OUT OF THE WEST COAST UPPER
LEVEL LOW AROUND PEAK HEATING/EARLY EVENING...WILL GIVE THE NEEDED
LIFT TO GET TSTMS GOING. MODELS HAVE BEEN FAIRLY CONSISTENT THE LAST
FEW NIGHTS WITH AN MCS DEVELOPING ACROSS CENTRAL AND EASTERN
NEBRASKA...SO THIS IS WHERE THE HIGHEST POPS WILL BE MAINTAINED.
SEVERE STORMS POSSIBLE...WITH STEEP MID LEVEL LAPSE RATES AND
ADEQUATE TO FAVORABLE DEEP LAYER SHEAR. LARGE HAIL APPEARS TO BE THE
MAIN THREAT...BUT A TORNADO POTENTIAL MAY EXIST JUST NORTH OF THE
WARM FRONT. AGAIN...LATER FORECASTS WILL BETTER DETERMINE WHERE THE
FRONT WILL BE LOCATED. IF SFC BASED STORMS FAIL TO MATERIALIZE NEAR
THE FRONT...THEN CHANCES WILL EXIST FOR ELEVATED STORMS NORTH OF THE
WARM FRONT AS A HEALTHY SOUTHERLY LLJ DEVELOPS SATURDAY EVENING.

CHANCES FOR TSTMS WILL BE NEARLY DAILY SUNDAY THROUGH MUCH OF NEXT
WEEK...AS A LARGE UPPER LEVEL LOW SLOWLY MOVES EAST FROM THE
WESTERN CONUS TOWARDS THE CENTRAL PLAINS. DIFFICULT TO NAIL DOWN
WHEN AND WHERE STORMS WILL BE...BUT EVENING THROUGH THE OVERNIGHT
HOURS WILL BRING THE BEST CHANCE EACH DAY. SOME SEVERE STORMS
POSSIBLE FROM TIME TO TIME...BUT AGAIN EACH DAYS STORMS WILL
DICTATE WHERE THE BEST FOCUS FOR THE NEXT DAY WILL BE.

TEMPERATURE WISE...WARM PERIOD EXPECTED...WITH HIGHS MAINLY IN THE
70S AND 80S...AND LOWS IN THE 50S WEST TO 60S EAST.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1231 AM CDT FRI MAY 24 2013

CEILINGS WILL LOWER OVERNIGHT AT BOTH THE KVTN AND KLBF TERMINALS
WITH CIGS RANGING FROM 800 AGL IN THE SOUTHWEST TO 1500 FT AGL IN
NORTHERN NEBRASKA. THEY WILL THEN LIFT TO 3000 TO 5000 FT AGL BY
FRIDAY AFTERNOON. FOR THE KLBF TERMINAL...THUNDERSTORMS ARE
POSSIBLE FRIDAY EVENING...WITH THE GREATEST CHANCE AFTER 02Z
SATURDAY. AT THIS TIME...OUR CONFIDENCE IS NOT HIGH THAT THEY WILL
OCCUR AT THE LBF TERMINAL. HOWEVER...THEY ARE LIKELY TO BE IN THE
AREA. WINDS OVER THE NEXT 24 HOURS WILL BE FROM THE SOUTHEAST AND
SOUTH AT 10 TO 20 KTS FOR THE REMAINDER OF TONIGHT...INCREASING TO
20 TO 30 KTS ON FRIDAY. SOME WIND GUSTS OF 25 TO 45 KTS ARE
POSSIBLE IN THE VICINITY OF THUNDERSTORMS FRIDAY EVENING AT THE
KLBF TERMINAL.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...TAYLOR
AVIATION...SPRINGER

000
FXUS63 KLBF 240534
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1234 AM CDT FRI MAY 24 2013

.UPDATE...
ISSUED AT 950 PM CDT THU MAY 23 2013

JUST UPDATED THE FORECAST TO ADDRESS CLOUD COVER IN THE WEST AND
ITS EXPECTED ONSET IN THE CENTRAL CWA OVERNIGHT. THE LATEST NAM
SOLN THIS EVENING HAS SLOWED THE PROGRESSION OF STRATUS TO THE
EAST AND HAVE ADJUSTED THE FORECAST ACCORDINGLY. ATTM NOT
EXPECTING ANY FOG POTENTIAL OVERNIGHT...AS SERLY WINDS CONTINUE TO
BE BREEZY AND WILL ONLY DIMINISH SOMEWHAT OVERNIGHT. LOWS IN THE
LOWER TO MID 50S REMAIN ON TRACK WITH THE DECENT MIXING AND THE
ARRIVAL OF LOW LEVEL MOISTURE. ISOLATED SHOWERS WILL BE POSSIBLE
TOWARD MORNING AS MID LEVEL WARM AIR ADVECTION INCREASES
OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 303 PM CDT THU MAY 23 2013

FOR TONIGHT...SURFACE HIGH PRESSURE WILL PUSH OFF TO OUR SOUTHEAST AS
LOW LEVEL WINDS VEER TOWARD THE SOUTHEAST. A SUBSTANTIAL AMOUNTS OF
LOW LEVEL MOISTURE WILL BE ADVECTED NORTHWEST TONIGHT FROM WESTERN
KANSAS ANS EASTERN COLORADO INTO WESTERN NEBRASKA. SKIES TO BECOME
OVERCAST MOST AREAS BY DAYBREAK. REGARDING RAIN CHANCES...DELAYED
ONSET OF SHOWERS/ISOLATED TSTMS UNTIL AFTER 06Z FOR AREAS WEST OF
VTN THROUGH BBW. STEEP MID LEVEL LAPSE RATES WITH THE APPROACH OF A
DISTURBANCE FROM COLORADO WILL INCREASE SHOWER CHANCES. LOW
TEMPERATURES WILL RANGE FROM THE UPPER 40S TO MID 50S.

ON FRIDAY...PASSING DISTURBANCE TO BRING CHANCE POPS TO MUCH OF
FORECAST AREA IN THE MORNING WITH THE HIGHEST POPS 40-50 PERCENT
EAST OF HWY 83. BY EARLY AFTERNOON...ONLY SLIGHT CHANCE IN THE WEST.
GFS AND NAM INDICATED A MOSTLY SATURATED LAYER FROM SFC THROUGH
800MB. HAVE LOWERED TEMPERATURES AS MUCH AS 5 DEGREES TOWARD THE
COOLEST MET GUIDANCE FOR CENTRAL AND SOUTHEAST ZONES WITH HIGHS FROM
66 TO 69. FAR WEST TIER OF COUNTIES FCST TO REACH THE LOWER/MID 70S
AS CEILINGS LIFT AND PARTIAL LATE AFTERNOON CLEARING. ANOTHER MAIN
FORECAST CONCERN WILL BE POTENTIAL FOR STORM INITIATION ALONG STRONG
DIFFERENTIAL HEATING BOUNDARY NEAR A LINE FROM KBFF-KSNY-KITR. AREAS
75 MILES EAST AND WEST OF THIS LINE ARE AT RISK FOR SEVERE STORMS BY
LATE FRIDAY AFTERNOON/EARLY EVENING. THIS INCLUDES THE SOUTHEAST
PANHANDLE AND MUCH OF SWRN NEBR. RICH THETA-E ADVECTION INDICATED BY
NAM AND GFS INTO THIS REGION ALONG WITH SFC DEWPOINTS REACHING THE
MID/UPPER 50S W/BACKED LOW LEVEL WINDS SUSTAINED NEAR 20KTS. THIS
FAVORABLE FOR DISCRETE ROTATING STORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 303 PM CDT THU MAY 23 2013

THE END OF THE WEEK IS DOMINATED BY TWO UPPER LEVEL LOW PRESSURE
SYSTEMS IN PLACE ALONG THE EASTERN AND WESTERN COASTS...WITH AN
AMPLIFIED RIDGE AXIS IN THE PLAINS REGION. THE RIDGE AXIS WILL
SLOWLY SHIFT EAST...PUTTING WESTERN NEBRASKA IN SOUTHWEST FLOW ALOFT
AND A RATHER UNSETTLED WEATHER PATTERN. THIS PATTERN WILL ALSO KEEP
TEMPERATURES WARM AND SOMEWHAT HUMID CONDITIONS AROUND THROUGH MOST
OF THE FORECAST PERIOD.

THE MAIN FORECAST CHALLENGE WILL BE THE POSSIBILITY FOR SEVERE
WEATHER...MAINLY FRIDAY NIGHT AND SATURDAY NIGHT. THE SOUTHWEST FLOW
WILL SETUP LEE SIDE TROUGHING IN EASTERN CO AND THE NE PANHANDLE.
SHORTWAVES EMBEDDED IN THE SOUTHWEST FLOW WILL MOVE OVER THE
PLAINS...HOWEVER THE PRIMARY AREA OF LIFT ASSOCIATED WITH MOST OF
THESE WAVES WILL BE CENTERED OVER THE ROCKIES. THE MAIN LIFTING
MECHANISM FOR THUNDERSTORM ACTIVITY IN THE HIGH PLAINS LOOKS TO BE
INSTABILITY BUILT UP BY DIURNAL HEATING.

THUNDERSTORMS...SOME SEVERE...MAY BE ONGOING AT THE BEGINNING OF THE
PERIOD ACROSS SOUTHWEST AND WESTERN NEBRASKA FRIDAY EVENING. THE
PRESENCE OF A 30-40KT LLJ WILL HELP MAINTAIN THIS ACTIVITY OVERNIGHT
AS IT VEERS OFF TO THE EAST. STEEP MID LEVEL LAPSE RATES AND AMPLE
MOISTURE WILL KEEP THUNDERSTORMS POSSIBLE...HOWEVER THE SEVERE
THREAT OVERNIGHT WILL BE LOW.

ATTENTION THEN TURNS TO SATURDAY AS SKIES BEGIN TO CLEAR OUT FROM
WEST TO EAST DURING THE MORNING AND AFTERNOON HOURS. THIS WILL BE
FAVORABLE FOR STRONG HEATING...WITH HIGHS PUSHING THE UPPER 80S FOR
MOST OF THE AREA BUT STILL COOLER IN OUR NORTHEAST ZONES. THE
HEATING WILL MAKE THE BOUNDARY LAYER VERY UNSTABLE WITH MLCAPE
VALUES EXCEEDING 2K J/KG...AND COUPLED WITH 30-40 KTS OF DEEP LAYER
SHEAR WILL PROMOTE AN ENVIRONMENT CONDUCIVE FOR SEVERE STORMS
BEGINNING LATE IN THE AFTERNOON. PRIMARY THREATS AT THIS TIME
LOOK TO BE LARGE HAIL AND DAMAGING WINDS. AGAIN...LLJ WILL
STRENGTHEN AFTER DARK AND HELP MAINTAIN THE THUNDERSTORM ACTIVITY AS
IT MOVES EAST.

STORM CHANCES WILL CONTINUE THROUGH THE EXTENDED PERIOD AS THE HIGH
PLAINS REMAINS IN A SOUTHWEST FLOW PATTERN. MODELS BEGIN TO DIVERGE
ON THEIR HANDLING OF THE LONGWAVE PATTERN TOWARD THE END OF THE
EXTENDED PERIOD WITH THE GFS EJECTING A TROUGH INTO THE NORTHERN
PLAINS...WITH THE 12Z EC DIGGING A TROUGH INTO THE RIO GRANDE
VALLEY. THIS WILL HAVE A BIG IMPACT ON PRECIP CHANCES FOR THE MIDDLE
OF NEXT WEEK GOING FORWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1231 AM CDT FRI MAY 24 2013

CEILINGS WILL LOWER OVERNIGHT AT BOTH THE KVTN AND KLBF TERMINALS
WITH CIGS RANGING FROM 800 AGL IN THE SOUTHWEST TO 1500 FT AGL IN
NORTHERN NEBRASKA. THEY WILL THEN LIFT TO 3000 TO 5000 FT AGL BY
FRIDAY AFTERNOON. FOR THE KLBF TERMINAL...THUNDERSTORMS ARE
POSSIBLE FRIDAY EVENING...WITH THE GREATEST CHANCE AFTER 02Z
SATURDAY. AT THIS TIME...OUR CONFIDENCE IS NOT HIGH THAT THEY WILL
OCCUR AT THE LBF TERMINAL. HOWEVER...THEY ARE LIKELY TO BE IN THE
AREA. WINDS OVER THE NEXT 24 HOURS WILL BE FROM THE SOUTHEAST AND
SOUTH AT 10 TO 20 KTS FOR THE REMAINDER OF TONIGHT...INCREASING TO
20 TO 30 KTS ON FRIDAY. SOME WIND GUSTS OF 25 TO 45 KTS ARE
POSSIBLE IN THE VICINITY OF THUNDERSTORMS FRIDAY EVENING AT THE
KLBF TERMINAL.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...CLB
SHORT TERM...ROBERG
LONG TERM...MARTIN
AVIATION...SPRINGER

000
FXUS63 KGID 240503
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1203 AM CDT FRI MAY 24 2013

.UPDATE...
ISSUED AT 654 PM CDT THU MAY 23 2013

MADE MINOR ADJUSTMENTS TO HOURLY WEATHER THIS EVENING.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 355 PM CDT THU MAY 23 2013

MORNING UPPER AIR ANALYSIS INDICATES MID TO UPPER LEVEL RIDGING
OVER THE CENTRAL CONUS...WITH TROUGHING OVER THE WEST AND EAST. A
CLOSED MID TO UPPER LEVEL LOW IS ALSO NOTED EMBEDDED WITHIN THE
WESTERN CONUS TROUGH. INCREASED MID TO UPPER LEVEL FLOW SURROUNDS
THE WESTERN CONUS LOW...AND ALSO EXTENDS FROM CENTRAL CANADA
SOUTH/SOUTHEASTWARD INTO PORTIONS OF THE MISSISSIPPI VALLEY AND
NORTHEASTERN CONUS. MID TO UPPER LEVEL FLOW OVER THE CENTRAL
PLAINS HOWEVER IS FAIRLY WEAK...MAXING OUT AT AROUND 40KTS NEAR
300MB PER 12Z SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR
IMAGERY CLEARLY SHOWS THE MID LEVEL LOW OVER THE WESTERN
CONUS...WITH INCREASED VALUES OF MID LEVEL MOISTURE EXTENDING FROM
THE SOUTHERN CONUS...NORTH/NORTHWESTWARD INTO THE ROCKIES AND HIGH
PLAINS. AT THE SURFACE A RIDGE OF HIGH BAROMETRIC PRESSURE EXTENDS
FROM THE UPPER MISSISSIPPI VALLEY...SOUTH/SOUTHWEST INTO THE
MISSOURI RIVER VALLEY. AN AREA OF LOW BAROMETRIC PRESSURE IS ALSO
NOTED OVER PORTIONS OF WYOMING. LOW LEVEL FLOW ACROSS OUR AREA
REMAINS FROM THE EAST/NORTHEAST FOR THE MOST PART...BUT IS
BEGINNING TO TURN MORE SOUTHEASTERLY ACROSS SOUTHWESTERN PORTIONS
OF OUR CWA AS THE SURFACE RIDGE CONTINUES MOVING EAST...AWAY FROM
OUR AREA.

AN OVERALL LACK IN KINEMATIC FORCING WILL CONTINUE PROMOTING DRY
CONDITIONS ACROSS OUR AREA THROUGH AT LEAST 06Z TONIGHT. GUIDANCE
SUGGESTS MULTIPLE MID LEVEL PERTURBATIONS WILL EJECT FROM THE
WESTERN CONUS TROUGH BEGINNING TONIGHT HOWEVER...WITH SOME OF
THESE PERTURBATIONS ROUNDING THE TOP OF THE CENTRAL CONUS RIDGE
THUS HELPING TO BREAK DOWN THE RIDGE SOMEWHAT. WEAK OMEGA AHEAD OF
THE MID LEVEL PERTURBATIONS MAY BE STRONG ENOUGH TO PROMOTE MID
LEVEL CLOUDS AND PERHAPS SOME VERY LIGHT PRECIPITATION ACROSS
PORTIONS OF OUR AREA TONIGHT. THAT BEING SAID...INCREASING LOW
LEVEL RETURN FLOW AND RESULTANT LOW LEVEL THETA-E ADVECTION WILL
LIKELY PLAY A LARGER ROLE IN CLOUD DEVELOPMENT AND POSSIBLE
PRECIPITATION PRODUCTION. THETA-E ADVECTION...BOTH FROM RETURN
FLOW NEAR THE SURFACE AS WELL AS ALONG THE AXIS OF A ~40KT LOW
LEVEL JET ACROSS OUR WEST...APPEARS AS THOUGH IT WILL PROMOTE
ENOUGH ISENTROPIC UPGLIDE AND SATURATION...PRIMARILY BETWEEN THE
305K AND 320K SURFACES...FOR STRATUS DEVELOPMENT ACROSS MUCH OF
OUR CWA BY SUNRISE FRIDAY. ALTHOUGH NOT LIKELY...FORECAST
PROXIMITY SOUNDINGS FROM ACROSS OUR CWA...PER THE
NAM...OPERATIONAL GFS AND EC...SUGGEST THE LOWER TROPOSPHERE MAY
BECOME SATURATED ENOUGH FOR PRECIPITATION TO BE REALIZED AT THE
SURFACE ACROSS EXTREME SOUTHWESTERN PORTIONS OF OUR CWA DURING THE
EARLY MORNING HOURS FRIDAY. GIVEN ALL THIS...WENT AHEAD WITH ~20%
POPS ACROSS EXTREME SOUTHWESTERN PORTIONS OF OUR CWA 06Z-12Z
FRIDAY.

INCREASING LOW LEVEL THETA-E ADVECTION...ALONG WITH
PERSISTENT...ALBEIT WEAK...MID LEVEL OMEGA AHEAD OF PASSING MID
LEVEL PERTURBATIONS...WILL ALLOW CHANCES FOR PRECIPITATION TO
OVERTAKE ALL OF OUR CWA DURING THE DAY FRIDAY. QPF FIELDS FROM THE
NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL SUGGEST MEASURABLE
PRECIPITATION WILL BE POSSIBLE ACROSS MOST ALL OF OUR CWA FRIDAY.
THAT BEING SAID...PRECIPITATION RATES DO NOT APPEAR AS THOUGH THEY
WILL BE ALL THAT HIGH AND PRECIPITATION AT ANY GIVEN POINT IN THE
DAY MAY BE SPOTTY AT BEST. SO...OPTED TO KEEP POPS IN THE 40-50%
RANGE FOR THE MOST PART...BUT IT IS BELIEVED THESE POPS WILL BE
INCREASED TONIGHT IF FUTURE MODEL RUNS CONTINUE INDICATING
MEASURABLE PRECIPITATION ACROSS MUCH OF THE CWA DURING THE DAY
FRIDAY.

INCREASING LOW LEVEL MOISTURE DUE TO THE AFOREMENTIONED THETA-E
ADVECTION...WORKING IN CONCERT WITH SOMEWHAT INCREASING MID LEVEL
LAPSE RATES AS MID LEVEL PERTURBATIONS PUSH OVERHEAD...SHOULD
PROMOTE AT LEAST SOME POTENTIAL INSTABILITY ACROSS PORTIONS OF OUR
AREA ON FRIDAY. AT THIS TIME GUIDANCE SUGGESTS LOCATIONS ACROSS
OUR AREA...GENERALLY SOUTH OF I-80 AND WEST OF HIGHWAY 281...COULD
SEE DEEP-LAYER MUCAPE VALUES OF AROUND 1000J/KG...IF NOT A TOUCH
HIGHER...FRIDAY AFTERNOON. DEEP-LAYER BULK SHEAR VALUES ON THE
ORDER OF ~30KTS ARE ALSO EXPECTED ACROSS OUR AREA DURING THIS TIME
PERIOD. GIVEN ALL THIS...SEVERE WEATHER IS NOT CURRENTLY
EXPECTED...BUT A FEW OF THE STRONGER UPDRAFTS COULD CERTAINLY BE
CAPABLE OF PRODUCING SUB-SEVERE HAIL AND WILL MENTION THIS IN THE
HWO.

SUBTLE LOW LEVEL WARM AIR ADVECTION SHOULD PROMOTE SLIGHTLY WARMER
WEATHER TOMORROW WHEN COMPARED TO TODAY...BUT NOT BY MUCH. AN
OVERNIGHT LOW TEMPERATURE NEAR 50 IS FORECAST FOR MOST LOCATIONS
TONIGHT WITH AN AFTERNOON HIGH TEMPERATURE IN THE UPPER 60S TO
NEAR 70 FOR FRIDAY.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 PM CDT THU MAY 23 2013

PRIMARY FORECAST CONCERN THROUGH THE LONG TERM REMAINS WITH
MULTIPLE THUNDERSTORM CHANCES...AS THE ACTIVE UPPER LEVEL PATTERN
CONTINUES ACROSS THE REGION.

HASNT BEEN ANY SIGNIFICANT CHANGES IN THE MODELS WITH THE UPPER
LEVEL PATTERN AT THE START OF THE FORECAST PERIOD...AS THE PLAINS
REMAIN WITH RIDGING IN PLACE...SET UP BETWEEN A LOW PRESSURE
SYSTEM OVER THE EAST COAST AND ANOTHER OVER THE PAC NW. THE FIRST
OF A NUMBER OF LOW AMPLITUDE DISTURBANCES TO AFFECT THE REGION
MAKES ITS WAY ACROSS THE AREA FRIDAY NIGHT...AND AIDED BY WARM
AIR/MOISTURE ADVECTION VIA A SRLY LLJ...BRING THUNDERSTORM CHANCES
TO THE CWA. MODELS IN GOOD AGREEMENT SHOWING INSTABILITY ALSO
BEGINNING TO WORK ITS WAY NORTH...PRIMARILY AFFECTING THE
SOUTHWESTERN HALF OF THE CWA...AND ALONG WITH SUFFICIENT SHEAR
VALUES...CERTAINLY CANT RULE OUT SOME STRONG/SEVERE THUNDERSTORMS.

INTO SATURDAY...EXPECTING THE MORNING HOURS TO BE AFFECTED BY THE
OVERNIGHT ACTIVITY...WITH SOME UNCERTAINTY HOW QUICKLY THINGS MAY
MOVE OUT. SHOULD BE A LULL IN THE ACTIVITY INTO THE
AFTERNOON...BEFORE ADDITIONAL THUNDERSTORM CHANCES RETURN AS THE
NEXT UPPER LEVEL DISTURBANCE MOVES IN FROM THE SOUTHWEST. AHEAD OF
THIS NEXT DISTURBANCE...SURFACE LOW PRESSURE IN PLACE OVER THE
FRONT RANGE/HIGH PLAINS LOOKS TO STRENGTHEN A BIT. LOOKING TO SEE
A TIGHTENING PRESSURE GRADIENT ACROSS THE AREA AS A RESULT...WITH
HIGH PRESSURE STILL IN PLACE OVER THE MIDWEST...WITH INCREASING
SOUTHERLY WINDS EXPECTED. ONE CONCERN IS WHERE A SURFACE WARM
FRONT WILL SET UP...WITH THE POTENTIAL FOR IT TO END UP DRAPED
ACROSS THE NORTHERN HALF OF THE CWA BY LATE AFTERNOON. MODELS
CONTINUE TO SHOW SEVERAL THOUSAND J/KG OF CAPE DEVELOPING AS
DEWPOINTS/MOISTURE CONTINUES TO POOL ALONG THE FRONT...BUT ALSO
SHOW CAPPING IN PLACE. QUESTION IS WHETHER CONVECTION CAN GET
GOING IN THE AREA OF WEAKER CAPPING /MAINLY ACROSS PORTIONS OF SC
NEB/...AND IF IT DOES HOW MUCH THERE WOULD BE. AGAIN...WHILE DEEP
LAYER SHEAR ISNT GREAT...ITS SUFFICIENT FOR STRONG/SEVERE
WEATHER...PLUS THERE IS PLENTY OF INSTABILITY IN PLACE ALONG WITH
THE POTENTIAL SFC FRONTAL BOUNDARY. PLENTY TO KEEP AN EYE ON FOR
SATURDAY.

ANY ONGOING ACTIVITY LOOKS TO CONTINUE TO AFFECT THE AREA DURING
THE OVERNIGHT HOURS...AND POTENTIALLY INTO THE MORNING HOURS ON
SUNDAY...BUT THERE IS SOME QUESTION ON WHAT WOULD BE GOING ON
BEYOND THAT. SOME OF THE 12Z MODELS CAME IN SHOWING NOT A WHOLE
HECK OF A LOT GOING ON DURING THE DAYTIME HOURS...BUT STILL CANT
RULE OUT SOME LATE AFTERNOON THUNDERSTORMS...SO WILL CONTINUE TO
KEEP SOME LOWER POPS GOING. BUT...WHATEVER BREAK THERE IS DOESNT
LOOK TO LAST LONG...WITH THE NEXT ROUND OF THUNDERSTORMS MOVING
WITH THE LATEST DISTURBANCE...AND A STRONGER CORRIDOR OF THE LLJ
NOSING INTO THE CWA. WITHOUT A FRONT MOVING THROUGH TO PUSH THE
BETTER MOISTURE IN PLACE OUT OF THE REGION...INSTABILITY CERTAINLY
REMAINS IN PLACE...SO THE THREAT FOR SOME THUNDERSTORMS TO BECOME
SEVERE CONTINUES.

LOOKING AT MONDAY THROUGH WEDNESDAY...THE OVERALL STORY DOESNT
CHANGE SIGNIFICANTLY...THE CWA REMAINS UNDER SOUTHWESTERLY FLOW IN
THE UPPER LEVELS...WITH CONTINUED PERIODIC THUNDERSTORM CHANCES AS
THESE DISTURBANCES MOVE THROUGH. UNCERTAINTY IN THE FORECAST GROWS
WITH TIME...WED FOR EXAMPLE...THE GFS SHOWS A MID/UPPER LEVEL
TROUGH SWINGING RIGHT INTO THE CENTRAL PLAINS...WHILE THE LATEST
ECMWF SHOWS A CUTOFF LOW OVER THE AZ/MEXICO BORDER. MANY DETAILS
TO WORK THROUGH IN THE COMING DAYS.

AS FAR AS TEMPERATURES GO...NOT EXPECTING ANY NOTABLE
SWINGS...WITH HIGHS REMAINING ABOVE AVERAGE OVERALL...RANGING
ANYWHERE FROM THE UPPER 70S TO MID/UPPER 80S. MILD OVERNIGHT LOWS
IN THE UPPER 50S/60S ALSO EXPECTED.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1156 PM CDT THU MAY 23 2013

THE TAF PERIOD WILL BEGIN WITH VFR CONDITIONS AND END WITH MVFR TO
IFR CONDITIONS. AN AREA OF STRATUS ALONG THE HIGH PLAINS WILL
SPREAD NORTHEAST ACROSS THE CENTRAL PLAINS AND REACH KGRI AROUND
08Z AND CIGS WILL DROP TO THE MVFR CATEGORY. IN INCREASING LLVL
FLOW...WARMER MOIST AIR WILL BE DRAWN NORTHWARD AND SHOWER AND
TSTM DEVELOPMENT IS EXPECTED AFTER DAYBREAK WITH CONVECTIVE
POTENTIAL CARRYING INTO THE DAY. SOUTHERLY WINDS WILL BE ON THE
INCREASE TODAY WITH GUSTS NEAR 30KTS POSSIBLE. HEADING INTO FRIDAY
EVENING...CIGS MAY LOWER TO IFR CATEGORY.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.

&&

$$

UPDATE...HEINLEIN
SHORT TERM...BRYANT
LONG TERM...ADO
AVIATION...FAY

000
FXUS63 KOAX 240425
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1125 PM CDT THU MAY 23 2013

.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.

VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH BKN-OVC MID LEVEL
CIGS MOVING INTO THE AREA. FLOW BECOMES SOUTHERLY AS HIGH
PRESSURE SHIFTS EAST OF THE AREA WITH WINDS INCREASING TO 15G25KT
BY 18Z.

&&

.PREV DISCUSSION... /ISSUED 235 PM CDT THU MAY 23 2013/

DISCUSSION...

HIGH PRESSURE ACROSS THE MISSOURI VALLEY WILL CONTINUE TO
TRANSITION EASTWARD OVERNIGHT GIVING US QUIET WEATHER AND EAST
NORTHEAST WINDS BECOMING SOUTHEAST BY DAYBREAK. MEANWHILE...AN
UPPER LEVEL IMPULSE MOVING THROUGH THE CENTRAL ROCKIES SHOULD
TRIGGER CONVECTION TONIGHT ACROSS THE HIGH PLAINS....WHICH WILL
SLOWLY PUSH EASTWARD INTO OUR FORECAST AREA THROUGH THE DAY
FRIDAY WITH THE BEST CHANCE FOR PRECIP ACROSS EASTERN NEBRASKA...
AND JUST A SMALL CHANCE ACROSS WESTERN IOWA DURING THE AFTERNOON.
INSTABILITY RETURNS TO THE REGION. GIVEN SHEAR AND INSTABILITY
PARAMETERS...A FEW STRONG STORMS COULD OCCUR. THIS FIRST IMPULSESEEMS
TO MOVE THROUGH DURING THE EVENING...ALTHOUGH THE CONVERGENCE
ALONG THE NOSE OF THE LOW LEVEL JET COULD STILL PROVIDE SUPPORT
FOR ISOLATED STORMS TO LINGER PAST MIDNIGHT.

FORECAST DETAILS BECOME LESS CLEAR THROUGH THE REMAINDER OF THE
WEEKEND AND THROUGH NEXT WEEK...BUT THERE WILL BE SEVERAL CHANCES
FOR PRECIP THROUGH THE PERIOD. CONVECTION FROM FRIDAY NIGHT COULD
LEAVE BEHIND A FEW BOUNDARIES...WHICH COULD BE THE FOCUS FOR NEW
CONVECTION SATURDAY ACROSS OUR AREA. INSTABILITY DEFINITELY
INCREASES DURING THIS TIME...AND WITH SUFFICIENT SHEAR...SEEMS
THERE COULD BE A SEVERE THREAT THIS DAY AS WELL.

THE REGION WILL ALSO REMAIN UNDER AN UPPER RIDGE FROM SATURDAY
AND BEYOND...WHICH PUTS IN THE WELL WITHIN THE AREA OF PRIME
ACTION AT LEAST THROUGH THE EARLY PART OF NEXT WEEK AS WEAK
IMPULSE CONTINUE TO EJECT OUT OF THE MEAN SOUTHWESTERN TROUGH AND
CONTINUE TO TRIGGER SEVERAL ROUNDS OF STORMS. BY THIS TIME...THE
DETAILS OF ANY WIDESPREAD SEVERE STORMS BECOMES INCREASINGLY
DIFFICULT TO PIN DOWN...OTHER THAN THERE WILL BE SEVERAL CHANCES
FOR RAIN. NOT TO SAY THAT IT WILL BE CONTINUOUS RAIN...BUT GIVEN
THAT IT`S A HOLIDAY WEEKEND AND THERE WILL BE MANY MORE OUTDOOR
ACTIVITIES THAN NORMAL...THERE WILL BE A CHANCE OF RAIN JUST
ABOUT EVERY 12 HOUR PERIOD THROUGH EARLY NEXT WEEK.

FOR LATER PORTIONS OF THE EXTENDED FORECAST...THE MODELS SUGGEST
THAT THE RIDGE AXIS DOES SHIFT EASTWARD JUST A BIT...BUT STILL
SMALL CHANCES OF RAIN WILL EXIST IN THE FORECAST FOR WEDNESDAY AND
THURSDAY OF NEXT WEEK.

DEWALD

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

FOBERT

000
FXUS63 KLBF 240251
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
951 PM CDT THU MAY 23 2013

.UPDATE...
ISSUED AT 950 PM CDT THU MAY 23 2013

JUST UPDATED THE FORECAST TO ADDRESS CLOUD COVER IN THE WEST AND
ITS EXPECTED ONSET IN THE CENTRAL CWA OVERNIGHT. THE LATEST NAM
SOLN THIS EVENING HAS SLOWED THE PROGRESSION OF STRATUS TO THE
EAST AND HAVE ADJUSTED THE FORECAST ACCORDINGLY. ATTM NOT
EXPECTING ANY FOG POTENTIAL OVERNIGHT...AS SERLY WINDS CONTINUE TO
BE BREEZY AND WILL ONLY DIMINISH SOMEWHAT OVERNIGHT. LOWS IN THE
LOWER TO MID 50S REMAIN ON TRACK WITH THE DECENT MIXING AND THE
ARRIVAL OF LOW LEVEL MOISTURE. ISOLATED SHOWERS WILL BE POSSIBLE
TOWARD MORNING AS MID LEVEL WARM AIR ADVECTION INCREASES
OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 303 PM CDT THU MAY 23 2013

FOR TONIGHT...SURFACE HIGH PRESSURE WILL PUSH OFF TO OUR SOUTHEAST AS
LOW LEVEL WINDS VEER TOWARD THE SOUTHEAST. A SUBSTANTIAL AMOUNTS OF
LOW LEVEL MOISTURE WILL BE ADVECTED NORTHWEST TONIGHT FROM WESTERN
KANSAS ANS EASTERN COLORADO INTO WESTERN NEBRASKA. SKIES TO BECOME
OVERCAST MOST AREAS BY DAYBREAK. REGARDING RAIN CHANCES...DELAYED
ONSET OF SHOWERS/ISOLATED TSTMS UNTIL AFTER 06Z FOR AREAS WEST OF
VTN THROUGH BBW. STEEP MID LEVEL LAPSE RATES WITH THE APPROACH OF A
DISTURBANCE FROM COLORADO WILL INCREASE SHOWER CHANCES. LOW
TEMPERATURES WILL RANGE FROM THE UPPER 40S TO MID 50S.

ON FRIDAY...PASSING DISTURBANCE TO BRING CHANCE POPS TO MUCH OF
FORECAST AREA IN THE MORNING WITH THE HIGHEST POPS 40-50 PERCENT
EAST OF HWY 83. BY EARLY AFTERNOON...ONLY SLIGHT CHANCE IN THE WEST.
GFS AND NAM INDICATED A MOSTLY SATURATED LAYER FROM SFC THROUGH
800MB. HAVE LOWERED TEMPERATURES AS MUCH AS 5 DEGREES TOWARD THE
COOLEST MET GUIDANCE FOR CENTRAL AND SOUTHEAST ZONES WITH HIGHS FROM
66 TO 69. FAR WEST TIER OF COUNTIES FCST TO REACH THE LOWER/MID 70S
AS CEILINGS LIFT AND PARTIAL LATE AFTERNOON CLEARING. ANOTHER MAIN
FORECAST CONCERN WILL BE POTENTIAL FOR STORM INITIATION ALONG STRONG
DIFFERENTIAL HEATING BOUNDARY NEAR A LINE FROM KBFF-KSNY-KITR. AREAS
75 MILES EAST AND WEST OF THIS LINE ARE AT RISK FOR SEVERE STORMS BY
LATE FRIDAY AFTERNOON/EARLY EVENING. THIS INCLUDES THE SOUTHEAST
PANHANDLE AND MUCH OF SWRN NEBR. RICH THETA-E ADVECTION INDICATED BY
NAM AND GFS INTO THIS REGION ALONG WITH SFC DEWPOINTS REACHING THE
MID/UPPER 50S W/BACKED LOW LEVEL WINDS SUSTAINED NEAR 20KTS. THIS
FAVORABLE FOR DISCRETE ROTATING STORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 303 PM CDT THU MAY 23 2013

THE END OF THE WEEK IS DOMINATED BY TWO UPPER LEVEL LOW PRESSURE
SYSTEMS IN PLACE ALONG THE EASTERN AND WESTERN COASTS...WITH AN
AMPLIFIED RIDGE AXIS IN THE PLAINS REGION. THE RIDGE AXIS WILL
SLOWLY SHIFT EAST...PUTTING WESTERN NEBRASKA IN SOUTHWEST FLOW ALOFT
AND A RATHER UNSETTLED WEATHER PATTERN. THIS PATTERN WILL ALSO KEEP
TEMPERATURES WARM AND SOMEWHAT HUMID CONDITIONS AROUND THROUGH MOST
OF THE FORECAST PERIOD.

THE MAIN FORECAST CHALLENGE WILL BE THE POSSIBILITY FOR SEVERE
WEATHER...MAINLY FRIDAY NIGHT AND SATURDAY NIGHT. THE SOUTHWEST FLOW
WILL SETUP LEE SIDE TROUGHING IN EASTERN CO AND THE NE PANHANDLE.
SHORTWAVES EMBEDDED IN THE SOUTHWEST FLOW WILL MOVE OVER THE
PLAINS...HOWEVER THE PRIMARY AREA OF LIFT ASSOCIATED WITH MOST OF
THESE WAVES WILL BE CENTERED OVER THE ROCKIES. THE MAIN LIFTING
MECHANISM FOR THUNDERSTORM ACTIVITY IN THE HIGH PLAINS LOOKS TO BE
INSTABILITY BUILT UP BY DIURNAL HEATING.

THUNDERSTORMS...SOME SEVERE...MAY BE ONGOING AT THE BEGINNING OF THE
PERIOD ACROSS SOUTHWEST AND WESTERN NEBRASKA FRIDAY EVENING. THE
PRESENCE OF A 30-40KT LLJ WILL HELP MAINTAIN THIS ACTIVITY OVERNIGHT
AS IT VEERS OFF TO THE EAST. STEEP MID LEVEL LAPSE RATES AND AMPLE
MOISTURE WILL KEEP THUNDERSTORMS POSSIBLE...HOWEVER THE SEVERE
THREAT OVERNIGHT WILL BE LOW.

ATTENTION THEN TURNS TO SATURDAY AS SKIES BEGIN TO CLEAR OUT FROM
WEST TO EAST DURING THE MORNING AND AFTERNOON HOURS. THIS WILL BE
FAVORABLE FOR STRONG HEATING...WITH HIGHS PUSHING THE UPPER 80S FOR
MOST OF THE AREA BUT STILL COOLER IN OUR NORTHEAST ZONES. THE
HEATING WILL MAKE THE BOUNDARY LAYER VERY UNSTABLE WITH MLCAPE
VALUES EXCEEDING 2K J/KG...AND COUPLED WITH 30-40 KTS OF DEEP LAYER
SHEAR WILL PROMOTE AN ENVIRONMENT CONDUCIVE FOR SEVERE STORMS
BEGINNING LATE IN THE AFTERNOON. PRIMARY THREATS AT THIS TIME
LOOK TO BE LARGE HAIL AND DAMAGING WINDS. AGAIN...LLJ WILL
STRENGTHEN AFTER DARK AND HELP MAINTAIN THE THUNDERSTORM ACTIVITY AS
IT MOVES EAST.

STORM CHANCES WILL CONTINUE THROUGH THE EXTENDED PERIOD AS THE HIGH
PLAINS REMAINS IN A SOUTHWEST FLOW PATTERN. MODELS BEGIN TO DIVERGE
ON THEIR HANDLING OF THE LONGWAVE PATTERN TOWARD THE END OF THE
EXTENDED PERIOD WITH THE GFS EJECTING A TROUGH INTO THE NORTHERN
PLAINS...WITH THE 12Z EC DIGGING A TROUGH INTO THE RIO GRANDE
VALLEY. THIS WILL HAVE A BIG IMPACT ON PRECIP CHANCES FOR THE MIDDLE
OF NEXT WEEK GOING FORWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 613 PM CDT THU MAY 23 2013

A SURFACE TROUGH OF LOW PRESSURE WILL DEEPEN ACROSS THE NEBRASKA
PANHANDLE TONIGHT AND FRIDAY...LEADING TO STRONG SOUTHERLY WINDS
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. WIND SPEEDS TONIGHT
WILL RANGE FROM 10 TO 20 KTS TONIGHT...AND FROM 20 TO 30 KTS ON FRIDAY.
MOSTLY CLEAR SKIES EARLY THIS EVENING WILL BECOME OVERCAST
OVERNIGHT WITH BROKEN CLOUDINESS EXPECTED FRIDAY AFTERNOON. LIGHT
RAIN SHOWERS ARE POSSIBLE ACROSS SOUTHWESTERN NEBRASKA OVERNIGHT
TONIGHT AND MAY IMPACT THE KLBF TERMINAL AFTER 08Z. CIGS AT TEH
KLBF TERMINAL WILL RANGE FROM 1000 TO 4000 FT AGL WITH THE LOWEST
CIGS BETWEEN 08Z AND 15Z FRIDAY. FOR THE KVTN TERMINAL...CIGS WILL
RANGE FROM 1500 TO 3000 AGL OVER THE NEXT 24 HOURS.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...CLB
SHORT TERM...ROBERG
LONG TERM...MARTIN
AVIATION...CLB

000
FXUS63 KGID 240000
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
700 PM CDT THU MAY 23 2013

.UPDATE...
ISSUED AT 654 PM CDT THU MAY 23 2013

MADE MINOR ADJUSTMENTS TO HOURLY WEATHER THIS EVENING.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 355 PM CDT THU MAY 23 2013

MORNING UPPER AIR ANALYSIS INDICATES MID TO UPPER LEVEL RIDGING
OVER THE CENTRAL CONUS...WITH TROUGHING OVER THE WEST AND EAST. A
CLOSED MID TO UPPER LEVEL LOW IS ALSO NOTED EMBEDDED WITHIN THE
WESTERN CONUS TROUGH. INCREASED MID TO UPPER LEVEL FLOW SURROUNDS
THE WESTERN CONUS LOW...AND ALSO EXTENDS FROM CENTRAL CANADA
SOUTH/SOUTHEASTWARD INTO PORTIONS OF THE MISSISSIPPI VALLEY AND
NORTHEASTERN CONUS. MID TO UPPER LEVEL FLOW OVER THE CENTRAL
PLAINS HOWEVER IS FAIRLY WEAK...MAXING OUT AT AROUND 40KTS NEAR
300MB PER 12Z SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR
IMAGERY CLEARLY SHOWS THE MID LEVEL LOW OVER THE WESTERN
CONUS...WITH INCREASED VALUES OF MID LEVEL MOISTURE EXTENDING FROM
THE SOUTHERN CONUS...NORTH/NORTHWESTWARD INTO THE ROCKIES AND HIGH
PLAINS. AT THE SURFACE A RIDGE OF HIGH BAROMETRIC PRESSURE EXTENDS
FROM THE UPPER MISSISSIPPI VALLEY...SOUTH/SOUTHWEST INTO THE
MISSOURI RIVER VALLEY. AN AREA OF LOW BAROMETRIC PRESSURE IS ALSO
NOTED OVER PORTIONS OF WYOMING. LOW LEVEL FLOW ACROSS OUR AREA
REMAINS FROM THE EAST/NORTHEAST FOR THE MOST PART...BUT IS
BEGINNING TO TURN MORE SOUTHEASTERLY ACROSS SOUTHWESTERN PORTIONS
OF OUR CWA AS THE SURFACE RIDGE CONTINUES MOVING EAST...AWAY FROM
OUR AREA.

AN OVERALL LACK IN KINEMATIC FORCING WILL CONTINUE PROMOTING DRY
CONDITIONS ACROSS OUR AREA THROUGH AT LEAST 06Z TONIGHT. GUIDANCE
SUGGESTS MULTIPLE MID LEVEL PERTURBATIONS WILL EJECT FROM THE
WESTERN CONUS TROUGH BEGINNING TONIGHT HOWEVER...WITH SOME OF
THESE PERTURBATIONS ROUNDING THE TOP OF THE CENTRAL CONUS RIDGE
THUS HELPING TO BREAK DOWN THE RIDGE SOMEWHAT. WEAK OMEGA AHEAD OF
THE MID LEVEL PERTURBATIONS MAY BE STRONG ENOUGH TO PROMOTE MID
LEVEL CLOUDS AND PERHAPS SOME VERY LIGHT PRECIPITATION ACROSS
PORTIONS OF OUR AREA TONIGHT. THAT BEING SAID...INCREASING LOW
LEVEL RETURN FLOW AND RESULTANT LOW LEVEL THETA-E ADVECTION WILL
LIKELY PLAY A LARGER ROLE IN CLOUD DEVELOPMENT AND POSSIBLE
PRECIPITATION PRODUCTION. THETA-E ADVECTION...BOTH FROM RETURN
FLOW NEAR THE SURFACE AS WELL AS ALONG THE AXIS OF A ~40KT LOW
LEVEL JET ACROSS OUR WEST...APPEARS AS THOUGH IT WILL PROMOTE
ENOUGH ISENTROPIC UPGLIDE AND SATURATION...PRIMARILY BETWEEN THE
305K AND 320K SURFACES...FOR STRATUS DEVELOPMENT ACROSS MUCH OF
OUR CWA BY SUNRISE FRIDAY. ALTHOUGH NOT LIKELY...FORECAST
PROXIMITY SOUNDINGS FROM ACROSS OUR CWA...PER THE
NAM...OPERATIONAL GFS AND EC...SUGGEST THE LOWER TROPOSPHERE MAY
BECOME SATURATED ENOUGH FOR PRECIPITATION TO BE REALIZED AT THE
SURFACE ACROSS EXTREME SOUTHWESTERN PORTIONS OF OUR CWA DURING THE
EARLY MORNING HOURS FRIDAY. GIVEN ALL THIS...WENT AHEAD WITH ~20%
POPS ACROSS EXTREME SOUTHWESTERN PORTIONS OF OUR CWA 06Z-12Z
FRIDAY.

INCREASING LOW LEVEL THETA-E ADVECTION...ALONG WITH
PERSISTENT...ALBEIT WEAK...MID LEVEL OMEGA AHEAD OF PASSING MID
LEVEL PERTURBATIONS...WILL ALLOW CHANCES FOR PRECIPITATION TO
OVERTAKE ALL OF OUR CWA DURING THE DAY FRIDAY. QPF FIELDS FROM THE
NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL SUGGEST MEASURABLE
PRECIPITATION WILL BE POSSIBLE ACROSS MOST ALL OF OUR CWA FRIDAY.
THAT BEING SAID...PRECIPITATION RATES DO NOT APPEAR AS THOUGH THEY
WILL BE ALL THAT HIGH AND PRECIPITATION AT ANY GIVEN POINT IN THE
DAY MAY BE SPOTTY AT BEST. SO...OPTED TO KEEP POPS IN THE 40-50%
RANGE FOR THE MOST PART...BUT IT IS BELIEVED THESE POPS WILL BE
INCREASED TONIGHT IF FUTURE MODEL RUNS CONTINUE INDICATING
MEASURABLE PRECIPITATION ACROSS MUCH OF THE CWA DURING THE DAY
FRIDAY.

INCREASING LOW LEVEL MOISTURE DUE TO THE AFOREMENTIONED THETA-E
ADVECTION...WORKING IN CONCERT WITH SOMEWHAT INCREASING MID LEVEL
LAPSE RATES AS MID LEVEL PERTURBATIONS PUSH OVERHEAD...SHOULD
PROMOTE AT LEAST SOME POTENTIAL INSTABILITY ACROSS PORTIONS OF OUR
AREA ON FRIDAY. AT THIS TIME GUIDANCE SUGGESTS LOCATIONS ACROSS
OUR AREA...GENERALLY SOUTH OF I-80 AND WEST OF HIGHWAY 281...COULD
SEE DEEP-LAYER MUCAPE VALUES OF AROUND 1000J/KG...IF NOT A TOUCH
HIGHER...FRIDAY AFTERNOON. DEEP-LAYER BULK SHEAR VALUES ON THE
ORDER OF ~30KTS ARE ALSO EXPECTED ACROSS OUR AREA DURING THIS TIME
PERIOD. GIVEN ALL THIS...SEVERE WEATHER IS NOT CURRENTLY
EXPECTED...BUT A FEW OF THE STRONGER UPDRAFTS COULD CERTAINLY BE
CAPABLE OF PRODUCING SUB-SEVERE HAIL AND WILL MENTION THIS IN THE
HWO.

SUBTLE LOW LEVEL WARM AIR ADVECTION SHOULD PROMOTE SLIGHTLY WARMER
WEATHER TOMORROW WHEN COMPARED TO TODAY...BUT NOT BY MUCH. AN
OVERNIGHT LOW TEMPERATURE NEAR 50 IS FORECAST FOR MOST LOCATIONS
TONIGHT WITH AN AFTERNOON HIGH TEMPERATURE IN THE UPPER 60S TO
NEAR 70 FOR FRIDAY.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 PM CDT THU MAY 23 2013

PRIMARY FORECAST CONCERN THROUGH THE LONG TERM REMAINS WITH
MULTIPLE THUNDERSTORM CHANCES...AS THE ACTIVE UPPER LEVEL PATTERN
CONTINUES ACROSS THE REGION.

HASNT BEEN ANY SIGNIFICANT CHANGES IN THE MODELS WITH THE UPPER
LEVEL PATTERN AT THE START OF THE FORECAST PERIOD...AS THE PLAINS
REMAIN WITH RIDGING IN PLACE...SET UP BETWEEN A LOW PRESSURE
SYSTEM OVER THE EAST COAST AND ANOTHER OVER THE PAC NW. THE FIRST
OF A NUMBER OF LOW AMPLITUDE DISTURBANCES TO AFFECT THE REGION
MAKES ITS WAY ACROSS THE AREA FRIDAY NIGHT...AND AIDED BY WARM
AIR/MOISTURE ADVECTION VIA A SRLY LLJ...BRING THUNDERSTORM CHANCES
TO THE CWA. MODELS IN GOOD AGREEMENT SHOWING INSTABILITY ALSO
BEGINNING TO WORK ITS WAY NORTH...PRIMARILY AFFECTING THE
SOUTHWESTERN HALF OF THE CWA...AND ALONG WITH SUFFICIENT SHEAR
VALUES...CERTAINLY CANT RULE OUT SOME STRONG/SEVERE THUNDERSTORMS.

INTO SATURDAY...EXPECTING THE MORNING HOURS TO BE AFFECTED BY THE
OVERNIGHT ACTIVITY...WITH SOME UNCERTAINTY HOW QUICKLY THINGS MAY
MOVE OUT. SHOULD BE A LULL IN THE ACTIVITY INTO THE
AFTERNOON...BEFORE ADDITIONAL THUNDERSTORM CHANCES RETURN AS THE
NEXT UPPER LEVEL DISTURBANCE MOVES IN FROM THE SOUTHWEST. AHEAD OF
THIS NEXT DISTURBANCE...SURFACE LOW PRESSURE IN PLACE OVER THE
FRONT RANGE/HIGH PLAINS LOOKS TO STRENGTHEN A BIT. LOOKING TO SEE
A TIGHTENING PRESSURE GRADIENT ACROSS THE AREA AS A RESULT...WITH
HIGH PRESSURE STILL IN PLACE OVER THE MIDWEST...WITH INCREASING
SOUTHERLY WINDS EXPECTED. ONE CONCERN IS WHERE A SURFACE WARM
FRONT WILL SET UP...WITH THE POTENTIAL FOR IT TO END UP DRAPED
ACROSS THE NORTHERN HALF OF THE CWA BY LATE AFTERNOON. MODELS
CONTINUE TO SHOW SEVERAL THOUSAND J/KG OF CAPE DEVELOPING AS
DEWPOINTS/MOISTURE CONTINUES TO POOL ALONG THE FRONT...BUT ALSO
SHOW CAPPING IN PLACE. QUESTION IS WHETHER CONVECTION CAN GET
GOING IN THE AREA OF WEAKER CAPPING /MAINLY ACROSS PORTIONS OF SC
NEB/...AND IF IT DOES HOW MUCH THERE WOULD BE. AGAIN...WHILE DEEP
LAYER SHEAR ISNT GREAT...ITS SUFFICIENT FOR STRONG/SEVERE
WEATHER...PLUS THERE IS PLENTY OF INSTABILITY IN PLACE ALONG WITH
THE POTENTIAL SFC FRONTAL BOUNDARY. PLENTY TO KEEP AN EYE ON FOR
SATURDAY.

ANY ONGOING ACTIVITY LOOKS TO CONTINUE TO AFFECT THE AREA DURING
THE OVERNIGHT HOURS...AND POTENTIALLY INTO THE MORNING HOURS ON
SUNDAY...BUT THERE IS SOME QUESTION ON WHAT WOULD BE GOING ON
BEYOND THAT. SOME OF THE 12Z MODELS CAME IN SHOWING NOT A WHOLE
HECK OF A LOT GOING ON DURING THE DAYTIME HOURS...BUT STILL CANT
RULE OUT SOME LATE AFTERNOON THUNDERSTORMS...SO WILL CONTINUE TO
KEEP SOME LOWER POPS GOING. BUT...WHATEVER BREAK THERE IS DOESNT
LOOK TO LAST LONG...WITH THE NEXT ROUND OF THUNDERSTORMS MOVING
WITH THE LATEST DISTURBANCE...AND A STRONGER CORRIDOR OF THE LLJ
NOSING INTO THE CWA. WITHOUT A FRONT MOVING THROUGH TO PUSH THE
BETTER MOISTURE IN PLACE OUT OF THE REGION...INSTABILITY CERTAINLY
REMAINS IN PLACE...SO THE THREAT FOR SOME THUNDERSTORMS TO BECOME
SEVERE CONTINUES.

LOOKING AT MONDAY THROUGH WEDNESDAY...THE OVERALL STORY DOESNT
CHANGE SIGNIFICANTLY...THE CWA REMAINS UNDER SOUTHWESTERLY FLOW IN
THE UPPER LEVELS...WITH CONTINUED PERIODIC THUNDERSTORM CHANCES AS
THESE DISTURBANCES MOVE THROUGH. UNCERTAINTY IN THE FORECAST GROWS
WITH TIME...WED FOR EXAMPLE...THE GFS SHOWS A MID/UPPER LEVEL
TROUGH SWINGING RIGHT INTO THE CENTRAL PLAINS...WHILE THE LATEST
ECMWF SHOWS A CUTOFF LOW OVER THE AZ/MEXICO BORDER. MANY DETAILS
TO WORK THROUGH IN THE COMING DAYS.

AS FAR AS TEMPERATURES GO...NOT EXPECTING ANY NOTABLE
SWINGS...WITH HIGHS REMAINING ABOVE AVERAGE OVERALL...RANGING
ANYWHERE FROM THE UPPER 70S TO MID/UPPER 80S. MILD OVERNIGHT LOWS
IN THE UPPER 50S/60S ALSO EXPECTED.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 654 PM CDT THU MAY 23 2013

EXPECT INCREASING AND LOWERING CLOUDINESS OVERNIGHT AS A WARM
FRONT APPROACHES. INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS
WILL OCCUR BY FRIDAY AFTERNOON AS THE WARM FRONT MOVES EAST ACROSS
THE AREA. LAPSE RATES WILL BE MARGINAL...SO THUNDER WILL BE HARDLY
CONSTANT IF IT OCCURS. WIND WILL REMAIN RATHER BREEZY FOR THIS
FORECAST.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...HEINLEIN
SHORT TERM...BRYANT
LONG TERM...ADO
AVIATION...HEINLEIN

000
FXUS63 KOAX 232327
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
627 PM CDT THU MAY 23 2013

.AVIATION...
00Z TAFS FOR KOFK...KOMA AND KLNK.

VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH FLOW BECOMING
SOUTHERLY AS HIGH PRESSURE SHIFTS EAST OF THE AREA. WINDS
INCREASING TO 15G25KT BY 18Z.

&&

.PREV DISCUSSION... /ISSUED 235 PM CDT THU MAY 23 2013/

DISCUSSION...

HIGH PRESSURE ACROSS THE MISSOURI VALLEY WILL CONTINUE TO
TRANSITION EASTWARD OVERNIGHT GIVING US QUIET WEATHER AND EAST
NORTHEAST WINDS BECOMING SOUTHEAST BY DAYBREAK. MEANWHILE...AN
UPPER LEVEL IMPULSE MOVING THROUGH THE CENTRAL ROCKIES SHOULD
TRIGGER CONVECTION TONIGHT ACROSS THE HIGH PLAINS....WHICH WILL
SLOWLY PUSH EASTWARD INTO OUR FORECAST AREA THROUGH THE DAY
FRIDAY WITH THE BEST CHANCE FOR PRECIP ACROSS EASTERN NEBRASKA...
AND JUST A SMALL CHANCE ACROSS WESTERN IOWA DURING THE AFTERNOON.
INSTABILITY RETURNS TO THE REGION. GIVEN SHEAR AND INSTABILITY
PARAMETERS...A FEW STRONG STORMS COULD OCCUR. THIS FIRST IMPULSESEEMS
TO MOVE THROUGH DURING THE EVENING...ALTHOUGH THE CONVERGENCE
ALONG THE NOSE OF THE LOW LEVEL JET COULD STILL PROVIDE SUPPORT
FOR ISOLATED STORMS TO LINGER PAST MIDNIGHT.

FORECAST DETAILS BECOME LESS CLEAR THROUGH THE REMAINDER OF THE
WEEKEND AND THROUGH NEXT WEEK...BUT THERE WILL BE SEVERAL CHANCES
FOR PRECIP THROUGH THE PERIOD. CONVECTION FROM FRIDAY NIGHT COULD
LEAVE BEHIND A FEW BOUNDARIES...WHICH COULD BE THE FOCUS FOR NEW
CONVECTION SATURDAY ACROSS OUR AREA. INSTABILITY DEFINITELY
INCREASES DURING THIS TIME...AND WITH SUFFICIENT SHEAR...SEEMS
THERE COULD BE A SEVERE THREAT THIS DAY AS WELL.

THE REGION WILL ALSO REMAIN UNDER AN UPPER RIDGE FROM SATURDAY
AND BEYOND...WHICH PUTS IN THE WELL WITHIN THE AREA OF PRIME
ACTION AT LEAST THROUGH THE EARLY PART OF NEXT WEEK AS WEAK
IMPULSE CONTINUE TO EJECT OUT OF THE MEAN SOUTHWESTERN TROUGH AND
CONTINUE TO TRIGGER SEVERAL ROUNDS OF STORMS. BY THIS TIME...THE
DETAILS OF ANY WIDESPREAD SEVERE STORMS BECOMES INCREASINGLY
DIFFICULT TO PIN DOWN...OTHER THAN THERE WILL BE SEVERAL CHANCES
FOR RAIN. NOT TO SAY THAT IT WILL BE CONTINUOUS RAIN...BUT GIVEN
THAT IT`S A HOLIDAY WEEKEND AND THERE WILL BE MANY MORE OUTDOOR
ACTIVITIES THAN NORMAL...THERE WILL BE A CHANCE OF RAIN JUST
ABOUT EVERY 12 HOUR PERIOD THROUGH EARLY NEXT WEEK.

FOR LATER PORTIONS OF THE EXTENDED FORECAST...THE MODELS SUGGEST
THAT THE RIDGE AXIS DOES SHIFT EASTWARD JUST A BIT...BUT STILL
SMALL CHANCES OF RAIN WILL EXIST IN THE FORECAST FOR WEDNESDAY AND
THURSDAY OF NEXT WEEK.

DEWALD

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

FOBERT

000
FXUS63 KLBF 232314
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
614 PM CDT THU MAY 23 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 303 PM CDT THU MAY 23 2013

FOR TONIGHT...SURFACE HIGH PRESSURE WILL PUSH OFF TO OUR SOUTHEAST AS
LOW LEVEL WINDS VEER TOWARD THE SOUTHEAST. A SUBSTANTIAL AMOUNTS OF
LOW LEVEL MOISTURE WILL BE ADVECTED NORTHWEST TONIGHT FROM WESTERN
KANSAS ANS EASTERN COLORADO INTO WESTERN NEBRASKA. SKIES TO BECOME
OVERCAST MOST AREAS BY DAYBREAK. REGARDING RAIN CHANCES...DELAYED
ONSET OF SHOWERS/ISOLATED TSTMS UNTIL AFTER 06Z FOR AREAS WEST OF
VTN THROUGH BBW. STEEP MID LEVEL LAPSE RATES WITH THE APPROACH OF A
DISTURBANCE FROM COLORADO WILL INCREASE SHOWER CHANCES. LOW
TEMPERATURES WILL RANGE FROM THE UPPER 40S TO MID 50S.

ON FRIDAY...PASSING DISTURBANCE TO BRING CHANCE POPS TO MUCH OF
FORECAST AREA IN THE MORNING WITH THE HIGHEST POPS 40-50 PERCENT
EAST OF HWY 83. BY EARLY AFTERNOON...ONLY SLIGHT CHANCE IN THE WEST.
GFS AND NAM INDICATED A MOSTLY SATURATED LAYER FROM SFC THROUGH
800MB. HAVE LOWERED TEMPERATURES AS MUCH AS 5 DEGREES TOWARD THE
COOLEST MET GUIDANCE FOR CENTRAL AND SOUTHEAST ZONES WITH HIGHS FROM
66 TO 69. FAR WEST TIER OF COUNTIES FCST TO REACH THE LOWER/MID 70S
AS CEILINGS LIFT AND PARTIAL LATE AFTERNOON CLEARING. ANOTHER MAIN
FORECAST CONCERN WILL BE POTENTIAL FOR STORM INITIATION ALONG STRONG
DIFFERENTIAL HEATING BOUNDARY NEAR A LINE FROM KBFF-KSNY-KITR. AREAS
75 MILES EAST AND WEST OF THIS LINE ARE AT RISK FOR SEVERE STORMS BY
LATE FRIDAY AFTERNOON/EARLY EVENING. THIS INCLUDES THE SOUTHEAST
PANHANDLE AND MUCH OF SWRN NEBR. RICH THETA-E ADVECTION INDICATED BY
NAM AND GFS INTO THIS REGION ALONG WITH SFC DEWPOINTS REACHING THE
MID/UPPER 50S W/BACKED LOW LEVEL WINDS SUSTAINED NEAR 20KTS. THIS
FAVORABLE FOR DISCRETE ROTATING STORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 303 PM CDT THU MAY 23 2013

THE END OF THE WEEK IS DOMINATED BY TWO UPPER LEVEL LOW PRESSURE
SYSTEMS IN PLACE ALONG THE EASTERN AND WESTERN COASTS...WITH AN
AMPLIFIED RIDGE AXIS IN THE PLAINS REGION. THE RIDGE AXIS WILL
SLOWLY SHIFT EAST...PUTTING WESTERN NEBRASKA IN SOUTHWEST FLOW ALOFT
AND A RATHER UNSETTLED WEATHER PATTERN. THIS PATTERN WILL ALSO KEEP
TEMPERATURES WARM AND SOMEWHAT HUMID CONDITIONS AROUND THROUGH MOST
OF THE FORECAST PERIOD.

THE MAIN FORECAST CHALLENGE WILL BE THE POSSIBILITY FOR SEVERE
WEATHER...MAINLY FRIDAY NIGHT AND SATURDAY NIGHT. THE SOUTHWEST FLOW
WILL SETUP LEE SIDE TROUGHING IN EASTERN CO AND THE NE PANHANDLE.
SHORTWAVES EMBEDDED IN THE SOUTHWEST FLOW WILL MOVE OVER THE
PLAINS...HOWEVER THE PRIMARY AREA OF LIFT ASSOCIATED WITH MOST OF
THESE WAVES WILL BE CENTERED OVER THE ROCKIES. THE MAIN LIFTING
MECHANISM FOR THUNDERSTORM ACTIVITY IN THE HIGH PLAINS LOOKS TO BE
INSTABILITY BUILT UP BY DIURNAL HEATING.

THUNDERSTORMS...SOME SEVERE...MAY BE ONGOING AT THE BEGINNING OF THE
PERIOD ACROSS SOUTHWEST AND WESTERN NEBRASKA FRIDAY EVENING. THE
PRESENCE OF A 30-40KT LLJ WILL HELP MAINTAIN THIS ACTIVITY OVERNIGHT
AS IT VEERS OFF TO THE EAST. STEEP MID LEVEL LAPSE RATES AND AMPLE
MOISTURE WILL KEEP THUNDERSTORMS POSSIBLE...HOWEVER THE SEVERE
THREAT OVERNIGHT WILL BE LOW.

ATTENTION THEN TURNS TO SATURDAY AS SKIES BEGIN TO CLEAR OUT FROM
WEST TO EAST DURING THE MORNING AND AFTERNOON HOURS. THIS WILL BE
FAVORABLE FOR STRONG HEATING...WITH HIGHS PUSHING THE UPPER 80S FOR
MOST OF THE AREA BUT STILL COOLER IN OUR NORTHEAST ZONES. THE
HEATING WILL MAKE THE BOUNDARY LAYER VERY UNSTABLE WITH MLCAPE
VALUES EXCEEDING 2K J/KG...AND COUPLED WITH 30-40 KTS OF DEEP LAYER
SHEAR WILL PROMOTE AN ENVIRONMENT CONDUCIVE FOR SEVERE STORMS
BEGINNING LATE IN THE AFTERNOON. PRIMARY THREATS AT THIS TIME
LOOK TO BE LARGE HAIL AND DAMAGING WINDS. AGAIN...LLJ WILL
STRENGTHEN AFTER DARK AND HELP MAINTAIN THE THUNDERSTORM ACTIVITY AS
IT MOVES EAST.

STORM CHANCES WILL CONTINUE THROUGH THE EXTENDED PERIOD AS THE HIGH
PLAINS REMAINS IN A SOUTHWEST FLOW PATTERN. MODELS BEGIN TO DIVERGE
ON THEIR HANDLING OF THE LONGWAVE PATTERN TOWARD THE END OF THE
EXTENDED PERIOD WITH THE GFS EJECTING A TROUGH INTO THE NORTHERN
PLAINS...WITH THE 12Z EC DIGGING A TROUGH INTO THE RIO GRANDE
VALLEY. THIS WILL HAVE A BIG IMPACT ON PRECIP CHANCES FOR THE MIDDLE
OF NEXT WEEK GOING FORWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 613 PM CDT THU MAY 23 2013

A SURFACE TROUGH OF LOW PRESSURE WILL DEEPEN ACROSS THE NEBRASKA
PANHANDLE TONIGHT AND FRIDAY...LEADING TO STRONG SOUTHERLY WINDS
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. WIND SPEEDS TONIGHT
WILL RANGE FROM 10 TO 20 KTS TONIGHT...AND FROM 20 TO 30 KTS ON FRIDAY.
MOSTLY CLEAR SKIES EARLY THIS EVENING WILL BECOME OVERCAST
OVERNIGHT WITH BROKEN CLOUDINESS EXPECTED FRIDAY AFTERNOON. LIGHT
RAIN SHOWERS ARE POSSIBLE ACROSS SOUTHWESTERN NEBRASKA OVERNIGHT
TONIGHT AND MAY IMPACT THE KLBF TERMINAL AFTER 08Z. CIGS AT TEH
KLBF TERMINAL WILL RANGE FROM 1000 TO 4000 FT AGL WITH THE LOWEST
CIGS BETWEEN 08Z AND 15Z FRIDAY. FOR THE KVTN TERMINAL...CIGS WILL
RANGE FROM 1500 TO 3000 AGL OVER THE NEXT 24 HOURS.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...ROBERG
LONG TERM...MARTIN
AVIATION...CLB

000
FXUS63 KGID 232055
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
355 PM CDT THU MAY 23 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 355 PM CDT THU MAY 23 2013

MORNING UPPER AIR ANALYSIS INDICATES MID TO UPPER LEVEL RIDGING
OVER THE CENTRAL CONUS...WITH TROUGHING OVER THE WEST AND EAST. A
CLOSED MID TO UPPER LEVEL LOW IS ALSO NOTED EMBEDDED WITHIN THE
WESTERN CONUS TROUGH. INCREASED MID TO UPPER LEVEL FLOW SURROUNDS
THE WESTERN CONUS LOW...AND ALSO EXTENDS FROM CENTRAL CANADA
SOUTH/SOUTHEASTWARD INTO PORTIONS OF THE MISSISSIPPI VALLEY AND
NORTHEASTERN CONUS. MID TO UPPER LEVEL FLOW OVER THE CENTRAL
PLAINS HOWEVER IS FAIRLY WEAK...MAXING OUT AT AROUND 40KTS NEAR
300MB PER 12Z SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR
IMAGERY CLEARLY SHOWS THE MID LEVEL LOW OVER THE WESTERN
CONUS...WITH INCREASED VALUES OF MID LEVEL MOISTURE EXTENDING FROM
THE SOUTHERN CONUS...NORTH/NORTHWESTWARD INTO THE ROCKIES AND HIGH
PLAINS. AT THE SURFACE A RIDGE OF HIGH BAROMETRIC PRESSURE EXTENDS
FROM THE UPPER MISSISSIPPI VALLEY...SOUTH/SOUTHWEST INTO THE
MISSOURI RIVER VALLEY. AN AREA OF LOW BAROMETRIC PRESSURE IS ALSO
NOTED OVER PORTIONS OF WYOMING. LOW LEVEL FLOW ACROSS OUR AREA
REMAINS FROM THE EAST/NORTHEAST FOR THE MOST PART...BUT IS
BEGINNING TO TURN MORE SOUTHEASTERLY ACROSS SOUTHWESTERN PORTIONS
OF OUR CWA AS THE SURFACE RIDGE CONTINUES MOVING EAST...AWAY FROM
OUR AREA.

AN OVERALL LACK IN KINEMATIC FORCING WILL CONTINUE PROMOTING DRY
CONDITIONS ACROSS OUR AREA THROUGH AT LEAST 06Z TONIGHT. GUIDANCE
SUGGESTS MULTIPLE MID LEVEL PERTURBATIONS WILL EJECT FROM THE
WESTERN CONUS TROUGH BEGINNING TONIGHT HOWEVER...WITH SOME OF
THESE PERTURBATIONS ROUNDING THE TOP OF THE CENTRAL CONUS RIDGE
THUS HELPING TO BREAK DOWN THE RIDGE SOMEWHAT. WEAK OMEGA AHEAD OF
THE MID LEVEL PERTURBATIONS MAY BE STRONG ENOUGH TO PROMOTE MID
LEVEL CLOUDS AND PERHAPS SOME VERY LIGHT PRECIPITATION ACROSS
PORTIONS OF OUR AREA TONIGHT. THAT BEING SAID...INCREASING LOW
LEVEL RETURN FLOW AND RESULTANT LOW LEVEL THETA-E ADVECTION WILL
LIKELY PLAY A LARGER ROLE IN CLOUD DEVELOPMENT AND POSSIBLE
PRECIPITATION PRODUCTION. THETA-E ADVECTION...BOTH FROM RETURN
FLOW NEAR THE SURFACE AS WELL AS ALONG THE AXIS OF A ~40KT LOW
LEVEL JET ACROSS OUR WEST...APPEARS AS THOUGH IT WILL PROMOTE
ENOUGH ISENTROPIC UPGLIDE AND SATURATION...PRIMARILY BETWEEN THE
305K AND 320K SURFACES...FOR STRATUS DEVELOPMENT ACROSS MUCH OF
OUR CWA BY SUNRISE FRIDAY. ALTHOUGH NOT LIKELY...FORECAST
PROXIMITY SOUNDINGS FROM ACROSS OUR CWA...PER THE
NAM...OPERATIONAL GFS AND EC...SUGGEST THE LOWER TROPOSPHERE MAY
BECOME SATURATED ENOUGH FOR PRECIPITATION TO BE REALIZED AT THE
SURFACE ACROSS EXTREME SOUTHWESTERN PORTIONS OF OUR CWA DURING THE
EARLY MORNING HOURS FRIDAY. GIVEN ALL THIS...WENT AHEAD WITH ~20%
POPS ACROSS EXTREME SOUTHWESTERN PORTIONS OF OUR CWA 06Z-12Z
FRIDAY.

INCREASING LOW LEVEL THETA-E ADVECTION...ALONG WITH
PERSISTENT...ALBEIT WEAK...MID LEVEL OMEGA AHEAD OF PASSING MID
LEVEL PERTURBATIONS...WILL ALLOW CHANCES FOR PRECIPITATION TO
OVERTAKE ALL OF OUR CWA DURING THE DAY FRIDAY. QPF FIELDS FROM THE
NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL SUGGEST MEASURABLE
PRECIPITATION WILL BE POSSIBLE ACROSS MOST ALL OF OUR CWA FRIDAY.
THAT BEING SAID...PRECIPITATION RATES DO NOT APPEAR AS THOUGH THEY
WILL BE ALL THAT HIGH AND PRECIPITATION AT ANY GIVEN POINT IN THE
DAY MAY BE SPOTTY AT BEST. SO...OPTED TO KEEP POPS IN THE 40-50%
RANGE FOR THE MOST PART...BUT IT IS BELIEVED THESE POPS WILL BE
INCREASED TONIGHT IF FUTURE MODEL RUNS CONTINUE INDICATING
MEASURABLE PRECIPITATION ACROSS MUCH OF THE CWA DURING THE DAY
FRIDAY.

INCREASING LOW LEVEL MOISTURE DUE TO THE AFOREMENTIONED THETA-E
ADVECTION...WORKING IN CONCERT WITH SOMEWHAT INCREASING MID LEVEL
LAPSE RATES AS MID LEVEL PERTURBATIONS PUSH OVERHEAD...SHOULD
PROMOTE AT LEAST SOME POTENTIAL INSTABILITY ACROSS PORTIONS OF OUR
AREA ON FRIDAY. AT THIS TIME GUIDANCE SUGGESTS LOCATIONS ACROSS
OUR AREA...GENERALLY SOUTH OF I-80 AND WEST OF HIGHWAY 281...COULD
SEE DEEP-LAYER MUCAPE VALUES OF AROUND 1000J/KG...IF NOT A TOUCH
HIGHER...FRIDAY AFTERNOON. DEEP-LAYER BULK SHEAR VALUES ON THE
ORDER OF ~30KTS ARE ALSO EXPECTED ACROSS OUR AREA DURING THIS TIME
PERIOD. GIVEN ALL THIS...SEVERE WEATHER IS NOT CURRENTLY
EXPECTED...BUT A FEW OF THE STRONGER UPDRAFTS COULD CERTAINLY BE
CAPABLE OF PRODUCING SUB-SEVERE HAIL AND WILL MENTION THIS IN THE
HWO.

SUBTLE LOW LEVEL WARM AIR ADVECTION SHOULD PROMOTE SLIGHTLY WARMER
WEATHER TOMORROW WHEN COMPARED TO TODAY...BUT NOT BY MUCH. AN
OVERNIGHT LOW TEMPERATURE NEAR 50 IS FORECAST FOR MOST LOCATIONS
TONIGHT WITH AN AFTERNOON HIGH TEMPERATURE IN THE UPPER 60S TO
NEAR 70 FOR FRIDAY.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 PM CDT THU MAY 23 2013

PRIMARY FORECAST CONCERN THROUGH THE LONG TERM REMAINS WITH
MULTIPLE THUNDERSTORM CHANCES...AS THE ACTIVE UPPER LEVEL PATTERN
CONTINUES ACROSS THE REGION.

HASNT BEEN ANY SIGNIFICANT CHANGES IN THE MODELS WITH THE UPPER
LEVEL PATTERN AT THE START OF THE FORECAST PERIOD...AS THE PLAINS
REMAIN WITH RIDGING IN PLACE...SET UP BETWEEN A LOW PRESSURE
SYSTEM OVER THE EAST COAST AND ANOTHER OVER THE PAC NW. THE FIRST
OF A NUMBER OF LOW AMPLITUDE DISTURBANCES TO AFFECT THE REGION
MAKES ITS WAY ACROSS THE AREA FRIDAY NIGHT...AND AIDED BY WARM
AIR/MOISTURE ADVECTION VIA A SRLY LLJ...BRING THUNDERSTORM CHANCES
TO THE CWA. MODELS IN GOOD AGREEMENT SHOWING INSTABILITY ALSO
BEGINNING TO WORK ITS WAY NORTH...PRIMARILY AFFECTING THE
SOUTHWESTERN HALF OF THE CWA...AND ALONG WITH SUFFICIENT SHEAR
VALUES...CERTAINLY CANT RULE OUT SOME STRONG/SEVERE THUNDERSTORMS.

INTO SATURDAY...EXPECTING THE MORNING HOURS TO BE AFFECTED BY THE
OVERNIGHT ACTIVITY...WITH SOME UNCERTAINTY HOW QUICKLY THINGS MAY
MOVE OUT. SHOULD BE A LULL IN THE ACTIVITY INTO THE
AFTERNOON...BEFORE ADDITIONAL THUNDERSTORM CHANCES RETURN AS THE
NEXT UPPER LEVEL DISTURBANCE MOVES IN FROM THE SOUTHWEST. AHEAD OF
THIS NEXT DISTURBANCE...SURFACE LOW PRESSURE IN PLACE OVER THE
FRONT RANGE/HIGH PLAINS LOOKS TO STRENGTHEN A BIT. LOOKING TO SEE
A TIGHTENING PRESSURE GRADIENT ACROSS THE AREA AS A RESULT...WITH
HIGH PRESSURE STILL IN PLACE OVER THE MIDWEST...WITH INCREASING
SOUTHERLY WINDS EXPECTED. ONE CONCERN IS WHERE A SURFACE WARM
FRONT WILL SET UP...WITH THE POTENTIAL FOR IT TO END UP DRAPED
ACROSS THE NORTHERN HALF OF THE CWA BY LATE AFTERNOON. MODELS
CONTINUE TO SHOW SEVERAL THOUSAND J/KG OF CAPE DEVELOPING AS
DEWPOINTS/MOISTURE CONTINUES TO POOL ALONG THE FRONT...BUT ALSO
SHOW CAPPING IN PLACE. QUESTION IS WHETHER CONVECTION CAN GET
GOING IN THE AREA OF WEAKER CAPPING /MAINLY ACROSS PORTIONS OF SC
NEB/...AND IF IT DOES HOW MUCH THERE WOULD BE. AGAIN...WHILE DEEP
LAYER SHEAR ISNT GREAT...ITS SUFFICIENT FOR STRONG/SEVERE
WEATHER...PLUS THERE IS PLENTY OF INSTABILITY IN PLACE ALONG WITH
THE POTENTIAL SFC FRONTAL BOUNDARY. PLENTY TO KEEP AN EYE ON FOR
SATURDAY.

ANY ONGOING ACTIVITY LOOKS TO CONTINUE TO AFFECT THE AREA DURING
THE OVERNIGHT HOURS...AND POTENTIALLY INTO THE MORNING HOURS ON
SUNDAY...BUT THERE IS SOME QUESTION ON WHAT WOULD BE GOING ON
BEYOND THAT. SOME OF THE 12Z MODELS CAME IN SHOWING NOT A WHOLE
HECK OF A LOT GOING ON DURING THE DAYTIME HOURS...BUT STILL CANT
RULE OUT SOME LATE AFTERNOON THUNDERSTORMS...SO WILL CONTINUE TO
KEEP SOME LOWER POPS GOING. BUT...WHATEVER BREAK THERE IS DOESNT
LOOK TO LAST LONG...WITH THE NEXT ROUND OF THUNDERSTORMS MOVING
WITH THE LATEST DISTURBANCE...AND A STRONGER CORRIDOR OF THE LLJ
NOSING INTO THE CWA. WITHOUT A FRONT MOVING THROUGH TO PUSH THE
BETTER MOISTURE IN PLACE OUT OF THE REGION...INSTABILITY CERTAINLY
REMAINS IN PLACE...SO THE THREAT FOR SOME THUNDERSTORMS TO BECOME
SEVERE CONTINUES.

LOOKING AT MONDAY THROUGH WEDNESDAY...THE OVERALL STORY DOESNT
CHANGE SIGNIFICANTLY...THE CWA REMAINS UNDER SOUTHWESTERLY FLOW IN
THE UPPER LEVELS...WITH CONTINUED PERIODIC THUNDERSTORM CHANCES AS
THESE DISTURBANCES MOVE THROUGH. UNCERTAINTY IN THE FORECAST GROWS
WITH TIME...WED FOR EXAMPLE...THE GFS SHOWS A MID/UPPER LEVEL
TROUGH SWINGING RIGHT INTO THE CENTRAL PLAINS...WHILE THE LATEST
ECMWF SHOWS A CUTOFF LOW OVER THE AZ/MEXICO BORDER. MANY DETAILS
TO WORK THROUGH IN THE COMING DAYS.

AS FAR AS TEMPERATURES GO...NOT EXPECTING ANY NOTABLE
SWINGS...WITH HIGHS REMAINING ABOVE AVERAGE OVERALL...RANGING
ANYWHERE FROM THE UPPER 70S TO MID/UPPER 80S. MILD OVERNIGHT LOWS
IN THE UPPER 50S/60S ALSO EXPECTED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1230 PM CDT THU MAY 23 2013

MVFR CONDITIONS TO CONTINUE AT KGRI THROUGH 19Z OR SO...WITH VFR
CONDITIONS FORECAST 19-10Z...AND THEN ANOTHER ROUND OF MVFR
CONDITIONS TO FINISH THE TAF PERIOD.

STRATUS ACROSS THE AREA CONTINUES ERODE AT THIS HOUR AND VISIBLE
SATELLITE IMAGERY INDICATES IT WILL NOT BE LONG BEFORE KGRI ALSO
SCATTERS OUT. WENT AHEAD WITH AN MVFR CEILING THROUGH 19Z AS A
RESULT. VFR CONDITIONS ARE THEN EXPECTED THROUGH THE REST OF THE
DAY AND MUCH OF TONIGHT. CLOSER TO SUNRISE FRIDAY HOWEVER...LOW
LEVEL THETA-E ADVECTION FROM THE SOUTHEAST WILL PROMOTE STRATUS
DEVELOPMENT ACROSS MUCH OF THE REGION...INCLUDING KGRI. MOST
GUIDANCE SUGGESTS AN MVFR CEILING WILL BE REALIZED BY SUNRISE
FRIDAY...ALTHOUGH SOME GUIDANCE DOES SUGGEST THE CEILING MAY DROP
TO IFR LEVELS. FOR NOW WILL SIDE WITH THE MAJORITY OF GUIDANCE AND
FORECAST AN MVFR CEILING...BUT FUTURE SHIFTS WILL WANT TO CONTINUE
MONITORING FOR THE POSSIBLE INSERTION OF AN IFR CEILING IN FUTURE
TAFS. THERE IS ALSO A LOW CHANCE OF THUNDERSTORM ACTIVITY...ALONG
WITH MEASURABLE RAINFALL...AT KGRI 12-18Z...BUT THE PROBABILITY OF
SUCH ACTIVITY BEING REALIZED IS TOO LOW FOR INSERTION INTO THE TAF
AT THIS TIME. THE SURFACE WIND WILL TRANSITION FROM THE
EAST/NORTHEAST TO MORE OF A SOUTHEASTERLY DIRECTION DURING THE TAF
PERIOD...SUSTAINED GENERALLY IN THE 10-15KT RANGE. VISIBILITY
RESTRICTION IS NOT EXPECTED AT KGRI THROUGH THE NEXT 24 HOURS.


&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...BRYANT
LONG TERM...ADO
AVIATION...BRYANT

000
FXUS63 KLBF 232004
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
304 PM CDT THU MAY 23 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 303 PM CDT THU MAY 23 2013

FOR TONIGHT...SURFACE HIGH PRESSURE WILL PUSH OFF TO OUR SOUTHEAST AS
LOW LEVEL WINDS VEER TOWARD THE SOUTHEAST. A SUBSTANTIAL AMOUNTS OF
LOW LEVEL MOISTURE WILL BE ADVECTED NORTHWEST TONIGHT FROM WESTERN
KANSAS ANS EASTERN COLORADO INTO WESTERN NEBRASKA. SKIES TO BECOME
OVERCAST MOST AREAS BY DAYBREAK. REGARDING RAIN CHANCES...DELAYED
ONSET OF SHOWERS/ISOLATED TSTMS UNTIL AFTER 06Z FOR AREAS WEST OF
VTN THROUGH BBW. STEEP MID LEVEL LAPSE RATES WITH THE APPROACH OF A
DISTURBANCE FROM COLORADO WILL INCREASE SHOWER CHANCES. LOW
TEMPERATURES WILL RANGE FROM THE UPPER 40S TO MID 50S.

ON FRIDAY...PASSING DISTURBANCE TO BRING CHANCE POPS TO MUCH OF
FORECAST AREA IN THE MORNING WITH THE HIGHEST POPS 40-50 PERCENT
EAST OF HWY 83. BY EARLY AFTERNOON...ONLY SLIGHT CHANCE IN THE WEST.
GFS AND NAM INDICATED A MOSTLY SATURATED LAYER FROM SFC THROUGH
800MB. HAVE LOWERED TEMPERATURES AS MUCH AS 5 DEGREES TOWARD THE
COOLEST MET GUIDANCE FOR CENTRAL AND SOUTHEAST ZONES WITH HIGHS FROM
66 TO 69. FAR WEST TIER OF COUNTIES FCST TO REACH THE LOWER/MID 70S
AS CEILINGS LIFT AND PARTIAL LATE AFTERNOON CLEARING. ANOTHER MAIN
FORECAST CONCERN WILL BE POTENTIAL FOR STORM INITIATION ALONG STRONG
DIFFERENTIAL HEATING BOUNDARY NEAR A LINE FROM KBFF-KSNY-KITR. AREAS
75 MILES EAST AND WEST OF THIS LINE ARE AT RISK FOR SEVERE STORMS BY
LATE FRIDAY AFTERNOON/EARLY EVENING. THIS INCLUDES THE SOUTHEAST
PANHANDLE AND MUCH OF SWRN NEBR. RICH THETA-E ADVECTION INDICATED BY
NAM AND GFS INTO THIS REGION ALONG WITH SFC DEWPOINTS REACHING THE
MID/UPPER 50S W/BACKED LOW LEVEL WINDS SUSTAINED NEAR 20KTS. THIS
FAVORABLE FOR DISCRETE ROTATING STORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 303 PM CDT THU MAY 23 2013

THE END OF THE WEEK IS DOMINATED BY TWO UPPER LEVEL LOW PRESSURE
SYSTEMS IN PLACE ALONG THE EASTERN AND WESTERN COASTS...WITH AN
AMPLIFIED RIDGE AXIS IN THE PLAINS REGION. THE RIDGE AXIS WILL
SLOWLY SHIFT EAST...PUTTING WESTERN NEBRASKA IN SOUTHWEST FLOW ALOFT
AND A RATHER UNSETTLED WEATHER PATTERN. THIS PATTERN WILL ALSO KEEP
TEMPERATURES WARM AND SOMEWHAT HUMID CONDITIONS AROUND THROUGH MOST
OF THE FORECAST PERIOD.

THE MAIN FORECAST CHALLENGE WILL BE THE POSSIBILITY FOR SEVERE
WEATHER...MAINLY FRIDAY NIGHT AND SATURDAY NIGHT. THE SOUTHWEST FLOW
WILL SETUP LEE SIDE TROUGHING IN EASTERN CO AND THE NE PANHANDLE.
SHORTWAVES EMBEDDED IN THE SOUTHWEST FLOW WILL MOVE OVER THE
PLAINS...HOWEVER THE PRIMARY AREA OF LIFT ASSOCIATED WITH MOST OF
THESE WAVES WILL BE CENTERED OVER THE ROCKIES. THE MAIN LIFTING
MECHANISM FOR THUNDERSTORM ACTIVITY IN THE HIGH PLAINS LOOKS TO BE
INSTABILITY BUILT UP BY DIURNAL HEATING.

THUNDERSTORMS...SOME SEVERE...MAY BE ONGOING AT THE BEGINNING OF THE
PERIOD ACROSS SOUTHWEST AND WESTERN NEBRASKA FRIDAY EVENING. THE
PRESENCE OF A 30-40KT LLJ WILL HELP MAINTAIN THIS ACTIVITY OVERNIGHT
AS IT VEERS OFF TO THE EAST. STEEP MID LEVEL LAPSE RATES AND AMPLE
MOISTURE WILL KEEP THUNDERSTORMS POSSIBLE...HOWEVER THE SEVERE
THREAT OVERNIGHT WILL BE LOW.

ATTENTION THEN TURNS TO SATURDAY AS SKIES BEGIN TO CLEAR OUT FROM
WEST TO EAST DURING THE MORNING AND AFTERNOON HOURS. THIS WILL BE
FAVORABLE FOR STRONG HEATING...WITH HIGHS PUSHING THE UPPER 80S FOR
MOST OF THE AREA BUT STILL COOLER IN OUR NORTHEAST ZONES. THE
HEATING WILL MAKE THE BOUNDARY LAYER VERY UNSTABLE WITH MLCAPE
VALUES EXCEEDING 2K J/KG...AND COUPLED WITH 30-40 KTS OF DEEP LAYER
SHEAR WILL PROMOTE AN ENVIRONMENT CONDUCIVE FOR SEVERE STORMS
BEGINNING LATE IN THE AFTERNOON. PRIMARY THREATS AT THIS TIME
LOOK TO BE LARGE HAIL AND DAMAGING WINDS. AGAIN...LLJ WILL
STRENGTHEN AFTER DARK AND HELP MAINTAIN THE THUNDERSTORM ACTIVITY AS
IT MOVES EAST.

STORM CHANCES WILL CONTINUE THROUGH THE EXTENDED PERIOD AS THE HIGH
PLAINS REMAINS IN A SOUTHWEST FLOW PATTERN. MODELS BEGIN TO DIVERGE
ON THEIR HANDLING OF THE LONGWAVE PATTERN TOWARD THE END OF THE
EXTENDED PERIOD WITH THE GFS EJECTING A TROUGH INTO THE NORTHERN
PLAINS...WITH THE 12Z EC DIGGING A TROUGH INTO THE RIO GRANDE
VALLEY. THIS WILL HAVE A BIG IMPACT ON PRECIP CHANCES FOR THE MIDDLE
OF NEXT WEEK GOING FORWARD.


&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY )
ISSUED AT 303 PM CDT THU MAY 23 2013

AFTER 06Z TONIGHT...STRATUS IS LIKELY TO RETURN FROM THE SOUTH AS A
WARM FRONT MAKES ITS WAY ONTO THE HIGH PLAINS. IN ADDITION... THE
RETURN OF MOISTURE WILL RESULT IN ISOLATED SHOWERS OR EVEN A
THUNDERSTORM LATE TONIGHT IN WESTERN NEBRASKA. HOWEVER...THE
COVERAGE WILL NOT BE ENOUGH TO WARRANT INCLUDING IT IN THE TERMINAL
FORECASTS FOR VTN AND LBF. CONTINUED STRATUS AND IFR CEILINGS TO
SLOWLY LIFT IN THE AFTERNOON. SOUTHEAST WINDS TO INCREASE TO 15G25KT
AFTER 12Z FRIDAY THROUGH THE END OF TAF PERIOD.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...ROBERG
LONG TERM...MARTIN
AVIATION...ROBERG

000
FXUS63 KOAX 231935
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
235 PM CDT THU MAY 23 2013

.DISCUSSION...

HIGH PRESSURE ACROSS THE MISSOURI VALLEY WILL CONTINUE TO
TRANSITION EASTWARD OVERNIGHT GIVING US QUIET WEATHER AND EAST
NORTHEAST WINDS BECOMING SOUTHEAST BY DAYBREAK. MEANWHILE...AN
UPPER LEVEL IMPULSE MOVING THROUGH THE CENTRAL ROCKIES SHOULD
TRIGGER CONVECTION TONIGHT ACROSS THE HIGH PLAINS....WHICH WILL
SLOWLY PUSH EASTWARD INTO OUR FORECAST AREA THROUGH THE DAY
FRIDAY WITH THE BEST CHANCE FOR PRECIP ACROSS EASTERN NEBRASKA...
AND JUST A SMALL CHANCE ACROSS WESTERN IOWA DURING THE AFTERNOON.
INSTABILITY RETURNS TO THE REGION. GIVEN SHEAR AND INSTABILITY
PARAMETERS...A FEW STRONG STORMS COULD OCCUR. THIS FIRST IMPULSESEEMS
TO MOVE THROUGH DURING THE EVENING...ALTHOUGH THE CONVERGENCE
ALONG THE NOSE OF THE LOW LEVEL JET COULD STILL PROVIDE SUPPORT
FOR ISOLATED STORMS TO LINGER PAST MIDNIGHT.

FORECAST DETAILS BECOME LESS CLEAR THROUGH THE REMAINDER OF THE
WEEKEND AND THROUGH NEXT WEEK...BUT THERE WILL BE SEVERAL CHANCES
FOR PRECIP THROUGH THE PERIOD. CONVECTION FROM FRIDAY NIGHT COULD
LEAVE BEHIND A FEW BOUNDARIES...WHICH COULD BE THE FOCUS FOR NEW
CONVECTION SATURDAY ACROSS OUR AREA. INSTABILITY DEFINITELY
INCREASES DURING THIS TIME...AND WITH SUFFICIENT SHEAR...SEEMS
THERE COULD BE A SEVERE THREAT THIS DAY AS WELL.

THE REGION WILL ALSO REMAIN UNDER AN UPPER RIDGE FROM SATURDAY
AND BEYOND...WHICH PUTS IN THE WELL WITHIN THE AREA OF PRIME
ACTION AT LEAST THROUGH THE EARLY PART OF NEXT WEEK AS WEAK
IMPULSE CONTINUE TO EJECT OUT OF THE MEAN SOUTHWESTERN TROUGH AND
CONTINUE TO TRIGGER SEVERAL ROUNDS OF STORMS. BY THIS TIME...THE
DETAILS OF ANY WIDESPREAD SEVERE STORMS BECOMES INCREASINGLY
DIFFICULT TO PIN DOWN...OTHER THAN THERE WILL BE SEVERAL CHANCES
FOR RAIN. NOT TO SAY THAT IT WILL BE CONTINUOUS RAIN...BUT GIVEN
THAT IT`S A HOLIDAY WEEKEND AND THERE WILL BE MANY MORE OUTDOOR
ACTIVITIES THAN NORMAL...THERE WILL BE A CHANCE OF RAIN JUST
ABOUT EVERY 12 HOUR PERIOD THROUGH EARLY NEXT WEEK.

FOR LATER PORTIONS OF THE EXTENDED FORECAST...THE MODELS SUGGEST
THAT THE RIDGE AXIS DOES SHIFT EASTWARD JUST A BIT...BUT STILL
SMALL CHANCES OF RAIN WILL EXIST IN THE FORECAST FOR WEDNESDAY AND
THURSDAY OF NEXT WEEK.

DEWALD

&&

.AVIATION...18Z TAFS FOR KOFK...KOMA AND KLNK.

CLEARING IS FINALLY TAKING PLACE ACROSS THE TAF SITES WITH KLNK
THE LAST TO CLEAR OUT BUT THIS SHOULD BE WITHIN THE FIRST HOUR OF
THE TAF. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE
TAF CYCLE AS SURFACE WINDS BECOME MORE SOUTHEASTERLY AND INCREASE
FRIDAY MORNING. MVFR CIGS POSSIBLE ONCE AGAIN BY LATE IN THE TAF
PERIOD BUT DID NOT INCLUDE THAT QUITE YET.

KERN

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

000
FXUS63 KGID 231730
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1230 PM CDT THU MAY 23 2013

.UPDATE...
ISSUED AT 655 AM CDT THU MAY 23 2013

OVERALL...FORECAST FOR TODAY STILL LOOKS ON TRACK FROM EARLIER
ISSUANCE...AND MADE ONLY A FEW MINOR TWEAKS TO THE FIRST FEW
HOURS. BROKEN BAND OF SPRINKLES/LIGHT RAIN CONTINUES TO PUSH EASTWARD
INTO THE FAR SOUTHWESTERN CWA AT THIS TIME. BASED ON UPSTREAM
OBS...STILL FEEL THAT LEGITIMATE MEASURABLE RAIN WILL BE TOUGH TO
COME BY WITH THIS ACTIVITY...AND THUS HAVE MAINTAINED WORDING AS
ONLY SPRINKLES. DAY SHIFT WILL HAVE TO KEEP AN EYE ON THE AREAL
COVERAGE OF THIS LIGHT PRECIP HOWEVER...AS CURRENT FORECAST HAS IT
CONFINED SOUTHWEST OF A LEXINGTON-BELOIT LINE. OTHERWISE...THE
COMBINATION OF EXTENSIVE LOW STRATUS AND INCOMING MID CLOUDS COULD
DELAY TEMP RISES A BIT THIS MORNING...BUT STILL THINKING INCREASING
AFTERNOON SUN SHOULD GET ALL AREAS UP AROUND 70 EVENTUALLY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM CDT THU MAY 23 2013

THIS 24 HOURS MARKS THE VERY BEGINNING STAGES OF THE MORE
ACTIVE/STORMY WEATHER PATTERN THAT WILL RAMP UP HEADING INTO THE
HOLIDAY WEEKEND. LIKE LAST NIGHT...LOW LEVEL STRATUS TRENDS ARE
PRESENTING A CHALLENGE MAINLY DURING THE FIRST 6 HOURS. PRECIP-
WISE...HAVE INTRODUCED SPRINKLES INTO SOUTHWEST ZONES THIS
MORNING...AND OVERALL MADE LITTLE NOTABLE CHANGE TO OVERNIGHT
SHOWERS/STORM CHANCES...WHICH SHOULD NOT BE OVERLY WIDESPREAD.
ALSO MADE ONLY MINOR TWEAKS TO TEMPS TODAY/TONIGHT.

08Z OBJECTIVE CENTRAL PLAINS SURFACE ANALYSIS IS HIGHLIGHTED BY
THE SOUTHWARD EXTENSION OF A RATHER STRONG 1032+ MILLIBAR HIGH
CENTERED WELL TO THE NORTH OVER CENTRAL CANADA...WITH PRESSURES TO
AROUND 1018MB AS FAR SOUTH AS THE LOCAL CWA. THIS HIGH IS DRIVING
STEADY NORTH BREEZES GENERALLY 5-15 MPH EARLY THIS MORNING...WITH
LOCALLY HIGHER GUSTS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM
MODEL DATA DEPICT THE DEPARTING MID LEVEL LOW THAT BROUGHT THE
LIGHT RAIN TO EASTERN AREAS 24 HOURS AGO NOW WELL OFF TO THE EAST
IN THE GREAT LAKES REGION...WHILE WELL UPSTREAM TO THE WEST AN
EXPANSIVE 500MB CLOSED LOW CONTINUES CHURNING OVER OR/WA. IN
BETWEEN THESE LOWS...A RIDGE AXIS EXTENDS NORTH-SOUTH THROUGH THE
HEART OF THE NATION...WITH ITS AXIS ALIGNED THROUGH WESTERN
PORTIONS OF NEB/KS. 11-3.9 MICRON SATELLITE IMAGERY CONFIRMS THAT
IN FACT THE STRATUS THAT ERODED NORTHWARD ACROSS MUCH OF THE CWA
ON WEDNESDAY HAS SUNK BACK SOUTHWARD OVERNIGHT...WITH THE MAJORITY
OF THE CWA SITTING UNDER A ROUGHLY 1500 FT CLOUD DECK. EARLIER IN
THE NIGHT...THERE WERE HINTS AT A FEW AUTOMATED STATIONS SUCH AS
ORD THAT BRIEF SPRINKLE/DRIZZLE MIGHT HAVE FALLEN...BUT OTHERWISE
THE CWA HAS REMAINED DRY THUS FAR...WITH OVERNIGHT LOW TEMPS
LIKELY ENDING UP BETWEEN 45-50 NEARLY ALL AREAS. LOOKING JUST TO
THE WEST...A CLASSIC NORTHWEST-SOUTHEAST BAND OF MID LEVEL THETA-E
ADVECTION EVIDENT ON BOTH THE 700MB AND 310K SURFACE IS DRIVING A
SURPRISINGLY HEALTHY AREA OF LIGHT RAIN SHOWERS OVER MAINLY
NORTHWEST KS/NORTHEAST CO...WITH A MORE ORGANIZED AREA OF
THUNDERSTORMS DEVELOPING ALONG THIS SAME ZONE OF LIFT MUCH FARTHER
SOUTH OVER OK.

HEADING INTO THE DAYTIME HOURS...THE MOST IMMEDIATE ISSUE IS TO
WHAT EXTENT THE LIGHT RAIN SHOWERS TO THE WEST WILL HOLD TOGETHER
AS THE MID LEVEL CORRIDOR OF LIFT CONTINUES EDGING EASTWARD TOWARD
THE CWA. GIVEN THAT THIS FORCING SHOULD CONTINUE WEAKENING A BIT
AS IT SPREADS EAST THIS MORNING...AND ALSO GIVEN A CONSIDERABLE
AMOUNT OF DRY AIR NOTED BELOW 600MB ON FORECAST SOUNDINGS...THINK
THE ODDS OF LEGITIMATE MEASURABLE RAIN AFFECTING MORE THAN A TINY
FRACTION OF THE WESTERN CWA THIS MORNING IS QUITE LOW. THAT BEING
SAID...WENT AHEAD AND INTRODUCED A SPRINKLE MENTION TO A
PREVIOUSLY RAIN-FREE FORECAST THROUGH MID-DAY FOR AREAS GENERALLY
SOUTHWEST OF A LEXINGTON-BELOIT LINE...WITH SEEMINGLY LITTLE RISK
FOR EVEN SPRINKLES FOR THE TRI-CITIES AND POINTS NORTH/EAST.
ALTHOUGH THIS SORT OF SETUP OFTEN PRODUCES AT LEAST A ROGUE
LIGHTNING STRIKE OR TWO...EVEN ELEVATED INSTABILITY IS ESSENTIALLY
NON-EXISTENT OVER THE CWA THIS MORNING SO WILL NOT GO THE
THUNDERSTORM ROUTE. AS FOR THE MID/UPPER LEVEL STORY TODAY...THE
AFOREMENTIONED RIDGE AXIS WILL AMPLIFY A BIT OVER THE CENTRAL
PLAINS TODAY...RESULTING IN RISING HEIGHTS. AT THE
SURFACE...WINDS WILL BE ON THE INCREASE A BIT AND TRANSITION FROM
NORTHERLY TO EASTERLY DUE TO THE COMBINATION OF HIGH PRESSURE TO
THE NORTH DRIFTING EAST...AND ALSO DECENT PRESSURE FALLS TO THE
WEST AS A FAIRLY STRONG SURFACE LOW RAMPS UP OVER WY. THIS
AFTERNOON...STEADY EASTERLY BREEZES AROUND 15 MPH WITH GUSTS INTO
THE 20-25 MPH RANGE WILL BE IN PLACE...STRONGEST WEST OF HIGHWAY
281. AS FOR THE EVOLUTION OF SKY COVER TODAY...WILL AGAIN LEAN
TOWARD THE LATEST RAP/HRRR LOW CLOUD/RELATIVE HUMIDITY
FIELDS...WHICH SUGGESTS A FAIRLY RAPID SCATTERING OUT/LIFTING OF
LOW CLOUDS THROUGH THE MID-LATE MORNING HOURS...PAVING THE WAY FOR
AN AFTERNOON THAT SHOULD AVERAGE NO WORSE THAN PARTLY CLOUDY.
ASSUMING THIS ALL PANS OUT AS PLANNED...TEMPS SHOULD HAVE NO
PROBLEM MAKING A DECENT RISE...AND HAVE AIMED HIGHS BETWEEN 68-72
DEGREES FOR NEARLY THE ENTIRE CWA...WHICH IS ONLY SLIGHTLY WARMER
THAN PREVIOUS IN SOME SPOTS. AS FOR AFTERNOON PRECIP
CHANCES...KEPT IT DRY AS ANY CONVECTION SHOULD FOCUS AT LEAST A
FEW COUNTIES OFF TO THE SOUTH AND/OR WEST.

FOR THE TONIGHT PERIOD...00Z-12Z...LITTLE OVERALL CHANGE IN
THINKING FROM PREVIOUS FORECASTS. IN THE MID-UPPER LEVELS...FAIRLY
WEAK QUASI-ZONAL FLOW CONTINUES ACROSS THE CENTRAL PLAINS WITHIN
THE RIDGE AXIS...WHILE OFF TO THE WEST A LEAD SHORTWAVE TROUGH
EJECTS NORTHEAST ACROSS WY/MT ALONG THE SOUTHEAST SIDE OF THE
PARENT PACIFIC NORTHWEST LOW. AS THE NIGHT WEARS ON...ANOTHER MORE
VIGOROUS BATCH OF MID LEVEL THETA-E ADVECTION WILL VEER EASTWARD
ACROSS WESTERN/CENTRAL PORTIONS OF NEBRASKA/KANSAS. SLIGHTLY
LOWER IN THE COLUMN...A DECENT SOUTHERLY 850MB LOW LEVEL JET WILL
STRENGTHEN TO 30-45KT LATE IN THE NIGHT MAINLY ALONG THE FAR
WESTERN EDGE OF THE CWA AND POINTS WEST. NEEDLESS TO SAY...MODELS
VARY ON HOW MUCH QPF THEY GENERATE OVER THE CWA TONIGHT...WITH
SOME SUCH AS THE NAM AND EVEN 4KM WRF-NMM SHOWING LITTLE IF
ANYTHING GOING ON LOCALLY...WITH BETTER CHANCES FOCUSED WEST.
HOWEVER...GIVEN THE DECENT MID LEVEL THETA-E ADVECTION AND
FORECAST OF 200 + J/KG OF ELEVATED MUCAPE IN THE 850-700MB LAYER
FORECAST INTO PARTS OF THE CWA AFTER MIDNIGHT...AND HIGHER VALUES
TO AROUND 1000 J/KG IN THE FAR WESTERN COUNTIES...KEPT FAIRLY
MODEST 20-30 POPS GOING ESPECIALLY FOR THE 09Z-12Z TIME
FRAME...WHILE KEEPING THE ENTIRE EVENING TIME FRAME RAIN-FREE.
RELEGATED THESE STORM CHANCES WEST OF AN ORD-HASTINGS-BELOIT LINE
THROUGH SUNRISE...WITH CHANCES IN EASTERN COUNTIES HOLDING OFF
UNTIL THE FRIDAY DAYTIME PERIOD. ALTHOUGH NOT EXPECTING ANY SEVERE
STORMS LATE TONIGHT...CERTAINLY CANNOT RULE OUT SOME SMALL HAIL
ESPECIALLY IN THE FAR WESTERN FRINGES OF THE CWA. COULD ALSO SEE
RENEWED LOW STRATUS DEVELOPMENT AS LOW LEVEL WINDS TURN MORE
SOUTHEASTERLY. SURFACE BREEZES OF 10-15 MPH WILL PREVAIL THROUGH
THE NIGHT...AND MADE ONLY MINOR CHANGES TO LOW TEMPS WITH MOST
AREAS BOTTOMING OUT WITHIN A FEW DEGREES EITHER SIDE OF 50.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 515 AM CDT THU MAY 23 2013

THE WEATHER PATTERN WILL BECOME MORE ACTIVE IN THESE EXTENDED PERIODS.
ON FRIDAY...AN UPPER LEVEL RIDGE AXIS WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS IN BETWEEN AN UPPER LOW IN THE PACIFIC NORTHWEST AND
AN UPPER LOW/TROUGH ALONG THE EASTERN CONUS.  A WARM FRONTAL
BOUNDARY LIFTS E/NE ACROSS THE CENTRAL PLAINS DURING THE DAY AND IN
WAA/THETA E ADVECTION...SHOWERS AND TSTMS ARE EXPECTED TO DEVELOP
AND SPREAD EAST/NORTHEAST FRIDAY/FRIDAY NIGHT.  DUE TO ANTICIPATED
PCPN AND CLOUD COVER ON FRIDAY...HAVE LOWERED HIGH TEMPS A FEW
DEGREES.  INSTABILITY PARAMETERS INDICATE CAPES INCREASING TO 1000
J/KG WITH SOME HIGHER INSTABILITY POTENTIAL GREATER THAN THIS
POSSIBLE ACROSS OUR WESTERN ZONES...AND EFFECTIVE SHEAR IS PROGGED
AROUND 30KTS.  COULD SEE A FEW STRONG/SEVERE STORMS BY FRIDAY
AFTN/EVE AND MORE SO INTO FRIDAY NIGHT...AS LLVL JET INCREASES.
MODELS SUGGEST ADDITIONAL CONVECTIVE POTENTIAL ALONG HIGH PLAINS
FRIDAY NIGHT IN VCNTY OF SFC LOW/DRY LINE WHICH MAY THEN ROLL ACROSS
OUR REGION OVERNIGHT.

ON SATURDAY...FLOW ALOFT WILL BE SOUTHWESTERLY AS RIDGE AXIS SHIFTS
EASTWARD...WHILE AT THE SFC...LOW PRESSURE SHOULD SETTLE ALONG THE
HIGH PLAINS WITH TWO POTENTIAL SFC LOW CENTERS DEVELOPING...ONE IN
EASTERN WY/MT AND ANOTHER TO THE SOUTH ACROSS WESTERN KS.  WARM
FRONTAL BOUNDARY LOOKS TO SETTLE NEAR THE NEB/KS START LINE WITH MUCH
GREATER INSTABILITY EXPECTED WITH CAPES IN EXCESS OF 3000 J/KG AS
MOISTURE POOLS ALONG THE BOUNDARY...AND AGAIN DECENT SHEAR IS
PROGGED AROUND 30KTS...ESPECIALLY ACROSS NEB WHICH INCREASES
OVERNIGHT WITH NOCTURNAL JET.  WARM MID LEVEL TEMPS COULD MAY INHIBIT
CONVECTION TO THE WEST ALONG THE DRY LINE...HOWEVER WARM FRONT LOOKS
TO BECOME ACTIVE AND IF STORMS FIRE IN VCNTY OF FRONT...CONDITIONS
ARE FAVORABLE FOR SEVERE WEATHER.  CONVECTIVE POTENTIAL CONTINUES
INTO SATURDAY NIGHT MAINLY ACROSS NEB NORTH OF FRONT ON NOSE OF 50KT
LLVL JET.

THROUGH THE REMAINDER OF THE MEMORIAL DAY HOLIDAY
WEEKEND...SUNDAY/MONDAY...CONVECTIVE POTENTIAL CONTINUES IN
SOUTHWEST FLOW ALOFT AS SHORTWAVE ENERGY LIFTS ACROSS THE PLAINS AND
INTERACTS WITH LLVL BOUNDARIES.  TIMING/LOCATION OF BEST PCPN CHCS
WILL BE REFINED WITH TIME.  THIS BEING SAID...THE WEATHER PATTERN
DOES LOOK ACTIVE WITH POTENTIAL FOR SEVERE WEATHER AND DECENT
RAINFALL/PCPN IS POSSIBLE FOR SEVERAL DAYS IN INCREASED
MOISTURE...AND PRECIPITABLE WATER VALUES INCREASE TO BETWEEN AN INCH
AND AN INCH AND A HALF.

BY MID WEEK...EXTENDED MODELS BEGIN TO DIVERGE IN HANDLING OF
TROUGH/UPPER LOW ACROSS THE WESTERN CONUS AND DUE TO MODEL
DIFFERENCES...DID NOT DEVIATE MUCH FROM EXTENDED INIT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1230 PM CDT THU MAY 23 2013

MVFR CONDITIONS TO CONTINUE AT KGRI THROUGH 19Z OR SO...WITH VFR
CONDITIONS FORECAST 19-10Z...AND THEN ANOTHER ROUND OF MVFR
CONDITIONS TO FINISH THE TAF PERIOD.

STRATUS ACROSS THE AREA CONTINUES ERODE AT THIS HOUR AND VISIBLE
SATELLITE IMAGERY INDICATES IT WILL NOT BE LONG BEFORE KGRI ALSO
SCATTERS OUT. WENT AHEAD WITH AN MVFR CEILING THROUGH 19Z AS A
RESULT. VFR CONDITIONS ARE THEN EXPECTED THROUGH THE REST OF THE
DAY AND MUCH OF TONIGHT. CLOSER TO SUNRISE FRIDAY HOWEVER...LOW
LEVEL THETA-E ADVECTION FROM THE SOUTHEAST WILL PROMOTE STRATUS
DEVELOPMENT ACROSS MUCH OF THE REGION...INCLUDING KGRI. MOST
GUIDANCE SUGGESTS AN MVFR CEILING WILL BE REALIZED BY SUNRISE
FRIDAY...ALTHOUGH SOME GUIDANCE DOES SUGGEST THE CEILING MAY DROP
TO IFR LEVELS. FOR NOW WILL SIDE WITH THE MAJORITY OF GUIDANCE AND
FORECAST AN MVFR CEILING...BUT FUTURE SHIFTS WILL WANT TO CONTINUE
MONITORING FOR THE POSSIBLE INSERTION OF AN IFR CEILING IN FUTURE
TAFS. THERE IS ALSO A LOW CHANCE OF THUNDERSTORM ACTIVITY...ALONG
WITH MEASURABLE RAINFALL...AT KGRI 12-18Z...BUT THE PROBABILITY OF
SUCH ACTIVITY BEING REALIZED IS TOO LOW FOR INSERTION INTO THE TAF
AT THIS TIME. THE SURFACE WIND WILL TRANSITION FROM THE
EAST/NORTHEAST TO MORE OF A SOUTHEASTERLY DIRECTION DURING THE TAF
PERIOD...SUSTAINED GENERALLY IN THE 10-15KT RANGE. VISIBILITY
RESTRICTION IS NOT EXPECTED AT KGRI THROUGH THE NEXT 24 HOURS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...FAY
AVIATION...BRYANT

000
FXUS63 KOAX 231717
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1217 PM CDT THU MAY 23 2013

.AVIATION...18Z TAFS FOR KOFK...KOMA AND KLNK.

CLEARING IS FINALLY TAKING PLACE ACROSS THE TAF SITES WITH KLNK
THE LAST TO CLEAR OUT BUT THIS SHOULD BE WITHIN THE FIRST HOUR OF
THE TAF. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE
TAF CYCLE AS SURFACE WINDS BECOME MORE SOUTHEASTERLY AND INCREASE
FRIDAY MORNING. MVFR CIGS POSSIBLE ONCE AGAIN BY LATE IN THE TAF
PERIOD BUT DID NOT INCLUDE THAT QUITE YET.

KERN


&&

.PREV DISCUSSION... /ISSUED 328 AM CDT THU MAY 23 2013/

DISCUSSION...
CLOUDY SKIES CONTINUE ACROSS MOST OF THE AREA...WITH SOME CLEARING
SLIDING INTO THE NORTHERN CWA. SUBJECTIVE 00Z UPPER AIR ANALYSIS
INDICATES WEAKENING UPPER LOW CENTERED IN NORTHEAST/SOUTHWEST
WI...WITH UPPER LOW ALSO OVER WA...AND STRENGTHENING RIDGE IN
BETWEEN OVER THE HIGH PLAINS. 500MB HEIGHT RISES ACROSS THE
CENTRAL PLAINS INDICATE RIDGE IS BUILDING IN AS EASTERN LOW EXITS.
850MB LOW WAS CENTERED IN NORTHERN LOWER MI...WITH TROUGH AXIS
TRAILING ACROSS SOUTHERN WI/CENTRAL IA/SOUTHWEST KS. 850MB
MOISTURE WAS MAINLY CONFINED TO THE MS RIVER VALLEY AND
EASTWARD...BUT 8-16C DEWPOINTS HAD RETURNED TO THE TX GULF COAST
AND RIO GRANDE VALLEY...WITH FLOW OFF THE GULF FAVORABLE FOR
MOISTURE RETURN. SURFACE RIDGE AXIS AT 07Z EXTENDED FROM ND
THROUGH CENTRAL SD/CENTRAL NEB/EASTERN KS...WITH SURFACE LOW
DEVELOPING IN NORTHEAST NM.

MAIN FORECAST CONCERNS REVOLVE AROUND THUNDERSTORM POTENTIAL FOR THE
HOLIDAY WEEKEND INTO NEXT WEEK.  UPPER-LEVEL PATTERN WILL TRANSITION
FROM OMEGA BLOCK TO WESTERN TROUGH/CENTRAL RIDGE THROUGH THE REST OF
THIS WEEK...WITH THE TROUGH/RIDGE MAKING EASTWARD PROGRESS THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK THAT WILL PLACE THE CENTRAL US
UNDER SOUTHWESTERLY UPPER-LEVEL FLOW.  PATTERN WILL THUS BE
FAVORABLE FOR CONVECTION FROM FRIDAY NIGHT THROUGH DAYS 7-10...AS
PATTERN IS IN NO HURRY TO BREAK DOWN.  MAIN INHIBITORS TO CONVECTION
WILL BE PROXIMITY TO UPPER RIDGE EARLY IN THE PERIOD...THEN
POTENTIAL FOR CAPPING LATER IN THE PERIOD.  CONVECTION WOULD BE
FAVORED AS SHORTWAVES SLIDE THROUGH THE UPPER-LEVEL FLOW...BUT OF
COURSE...TIMING THESE INDIVIDUAL IMPULSES IS CHALLENGING TO SAY THE
LEAST MORE THAN A COUPLE OF DAYS IN ADVANCE.  HAVE NUDGED TEMPS
UPWARD THROUGH MUCH OF THE FORECAST AS MID-LEVEL TEMPERATURES
WARM...WITH 850MB TEMPERATURES WARMING INTO THE UPPER TEENS TO LOW
20S BY THE END OF THE PERIOD.

HAVE BACKED OFF MORNING POPS ON FRIDAY...AS ISENTROPIC LIFT AND GOOD
WARM/MOIST AIR ADVECTION REALLY GET GOING IN THE AFTERNOON IN
EASTERN NEBRASKA...AND LIKELY CLOSER TO EVENING IN WESTERN IOWA.
SOUNDINGS ARE NOT ESPECIALLY UNSTABLE...AND THINK ANY PRECIP ON
FRIDAY WOULD BE MORE OF A CHARACTER OF SHOWERS WITH A FEW RUMBLES
THAN GENERAL THUNDERSTORMS.  AM NOT CONVINCED OF WIDESPREAD COVERAGE
BASED ON NAM/SREF PROGS...AND THUS HAVE KEPT POPS IN CHANCE RANGE
DURING THE DAY...WITH A SMALL AREA OF LIKELIES IN THE NORTHEAST CWA
IN THE EVENING BEFORE LOW-LEVEL JET VEERS TO THE EAST AND TAKES
SUPPORT FOR PRECIP EASTWARD WITH IT.

BELIEVE SATURDAY MORNING WILL ACTUALLY BE PRETTY MUCH DRY IN THE
CWA...AS LOW-LEVEL JET RE-ORIENTS ITSELF INTO WESTERN NEB...WITH A
MID-LEVEL SHORTWAVE RIDGE MOVING THROUGH.  BY AFTERNOON...A WARM
FRONT WILL BECOME ESTABLISHED ACROSS NORTH CENTRAL TO SOUTHEAST
NEBRASKA...WHICH SHOULD PROVIDE A FOCUS FOR SOME STORMS ON SATURDAY
AFTERNOON AND EVENING.  CAN`T RULE OUT POTENTIAL FOR A COUPLE OF
SEVERE STORMS...THOUGH BETTER POTENTIAL WILL BE WEST OF THE CWA.
STORMS ARE LIKELY TO FORM INTO A COMPLEX THAT MOVES ACROSS THE AREA
ON SATURDAY NIGHT.  A SIMILAR PATTERN LOOKS TO BE IN PLACE FOR
SUNDAY...WITH MUCH OF THE MORNING LIKELY TO BE DRY BEHIND THE
EXITING OVERNIGHT COMPLEX...FOLLOWED BY CONVECTIVE DEVELOPMENT WEST
OF THE AREA THAT MOVES ACROSS ON SUNDAY NIGHT.

FROM MONDAY ONWARD...FORECAST CONTINUES TO HAVE A PARADE OF SLIGHT
CHANCE TO CHANCE POPS IN EVERY PERIOD.  FORECAST WILL BY NO MEANS BE
A WASHOUT.  SOME OF THOSE DAYS...TSTORM CHANCES WILL FOCUS IN THE
AFTERNOON AND EVENING...WHILE OTHERS FOCUS IN THE OVERNIGHT PERIODS
WHEN CONVECTION FIRES FURTHER WEST.  THERE WILL LIKELY BE DRY
PERIODS IN THE MIX AS WELL.  THE ECWMF TRENDS MUCH WARMER THAN GFS
BY MID TO LATE WEEK AND WOULD IMPLY CAPPING WITH 12-14C 700MB
TEMPS...WHILE THE GFS BRINGS THE SURFACE LOW MUCH CLOSER BY THEN AND
KEEPS TEMPS SEVERAL DEGREES LOWER.  ALL IN ALL...MUCH UNCERTAINTY
REMAINS...AND HAVE KEPT POPS FROM GETTING TOO AGGRESSIVE UNTIL
PERIODS ARE CLOSER AND BETTER AGREEMENT IS ESTABLISHED.

MAYES

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

000
FXUS63 KGID 231202
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
702 AM CDT THU MAY 23 2013

.UPDATE...
ISSUED AT 655 AM CDT THU MAY 23 2013

OVERALL...FORECAST FOR TODAY STILL LOOKS ON TRACK FROM EARLIER
ISSUANCE...AND MADE ONLY A FEW MINOR TWEAKS TO THE FIRST FEW
HOURS. BROKEN BAND OF SPRINKLES/LIGHT RAIN CONTINUES TO PUSH EASTWARD
INTO THE FAR SOUTHWESTERN CWA AT THIS TIME. BASED ON UPSTREAM
OBS...STILL FEEL THAT LEGITIMATE MEASURABLE RAIN WILL BE TOUGH TO
COME BY WITH THIS ACTIVITY...AND THUS HAVE MAINTAINED WORDING AS
ONLY SPRINKLES. DAY SHIFT WILL HAVE TO KEEP AN EYE ON THE AREAL
COVERAGE OF THIS LIGHT PRECIP HOWEVER...AS CURRENT FORECAST HAS IT
CONFINED SOUTHWEST OF A LEXINGTON-BELOIT LINE. OTHERWISE...THE
COMBINATION OF EXTENSIVE LOW STRATUS AND INCOMING MID CLOUDS COULD
DELAY TEMP RISES A BIT THIS MORNING...BUT STILL THINKING INCREASING
AFTERNOON SUN SHOULD GET ALL AREAS UP AROUND 70 EVENTUALLY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM CDT THU MAY 23 2013

THIS 24 HOURS MARKS THE VERY BEGINNING STAGES OF THE MORE
ACTIVE/STORMY WEATHER PATTERN THAT WILL RAMP UP HEADING INTO THE
HOLIDAY WEEKEND. LIKE LAST NIGHT...LOW LEVEL STRATUS TRENDS ARE
PRESENTING A CHALLENGE MAINLY DURING THE FIRST 6 HOURS. PRECIP-
WISE...HAVE INTRODUCED SPRINKLES INTO SOUTHWEST ZONES THIS
MORNING...AND OVERALL MADE LITTLE NOTABLE CHANGE TO OVERNIGHT
SHOWERS/STORM CHANCES...WHICH SHOULD NOT BE OVERLY WIDESPREAD.
ALSO MADE ONLY MINOR TWEAKS TO TEMPS TODAY/TONIGHT.

08Z OBJECTIVE CENTRAL PLAINS SURFACE ANALYSIS IS HIGHLIGHTED BY
THE SOUTHWARD EXTENSION OF A RATHER STRONG 1032+ MILLIBAR HIGH
CENTERED WELL TO THE NORTH OVER CENTRAL CANADA...WITH PRESSURES TO
AROUND 1018MB AS FAR SOUTH AS THE LOCAL CWA. THIS HIGH IS DRIVING
STEADY NORTH BREEZES GENERALLY 5-15 MPH EARLY THIS MORNING...WITH
LOCALLY HIGHER GUSTS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM
MODEL DATA DEPICT THE DEPARTING MID LEVEL LOW THAT BROUGHT THE
LIGHT RAIN TO EASTERN AREAS 24 HOURS AGO NOW WELL OFF TO THE EAST
IN THE GREAT LAKES REGION...WHILE WELL UPSTREAM TO THE WEST AN
EXPANSIVE 500MB CLOSED LOW CONTINUES CHURNING OVER OR/WA. IN
BETWEEN THESE LOWS...A RIDGE AXIS EXTENDS NORTH-SOUTH THROUGH THE
HEART OF THE NATION...WITH ITS AXIS ALIGNED THROUGH WESTERN
PORTIONS OF NEB/KS. 11-3.9 MICRON SATELLITE IMAGERY CONFIRMS THAT
IN FACT THE STRATUS THAT ERODED NORTHWARD ACROSS MUCH OF THE CWA
ON WEDNESDAY HAS SUNK BACK SOUTHWARD OVERNIGHT...WITH THE MAJORITY
OF THE CWA SITTING UNDER A ROUGHLY 1500 FT CLOUD DECK. EARLIER IN
THE NIGHT...THERE WERE HINTS AT A FEW AUTOMATED STATIONS SUCH AS
ORD THAT BRIEF SPRINKLE/DRIZZLE MIGHT HAVE FALLEN...BUT OTHERWISE
THE CWA HAS REMAINED DRY THUS FAR...WITH OVERNIGHT LOW TEMPS
LIKELY ENDING UP BETWEEN 45-50 NEARLY ALL AREAS. LOOKING JUST TO
THE WEST...A CLASSIC NORTHWEST-SOUTHEAST BAND OF MID LEVEL THETA-E
ADVECTION EVIDENT ON BOTH THE 700MB AND 310K SURFACE IS DRIVING A
SURPRISINGLY HEALTHY AREA OF LIGHT RAIN SHOWERS OVER MAINLY
NORTHWEST KS/NORTHEAST CO...WITH A MORE ORGANIZED AREA OF
THUNDERSTORMS DEVELOPING ALONG THIS SAME ZONE OF LIFT MUCH FARTHER
SOUTH OVER OK.

HEADING INTO THE DAYTIME HOURS...THE MOST IMMEDIATE ISSUE IS TO
WHAT EXTENT THE LIGHT RAIN SHOWERS TO THE WEST WILL HOLD TOGETHER
AS THE MID LEVEL CORRIDOR OF LIFT CONTINUES EDGING EASTWARD TOWARD
THE CWA. GIVEN THAT THIS FORCING SHOULD CONTINUE WEAKENING A BIT
AS IT SPREADS EAST THIS MORNING...AND ALSO GIVEN A CONSIDERABLE
AMOUNT OF DRY AIR NOTED BELOW 600MB ON FORECAST SOUNDINGS...THINK
THE ODDS OF LEGITIMATE MEASURABLE RAIN AFFECTING MORE THAN A TINY
FRACTION OF THE WESTERN CWA THIS MORNING IS QUITE LOW. THAT BEING
SAID...WENT AHEAD AND INTRODUCED A SPRINKLE MENTION TO A
PREVIOUSLY RAIN-FREE FORECAST THROUGH MID-DAY FOR AREAS GENERALLY
SOUTHWEST OF A LEXINGTON-BELOIT LINE...WITH SEEMINGLY LITTLE RISK
FOR EVEN SPRINKLES FOR THE TRI-CITIES AND POINTS NORTH/EAST.
ALTHOUGH THIS SORT OF SETUP OFTEN PRODUCES AT LEAST A ROGUE
LIGHTNING STRIKE OR TWO...EVEN ELEVATED INSTABILITY IS ESSENTIALLY
NON-EXISTENT OVER THE CWA THIS MORNING SO WILL NOT GO THE
THUNDERSTORM ROUTE. AS FOR THE MID/UPPER LEVEL STORY TODAY...THE
AFOREMENTIONED RIDGE AXIS WILL AMPLIFY A BIT OVER THE CENTRAL
PLAINS TODAY...RESULTING IN RISING HEIGHTS. AT THE
SURFACE...WINDS WILL BE ON THE INCREASE A BIT AND TRANSITION FROM
NORTHERLY TO EASTERLY DUE TO THE COMBINATION OF HIGH PRESSURE TO
THE NORTH DRIFTING EAST...AND ALSO DECENT PRESSURE FALLS TO THE
WEST AS A FAIRLY STRONG SURFACE LOW RAMPS UP OVER WY. THIS
AFTERNOON...STEADY EASTERLY BREEZES AROUND 15 MPH WITH GUSTS INTO
THE 20-25 MPH RANGE WILL BE IN PLACE...STRONGEST WEST OF HIGHWAY
281. AS FOR THE EVOLUTION OF SKY COVER TODAY...WILL AGAIN LEAN
TOWARD THE LATEST RAP/HRRR LOW CLOUD/RELATIVE HUMIDITY
FIELDS...WHICH SUGGESTS A FAIRLY RAPID SCATTERING OUT/LIFTING OF
LOW CLOUDS THROUGH THE MID-LATE MORNING HOURS...PAVING THE WAY FOR
AN AFTERNOON THAT SHOULD AVERAGE NO WORSE THAN PARTLY CLOUDY.
ASSUMING THIS ALL PANS OUT AS PLANNED...TEMPS SHOULD HAVE NO
PROBLEM MAKING A DECENT RISE...AND HAVE AIMED HIGHS BETWEEN 68-72
DEGREES FOR NEARLY THE ENTIRE CWA...WHICH IS ONLY SLIGHTLY WARMER
THAN PREVIOUS IN SOME SPOTS. AS FOR AFTERNOON PRECIP
CHANCES...KEPT IT DRY AS ANY CONVECTION SHOULD FOCUS AT LEAST A
FEW COUNTIES OFF TO THE SOUTH AND/OR WEST.

FOR THE TONIGHT PERIOD...00Z-12Z...LITTLE OVERALL CHANGE IN
THINKING FROM PREVIOUS FORECASTS. IN THE MID-UPPER LEVELS...FAIRLY
WEAK QUASI-ZONAL FLOW CONTINUES ACROSS THE CENTRAL PLAINS WITHIN
THE RIDGE AXIS...WHILE OFF TO THE WEST A LEAD SHORTWAVE TROUGH
EJECTS NORTHEAST ACROSS WY/MT ALONG THE SOUTHEAST SIDE OF THE
PARENT PACIFIC NORTHWEST LOW. AS THE NIGHT WEARS ON...ANOTHER MORE
VIGOROUS BATCH OF MID LEVEL THETA-E ADVECTION WILL VEER EASTWARD
ACROSS WESTERN/CENTRAL PORTIONS OF NEBRASKA/KANSAS. SLIGHTLY
LOWER IN THE COLUMN...A DECENT SOUTHERLY 850MB LOW LEVEL JET WILL
STRENGTHEN TO 30-45KT LATE IN THE NIGHT MAINLY ALONG THE FAR
WESTERN EDGE OF THE CWA AND POINTS WEST. NEEDLESS TO SAY...MODELS
VARY ON HOW MUCH QPF THEY GENERATE OVER THE CWA TONIGHT...WITH
SOME SUCH AS THE NAM AND EVEN 4KM WRF-NMM SHOWING LITTLE IF
ANYTHING GOING ON LOCALLY...WITH BETTER CHANCES FOCUSED WEST.
HOWEVER...GIVEN THE DECENT MID LEVEL THETA-E ADVECTION AND
FORECAST OF 200 + J/KG OF ELEVATED MUCAPE IN THE 850-700MB LAYER
FORECAST INTO PARTS OF THE CWA AFTER MIDNIGHT...AND HIGHER VALUES
TO AROUND 1000 J/KG IN THE FAR WESTERN COUNTIES...KEPT FAIRLY
MODEST 20-30 POPS GOING ESPECIALLY FOR THE 09Z-12Z TIME
FRAME...WHILE KEEPING THE ENTIRE EVENING TIME FRAME RAIN-FREE.
RELEGATED THESE STORM CHANCES WEST OF AN ORD-HASTINGS-BELOIT LINE
THROUGH SUNRISE...WITH CHANCES IN EASTERN COUNTIES HOLDING OFF
UNTIL THE FRIDAY DAYTIME PERIOD. ALTHOUGH NOT EXPECTING ANY SEVERE
STORMS LATE TONIGHT...CERTAINLY CANNOT RULE OUT SOME SMALL HAIL
ESPECIALLY IN THE FAR WESTERN FRINGES OF THE CWA. COULD ALSO SEE
RENEWED LOW STRATUS DEVELOPMENT AS LOW LEVEL WINDS TURN MORE
SOUTHEASTERLY. SURFACE BREEZES OF 10-15 MPH WILL PREVAIL THROUGH
THE NIGHT...AND MADE ONLY MINOR CHANGES TO LOW TEMPS WITH MOST
AREAS BOTTOMING OUT WITHIN A FEW DEGREES EITHER SIDE OF 50.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 515 AM CDT THU MAY 23 2013

THE WEATHER PATTERN WILL BECOME MORE ACTIVE IN THESE EXTENDED PERIODS.
ON FRIDAY...AN UPPER LEVEL RIDGE AXIS WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS IN BETWEEN AN UPPER LOW IN THE PACIFIC NORTHWEST AND
AN UPPER LOW/TROUGH ALONG THE EASTERN CONUS.  A WARM FRONTAL
BOUNDARY LIFTS E/NE ACROSS THE CENTRAL PLAINS DURING THE DAY AND IN
WAA/THETA E ADVECTION...SHOWERS AND TSTMS ARE EXPECTED TO DEVELOP
AND SPREAD EAST/NORTHEAST FRIDAY/FRIDAY NIGHT.  DUE TO ANTICIPATED
PCPN AND CLOUD COVER ON FRIDAY...HAVE LOWERED HIGH TEMPS A FEW
DEGREES.  INSTABILITY PARAMETERS INDICATE CAPES INCREASING TO 1000
J/KG WITH SOME HIGHER INSTABILITY POTENTIAL GREATER THAN THIS
POSSIBLE ACROSS OUR WESTERN ZONES...AND EFFECTIVE SHEAR IS PROGGED
AROUND 30KTS.  COULD SEE A FEW STRONG/SEVERE STORMS BY FRIDAY
AFTN/EVE AND MORE SO INTO FRIDAY NIGHT...AS LLVL JET INCREASES.
MODELS SUGGEST ADDITIONAL CONVECTIVE POTENTIAL ALONG HIGH PLAINS
FRIDAY NIGHT IN VCNTY OF SFC LOW/DRY LINE WHICH MAY THEN ROLL ACROSS
OUR REGION OVERNIGHT.

ON SATURDAY...FLOW ALOFT WILL BE SOUTHWESTERLY AS RIDGE AXIS SHIFTS
EASTWARD...WHILE AT THE SFC...LOW PRESSURE SHOULD SETTLE ALONG THE
HIGH PLAINS WITH TWO POTENTIAL SFC LOW CENTERS DEVELOPING...ONE IN
EASTERN WY/MT AND ANOTHER TO THE SOUTH ACROSS WESTERN KS.  WARM
FRONTAL BOUNDARY LOOKS TO SETTLE NEAR THE NEB/KS START LINE WITH MUCH
GREATER INSTABILITY EXPECTED WITH CAPES IN EXCESS OF 3000 J/KG AS
MOISTURE POOLS ALONG THE BOUNDARY...AND AGAIN DECENT SHEAR IS
PROGGED AROUND 30KTS...ESPECIALLY ACROSS NEB WHICH INCREASES
OVERNIGHT WITH NOCTURNAL JET.  WARM MID LEVEL TEMPS COULD MAY INHIBIT
CONVECTION TO THE WEST ALONG THE DRY LINE...HOWEVER WARM FRONT LOOKS
TO BECOME ACTIVE AND IF STORMS FIRE IN VCNTY OF FRONT...CONDITIONS
ARE FAVORABLE FOR SEVERE WEATHER.  CONVECTIVE POTENTIAL CONTINUES
INTO SATURDAY NIGHT MAINLY ACROSS NEB NORTH OF FRONT ON NOSE OF 50KT
LLVL JET.

THROUGH THE REMAINDER OF THE MEMORIAL DAY HOLIDAY
WEEKEND...SUNDAY/MONDAY...CONVECTIVE POTENTIAL CONTINUES IN
SOUTHWEST FLOW ALOFT AS SHORTWAVE ENERGY LIFTS ACROSS THE PLAINS AND
INTERACTS WITH LLVL BOUNDARIES.  TIMING/LOCATION OF BEST PCPN CHCS
WILL BE REFINED WITH TIME.  THIS BEING SAID...THE WEATHER PATTERN
DOES LOOK ACTIVE WITH POTENTIAL FOR SEVERE WEATHER AND DECENT
RAINFALL/PCPN IS POSSIBLE FOR SEVERAL DAYS IN INCREASED
MOISTURE...AND PRECIPITABLE WATER VALUES INCREASE TO BETWEEN AN INCH
AND AN INCH AND A HALF.

BY MID WEEK...EXTENDED MODELS BEGIN TO DIVERGE IN HANDLING OF
TROUGH/UPPER LOW ACROSS THE WESTERN CONUS AND DUE TO MODEL
DIFFERENCES...DID NOT DEVIATE MUCH FROM EXTENDED INIT.

&&

.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z FRIDAY MORNING)
ISSUED AT 655 AM CDT THU MAY 23 2013

CONFIDENCE REMAINS RATHER HIGH THAT VFR VISIBILITY AND PRECIP-FREE
CONDITIONS WILL CONTINUE TO PREVAIL AT KGRI THROUGH SUNRISE FRIDAY
MORNING...ALTHOUGH TOWARD THE VERY END OF THE PERIOD LATE TONIGHT
SOME SHOWER/THUNDERSTORM ACTIVITY COULD BE APPROACHING FROM THE
WEST...AND THIS MAY NEED INCLUDED IN NEXT ROUTINE ISSUANCE. THAT
LEAVES CEILINGS AS THE CONTINUING MAIN CHALLENGE...AS THE PERIOD
STARTS OFF WITH AN EXPANSIVE MVFR STRATUS DECK BLANKETING MUCH OF
NEBRASKA. ALTHOUGH CONFIDENCE IN THE HOURLY DETAILS IS ONLY
AVERAGE...HAVE CONTINUED TO INDICATE A GRADUAL LIFTING OF THE
CLOUD DECK THROUGH THE MORNING...WITH LOW CEILING EITHER
SCATTERING OR LIFTING INTO VFR TERRITORY BY EARLY AFTERNOON. VFR
CEILING IS THEN EXPECTED TO PREVAIL THROUGH THE AFTERNOON AND
EVENING...BEFORE A POSSIBLE RETURN TO MVFR WELL AFTER MIDNIGHT.
SURFACE WINDS WILL UNDERGO A DIRECTIONAL CHANGE FROM NORTHERLY
THIS MORNING TO EASTERLY BY THIS AFTERNOON...WITH GUST POTENTIAL
TO AT LEAST 19KT. SPEEDS WILL EASE UP A BIT OVERNIGHT AS DIRECTION
CONTINUES TO VEER TO SOUTHEAST.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...FAY
AVIATION...PFANNKUCH

000
FXUS63 KLBF 231144
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
644 AM CDT THU MAY 23 2013

.SYNOPSIS...
ISSUED AT 345 AM CDT THU MAY 23 2013

AT 08Z...THE MSL DATA SHOWED LOW PRESSURE CENTERED OVER SOUTHWEST
WYOMING WITH A WARM FRONT ACROSS WESTERN COLORADO. ANOTHER LOW WAS
CENTERED OVER EASTERN NEW MEXICO WITH A WARM FRONT EXTENDING INTO
SOUTHWEST KANSAS. THE STRATUS CLOUDS WERE CLEARING AS HIGH PRESSURE
FORCED ITS WAY INTO NORTHERN NEBRASKA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT THU MAY 23 2013

CLOUDINESS WILL PROBABLY BE PERSISTENT IN SOUTH CENTRAL AND
SOUTHWEST NEBRASKA UNTIL EARLY AFTERNOON. LOW LEVEL WIND FROM THE
EAST TO SOUTHEAST WILL BRING AN INCREASE IN PRECIPITABLE WATER LATER
THIS AFTERNOON OR EARLY EVENING.

THIS EVENING...AS THE SURFACE LOW MAKES ITS WAY OUT OF WYOMING AND
INTO MONTANA...A WARM FRONT RE-FORMS IN THE LEE OF THE ROCKIES. WARM
ADVECTION WILL THEN LIFT AIR UP OVER THE FRONT AND BRING SHOWERS TO
CENTRAL AND WESTERN NEBRASKA...ESPECIALLY AFTER MIDNIGHT. THERE
SHOULD BE ENOUGH INSTABILITY FOR ISOLATED THUNDERSTORMS TO BECOME
EMBEDDED IN THE SHOWERS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 AM CDT THU MAY 23 2013

LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL REMAIN NEARLY STATIONARY
ACROSS THE PACIFIC NORTHWEST FRIDAY...WITH THE CENTRAL PLAINS IN
SOUTHWEST FLOW ALOFT. THE FLOW WILL BE MODEST...WITH H5 SPEEDS
AROUND 35 KTS. APPEARS ELEVATED SHOWERS AND TSTMS WILL BE POSSIBLE
IN WARM AIR ADVECTION PATTERN THROUGH MID AFTERNOON...THEN ATTENTION
TURNS TO POSSIBLE SFC BASED CONVECTION ALONG THE LEE TROUGH/DRY LINE
DURING THE LATE AFTERNOON. VERY STEEP LOW LEVEL LAPSE RATES DEVELOP
EASTWARD INTO NORTHEAST COLORADO AND THE SOUTHERN NEB PANHANDLE BY
LATE FRIDAY AFTERNOON...WITH MLCAPE VALUES AROUND 2000 J/KG AND
ADEQUATE SHEAR. AS A WEAK VORTICITY MAXIMA MOVES NORTHEAST AROUND
PEAK HEATING...AT LEAST ISOLATED TSTM DEVELOPMENT SEEMS POSSIBLE.
THESE WOULD MOST LIKELY DEVELOP ON THE NOSE OF THE STEEPER LOW LEVEL
LAPSE RATES ACROSS NORTHEAST COLORADO INTO THE SOUTHERN NEB
PANHANDLE. A SEVERE STORM IS POSSIBLE...AS SHEAR AND INSTABILITY ARE
ADEQUATE ENOUGH TO SUPPORT THE POTENTIAL. IT IS UNCLEAR HOW FAR EAST
THESE STORMS WILL MAKE IT INTO SOUTHWEST OR WESTERN NEBRASKA...AS
EXTENSIVE LOW LEVEL MOISTURE IN THE FORM OF STRATUS CLOUDS WILL
LIKELY INHIBIT INSTABILITY. SOME CHANCE THAT STORMS WILL DEVELOP
EAST DURING THE EVENING AIDED BY A SOUTHERLY LLJ...AND THE GFS HINTS
AT THIS...BUT UNCERTAIN OF THIS SCENARIO...AND WILL KEEP POPS FAIRLY
LOW FRIDAY NIGHT.

SATURDAY AFTERNOON AND EVENING STILL EXPECTING A ROUND OF TSTMS.
BOTH THE 23/00Z RUNS OF THE GFS AND ECMWF HAVE A SHORT WAVE TROUGH
EJECTING NORTHEAST ACROSS THE AREA PROVIDING LIFT...THE ONLY
NEGATIVE FOR CONVECTION IS A WELL DEFINED BOUNDARY TO FOCUS
INITIATION ON. THERE DOES APPEAR TO BE A WEAK INVERTED TROUGH ACROSS
WEST CENTRAL NEB...AND A WEAK WARM FRONT ACROSS SOUTHERN/CENTRAL
NEB. OTHER SUBTLE BOUNDARIES MAY EXIST FROM ANY PRIOR CONVECTION.
IF STORMS DO INDEED DEVELOP...ATMOSPHERE IS QUITE UNSTABLE
AND 0 TO 6 KM SHEAR ON THE ORDER OF 30 TO 40 KTS WOULD SUPPORT SOME
SEVERE STORMS.

WITH THE LARGE UPPER LEVEL LOW REMAINING WEST OF THE AREA SUNDAY
INTO NEXT WEEK...CONVECTIVE CHANCES WILL REMAIN. BUT TIMING AND
LOCATION IS UNCERTAIN...AS PREVIOUS BOUTS OF CONVECTION WILL LIKELY
HAVE AN IMPACT ON BOUNDARY PLACEMENT ETC.

TEMPERATURE WISE...A FAIRLY WARM PERIOD EXPECTED FRIDAY THROUGH THE
HOLIDAY WEEKEND AND INTO NEXT WEEK. IT WILL BE RATHER MUGGY AS WELL
WITH THE INCREASED GULF OF MEXICO MOISTURE. HIGHS SHOULD MAKE IT
INTO AT LEAST THE 70S EACH DAY...WITH 80S POSSIBLE ESPECIALLY ACROSS
WESTERN/SOUTHWEST NEB. CLOUDS AND PRECIP COULD HAVE AN IMPACT AT
TIMES HOWEVER...BUT OVERALL PRETTY DECENT TEMPERATURES EXPECTED FOR
THE HOLIDAY WEEKEND.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 643 AM CDT THU MAY 23 2013

PATCHY FOG IN NORTHERN NEBRASKA THIS MORNING SHOULD CLEAR RATHER
QUICKLY SINCE THERE ARE NO LOW OR MIDDLE CLOUDS ABOVE IT. THE
STRATUS IN SOUTH CENTRAL AND SOUTHWEST NEBRASKA WILL BE SLOW
CLEARING. EAST TO SOUTHEAST WIND IN THE LOWEST 3000 FEET WILL NOT BE
MUCH HELP CLEARING IT OUT.

AFTER 06Z TONIGHT...STRATUS IS LIKELY TO RETURN FROM THE SOUTHWEST
AS A WARM FRONT MAKES ITS WAY ONTO THE HIGH PLAINS. IN ADDITION...
THE RETURN OF MOISTURE WILL RESULT IN ISOLATED SHOWERS OR EVEN A
THUNDERSTORM LATE TONIGHT IN WESTERN NEBRASKA. HOWEVER...THE
COVERAGE WILL NOT BE ENOUGH TO WARRANT INCLUDING IT IN THE TERMINAL
FORECASTS FOR VTN AND LBF.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...TAYLOR
AVIATION...SPRINGER

000
FXUS63 KOAX 231117
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
617 AM CDT THU MAY 23 2013

.UPDATE...

HAVE HAD A LITTLE PATCHY DRIZZLE REPORTED AROUND PARTS OF THE
AREA EARLY THIS MORNING. SENT OUT A MINOR UPDATE FOR THAT...BUT
OTHERWISE NO CHANGES WERE MADE TO PREVIOUS FORECAST.

MILLER

&&

.AVIATION...

12Z TAFS FOR KOMA...KLNK...KOFK.

CEILINGS BETWEEN ABOUT 1000 AND 1500 FEET AT 6 AM THIS MORNING
SHOULD SLOWLY LIFT THIS MORNING WITH CLOUDS TENDING TO BECOME
SCATTERED 14Z-16Z AT KOFK...THEN 15Z-17Z AT KOMA AND KLNK. THE
REST OF THE PERIOD AFTER THAT SHOULD BE VFR. NORTH WINDS WILL
BECOME NORTHEAST OR EAST DURING THE DAY AND THEN SOUTHEAST BY
THIS EVENING. WE WILL HAVE TO WATCH FOR POSSIBLE RETURN OF LOW
CLOUDS AS MOISTURE STARTS TO COME BACK TONIGHT AND FRIDAY.

MILLER

&&

.PREV DISCUSSION... /ISSUED 328 AM CDT THU MAY 23 2013/

DISCUSSION...
CLOUDY SKIES CONTINUE ACROSS MOST OF THE AREA...WITH SOME CLEARING
SLIDING INTO THE NORTHERN CWA. SUBJECTIVE 00Z UPPER AIR ANALYSIS
INDICATES WEAKENING UPPER LOW CENTERED IN NORTHEAST/SOUTHWEST
WI...WITH UPPER LOW ALSO OVER WA...AND STRENGTHENING RIDGE IN
BETWEEN OVER THE HIGH PLAINS. 500MB HEIGHT RISES ACROSS THE
CENTRAL PLAINS INDICATE RIDGE IS BUILDING IN AS EASTERN LOW EXITS.
850MB LOW WAS CENTERED IN NORTHERN LOWER MI...WITH TROUGH AXIS
TRAILING ACROSS SOUTHERN WI/CENTRAL IA/SOUTHWEST KS. 850MB
MOISTURE WAS MAINLY CONFINED TO THE MS RIVER VALLEY AND
EASTWARD...BUT 8-16C DEWPOINTS HAD RETURNED TO THE TX GULF COAST
AND RIO GRANDE VALLEY...WITH FLOW OFF THE GULF FAVORABLE FOR
MOISTURE RETURN. SURFACE RIDGE AXIS AT 07Z EXTENDED FROM ND
THROUGH CENTRAL SD/CENTRAL NEB/EASTERN KS...WITH SURFACE LOW
DEVELOPING IN NORTHEAST NM.

MAIN FORECAST CONCERNS REVOLVE AROUND THUNDERSTORM POTENTIAL FOR THE
HOLIDAY WEEKEND INTO NEXT WEEK.  UPPER-LEVEL PATTERN WILL TRANSITION
FROM OMEGA BLOCK TO WESTERN TROUGH/CENTRAL RIDGE THROUGH THE REST OF
THIS WEEK...WITH THE TROUGH/RIDGE MAKING EASTWARD PROGRESS THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK THAT WILL PLACE THE CENTRAL US
UNDER SOUTHWESTERLY UPPER-LEVEL FLOW.  PATTERN WILL THUS BE
FAVORABLE FOR CONVECTION FROM FRIDAY NIGHT THROUGH DAYS 7-10...AS
PATTERN IS IN NO HURRY TO BREAK DOWN.  MAIN INHIBITORS TO CONVECTION
WILL BE PROXIMITY TO UPPER RIDGE EARLY IN THE PERIOD...THEN
POTENTIAL FOR CAPPING LATER IN THE PERIOD.  CONVECTION WOULD BE
FAVORED AS SHORTWAVES SLIDE THROUGH THE UPPER-LEVEL FLOW...BUT OF
COURSE...TIMING THESE INDIVIDUAL IMPULSES IS CHALLENGING TO SAY THE
LEAST MORE THAN A COUPLE OF DAYS IN ADVANCE.  HAVE NUDGED TEMPS
UPWARD THROUGH MUCH OF THE FORECAST AS MID-LEVEL TEMPERATURES
WARM...WITH 850MB TEMPERATURES WARMING INTO THE UPPER TEENS TO LOW
20S BY THE END OF THE PERIOD.

HAVE BACKED OFF MORNING POPS ON FRIDAY...AS ISENTROPIC LIFT AND GOOD
WARM/MOIST AIR ADVECTION REALLY GET GOING IN THE AFTERNOON IN
EASTERN NEBRASKA...AND LIKELY CLOSER TO EVENING IN WESTERN IOWA.
SOUNDINGS ARE NOT ESPECIALLY UNSTABLE...AND THINK ANY PRECIP ON
FRIDAY WOULD BE MORE OF A CHARACTER OF SHOWERS WITH A FEW RUMBLES
THAN GENERAL THUNDERSTORMS.  AM NOT CONVINCED OF WIDESPREAD COVERAGE
BASED ON NAM/SREF PROGS...AND THUS HAVE KEPT POPS IN CHANCE RANGE
DURING THE DAY...WITH A SMALL AREA OF LIKELIES IN THE NORTHEAST CWA
IN THE EVENING BEFORE LOW-LEVEL JET VEERS TO THE EAST AND TAKES
SUPPORT FOR PRECIP EASTWARD WITH IT.

BELIEVE SATURDAY MORNING WILL ACTUALLY BE PRETTY MUCH DRY IN THE
CWA...AS LOW-LEVEL JET RE-ORIENTS ITSELF INTO WESTERN NEB...WITH A
MID-LEVEL SHORTWAVE RIDGE MOVING THROUGH.  BY AFTERNOON...A WARM
FRONT WILL BECOME ESTABLISHED ACROSS NORTH CENTRAL TO SOUTHEAST
NEBRASKA...WHICH SHOULD PROVIDE A FOCUS FOR SOME STORMS ON SATURDAY
AFTERNOON AND EVENING.  CAN`T RULE OUT POTENTIAL FOR A COUPLE OF
SEVERE STORMS...THOUGH BETTER POTENTIAL WILL BE WEST OF THE CWA.
STORMS ARE LIKELY TO FORM INTO A COMPLEX THAT MOVES ACROSS THE AREA
ON SATURDAY NIGHT.  A SIMILAR PATTERN LOOKS TO BE IN PLACE FOR
SUNDAY...WITH MUCH OF THE MORNING LIKELY TO BE DRY BEHIND THE
EXITING OVERNIGHT COMPLEX...FOLLOWED BY CONVECTIVE DEVELOPMENT WEST
OF THE AREA THAT MOVES ACROSS ON SUNDAY NIGHT.

FROM MONDAY ONWARD...FORECAST CONTINUES TO HAVE A PARADE OF SLIGHT
CHANCE TO CHANCE POPS IN EVERY PERIOD.  FORECAST WILL BY NO MEANS BE
A WASHOUT.  SOME OF THOSE DAYS...TSTORM CHANCES WILL FOCUS IN THE
AFTERNOON AND EVENING...WHILE OTHERS FOCUS IN THE OVERNIGHT PERIODS
WHEN CONVECTION FIRES FURTHER WEST.  THERE WILL LIKELY BE DRY
PERIODS IN THE MIX AS WELL.  THE ECWMF TRENDS MUCH WARMER THAN GFS
BY MID TO LATE WEEK AND WOULD IMPLY CAPPING WITH 12-14C 700MB
TEMPS...WHILE THE GFS BRINGS THE SURFACE LOW MUCH CLOSER BY THEN AND
KEEPS TEMPS SEVERAL DEGREES LOWER.  ALL IN ALL...MUCH UNCERTAINTY
REMAINS...AND HAVE KEPT POPS FROM GETTING TOO AGGRESSIVE UNTIL
PERIODS ARE CLOSER AND BETTER AGREEMENT IS ESTABLISHED.

MAYES

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

000
FXUS63 KGID 231016
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
516 AM CDT THU MAY 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM CDT THU MAY 23 2013

THIS 24 HOURS MARKS THE VERY BEGINNING STAGES OF THE MORE
ACTIVE/STORMY WEATHER PATTERN THAT WILL RAMP UP HEADING INTO THE
HOLIDAY WEEKEND. LIKE LAST NIGHT...LOW LEVEL STRATUS TRENDS ARE
PRESENTING A CHALLENGE MAINLY DURING THE FIRST 6 HOURS. PRECIP-
WISE...HAVE INTRODUCED SPRINKLES INTO SOUTHWEST ZONES THIS
MORNING...AND OVERALL MADE LITTLE NOTABLE CHANGE TO OVERNIGHT
SHOWERS/STORM CHANCES...WHICH SHOULD NOT BE OVERLY WIDESPREAD.
ALSO MADE ONLY MINOR TWEAKS TO TEMPS TODAY/TONIGHT.

08Z OBJECTIVE CENTRAL PLAINS SURFACE ANALYSIS IS HIGHLIGHTED BY
THE SOUTHWARD EXTENSION OF A RATHER STRONG 1032+ MILLIBAR HIGH
CENTERED WELL TO THE NORTH OVER CENTRAL CANADA...WITH PRESSURES TO
AROUND 1018MB AS FAR SOUTH AS THE LOCAL CWA. THIS HIGH IS DRIVING
STEADY NORTH BREEZES GENERALLY 5-15 MPH EARLY THIS MORNING...WITH
LOCALLY HIGHER GUSTS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM
MODEL DATA DEPICT THE DEPARTING MID LEVEL LOW THAT BROUGHT THE
LIGHT RAIN TO EASTERN AREAS 24 HOURS AGO NOW WELL OFF TO THE EAST
IN THE GREAT LAKES REGION...WHILE WELL UPSTREAM TO THE WEST AN
EXPANSIVE 500MB CLOSED LOW CONTINUES CHURNING OVER OR/WA. IN
BETWEEN THESE LOWS...A RIDGE AXIS EXTENDS NORTH-SOUTH THROUGH THE
HEART OF THE NATION...WITH ITS AXIS ALIGNED THROUGH WESTERN
PORTIONS OF NEB/KS. 11-3.9 MICRON SATELLITE IMAGERY CONFIRMS THAT
IN FACT THE STRATUS THAT ERODED NORTHWARD ACROSS MUCH OF THE CWA
ON WEDNESDAY HAS SUNK BACK SOUTHWARD OVERNIGHT...WITH THE MAJORITY
OF THE CWA SITTING UNDER A ROUGHLY 1500 FT CLOUD DECK. EARLIER IN
THE NIGHT...THERE WERE HINTS AT A FEW AUTOMATED STATIONS SUCH AS
ORD THAT BRIEF SPRINKLE/DRIZZLE MIGHT HAVE FALLEN...BUT OTHERWISE
THE CWA HAS REMAINED DRY THUS FAR...WITH OVERNIGHT LOW TEMPS
LIKELY ENDING UP BETWEEN 45-50 NEARLY ALL AREAS. LOOKING JUST TO
THE WEST...A CLASSIC NORTHWEST-SOUTHEAST BAND OF MID LEVEL THETA-E
ADVECTION EVIDENT ON BOTH THE 700MB AND 310K SURFACE IS DRIVING A
SURPRISINGLY HEALTHY AREA OF LIGHT RAIN SHOWERS OVER MAINLY
NORTHWEST KS/NORTHEAST CO...WITH A MORE ORGANIZED AREA OF
THUNDERSTORMS DEVELOPING ALONG THIS SAME ZONE OF LIFT MUCH FARTHER
SOUTH OVER OK.

HEADING INTO THE DAYTIME HOURS...THE MOST IMMEDIATE ISSUE IS TO
WHAT EXTENT THE LIGHT RAIN SHOWERS TO THE WEST WILL HOLD TOGETHER
AS THE MID LEVEL CORRIDOR OF LIFT CONTINUES EDGING EASTWARD TOWARD
THE CWA. GIVEN THAT THIS FORCING SHOULD CONTINUE WEAKENING A BIT
AS IT SPREADS EAST THIS MORNING...AND ALSO GIVEN A CONSIDERABLE
AMOUNT OF DRY AIR NOTED BELOW 600MB ON FORECAST SOUNDINGS...THINK
THE ODDS OF LEGITIMATE MEASURABLE RAIN AFFECTING MORE THAN A TINY
FRACTION OF THE WESTERN CWA THIS MORNING IS QUITE LOW. THAT BEING
SAID...WENT AHEAD AND INTRODUCED A SPRINKLE MENTION TO A
PREVIOUSLY RAIN-FREE FORECAST THROUGH MID-DAY FOR AREAS GENERALLY
SOUTHWEST OF A LEXINGTON-BELOIT LINE...WITH SEEMINGLY LITTLE RISK
FOR EVEN SPRINKLES FOR THE TRI-CITIES AND POINTS NORTH/EAST.
ALTHOUGH THIS SORT OF SETUP OFTEN PRODUCES AT LEAST A ROGUE
LIGHTNING STRIKE OR TWO...EVEN ELEVATED INSTABILITY IS ESSENTIALLY
NON-EXISTENT OVER THE CWA THIS MORNING SO WILL NOT GO THE
THUNDERSTORM ROUTE. AS FOR THE MID/UPPER LEVEL STORY TODAY...THE
AFOREMENTIONED RIDGE AXIS WILL AMPLIFY A BIT OVER THE CENTRAL
PLAINS TODAY...RESULTING IN RISING HEIGHTS. AT THE
SURFACE...WINDS WILL BE ON THE INCREASE A BIT AND TRANSITION FROM
NORTHERLY TO EASTERLY DUE TO THE COMBINATION OF HIGH PRESSURE TO
THE NORTH DRIFTING EAST...AND ALSO DECENT PRESSURE FALLS TO THE
WEST AS A FAIRLY STRONG SURFACE LOW RAMPS UP OVER WY. THIS
AFTERNOON...STEADY EASTERLY BREEZES AROUND 15 MPH WITH GUSTS INTO
THE 20-25 MPH RANGE WILL BE IN PLACE...STRONGEST WEST OF HIGHWAY
281. AS FOR THE EVOLUTION OF SKY COVER TODAY...WILL AGAIN LEAN
TOWARD THE LATEST RAP/HRRR LOW CLOUD/RELATIVE FIELDS...WHICH
SUGGESTS A FAIRLY RAPID SCATTERING OUT/LIFTING OF LOW CLOUDS
THROUGH THE MID-LATE MORNING HOURS...PAVING THE WAY FOR AN
AFTERNOON THAT SHOULD AVERAGE NO WORSE THAN PARTLY CLOUDY.
ASSUMING THIS ALL PANS OUT AS PLANNED...TEMPS SHOULD HAVE NO
PROBLEM MAKING A DECENT RISE...AND HAVE AIMED HIGHS BETWEEN 68-72
DEGREES FOR NEARLY THE ENTIRE CWA...WHICH IS ONLY SLIGHTLY WARMER
THAN PREVIOUS IN SOME SPOTS. AS FOR AFTERNOON PRECIP
CHANCES...KEPT IT DRY AS ANY CONVECTION SHOULD FOCUS AT LEAST A
FEW COUNTIES OFF TO THE SOUTH AND/OR WEST.

FOR THE TONIGHT PERIOD...00Z-12Z...LITTLE OVERALL CHANGE IN
THINKING FROM PREVIOUS FORECASTS. IN THE MID-UPPER LEVELS...FAIRLY
WEAK QUASI-ZONAL FLOW CONTINUES ACROSS THE CENTRAL PLAINS WITHIN
THE RIDGE AXIS...WHILE OFF TO THE WEST A LEAD SHORTWAVE TROUGH
EJECTS NORTHEAST ACROSS WY/MT ALONG THE SOUTHEAST SIDE OF THE
PARENT PACIFIC NORTHWEST LOW. AS THE NIGHT WEARS ON...ANOTHER MORE
VIGOROUS BATCH OF MID LEVEL THETA-E ADVECTION WILL VEER EASTWARD
ACROSS WESTERN/CENTRAL PORTIONS OF NEBRASKA/KANSAS. SLIGHTLY
LOWER IN THE COLUMN...A DECENT SOUTHERLY 850MB LOW LEVEL JET WILL
STRENGTHEN TO 30-45KT LATE IN THE NIGHT MAINLY ALONG THE FAR
WESTERN EDGE OF THE CWA AND POINTS WEST. NEEDLESS TO SAY...MODELS
VARY ON HOW MUCH QPF THEY GENERATE OVER THE CWA TONIGHT...WITH
SOME SUCH AS THE NAM AND EVEN 4KM WRF-NMM SHOWING LITTLE IF
ANYTHING GOING ON LOCALLY...WITH BETTER CHANCES FOCUSED WEST.
HOWEVER...GIVEN THE DECENT MID LEVEL THETA-E ADVECTION AND
FORECAST OF 200 + J/KG OF ELEVATED MUCAPE IN THE 850-700MB LAYER
FORECAST INTO PARTS OF THE CWA AFTER MIDNIGHT...AND HIGHER VALUES
TO AROUND 1000 J/KG IN THE FAR WESTERN COUNTIES...KEPT FAIRLY
MODEST 20-30 POPS GOING ESPECIALLY FOR THE 09Z-12Z TIME
FRAME...WHILE KEEPING THE ENTIRE EVENING TIME FRAME RAIN-FREE.
RELEGATED THESE STORM CHANCES WEST OF AN ORD-HASTINGS-BELOIT LINE
THROUGH SUNRISE...WITH CHANCES IN EASTERN COUNTIES HOLDING OFF
UNTIL THE FRIDAY DAYTIME PERIOD. ALTHOUGH NOT EXPECTING ANY SEVERE
STORMS LATE TONIGHT...CERTAINLY CANNOT RULE OUT SOME SMALL HAIL
ESPECIALLY IN THE FAR WESTERN FRINGES OF THE CWA. COULD ALSO SEE
RENEWED LOW STRATUS DEVELOPMENT AS LOW LEVEL WINDS TURN MORE
SOUTHEASTERLY. SURFACE BREEZES OF 10-15 MPH WILL PREVAIL THROUGH
THE NIGHT...AND MADE ONLY MINOR CHANGES TO LOW TEMPS WITH MOST
AREAS BOTTOMING OUT WITHIN A FEW DEGREES EITHER SIDE OF 50.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 515 AM CDT THU MAY 23 2013

THE WEATHER PATTERN WILL BECOME MORE ACTIVE IN THESE EXTENDED PERIODS.
ON FRIDAY...AN UPPER LEVEL RIDGE AXIS WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS IN BETWEEN AN UPPER LOW IN THE PACIFIC NORTHWEST AND
AN UPPER LOW/TROUGH ALONG THE EASTERN CONUS.  A WARM FRONTAL
BOUNDARY LIFTS E/NE ACROSS THE CENTRAL PLAINS DURING THE DAY AND IN
WAA/THETA E ADVECTION...SHOWERS AND TSTMS ARE EXPECTED TO DEVELOP
AND SPREAD EAST/NORTHEAST FRIDAY/FRIDAY NIGHT.  DUE TO ANTICIPATED
PCPN AND CLOUD COVER ON FRIDAY...HAVE LOWERED HIGH TEMPS A FEW
DEGREES.  INSTABILITY PARAMETERS INDICATE CAPES INCREASING TO 1000
J/KG WITH SOME HIGHER INSTABILITY POTENTIAL GREATER THAN THIS
POSSIBLE ACROSS OUR WESTERN ZONES...AND EFFECTIVE SHEAR IS PROGGED
AROUND 30KTS.  COULD SEE A FEW STRONG/SEVERE STORMS BY FRIDAY
AFTN/EVE AND MORE SO INTO FRIDAY NIGHT...AS LLVL JET INCREASES.
MODELS SUGGEST ADDITIONAL CONVECTIVE POTENTIAL ALONG HIGH PLAINS
FRIDAY NIGHT IN VCNTY OF SFC LOW/DRY LINE WHICH MAY THEN ROLL ACROSS
OUR REGION OVERNIGHT.

ON SATURDAY...FLOW ALOFT WILL BE SOUTHWESTERLY AS RIDGE AXIS SHIFTS
EASTWARD...WHILE AT THE SFC...LOW PRESSURE SHOULD SETTLE ALONG THE
HIGH PLAINS WITH TWO POTENTIAL SFC LOW CENTERS DEVELOPING...ONE IN
EASTERN WY/MT AND ANOTHER TO THE SOUTH ACROSS WESTERN KS.  WARM
FRONTAL BOUNDARY LOOKS TO SETTLE NEAR THE NEB/KS START LINE WITH MUCH
GREATER INSTABILITY EXPECTED WITH CAPES IN EXCESS OF 3000 J/KG AS
MOISTURE POOLS ALONG THE BOUNDARY...AND AGAIN DECENT SHEAR IS
PROGGED AROUND 30KTS...ESPECIALLY ACROSS NEB WHICH INCREASES
OVERNIGHT WITH NOCTURNAL JET.  WARM MID LEVEL TEMPS COULD MAY INHIBIT
CONVECTION TO THE WEST ALONG THE DRY LINE...HOWEVER WARM FRONT LOOKS
TO BECOME ACTIVE AND IF STORMS FIRE IN VCNTY OF FRONT...CONDITIONS
ARE FAVORABLE FOR SEVERE WEATHER.  CONVECTIVE POTENTIAL CONTINUES
INTO SATURDAY NIGHT MAINLY ACROSS NEB NORTH OF FRONT ON NOSE OF 50KT
LLVL JET.

THROUGH THE REMAINDER OF THE MEMORIAL DAY HOLIDAY
WEEKEND...SUNDAY/MONDAY...CONVECTIVE POTENTIAL CONTINUES IN
SOUTHWEST FLOW ALOFT AS SHORTWAVE ENERGY LIFTS ACROSS THE PLAINS AND
INTERACTS WITH LLVL BOUNDARIES.  TIMING/LOCATION OF BEST PCPN CHCS
WILL BE REFINED WITH TIME.  THIS BEING SAID...THE WEATHER PATTERN
DOES LOOK ACTIVE WITH POTENTIAL FOR SEVERE WEATHER AND DECENT
RAINFALL/PCPN IS POSSIBLE FOR SEVERAL DAYS IN INCREASED
MOISTURE...AND PRECIPITABLE WATER VALUES INCREASE TO BETWEEN AN INCH
AND AN INCH AND A HALF.

BY MID WEEK...EXTENDED MODELS BEGIN TO DIVERGE IN HANDLING OF
TROUGH/UPPER LOW ACROSS THE WESTERN CONUS AND DUE TO MODEL
DIFFERENCES...DID NOT DEVIATE MUCH FROM EXTENDED INIT.

&&

.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1252 AM CDT THU MAY 23 2013

AS WAS THE CASE 24 HOURS AGO...CEILING TRENDS VARYING BETWEEN MVFR
AND VFR CONTINUE TO BE THE BIGGEST...TRICKY CHALLENGE...ESPECIALLY
THROUGH THE FIRST 12 HOURS OF THE PERIOD. HOWEVER...CONFIDENCE
REMAINS RATHER HIGH IN VFR VISIBILITY...AND ALSO THAT IT SHOULD
REMAIN RAIN-FREE THROUGH THE PERIOD. GETTING BACK TO CEILINGS...A
FAIRLY SOLID DECK OF STRATUS RANGING ANYWHERE FROM 1500 TO AROUND
3000 FT CONTINUES SINKING SOUTHWARD ACROSS SOUTHERN NEBRASKA.
ALTHOUGH KGRI COULD VERY WELL BOUNCE BACK AND FORTH BETWEEN VFR
AND MVFR THROUGH MUCH OF THE NIGHT...WILL AIM FOR PREVAILING MVFR
FOR SEVERAL HOURS AND LIKELY LASTING THROUGH SOMETIME AROUND MID-
DAY BEFORE LOW STRATUS IS EXPECTED TO EITHER START SCATTERING OUT
AND/OR LIFTING INTO LOW-END VFR LEVELS...AND REMAINING THAT WAY
THROUGH THE END OF THE PERIOD. AS FOR SURFACE WINDS...A FAIRLY
LIGHT NORTHERLY BREEZE WILL PREVAIL EARLY THIS MORNING...BEFORE
STEADILY TURNING MORE EASTERLY BY MID-DAY WITH GUST POTENTIAL TO
AT LEAST 18KT FOR MUCH OF THE AFTERNOON. WINDS WILL REMAIN
EASTERLY THURSDAY EVENING SUSTAINED ROUGHLY 10KT.


&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...PFANNKUCH
LONG TERM...FAY
AVIATION...PFANNKUCH

000
FXUS63 KLBF 230848
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
348 AM CDT THU MAY 23 2013

.SYNOPSIS...
ISSUED AT 345 AM CDT THU MAY 23 2013

AT 08Z...THE MSL DATA SHOWED LOW PRESSURE CENTERED OVER SOUTHWEST
WYOMING WITH A WARM FRONT ACROSS WESTERN COLORADO. ANOTHER LOW WAS
CENTERED OVER EASTERN NEW MEXICO WITH A WARM FRONT EXTENDING INTO
SOUTHWEST KANSAS. THE STRATUS CLOUDS WERE CLEARING AS HIGH PRESSURE
FORCED ITS WAY INTO NORTHERN NEBRASKA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT THU MAY 23 2013

CLOUDINESS WILL PROBABLY BE PERSISTENT IN SOUTH CENTRAL AND
SOUTHWEST NEBRASKA UNTIL EARLY AFTERNOON. LOW LEVEL WIND FROM THE
EAST TO SOUTHEAST WILL BRING AN INCREASE IN PRECIPITABLE WATER LATER
THIS AFTERNOON OR EARLY EVENING.

THIS EVENING...AS THE SURFACE LOW MAKES ITS WAY OUT OF WYOMING AND
INTO MONTANA...A WARM FRONT RE-FORMS IN THE LEE OF THE ROCKIES. WARM
ADVECTION WILL THEN LIFT AIR UP OVER THE FRONT AND BRING SHOWERS TO
CENTRAL AND WESTERN NEBRASKA...ESPECIALLY AFTER MIDNIGHT. THERE
SHOULD BE ENOUGH INSTABILITY FOR ISOLATED THUNDERSTORMS TO BECOME
EMBEDDED IN THE SHOWERS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 AM CDT THU MAY 23 2013

LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL REMAIN NEARLY STATIONARY
ACROSS THE PACIFIC NORTHWEST FRIDAY...WITH THE CENTRAL PLAINS IN
SOUTHWEST FLOW ALOFT. THE FLOW WILL BE MODEST...WITH H5 SPEEDS
AROUND 35 KTS. APPEARS ELEVATED SHOWERS AND TSTMS WILL BE POSSIBLE
IN WARM AIR ADVECTION PATTERN THROUGH MID AFTERNOON...THEN ATTENTION
TURNS TO POSSIBLE SFC BASED CONVECTION ALONG THE LEE TROUGH/DRY LINE
DURING THE LATE AFTERNOON. VERY STEEP LOW LEVEL LAPSE RATES DEVELOP
EASTWARD INTO NORTHEAST COLORADO AND THE SOUTHERN NEB PANHANDLE BY
LATE FRIDAY AFTERNOON...WITH MLCAPE VALUES AROUND 2000 J/KG AND
ADEQUATE SHEAR. AS A WEAK VORTICITY MAXIMA MOVES NORTHEAST AROUND
PEAK HEATING...AT LEAST ISOLATED TSTM DEVELOPMENT SEEMS POSSIBLE.
THESE WOULD MOST LIKELY DEVELOP ON THE NOSE OF THE STEEPER LOW LEVEL
LAPSE RATES ACROSS NORTHEAST COLORADO INTO THE SOUTHERN NEB
PANHANDLE. A SEVERE STORM IS POSSIBLE...AS SHEAR AND INSTABILITY ARE
ADEQUATE ENOUGH TO SUPPORT THE POTENTIAL. IT IS UNCLEAR HOW FAR EAST
THESE STORMS WILL MAKE IT INTO SOUTHWEST OR WESTERN NEBRASKA...AS
EXTENSIVE LOW LEVEL MOISTURE IN THE FORM OF STRATUS CLOUDS WILL
LIKELY INHIBIT INSTABILITY. SOME CHANCE THAT STORMS WILL DEVELOP
EAST DURING THE EVENING AIDED BY A SOUTHERLY LLJ...AND THE GFS HINTS
AT THIS...BUT UNCERTAIN OF THIS SCENARIO...AND WILL KEEP POPS FAIRLY
LOW FRIDAY NIGHT.

SATURDAY AFTERNOON AND EVENING STILL EXPECTING A ROUND OF TSTMS.
BOTH THE 23/00Z RUNS OF THE GFS AND ECMWF HAVE A SHORT WAVE TROUGH
EJECTING NORTHEAST ACROSS THE AREA PROVIDING LIFT...THE ONLY
NEGATIVE FOR CONVECTION IS A WELL DEFINED BOUNDARY TO FOCUS
INITIATION ON. THERE DOES APPEAR TO BE A WEAK INVERTED TROUGH ACROSS
WEST CENTRAL NEB...AND A WEAK WARM FRONT ACROSS SOUTHERN/CENTRAL
NEB. OTHER SUBTLE BOUNDARIES MAY EXIST FROM ANY PRIOR CONVECTION.
IF STORMS DO INDEED DEVELOP...ATMOSPHERE IS QUITE UNSTABLE
AND 0 TO 6 KM SHEAR ON THE ORDER OF 30 TO 40 KTS WOULD SUPPORT SOME
SEVERE STORMS.

WITH THE LARGE UPPER LEVEL LOW REMAINING WEST OF THE AREA SUNDAY
INTO NEXT WEEK...CONVECTIVE CHANCES WILL REMAIN. BUT TIMING AND
LOCATION IS UNCERTAIN...AS PREVIOUS BOUTS OF CONVECTION WILL LIKELY
HAVE AN IMPACT ON BOUNDARY PLACEMENT ETC.

TEMPERATURE WISE...A FAIRLY WARM PERIOD EXPECTED FRIDAY THROUGH THE
HOLIDAY WEEKEND AND INTO NEXT WEEK. IT WILL BE RATHER MUGGY AS WELL
WITH THE INCREASED GULF OF MEXICO MOISTURE. HIGHS SHOULD MAKE IT
INTO AT LEAST THE 70S EACH DAY...WITH 80S POSSIBLE ESPECIALLY ACROSS
WESTERN/SOUTHWEST NEB. CLOUDS AND PRECIP COULD HAVE AN IMPACT AT
TIMES HOWEVER...BUT OVERALL PRETTY DECENT TEMPERATURES EXPECTED FOR
THE HOLIDAY WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1231 AM CDT THU MAY 23 2013

NORTHEASTERLY WINDS WILL TRANSITION EAST OVER THE NEXT 24 HOURS
PUSHING LOW CLOUDINESS INTO WESTERN AND SOUTHWESTERN NEBRASKA
OVERNIGHT TONIGHT. ACROSS SOUTHWESTERN NEBRASKA...INCLUDING THE
KLBF TERMINAL...CIGS WILL RANGE FROM 1500 TO 2500 FT AGL THROUGH
EARLY AFTERNOON ON THURSDAY. CIGS WILL INCREASE TO 3000 TO 5000 FT
AGL LATE THURSDAY AFTERNOON AND THURSDAY EVENING. FOR NORTHERN
NEBRASKA...INCLUDING THE KVTN TERMINAL...CIGS OF 1000 TO 3000 FT
AGL WILL PERSIST THROUGH LATE MORNING THURSDAY. BY EARLY
AFTERNOON...EXPECT ONLY HIGH CLOUD CEILINGS.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...TAYLOR
AVIATION...CLB

000
FXUS63 KOAX 230828
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
328 AM CDT THU MAY 23 2013

.DISCUSSION...
CLOUDY SKIES CONTINUE ACROSS MOST OF THE AREA...WITH SOME CLEARING
SLIDING INTO THE NORTHERN CWA. SUBJECTIVE 00Z UPPER AIR ANALYSIS
INDICATES WEAKENING UPPER LOW CENTERED IN NORTHEAST/SOUTHWEST
WI...WITH UPPER LOW ALSO OVER WA...AND STRENGTHENING RIDGE IN
BETWEEN OVER THE HIGH PLAINS. 500MB HEIGHT RISES ACROSS THE
CENTRAL PLAINS INDICATE RIDGE IS BUILDING IN AS EASTERN LOW EXITS.
850MB LOW WAS CENTERED IN NORTHERN LOWER MI...WITH TROUGH AXIS
TRAILING ACROSS SOUTHERN WI/CENTRAL IA/SOUTHWEST KS. 850MB
MOISTURE WAS MAINLY CONFINED TO THE MS RIVER VALLEY AND
EASTWARD...BUT 8-16C DEWPOINTS HAD RETURNED TO THE TX GULF COAST
AND RIO GRANDE VALLEY...WITH FLOW OFF THE GULF FAVORABLE FOR
MOISTURE RETURN. SURFACE RIDGE AXIS AT 07Z EXTENDED FROM ND
THROUGH CENTRAL SD/CENTRAL NEB/EASTERN KS...WITH SURFACE LOW
DEVELOPING IN NORTHEAST NM.

MAIN FORECAST CONCERNS REVOLVE AROUND THUNDERSTORM POTENTIAL FOR THE
HOLIDAY WEEKEND INTO NEXT WEEK.  UPPER-LEVEL PATTERN WILL TRANSITION
FROM OMEGA BLOCK TO WESTERN TROUGH/CENTRAL RIDGE THROUGH THE REST OF
THIS WEEK...WITH THE TROUGH/RIDGE MAKING EASTWARD PROGRESS THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK THAT WILL PLACE THE CENTRAL US
UNDER SOUTHWESTERLY UPPER-LEVEL FLOW.  PATTERN WILL THUS BE
FAVORABLE FOR CONVECTION FROM FRIDAY NIGHT THROUGH DAYS 7-10...AS
PATTERN IS IN NO HURRY TO BREAK DOWN.  MAIN INHIBITORS TO CONVECTION
WILL BE PROXIMITY TO UPPER RIDGE EARLY IN THE PERIOD...THEN
POTENTIAL FOR CAPPING LATER IN THE PERIOD.  CONVECTION WOULD BE
FAVORED AS SHORTWAVES SLIDE THROUGH THE UPPER-LEVEL FLOW...BUT OF
COURSE...TIMING THESE INDIVIDUAL IMPULSES IS CHALLENGING TO SAY THE
LEAST MORE THAN A COUPLE OF DAYS IN ADVANCE.  HAVE NUDGED TEMPS
UPWARD THROUGH MUCH OF THE FORECAST AS MID-LEVEL TEMPERATURES
WARM...WITH 850MB TEMPERATURES WARMING INTO THE UPPER TEENS TO LOW
20S BY THE END OF THE PERIOD.

HAVE BACKED OFF MORNING POPS ON FRIDAY...AS ISENTROPIC LIFT AND GOOD
WARM/MOIST AIR ADVECTION REALLY GET GOING IN THE AFTERNOON IN
EASTERN NEBRASKA...AND LIKELY CLOSER TO EVENING IN WESTERN IOWA.
SOUNDINGS ARE NOT ESPECIALLY UNSTABLE...AND THINK ANY PRECIP ON
FRIDAY WOULD BE MORE OF A CHARACTER OF SHOWERS WITH A FEW RUMBLES
THAN GENERAL THUNDERSTORMS.  AM NOT CONVINCED OF WIDESPREAD COVERAGE
BASED ON NAM/SREF PROGS...AND THUS HAVE KEPT POPS IN CHANCE RANGE
DURING THE DAY...WITH A SMALL AREA OF LIKELIES IN THE NORTHEAST CWA
IN THE EVENING BEFORE LOW-LEVEL JET VEERS TO THE EAST AND TAKES
SUPPORT FOR PRECIP EASTWARD WITH IT.

BELIEVE SATURDAY MORNING WILL ACTUALLY BE PRETTY MUCH DRY IN THE
CWA...AS LOW-LEVEL JET RE-ORIENTS ITSELF INTO WESTERN NEB...WITH A
MID-LEVEL SHORTWAVE RIDGE MOVING THROUGH.  BY AFTERNOON...A WARM
FRONT WILL BECOME ESTABLISHED ACROSS NORTH CENTRAL TO SOUTHEAST
NEBRASKA...WHICH SHOULD PROVIDE A FOCUS FOR SOME STORMS ON SATURDAY
AFTERNOON AND EVENING.  CAN`T RULE OUT POTENTIAL FOR A COUPLE OF
SEVERE STORMS...THOUGH BETTER POTENTIAL WILL BE WEST OF THE CWA.
STORMS ARE LIKELY TO FORM INTO A COMPLEX THAT MOVES ACROSS THE AREA
ON SATURDAY NIGHT.  A SIMILAR PATTERN LOOKS TO BE IN PLACE FOR
SUNDAY...WITH MUCH OF THE MORNING LIKELY TO BE DRY BEHIND THE
EXITING OVERNIGHT COMPLEX...FOLLOWED BY CONVECTIVE DEVELOPMENT WEST
OF THE AREA THAT MOVES ACROSS ON SUNDAY NIGHT.

FROM MONDAY ONWARD...FORECAST CONTINUES TO HAVE A PARADE OF SLIGHT
CHANCE TO CHANCE POPS IN EVERY PERIOD.  FORECAST WILL BY NO MEANS BE
A WASHOUT.  SOME OF THOSE DAYS...TSTORM CHANCES WILL FOCUS IN THE
AFTERNOON AND EVENING...WHILE OTHERS FOCUS IN THE OVERNIGHT PERIODS
WHEN CONVECTION FIRES FURTHER WEST.  THERE WILL LIKELY BE DRY
PERIODS IN THE MIX AS WELL.  THE ECWMF TRENDS MUCH WARMER THAN GFS
BY MID TO LATE WEEK AND WOULD IMPLY CAPPING WITH 12-14C 700MB
TEMPS...WHILE THE GFS BRINGS THE SURFACE LOW MUCH CLOSER BY THEN AND
KEEPS TEMPS SEVERAL DEGREES LOWER.  ALL IN ALL...MUCH UNCERTAINTY
REMAINS...AND HAVE KEPT POPS FROM GETTING TOO AGGRESSIVE UNTIL
PERIODS ARE CLOSER AND BETTER AGREEMENT IS ESTABLISHED.

MAYES

&&

.AVIATION...
06Z TAFS FOR KOMA...KOFK...AND KLNK.

MVFR CIGS WITH INTERMITTENT IFR ARE EXPECTED OVERNIGHT. SHORTLY
AFTER SUNRISE...CLOUDS SHOULD SCATTER OUT AND BECOME VFR OVER ALL
3 TAF SITES FOR THE REMAINDER OF THE FORECAST CYCLE AS AN AREA OF
HIGH PRESSURE BUILDS INTO THE REGION. NORTHWEST SURFACE WINDS
INITIALLY WILL BECOME NORTHEAST BY MORNING AND EVENTUALLY
SOUTHEAST BY LATE AFTERNOON INTO EARLY EVENING.

KERN

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

000
FXUS63 KGID 230553
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1253 AM CDT THU MAY 23 2013

.UPDATE...
ISSUED AT 703 PM CDT WED MAY 22 2013

MADE MINOR ADJUSTMENTS TO THE HOURLY FORECAST FOR THIS EVENING.
FORECAST IS PRETTY MUCH ON TRACK.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 351 PM CDT WED MAY 22 2013

MORNING UPPER AIR ANALYSIS INDICATES A MID LEVEL LOW BETWEEN THE
NORTHERN MISSOURI RIVER VALLEY AND THE UPPER MISSISSIPPI
VALLEY...WITH SUBTLE MID TO UPPER LEVEL RIDGING OVER THE ROCKY
MOUNTAIN RANGE...AND A MID TO UPPER LEVEL LOW OVER THE
NORTHWESTERN CONUS. MID TO UPPER LEVEL JET ENERGY EXTENDS FROM THE
WEST-CENTRAL CONUS...EAST/SOUTHEAST ACROSS THE SOUTHERN CONUS AND
THEN NORTH/NORTHEAST INTO THE GREAT LAKES REGION AND SOUTHEASTERN
CANADA. MID AND UPPER LEVEL FLOW IS FAIRLY WEAK OVER OUR AREA AS A
RESULT...MAXING OUT AT BETWEEN 30 AND 40KTS NEAR 400MB...PER 12Z
SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY ALSO SHOWS
THE MID LEVEL LOW BETWEEN THE NORTHERN MISSOURI RIVER VALLEY AND
UPPER MISSISSIPPI VALLEY...AND THE MID LEVEL LOW OVER THE
NORTHWESTERN CONUS. INCREASED MID LEVEL MOISTURE IS ALSO NOTED
EXTENDING FROM THE SOUTHERN/SOUTHEASTERN CONUS...NORTHWARD INTO
THE OHIO RIVER VALLEY AND GREAT LAKES REGION. MID LEVEL MOISTURE
OVER THE CENTRAL PLAINS HOWEVER IS FAIRLY LACKING. AT THE SURFACE
A RIDGE OF HIGH BAROMETRIC PRESSURE EXISTS ACROSS PORTIONS OF THE
NORTHERN AND CENTRAL HIGH PLAINS...AND AN AREA OF LOW BAROMETRIC
PRESSURE IS NOTED ACROSS PORTIONS OF THE UPPER MISSISSIPPI VALLEY.
THE LOW LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE
NORTHWEST AS A RESULT.

GUIDANCE SUGGESTS THE MID LEVEL LOW...CURRENTLY TO OUR EAST...WILL
CONTINUING MOVING EAST TONIGHT INTO TOMORROW. THE SUBTLE MID TO
UPPER LEVEL RIDGE...CURRENTLY OVER PORTIONS OF THE ROCKIES...IS
EXPECTED TO OVERTAKE OUR AREA AND THE RESULTANT LACK IN KINEMATIC
FORCING SHOULD PROVIDE DRY CONDITIONS...AND NOTHING IN THE WAY OF
HIGH-IMPACT WEATHER...TO OUR AREA THROUGH THE NEXT 24 HOURS.

LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS SIMILAR HIGH AND
LOW TEMPERATURES WILL BE OBSERVED ACROSS OUR AREA TOMORROW WHEN
COMPARED TO TODAY. AN OVERNIGHT LOW IN THE 40S IS FORECAST FOR
MOST LOCATIONS TONIGHT...WITH A HIGH IN MID 60S TO LOW 70S ON
THURSDAY...AS A RESULT.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM CDT WED MAY 22 2013

THIS IS MESSY AND LOWER CONFIDENCE LONG TERM FORECAST PERIOD. ARE
GOING TO BE SEEING PERIODIC THUNDERSTORM CHANCES ACROSS THE
CWA...THE BIG QUESTION LIES WITH THE TIMING...ESPECIALLY THE
FURTHER OUT IN TIME YOU GO.

LOOKING AT THE UPPER LEVEL PATTERN AT THE START OF THE
PERIOD...MODELS ARE IN PRETTY GOOD AGREEMENT. THE PLAINS ARE UNDER
THE INFLUENCE OF AN RIDGE AXIS EXTENDING WELL INTO
CANADA...BASICALLY SANDWICHED BETWEEN A TROUGH OVER THE ERN THIRD
OF THE CONUS...AND A LOW PRESSURE SYSTEM PARKED OVER THE PAC NW.
THROUGH THE REST OF THE FORECAST PERIOD...THE BASIC IDEA REMAINS
THE SAME...WITH SOME VARIATION OF THAT RIDGING REMAINS IN PLACE
OVER THE AREA...DEPENDING ON THE MODEL. WITH LOW
PRESSURE/TROUGHING ANCHORED OVER THE WRN CONUS...WILL SEE PERIODIC
WAVES OF ENERGY EJECTED OUT THROUGH THE ROCKIES AND ONTO THE
PLAINS. THE FIRST OF THESE WAVES LOOKS TO AFFECT THE REGION LATE
THURSDAY NIGHT AND INTO FRIDAY...WITH ADDITIONAL PRECIPITATION
CHANCES COMING BASICALLY EACH DAY AFTER THAT AS ADDITIONAL WAVES
MOVE THROUGH.

AT THE SURFACE...MODELS SHOWING THAT OVERALL...THE CWA GENERALLY
REMAINS BETWEEN HIGH PRESSURE EXTENDING THROUGH THE GREAT
LAKES/MIDWEST DOWN TO THE GULF...AND VARYING STRENGTHENS OF LOW
PRESSURE OVER THE FRONT RANGE/HIGH PLAINS. ON FRIDAY /ESP EARLY IN
THE DAY/...DRIER AIR ASSOCIATED WITH THE AREA OF HIGH PRESSURE
OVER THE MN/WI AREA WILL KEEP DEWPOINTS DOWN A BIT...BUT ONCE THAT
HIGH SLIDES EAST AND THE PRESSURE GRADIENT TIGHTENS UP AS THE LOW
DEEPENS TO THE WEST AND THE SOUTHERLY FLOW PICKS UP...MODELS IN
GOOD AGREEMENT SHOWING INCREASED DEWPOINTS FOR THE REST OF THE
PERIOD. ALONG WITH THE DEWPOINTS WILL BE INCREASING AMOUNTS OF
INSTABILITY...MORE FOR SATURDAY AND BEYOND THAN FRIDAY. SO HAS
BEEN MENTIONED PREVIOUSLY...STRONG/SEVERE THUNDERSTORMS WILL
REMAIN CONCERN...ESPECIALLY SO IF WE CAN GET A SURFACE BOUNDARY TO
SET UP IN/NEAR THE CWA. ONE THING MODELS DO SHOW IS THAT OVERALL
DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE...BUT ISNT ON THE
EXTREMELY LOW SIDE EITHER. PLENTY OF DETAILS TO IRON OUT OVER THE
COMING DAYS.

NO SIGNIFICANT CHANGES WERE MADE TO THE TEMPERATURES...WHICH
GENERALLY REMAIN IN THE UPPER 70S TO MID 80S RANGE.

&&

.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1252 AM CDT THU MAY 23 2013

AS WAS THE CASE 24 HOURS AGO...CEILING TRENDS VARYING BETWEEN MVFR
AND VFR CONTINUE TO BE THE BIGGEST...TRICKY CHALLENGE...ESPECIALLY
THROUGH THE FIRST 12 HOURS OF THE PERIOD. HOWEVER...CONFIDENCE
REMAINS RATHER HIGH IN VFR VISIBILITY...AND ALSO THAT IT SHOULD
REMAIN RAIN-FREE THROUGH THE PERIOD. GETTING BACK TO CEILINGS...A
FAIRLY SOLID DECK OF STRATUS RANGING ANYWHERE FROM 1500 TO AROUND
3000 FT CONTINUES SINKING SOUTHWARD ACROSS SOUTHERN NEBRASKA.
ALTHOUGH KGRI COULD VERY WELL BOUNCE BACK AND FORTH BETWEEN VFR
AND MVFR THROUGH MUCH OF THE NIGHT...WILL AIM FOR PREVAILING MVFR
FOR SEVERAL HOURS AND LIKELY LASTING THROUGH SOMETIME AROUND MID-
DAY BEFORE LOW STRATUS IS EXPECTED TO EITHER START SCATTERING OUT
AND/OR LIFTING INTO LOW-END VFR LEVELS...AND REMAINING THAT WAY
THROUGH THE END OF THE PERIOD. AS FOR SURFACE WINDS...A FAIRLY
LIGHT NORTHERLY BREEZE WILL PREVAIL EARLY THIS MORNING...BEFORE
STEADILY TURNING MORE EASTERLY BY MID-DAY WITH GUST POTENTIAL TO
AT LEAST 18KT FOR MUCH OF THE AFTERNOON. WINDS WILL REMAIN
EASTERLY THURSDAY EVENING SUSTAINED ROUGHLY 10KT.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...HEINLEIN
SHORT TERM...BRYANT
LONG TERM...ADO
AVIATION...PFANNKUCH

000
FXUS63 KLBF 230534
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1234 AM CDT THU MAY 23 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM CDT WED MAY 22 2013

LOW PRESSURE WAS CENTERED OVER SOUTHWEST WISCONSIN AT MID AFTERNOON
WEDNESDAY...WITH HIGH PRESSURE BUILDING INTO THE PLAINS. 850MB
TEMPERATURES AS OBSERVED FROM 22.12Z SOUNDINGS WERE FROM 3-6C ACROSS
THE NORTHERN PLAINS. LOOKING UPSTREAM...RIDGING ALOFT WAS SEEN ON
WATER VAPOR AS A STRONG UPPER LOW HAS MOVED INTO THE PACIFIC
NORTHWEST.

BACKDOOR COLD FRONT MOVES THROUGH THE FORECAST AREA THIS EVENING AS
HIGH PRESSURE IS CENTRALIZED OVER THE NORTHERN PLAINS. FOR
TONIGHT...WITH RETURN FLOW INTO THE WESTERN PART OF THE FORECAST
AREA...COULD SEE MOISTURE ADVECTING IN...AS WELL AS MOISTURE POOLING
AROUND THE FRONT FOR FURTHER DEVELOPMENT OF STRATUS. SO BELIEVE
CLOUDS WILL AGAIN BE ON THE INCREASE ACROSS THE ENTIRE FORECAST
AREA. THIS WILL KEEP TEMPERATURES FROM DROPPING OFF TOO FAR
OVERNIGHT...AND WILL KEEP LOWS IN THE MID 40S...DESPITE SUGGESTIONS
FROM MODEL GUIDANCE TO HAVE LOWS IN THE UPPER 30S AND LOW 40S /WHICH
WOULD BE POSSIBLE IF SKIES CLEAR RATHER THAN STAY CLOUDY DUE TO THE
COOLER THAN NORMAL AIRMASS IN PLACE.

WILL GET RETURN FLOW BEGINNING ON THURSDAY...WITH THE UPPER LEVEL
RIDGE BUILDING IN AT THE MID LEVELS. BUT TEMPERATURES AT 850-700MB
DON/T REALLY START TO WARM UNTIL AFTER 24.00Z SO EXPECTING ANOTHER
COOL DAY ON THURSDAY...EVEN THOUGH SHOULD GET AT LEAST PARTIAL
SUNSHINE ACROSS MUCH OF NEBRASKA. ONGOING FORECAST HAD MID TO UPPER
60S FOR HIGHS AND THIS STILL LOOKS REASONABLE SO ONLY MINOR
ADJUSTMENTS MADE FOR TEMPERATURES.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED MAY 22 2013

THE END OF THE WEEK IS DOMINATED BY TWO UPPER LEVEL LOW PRESSURE
SYSTEMS FIRMLY IN PLACE ALONG THE EASTERN AND WESTERN COASTS...WITH
AN AMPLIFIED RIDGE AXIS RIGHT UP THE PLAINS REGION. THE RIDGE AXIS
WILL SLOWLY SHIFT EAST...PUTTING WESTERN NEBRASKA IN SOUTHWEST FLOW
ALOFT AND A RATHER UNSETTLED WEATHER PATTERN. MODELS ARE IN GOOD
AGREEMENT ON A SHORTWAVE TROUGH EMBEDDED IN THE SOUTHWEST FLOW
MOVING OVER THE CENTRAL PLAINS THURSDAY NIGHT. AN INVERTED LEE SIDE
TROUGH WILL ALLOW FOR SOUTHERLY FLOW TO ADVECT MOISTURE BACK INTO
THE AREA. THIS COMBINATION SHOULD ALLOW FOR A CHANCE OF SHOWERS AND
MAYBE A FEW THUNDERSTORMS THURSDAY NIGHT...MAINLY ALONG THE NOSE OF
THE 20 TO 30 KT LLJ WHICH WILL VEER OFF INTO CENTRAL NE BY THE
MORNING HOURS.

STORM CHANCES WILL CONTINUE FRIDAY INTO FRIDAY NIGHT. STORMS MAY
INITIATE FRIDAY EVENING ACROSS THE EASTERN PANHANDLE AND WESTERN
SANDHILLS AND THEN MOVE NORTHEAST. A FEW STRONG TO SEVERE STORMS
WILL BE POSSIBLE AS SFC CAPE BUILDS TO AOA 1000 J/KG BENEATH 30 KTS
OF DEEP LAYER SHEAR. ONE LIMITING FACTOR WILL BE A STOUT CAP IN
PLACE WHICH COULD KEEP ACTIVITY ISOLATED UNTIL THE LLJ CRANKS UP
OVERNIGHT.

THE SEVERE WEATHER POTENTIAL FOR SATURDAY WILL HAVE TO BE CLOSELY
MONITORED AS MODELS ARE INDICATING A SETUP FAVORABLE FOR MORE ROBUST
SEVERE STORMS...ALTHOUGH A FEW DIFFERENCES IN THE MODELS SUCH AS THE
POSITION OF THE WARM FRONT WILL NEED TO BE IRONED OUT. MODEST
LOW-LEVEL/DEEP LAYER SHEAR PROFILES AND SFC CAPE ON THE ORDER OF
2000-3000 J/KG WILL BE WELL ESTABLISHED OVER WESTERN NE BY THE EARLY
EVENING HOURS. SFC WINDS WILL BACK SOUTHEAST AS ANOTHER SHORTWAVE
TROUGH WILL DEEPEN A SFC LOW OVER NORTHEAST COLORADO. STORMS WOULD
LIKELY CONGEAL INTO A LINEAR SYSTEM AND MOVE EAST SATURDAY NIGHT AS
LLJ STRENGTHENS TO 40+ KTS AND VEERS OFF TO THE EAST.

STORM CHANCES CONTINUE THROUGH THE EXTENDED PERIOD AS THE HIGH
PLAINS REMAINS IN A SOUTHWEST FLOW PATTERN. WEST COAST LOW WILL
CONTINUE TO EJECT SHORTWAVES OVER THE AREA AS THE RIDGE AXIS
CONTINUES TO SHIFT EAST AND THE FLOW BECOMES LESS AMPLIFIED. MODELS
ARE HAVING DIFFICULTIES RESOLVING THE TIMING OF THESE SHORTWAVES SO
HAVE LEFT POP GRIDS WITH MOSTLY SLIGHT TO LOW END POPS FOR NOW.
HIGH TEMPERATURES LOOK TO REMAIN STEADY IN THE UPPER 70S/LOW 80S
THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1231 AM CDT THU MAY 23 2013

NORTHEASTERLY WINDS WILL TRANSITION EAST OVER THE NEXT 24 HOURS
PUSHING LOW CLOUDINESS INTO WESTERN AND SOUTHWESTERN NEBRASKA
OVERNIGHT TONIGHT. ACROSS SOUTHWESTERN NEBRASKA...INCLUDING THE
KLBF TERMINAL...CIGS WILL RANGE FROM 1500 TO 2500 FT AGL THROUGH
EARLY AFTERNOON ON THURSDAY. CIGS WILL INCREASE TO 3000 TO 5000 FT
AGL LATE THURSDAY AFTERNOON AND THURSDAY EVENING. FOR NORTHERN
NEBRASKA...INCLUDING THE KVTN TERMINAL...CIGS OF 1000 TO 3000 FT
AGL WILL PERSIST THROUGH LATE MORNING THURSDAY. BY EARLY
AFTERNOON...EXPECT ONLY HIGH CLOUD CEILINGS.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...BROOKS
LONG TERM...MARTIN
AVIATION...SPRINGER

000
FXUS63 KOAX 230441
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1141 PM CDT WED MAY 22 2013

.AVIATION...06Z TAFS FOR KOMA...KOFK AND KLNK.

MVFR CIGS WITH INTERMITTENT IFR ARE EXPECTED OVERNIGHT. SHORTLY
AFTER SUNRISE...CLOUDS SHOULD SCATTER OUT AND BECOME VFR OVER ALL
3 TAF SITES FOR THE REMAINDER OF THE FORECAST CYCLE AS AN AREA OF
HIGH PRESSURE BUILDS INTO THE REGION. NORTHWEST SURFACE WINDS
INITIALLY WILL BECOME NORTHEAST BY MORNING AND EVENTUALLY
SOUTHEAST BY LATE AFTERNOON INTO EARLY EVENING.

&&

.PREV DISCUSSION... /ISSUED 426 PM CDT WED MAY 22 2013/

DISCUSSION...

CYCLONIC LOW LEVEL FLOW AROUND LOW PRESSURE OVER SRN WI WILL
CONTINUE TO PROVIDE A GOOD DEAL OF CLOUDS FOR THE FA OVERNIGHT
ALONG WITH SEASONABLY COOL TEMPERATURES. AS AN UPPER LEVEL RIDGE
OF HIGH PRESSURE /CURRENTLY OVER THE HIGH PLAINS/ SHIFTS EWD ON
THURSDAY WE SHOULD SEE INCREASING AMOUNTS OF SUN AND MUCH WARMER
TEMPERATURES THAN SEEN TODAY. THE BREAK FROM ACTIVE WEATHER WILL
BE SHORT-LIVED HOWEVER AS A MEAN WESTERN US TROUGH STARTS TO
DEVELOP WITH SOUTHWEST FLOW ACROSS THE CENTRAL PLAINS. MOISTURE
WILL START TO RETURN TO THE AREA AS EARLY AS FRIDAY LEADING TO
PERIODIC CHANCES OF SHOWERS AND THUNDERSTORMS OVER THE WEEKEND AND
INTO EARLY NEXT WEEK. THE MOST LIKELY TIME PERIODS FOR SHOWERS AND
STORMS WILL BE IN THE OVERNIGHT HOURS ASSOCIATED WITH THE
NOCTURNAL LOW LEVEL JET BUT WILL LINGER SOME POPS INTO THE DAYTIME
HOURS FOR LEFT OVER CONVECTION. SEVERE THREAT IS A BIT DIFFICULT
TO PIN DOWN WITH MULTIPLE PERIODS OF SHOWERS AND THUNDERSTORMS AND
SOME DIFFERENCES IN THE GLOBAL MODELS STARTING AS EARLY AS
SAT...BUT IT IS LATE MAY AND THERE APPEARS TO BE SOME MOISTURE AND
INSTABILITY SO ISO SEVERE CANNOT BE RULED OUT. TEMPERATURES WILL
ALSO WARM BACK TO SEASONABLE HIGHS/LOWS FOR THE EXTENDED WITH THE
CONTINUED SOUTHERLY LOW LEVEL FLOW.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

000
FXUS63 KGID 230006
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
706 PM CDT WED MAY 22 2013

.UPDATE...
ISSUED AT 703 PM CDT WED MAY 22 2013

MADE MINOR ADJUSTMENTS TO THE HOURLY FORECAST FOR THIS EVENING.
FORECAST IS PRETTY MUCH ON TRACK.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 351 PM CDT WED MAY 22 2013

MORNING UPPER AIR ANALYSIS INDICATES A MID LEVEL LOW BETWEEN THE
NORTHERN MISSOURI RIVER VALLEY AND THE UPPER MISSISSIPPI
VALLEY...WITH SUBTLE MID TO UPPER LEVEL RIDGING OVER THE ROCKY
MOUNTAIN RANGE...AND A MID TO UPPER LEVEL LOW OVER THE
NORTHWESTERN CONUS. MID TO UPPER LEVEL JET ENERGY EXTENDS FROM THE
WEST-CENTRAL CONUS...EAST/SOUTHEAST ACROSS THE SOUTHERN CONUS AND
THEN NORTH/NORTHEAST INTO THE GREAT LAKES REGION AND SOUTHEASTERN
CANADA. MID AND UPPER LEVEL FLOW IS FAIRLY WEAK OVER OUR AREA AS A
RESULT...MAXING OUT AT BETWEEN 30 AND 40KTS NEAR 400MB...PER 12Z
SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY ALSO SHOWS
THE MID LEVEL LOW BETWEEN THE NORTHERN MISSOURI RIVER VALLEY AND
UPPER MISSISSIPPI VALLEY...AND THE MID LEVEL LOW OVER THE
NORTHWESTERN CONUS. INCREASED MID LEVEL MOISTURE IS ALSO NOTED
EXTENDING FROM THE SOUTHERN/SOUTHEASTERN CONUS...NORTHWARD INTO
THE OHIO RIVER VALLEY AND GREAT LAKES REGION. MID LEVEL MOISTURE
OVER THE CENTRAL PLAINS HOWEVER IS FAIRLY LACKING. AT THE SURFACE
A RIDGE OF HIGH BAROMETRIC PRESSURE EXISTS ACROSS PORTIONS OF THE
NORTHERN AND CENTRAL HIGH PLAINS...AND AN AREA OF LOW BAROMETRIC
PRESSURE IS NOTED ACROSS PORTIONS OF THE UPPER MISSISSIPPI VALLEY.
THE LOW LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE
NORTHWEST AS A RESULT.

GUIDANCE SUGGESTS THE MID LEVEL LOW...CURRENTLY TO OUR EAST...WILL
CONTINUING MOVING EAST TONIGHT INTO TOMORROW. THE SUBTLE MID TO
UPPER LEVEL RIDGE...CURRENTLY OVER PORTIONS OF THE ROCKIES...IS
EXPECTED TO OVERTAKE OUR AREA AND THE RESULTANT LACK IN KINEMATIC
FORCING SHOULD PROVIDE DRY CONDITIONS...AND NOTHING IN THE WAY OF
HIGH-IMPACT WEATHER...TO OUR AREA THROUGH THE NEXT 24 HOURS.

LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS SIMILAR HIGH AND
LOW TEMPERATURES WILL BE OBSERVED ACROSS OUR AREA TOMORROW WHEN
COMPARED TO TODAY. AN OVERNIGHT LOW IN THE 40S IS FORECAST FOR
MOST LOCATIONS TONIGHT...WITH A HIGH IN MID 60S TO LOW 70S ON
THURSDAY...AS A RESULT.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM CDT WED MAY 22 2013

THIS IS MESSY AND LOWER CONFIDENCE LONG TERM FORECAST PERIOD. ARE
GOING TO BE SEEING PERIODIC THUNDERSTORM CHANCES ACROSS THE
CWA...THE BIG QUESTION LIES WITH THE TIMING...ESPECIALLY THE
FURTHER OUT IN TIME YOU GO.

LOOKING AT THE UPPER LEVEL PATTERN AT THE START OF THE
PERIOD...MODELS ARE IN PRETTY GOOD AGREEMENT. THE PLAINS ARE UNDER
THE INFLUENCE OF AN RIDGE AXIS EXTENDING WELL INTO
CANADA...BASICALLY SANDWICHED BETWEEN A TROUGH OVER THE ERN THIRD
OF THE CONUS...AND A LOW PRESSURE SYSTEM PARKED OVER THE PAC NW.
THROUGH THE REST OF THE FORECAST PERIOD...THE BASIC IDEA REMAINS
THE SAME...WITH SOME VARIATION OF THAT RIDGING REMAINS IN PLACE
OVER THE AREA...DEPENDING ON THE MODEL. WITH LOW
PRESSURE/TROUGHING ANCHORED OVER THE WRN CONUS...WILL SEE PERIODIC
WAVES OF ENERGY EJECTED OUT THROUGH THE ROCKIES AND ONTO THE
PLAINS. THE FIRST OF THESE WAVES LOOKS TO AFFECT THE REGION LATE
THURSDAY NIGHT AND INTO FRIDAY...WITH ADDITIONAL PRECIPITATION
CHANCES COMING BASICALLY EACH DAY AFTER THAT AS ADDITIONAL WAVES
MOVE THROUGH.

AT THE SURFACE...MODELS SHOWING THAT OVERALL...THE CWA GENERALLY
REMAINS BETWEEN HIGH PRESSURE EXTENDING THROUGH THE GREAT
LAKES/MIDWEST DOWN TO THE GULF...AND VARYING STRENGTHENS OF LOW
PRESSURE OVER THE FRONT RANGE/HIGH PLAINS. ON FRIDAY /ESP EARLY IN
THE DAY/...DRIER AIR ASSOCIATED WITH THE AREA OF HIGH PRESSURE
OVER THE MN/WI AREA WILL KEEP DEWPOINTS DOWN A BIT...BUT ONCE THAT
HIGH SLIDES EAST AND THE PRESSURE GRADIENT TIGHTENS UP AS THE LOW
DEEPENS TO THE WEST AND THE SOUTHERLY FLOW PICKS UP...MODELS IN
GOOD AGREEMENT SHOWING INCREASED DEWPOINTS FOR THE REST OF THE
PERIOD. ALONG WITH THE DEWPOINTS WILL BE INCREASING AMOUNTS OF
INSTABILITY...MORE FOR SATURDAY AND BEYOND THAN FRIDAY. SO HAS
BEEN MENTIONED PREVIOUSLY...STRONG/SEVERE THUNDERSTORMS WILL
REMAIN CONCERN...ESPECIALLY SO IF WE CAN GET A SURFACE BOUNDARY TO
SET UP IN/NEAR THE CWA. ONE THING MODELS DO SHOW IS THAT OVERALL
DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE...BUT ISNT ON THE
EXTREMELY LOW SIDE EITHER. PLENTY OF DETAILS TO IRON OUT OVER THE
COMING DAYS.

NO SIGNIFICANT CHANGES WERE MADE TO THE TEMPERATURES...WHICH
GENERALLY REMAIN IN THE UPPER 70S TO MID 80S RANGE.

&&

.AVIATION...(FOR THE 00Z KGRI TAF THROUGH 00Z THURSDAY EVENING)
ISSUED AT 703 PM CDT WED MAY 22 2013

THIS WILL BE A TRICKY CEILING FORECAST AS SOME CEILINGS UPSTREAM
ARE IN THE MVFR RANGE. DIFFICULT TO TELL HOW LONG THIS WILL LAST
BEFORE THE CEILINGS MOVE OFF TO THE EAST...SO CONFIDENCE IS NOT
THE HIGHEST.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...HEINLEIN
SHORT TERM...BRYANT
LONG TERM...ADO
AVIATION...HEINLEIN

000
FXUS63 KLBF 222344
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
644 PM CDT WED MAY 22 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM CDT WED MAY 22 2013

LOW PRESSURE WAS CENTERED OVER SOUTHWEST WISCONSIN AT MID AFTERNOON
WEDNESDAY...WITH HIGH PRESSURE BUILDING INTO THE PLAINS. 850MB
TEMPERATURES AS OBSERVED FROM 22.12Z SOUNDINGS WERE FROM 3-6C ACROSS
THE NORTHERN PLAINS. LOOKING UPSTREAM...RIDGING ALOFT WAS SEEN ON
WATER VAPOR AS A STRONG UPPER LOW HAS MOVED INTO THE PACIFIC
NORTHWEST.

BACKDOOR COLD FRONT MOVES THROUGH THE FORECAST AREA THIS EVENING AS
HIGH PRESSURE IS CENTRALIZED OVER THE NORTHERN PLAINS. FOR
TONIGHT...WITH RETURN FLOW INTO THE WESTERN PART OF THE FORECAST
AREA...COULD SEE MOISTURE ADVECTING IN...AS WELL AS MOISTURE POOLING
AROUND THE FRONT FOR FURTHER DEVELOPMENT OF STRATUS. SO BELIEVE
CLOUDS WILL AGAIN BE ON THE INCREASE ACROSS THE ENTIRE FORECAST
AREA. THIS WILL KEEP TEMPERATURES FROM DROPPING OFF TOO FAR
OVERNIGHT...AND WILL KEEP LOWS IN THE MID 40S...DESPITE SUGGESTIONS
FROM MODEL GUIDANCE TO HAVE LOWS IN THE UPPER 30S AND LOW 40S /WHICH
WOULD BE POSSIBLE IF SKIES CLEAR RATHER THAN STAY CLOUDY DUE TO THE
COOLER THAN NORMAL AIRMASS IN PLACE.

WILL GET RETURN FLOW BEGINNING ON THURSDAY...WITH THE UPPER LEVEL
RIDGE BUILDING IN AT THE MID LEVELS. BUT TEMPERATURES AT 850-700MB
DON/T REALLY START TO WARM UNTIL AFTER 24.00Z SO EXPECTING ANOTHER
COOL DAY ON THURSDAY...EVEN THOUGH SHOULD GET AT LEAST PARTIAL
SUNSHINE ACROSS MUCH OF NEBRASKA. ONGOING FORECAST HAD MID TO UPPER
60S FOR HIGHS AND THIS STILL LOOKS REASONABLE SO ONLY MINOR
ADJUSTMENTS MADE FOR TEMPERATURES.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED MAY 22 2013

THE END OF THE WEEK IS DOMINATED BY TWO UPPER LEVEL LOW PRESSURE
SYSTEMS FIRMLY IN PLACE ALONG THE EASTERN AND WESTERN COASTS...WITH
AN AMPLIFIED RIDGE AXIS RIGHT UP THE PLAINS REGION. THE RIDGE AXIS
WILL SLOWLY SHIFT EAST...PUTTING WESTERN NEBRASKA IN SOUTHWEST FLOW
ALOFT AND A RATHER UNSETTLED WEATHER PATTERN. MODELS ARE IN GOOD
AGREEMENT ON A SHORTWAVE TROUGH EMBEDDED IN THE SOUTHWEST FLOW
MOVING OVER THE CENTRAL PLAINS THURSDAY NIGHT. AN INVERTED LEE SIDE
TROUGH WILL ALLOW FOR SOUTHERLY FLOW TO ADVECT MOISTURE BACK INTO
THE AREA. THIS COMBINATION SHOULD ALLOW FOR A CHANCE OF SHOWERS AND
MAYBE A FEW THUNDERSTORMS THURSDAY NIGHT...MAINLY ALONG THE NOSE OF
THE 20 TO 30 KT LLJ WHICH WILL VEER OFF INTO CENTRAL NE BY THE
MORNING HOURS.

STORM CHANCES WILL CONTINUE FRIDAY INTO FRIDAY NIGHT. STORMS MAY
INITIATE FRIDAY EVENING ACROSS THE EASTERN PANHANDLE AND WESTERN
SANDHILLS AND THEN MOVE NORTHEAST. A FEW STRONG TO SEVERE STORMS
WILL BE POSSIBLE AS SFC CAPE BUILDS TO AOA 1000 J/KG BENEATH 30 KTS
OF DEEP LAYER SHEAR. ONE LIMITING FACTOR WILL BE A STOUT CAP IN
PLACE WHICH COULD KEEP ACTIVITY ISOLATED UNTIL THE LLJ CRANKS UP
OVERNIGHT.

THE SEVERE WEATHER POTENTIAL FOR SATURDAY WILL HAVE TO BE CLOSELY
MONITORED AS MODELS ARE INDICATING A SETUP FAVORABLE FOR MORE ROBUST
SEVERE STORMS...ALTHOUGH A FEW DIFFERENCES IN THE MODELS SUCH AS THE
POSITION OF THE WARM FRONT WILL NEED TO BE IRONED OUT. MODEST
LOW-LEVEL/DEEP LAYER SHEAR PROFILES AND SFC CAPE ON THE ORDER OF
2000-3000 J/KG WILL BE WELL ESTABLISHED OVER WESTERN NE BY THE EARLY
EVENING HOURS. SFC WINDS WILL BACK SOUTHEAST AS ANOTHER SHORTWAVE
TROUGH WILL DEEPEN A SFC LOW OVER NORTHEAST COLORADO. STORMS WOULD
LIKELY CONGEAL INTO A LINEAR SYSTEM AND MOVE EAST SATURDAY NIGHT AS
LLJ STRENGTHENS TO 40+ KTS AND VEERS OFF TO THE EAST.

STORM CHANCES CONTINUE THROUGH THE EXTENDED PERIOD AS THE HIGH
PLAINS REMAINS IN A SOUTHWEST FLOW PATTERN. WEST COAST LOW WILL
CONTINUE TO EJECT SHORTWAVES OVER THE AREA AS THE RIDGE AXIS
CONTINUES TO SHIFT EAST AND THE FLOW BECOMES LESS AMPLIFIED. MODELS
ARE HAVING DIFFICULTIES RESOLVING THE TIMING OF THESE SHORTWAVES SO
HAVE LEFT POP GRIDS WITH MOSTLY SLIGHT TO LOW END POPS FOR NOW.
HIGH TEMPERATURES LOOK TO REMAIN STEADY IN THE UPPER 70S/LOW 80S
THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 644 PM CDT WED MAY 22 2013

NORTHEASTERLY WINDS WILL TRANSITION EAST OVER THE NEXT
24 HOURS PUSHING LOW CLOUDINESS INTO WESTERN AND SOUTHWESTERN
NEBRASKA OVERNIGHT TONIGHT. FOR THE KLBF TERMINAL...CIGS WILL DROP
TO AROUND 1500 FT AGL OVERNIGHT...LIFTING TO 3000 FT BY LATE
THURSDAY MORNING. BROKEN CIGS AON 5000 FT AGL ARE EXPECTED BY LATE
AFTERNOON. FOR THE KVTN TERMINAL...OVERCAST CIGS AON 1500 FT AGL ARE
LIKELY OVERNIGHT WITH CIGS LIFTING TO 3000 FT AGL BY MID MORNING.
SKIES WILL SCATTER OUT THURSDAY AFTERNOON WITH SCATTERED CLOUDS AON
25000 FT EXPECTED.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...BROOKS
LONG TERM...MARTIN
AVIATION...CLB

000
FXUS63 KOAX 222312
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
612 PM CDT WED MAY 22 2013

.AVIATION...00Z TAFS FOR KOFK...KOMA AND KLNK.

VFR TO MVFR CONDITIONS ARE EXPECTED INITIALLY...BUT CONDITIONS
SHOULD DROP TO MVFR TO IFR OVERNIGHT. SPOTTY DRIZZLE IS POSSIBLE
AND WAS ONGOING AT KOFK AT TAF ISSUANCE SO INCLUDED A TEMPO GROUP.
CLOUDS ARE EXPECTED TO FINALLY SCATTER OUT THURSDAY MORNING AS
HIGH PRESSURE BUILDS INTO THE CENTRAL PLAINS.

KERN

&&

.PREV DISCUSSION... /ISSUED 426 PM CDT WED MAY 22 2013/

DISCUSSION...

CYCLONIC LOW LEVEL FLOW AROUND LOW PRESSURE OVER SRN WI WILL
CONTINUE TO PROVIDE A GOOD DEAL OF CLOUDS FOR THE FA OVERNIGHT
ALONG WITH SEASONABLY COOL TEMPERATURES. AS AN UPPER LEVEL RIDGE
OF HIGH PRESSURE /CURRENTLY OVER THE HIGH PLAINS/ SHIFTS EWD ON
THURSDAY WE SHOULD SEE INCREASING AMOUNTS OF SUN AND MUCH WARMER
TEMPERATURES THAN SEEN TODAY. THE BREAK FROM ACTIVE WEATHER WILL
BE SHORT-LIVED HOWEVER AS A MEAN WESTERN US TROUGH STARTS TO
DEVELOP WITH SOUTHWEST FLOW ACROSS THE CENTRAL PLAINS. MOISTURE
WILL START TO RETURN TO THE AREA AS EARLY AS FRIDAY LEADING TO
PERIODIC CHANCES OF SHOWERS AND THUNDERSTORMS OVER THE WEEKEND AND
INTO EARLY NEXT WEEK. THE MOST LIKELY TIME PERIODS FOR SHOWERS AND
STORMS WILL BE IN THE OVERNIGHT HOURS ASSOCIATED WITH THE
NOCTURNAL LOW LEVEL JET BUT WILL LINGER SOME POPS INTO THE DAYTIME
HOURS FOR LEFT OVER CONVECTION. SEVERE THREAT IS A BIT DIFFICULT
TO PIN DOWN WITH MULTIPLE PERIODS OF SHOWERS AND THUNDERSTORMS AND
SOME DIFFERENCES IN THE GLOBAL MODELS STARTING AS EARLY AS
SAT...BUT IT IS LATE MAY AND THERE APPEARS TO BE SOME MOISTURE AND
INSTABILITY SO ISO SEVERE CANNOT BE RULED OUT. TEMPERATURES WILL
ALSO WARM BACK TO SEASONABLE HIGHS/LOWS FOR THE EXTENDED WITH THE
CONTINUED SOUTHERLY LOW LEVEL FLOW.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

000
FXUS63 KOAX 222126
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
426 PM CDT WED MAY 22 2013

.DISCUSSION...

CYCLONIC LOW LEVEL FLOW AROUND LOW PRESSURE OVER SRN WI WILL
CONTINUE TO PROVIDE A GOOD DEAL OF CLOUDS FOR THE FA OVERNIGHT
ALONG WITH SEASONABLY COOL TEMPERATURES. AS AN UPPER LEVEL RIDGE
OF HIGH PRESSURE /CURRENTLY OVER THE HIGH PLAINS/ SHIFTS EWD ON
THURSDAY WE SHOULD SEE INCREASING AMOUNTS OF SUN AND MUCH WARMER
TEMPERATURES THAN SEEN TODAY. THE BREAK FROM ACTIVE WEATHER WILL
BE SHORT-LIVED HOWEVER AS A MEAN WESTERN US TROUGH STARTS TO
DEVELOP WITH SOUTHWEST FLOW ACROSS THE CENTRAL PLAINS. MOISTURE
WILL START TO RETURN TO THE AREA AS EARLY AS FRIDAY LEADING TO
PERIODIC CHANCES OF SHOWERS AND THUNDERSTORMS OVER THE WEEKEND AND
INTO EARLY NEXT WEEK. THE MOST LIKELY TIME PERIODS FOR SHOWERS AND
STORMS WILL BE IN THE OVERNIGHT HOURS ASSOCIATED WITH THE
NOCTURNAL LOW LEVEL JET BUT WILL LINGER SOME POPS INTO THE DAYTIME
HOURS FOR LEFT OVER CONVECTION. SEVERE THREAT IS A BIT DIFFICULT
TO PIN DOWN WITH MULTIPLE PERIODS OF SHOWERS AND THUNDERSTORMS AND
SOME DIFFERENCES IN THE GLOBAL MODELS STARTING AS EARLY AS
SAT...BUT IT IS LATE MAY AND THERE APPEARS TO BE SOME MOISTURE AND
INSTABILITY SO ISO SEVERE CANNOT BE RULED OUT. TEMPERATURES WILL
ALSO WARM BACK TO SEASONABLE HIGHS/LOWS FOR THE EXTENDED WITH THE
CONTINUED SOUTHERLY LOW LEVEL FLOW.

&&

.AVIATION...
18Z TAFS FOR KOMA...KLNK...KOFK.

AREA EXPECTED TO REMAIN UNDER THE INFLUENCE OF CLOSED UPPER LOW
OVER NORTH CENTRAL IOWA THROUGH 06Z AS IT TRACKS SLOWLY SOUTHEAST
TOWARD THE OHIO VALLEY. MVFR CIGS ARE EXPECTED TO IMPROVE TO VFR
DURING THE 18Z-00Z PERIOD THEN RETURN TO MVFR AFTER 02Z AS WINDS
DIMINISH AND LOW LEVEL MOISTURE LINGERS THROUGH MUCH OF THE NIGHT.
DRIER AIR AND VFR CONDITIONS RETURN TO THE AREA AFTER 12Z AS
UPPER SYSTEM MOVES OFF AND HIGH PRESSURE BUILDS INTO THE UPPER
MIDWEST.

FOBERT

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.

&&

$$

000
FXUS63 KGID 222051
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
351 PM CDT WED MAY 22 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 351 PM CDT WED MAY 22 2013

MORNING UPPER AIR ANALYSIS INDICATES A MID LEVEL LOW BETWEEN THE
NORTHERN MISSOURI RIVER VALLEY AND THE UPPER MISSISSIPPI
VALLEY...WITH SUBTLE MID TO UPPER LEVEL RIDGING OVER THE ROCKY
MOUNTAIN RANGE...AND A MID TO UPPER LEVEL LOW OVER THE
NORTHWESTERN CONUS. MID TO UPPER LEVEL JET ENERGY EXTENDS FROM THE
WEST-CENTRAL CONUS...EAST/SOUTHEAST ACROSS THE SOUTHERN CONUS AND
THEN NORTH/NORTHEAST INTO THE GREAT LAKES REGION AND SOUTHEASTERN
CANADA. MID AND UPPER LEVEL FLOW IS FAIRLY WEAK OVER OUR AREA AS A
RESULT...MAXING OUT AT BETWEEN 30 AND 40KTS NEAR 400MB...PER 12Z
SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY ALSO SHOWS
THE MID LEVEL LOW BETWEEN THE NORTHERN MISSOURI RIVER VALLEY AND
UPPER MISSISSIPPI VALLEY...AND THE MID LEVEL LOW OVER THE
NORTHWESTERN CONUS. INCREASED MID LEVEL MOISTURE IS ALSO NOTED
EXTENDING FROM THE SOUTHERN/SOUTHEASTERN CONUS...NORTHWARD INTO
THE OHIO RIVER VALLEY AND GREAT LAKES REGION. MID LEVEL MOISTURE
OVER THE CENTRAL PLAINS HOWEVER IS FAIRLY LACKING. AT THE SURFACE
A RIDGE OF HIGH BAROMETRIC PRESSURE EXISTS ACROSS PORTIONS OF THE
NORTHERN AND CENTRAL HIGH PLAINS...AND AN AREA OF LOW BAROMETRIC
PRESSURE IS NOTED ACROSS PORTIONS OF THE UPPER MISSISSIPPI VALLEY.
THE LOW LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE
NORTHWEST AS A RESULT.

GUIDANCE SUGGESTS THE MID LEVEL LOW...CURRENTLY TO OUR EAST...WILL
CONTINUING MOVING EAST TONIGHT INTO TOMORROW. THE SUBTLE MID TO
UPPER LEVEL RIDGE...CURRENTLY OVER PORTIONS OF THE ROCKIES...IS
EXPECTED TO OVERTAKE OUR AREA AND THE RESULTANT LACK IN KINEMATIC
FORCING SHOULD PROVIDE DRY CONDITIONS...AND NOTHING IN THE WAY OF
HIGH-IMPACT WEATHER...TO OUR AREA THROUGH THE NEXT 24 HOURS.

LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS SIMILAR HIGH AND
LOW TEMPERATURES WILL BE OBSERVED ACROSS OUR AREA TOMORROW WHEN
COMPARED TO TODAY. AN OVERNIGHT LOW IN THE 40S IS FORECAST FOR
MOST LOCATIONS TONIGHT...WITH A HIGH IN MID 60S TO LOW 70S ON
THURSDAY...AS A RESULT.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM CDT WED MAY 22 2013

THIS IS MESSY AND LOWER CONFIDENCE LONG TERM FORECAST PERIOD. ARE
GOING TO BE SEEING PERIODIC THUNDERSTORM CHANCES ACROSS THE
CWA...THE BIG QUESTION LIES WITH THE TIMING...ESPECIALLY THE
FURTHER OUT IN TIME YOU GO.

LOOKING AT THE UPPER LEVEL PATTERN AT THE START OF THE
PERIOD...MODELS ARE IN PRETTY GOOD AGREEMENT. THE PLAINS ARE UNDER
THE INFLUENCE OF AN RIDGE AXIS EXTENDING WELL INTO
CANADA...BASICALLY SANDWICHED BETWEEN A TROUGH OVER THE ERN THIRD
OF THE CONUS...AND A LOW PRESSURE SYSTEM PARKED OVER THE PAC NW.
THROUGH THE REST OF THE FORECAST PERIOD...THE BASIC IDEA REMAINS
THE SAME...WITH SOME VARIATION OF THAT RIDGING REMAINS IN PLACE
OVER THE AREA...DEPENDING ON THE MODEL. WITH LOW
PRESSURE/TROUGHING ANCHORED OVER THE WRN CONUS...WILL SEE PERIODIC
WAVES OF ENERGY EJECTED OUT THROUGH THE ROCKIES AND ONTO THE
PLAINS. THE FIRST OF THESE WAVES LOOKS TO AFFECT THE REGION LATE
THURSDAY NIGHT AND INTO FRIDAY...WITH ADDITIONAL PRECIPITATION
CHANCES COMING BASICALLY EACH DAY AFTER THAT AS ADDITIONAL WAVES
MOVE THROUGH.

AT THE SURFACE...MODELS SHOWING THAT OVERALL...THE CWA GENERALLY
REMAINS BETWEEN HIGH PRESSURE EXTENDING THROUGH THE GREAT
LAKES/MIDWEST DOWN TO THE GULF...AND VARYING STRENGTHENS OF LOW
PRESSURE OVER THE FRONT RANGE/HIGH PLAINS. ON FRIDAY /ESP EARLY IN
THE DAY/...DRIER AIR ASSOCIATED WITH THE AREA OF HIGH PRESSURE
OVER THE MN/WI AREA WILL KEEP DEWPOINTS DOWN A BIT...BUT ONCE THAT
HIGH SLIDES EAST AND THE PRESSURE GRADIENT TIGHTENS UP AS THE LOW
DEEPENS TO THE WEST AND THE SOUTHERLY FLOW PICKS UP...MODELS IN
GOOD AGREEMENT SHOWING INCREASED DEWPOINTS FOR THE REST OF THE
PERIOD. ALONG WITH THE DEWPOINTS WILL BE INCREASING AMOUNTS OF
INSTABILITY...MORE FOR SATURDAY AND BEYOND THAN FRIDAY. SO HAS
BEEN MENTIONED PREVIOUSLY...STRONG/SEVERE THUNDERSTORMS WILL
REMAIN CONCERN...ESPECIALLY SO IF WE CAN GET A SURFACE BOUNDARY TO
SET UP IN/NEAR THE CWA. ONE THING MODELS DO SHOW IS THAT OVERALL
DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE...BUT ISNT ON THE
EXTREMELY LOW SIDE EITHER. PLENTY OF DETAILS TO IRON OUT OVER THE
COMING DAYS.

NO SIGNIFICANT CHANGES WERE MADE TO THE TEMPERATURES...WHICH
GENERALLY REMAIN IN THE UPPER 70S TO MID 80S RANGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1248 PM CDT WED MAY 22 2013

MVFR CONDITIONS FORECAST THROUGH 20Z...VFR 20-02Z...THEN MVFR
CONDITIONS 02-15Z.

AS OF MIDDAY A STRATUS DECK...WITH A CEILING NEAR 2000FT
AGL...PERSISTS AT KGRI. THIS CEILING IS EXPECTED TO CONTINUE
THROUGH ANOTHER COUPLE HOURS...BUT IS THEN EXPECTED TO SCATTER OUT
BY MID AFTERNOON...THUS THE VFR FORECAST BEGINNING 20Z. VFR
CONDITIONS ARE THEN FORECAST THROUGH THIS EVENING...HOWEVER
GUIDANCE SUGGESTS AN MVFR DECK WILL ONCE AGAIN INFILTRATE THE AREA
THIS EVENING AND INTO THE OVERNIGHT HOURS. IT IS WORTH NOTING THAT
SOME GUIDANCE SUGGESTS IFR CEILINGS...OR LOWER...WILL BE REALIZED
TONIGHT THROUGH EARLY THURSDAY MORNING...BUT AT THIS TIME
CONFIDENCE IS NOT HIGH ENOUGH TO INSERT SUCH CONDITIONS IN THE
TAF. FUTURE SHIFTS WILL WANT TO CONTINUE MONITORING FOR THE
POSSIBLE INSERTION OF A LOWER CEILING IN FUTURE TAFS. WHAT CEILING
DOES DEVELOP OVERNIGHT TONIGHT SHOULD SCATTER OUT POST- SUNRISE
THURSDAY. THE SURFACE WIND WILL TRANSITION FROM THE NORTHWEST TO
MORE OF A NORTH/NORTHEAST DIRECTION THROUGH THE NEXT 24
HOURS...SUSTAINED AT AROUND 14KTS AND GUSTING NEAR 20KTS THROUGH
THIS EVENING. VISIBILITY RESTRICTION IS NOT CURRENTLY EXPECTED AT
KGRI THROUGH THE NEXT 24 HOURS.


&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...BRYANT
LONG TERM...ADO
AVIATION...BRYANT/BRUM

000
FXUS63 KLBF 222025
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
325 PM CDT WED MAY 22 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM CDT WED MAY 22 2013

LOW PRESSURE WAS CENTERED OVER SOUTHWEST WISCONSIN AT MID AFTERNOON
WEDNESDAY...WITH HIGH PRESSURE BUILDING INTO THE PLAINS. 850MB
TEMPERATURES AS OBSERVED FROM 22.12Z SOUNDINGS WERE FROM 3-6C ACROSS
THE NORTHERN PLAINS. LOOKING UPSTREAM...RIDGING ALOFT WAS SEEN ON
WATER VAPOR AS A STRONG UPPER LOW HAS MOVED INTO THE PACIFIC
NORTHWEST.

BACKDOOR COLD FRONT MOVES THROUGH THE FORECAST AREA THIS EVENING AS
HIGH PRESSURE IS CENTRALIZED OVER THE NORTHERN PLAINS. FOR
TONIGHT...WITH RETURN FLOW INTO THE WESTERN PART OF THE FORECAST
AREA...COULD SEE MOISTURE ADVECTING IN...AS WELL AS MOISTURE POOLING
AROUND THE FRONT FOR FURTHER DEVELOPMENT OF STRATUS. SO BELIEVE
CLOUDS WILL AGAIN BE ON THE INCREASE ACROSS THE ENTIRE FORECAST
AREA. THIS WILL KEEP TEMPERATURES FROM DROPPING OFF TOO FAR
OVERNIGHT...AND WILL KEEP LOWS IN THE MID 40S...DESPITE SUGGESTIONS
FROM MODEL GUIDANCE TO HAVE LOWS IN THE UPPER 30S AND LOW 40S /WHICH
WOULD BE POSSIBLE IF SKIES CLEAR RATHER THAN STAY CLOUDY DUE TO THE
COOLER THAN NORMAL AIRMASS IN PLACE.

WILL GET RETURN FLOW BEGINNING ON THURSDAY...WITH THE UPPER LEVEL
RIDGE BUILDING IN AT THE MID LEVELS. BUT TEMPERATURES AT 850-700MB
DON/T REALLY START TO WARM UNTIL AFTER 24.00Z SO EXPECTING ANOTHER
COOL DAY ON THURSDAY...EVEN THOUGH SHOULD GET AT LEAST PARTIAL
SUNSHINE ACROSS MUCH OF NEBRASKA. ONGOING FORECAST HAD MID TO UPPER
60S FOR HIGHS AND THIS STILL LOOKS REASONABLE SO ONLY MINOR
ADJUSTMENTS MADE FOR TEMPERATURES.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED MAY 22 2013

THE END OF THE WEEK IS DOMINATED BY TWO UPPER LEVEL LOW PRESSURE
SYSTEMS FIRMLY IN PLACE ALONG THE EASTERN AND WESTERN COASTS...WITH
AN AMPLIFIED RIDGE AXIS RIGHT UP THE PLAINS REGION. THE RIDGE AXIS
WILL SLOWLY SHIFT EAST...PUTTING WESTERN NEBRASKA IN SOUTHWEST FLOW
ALOFT AND A RATHER UNSETTLED WEATHER PATTERN. MODELS ARE IN GOOD
AGREEMENT ON A SHORTWAVE TROUGH EMBEDDED IN THE SOUTHWEST FLOW
MOVING OVER THE CENTRAL PLAINS THURSDAY NIGHT. AN INVERTED LEE SIDE
TROUGH WILL ALLOW FOR SOUTHERLY FLOW TO ADVECT MOISTURE BACK INTO
THE AREA. THIS COMBINATION SHOULD ALLOW FOR A CHANCE OF SHOWERS AND
MAYBE A FEW THUNDERSTORMS THURSDAY NIGHT...MAINLY ALONG THE NOSE OF
THE 20 TO 30 KT LLJ WHICH WILL VEER OFF INTO CENTRAL NE BY THE
MORNING HOURS.

STORM CHANCES WILL CONTINUE FRIDAY INTO FRIDAY NIGHT. STORMS MAY
INITIATE FRIDAY EVENING ACROSS THE EASTERN PANHANDLE AND WESTERN
SANDHILLS AND THEN MOVE NORTHEAST. A FEW STRONG TO SEVERE STORMS
WILL BE POSSIBLE AS SFC CAPE BUILDS TO AOA 1000 J/KG BENEATH 30 KTS
OF DEEP LAYER SHEAR. ONE LIMITING FACTOR WILL BE A STOUT CAP IN
PLACE WHICH COULD KEEP ACTIVITY ISOLATED UNTIL THE LLJ CRANKS UP
OVERNIGHT.

THE SEVERE WEATHER POTENTIAL FOR SATURDAY WILL HAVE TO BE CLOSELY
MONITORED AS MODELS ARE INDICATING A SETUP FAVORABLE FOR MORE ROBUST
SEVERE STORMS...ALTHOUGH A FEW DIFFERENCES IN THE MODELS SUCH AS THE
POSITION OF THE WARM FRONT WILL NEED TO BE IRONED OUT. MODEST
LOW-LEVEL/DEEP LAYER SHEAR PROFILES AND SFC CAPE ON THE ORDER OF
2000-3000 J/KG WILL BE WELL ESTABLISHED OVER WESTERN NE BY THE EARLY
EVENING HOURS. SFC WINDS WILL BACK SOUTHEAST AS ANOTHER SHORTWAVE
TROUGH WILL DEEPEN A SFC LOW OVER NORTHEAST COLORADO. STORMS WOULD
LIKELY CONGEAL INTO A LINEAR SYSTEM AND MOVE EAST SATURDAY NIGHT AS
LLJ STRENGTHENS TO 40+ KTS AND VEERS OFF TO THE EAST.

STORM CHANCES CONTINUE THROUGH THE EXTENDED PERIOD AS THE HIGH
PLAINS REMAINS IN A SOUTHWEST FLOW PATTERN. WEST COAST LOW WILL
CONTINUE TO EJECT SHORTWAVES OVER THE AREA AS THE RIDGE AXIS
CONTINUES TO SHIFT EAST AND THE FLOW BECOMES LESS AMPLIFIED. MODELS
ARE HAVING DIFFICULTIES RESOLVING THE TIMING OF THESE SHORTWAVES SO
HAVE LEFT POP GRIDS WITH MOSTLY SLIGHT TO LOW END POPS FOR NOW.
HIGH TEMPERATURES LOOK TO REMAIN STEADY IN THE UPPER 70S/LOW 80S
THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 103 PM CDT WED MAY 22 2013

FORECAST THROUGH THURSDAY IS PLAGUED BY CLOUD COVER WITH PASSAGE
OF BACKDOOR COLD FRONT TONIGHT. SHOULD GET STRATUS IN THE VICINITY
OF THE FRONT...WHICH WOULD OCCUR ACROSS ALL OF WESTERN AND NORTH
CENTRAL NEBRASKA. MODELS WOULD SUGGEST THE STRATUS MOVING OUT OF
NORTH CENTRAL NEBRASKA BY 12Z...BUT WITH INVERSION SET UP...KEPT
THE STRATUS IN THROUGH MID MORNING AT KVTN AND KLBF. WINDS WILL
SWITCH OVER TO THE EAST BY THURSDAY MORNING...AND COULD GET SOME
GUSTS TO 20 MPH BY LATE MORNING. SHOULD THE STRATUS NOT DEVELOP AS
ANTICIPATED...FORECAST WILL IMPROVE GREATLY.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...BROOKS
LONG TERM...MARTIN
AVIATION...BROOKS

000
FXUS63 KOAX 221810
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
110 PM CDT WED MAY 22 2013

.AVIATION...
18Z TAFS FOR KOMA...KLNK...KOFK.

AREA EXPECTED TO REMAIN UNDER THE INFLUENCE OF CLOSED UPPER LOW
OVER NORTH CENTRAL IOWA THROUGH 06Z AS IT TRACKS SLOWLY SOUTHEAST
TOWARD THE OHIO VALLEY. MVFR CIGS ARE EXPECTED TO IMPROVE TO VFR
DURING THE 18Z-00Z PERIOD THEN RETURN TO MVFR AFTER 02Z AS WINDS
DIMINISH AND LOW LEVEL MOISTURE LINGERS THROUGH MUCH OF THE NIGHT.
DRIER AIR AND VFR CONDITIONS RETURN TO THE AREA AFTER 12Z AS
UPPER SYSTEM MOVES OFF AND HIGH PRESSURE BUILDS INTO THE UPPER
MIDWEST.

&&

.PREV DISCUSSION... /ISSUED 328 AM CDT WED MAY 22 2013/

.DISCUSSION...
COOL UPPER-LEVEL LOW CONTINUES TO ROAM ACROSS THE NORTHERN PLAINS.
SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES UPPER LOW CENTERED IN
SOUTHEAST SD...WITH RIDGING OVER THE ROCKIES...AND AN UPPER-LEVEL
LOW COMING ASHORE IN THE PACIFIC NORTHWEST.  115KT UPPER-LEVEL JET
STREAK AHEAD OF THE LOW EXTENDED FROM CENTRAL OK THROUGH EASTERN NEB
TO NORTHEAST WI.  850MB LOW WAS CENTERED IN CENTRAL MN...WITH COLD
FRONT EXTENDING FROM THERE THROUGH CENTRAL IA/WESTERN MO/EASTERN OK.
COLD POCKET OF TEMPS COVERED MUCH OF THE DAKOTAS INTO NEB...WITH
COLDEST 850MB TEMP OF 4C AT KBIS/KRAP. HIGHER 850MB MOISTURE OF
8C+ WAS CONFINED TO AREAS AHEAD OF THE COLD FRONT AND SOUTH OF THE
WARM FRONT...THOUGH TEMPERATURE/DEWPOINT SPREADS WERE AT OR BELOW
A DEGREE FROM EASTERN NEB THROUGH THE DAKOTAS AND MN. NOT
SURPRISINGLY...EXTENSIVE STRATUS DECK COVERS THE AREA AT 07Z...
WITH SPOTTY SPRINKLES OR LIGHT SHOWERS IN EASTERN SD/NORTHEAST
NEB/NORTHWEST IA/SOUTHERN MN.

MAIN FORECAST CONCERNS INCLUDE COOL TEMPERATURES AND SHOWERS
TODAY...THEN A PERIOD OF MILD WEATHER BEFORE ACTIVE PATTERN RETURNS
FOR THE WEEKEND.  LINGERING IMPACTS OF UPPER-LEVEL LOW TODAY INCLUDE
COLD AIR ADVECTION...STRATUS...AND OCCASIONAL SPRINKLES OR LIGHT
SHOWERS...AS THE LOW IS IN NO HURRY TO EXIT THE AREA.  HAVE GONE
MORE PESSIMISTIC WITH SKY COVER ALL THE WAY THROUGH TONIGHT...AS
AREA REMAINS IN SATURATED CYCLONIC FLOW.  ALSO COOLED TEMPS A BIT
FOR TODAY AS TEMPERATURES SHOULD STRUGGLE TO RISE UNDER CLOUDY SKIES
AND COLD AIR ADVECTION.  DO THINK POTENTIAL FOR SHOWERS WILL
DIMINISH THIS AFTERNOON AS LOW BEGINS TO PULL AWAY...BUT IN THE
MEANTIME...HAVE INCLUDED ISOLATED TO SCATTERED SHOWERS ACROSS THE
AREA. SKIES SHOULD CLEAR ON OR AROUND THURSDAY MORNING...BUT
EASTERLY LOW-LEVEL FLOW WILL NOT AID WARMING MUCH...AND HAVE SHAVED
A COUPLE DEGREES OFF THE TEMPERATURE FORECAST FOR THURSDAY.  QUIET
WEATHER WILL CONTINUE INTO THURSDAY NIGHT AS LOW-LEVEL JET FOCUSES
WELL SOUTHWEST OF THE AREA...THOUGH A FEW CLOUDS MAY START TO SNEAK
INTO THE SOUTHWEST CWA.

WARM AIR ADVECTION WILL COMMENCE ON FRIDAY...WITH UPPER-LEVEL RIDGE
BECOMING ESTABLISHED OVER THE CENTRAL PLAINS...AND SOUTHERLY 850MB
WINDS BRINGING WARM/MOIST AIR ADVECTION INTO THE AREA.  SHOULD SEE
SHOWERS DEVELOP DURING THE DAY UNDER WARM AIR ADVECTION AND
ISENTROPIC LIFT...THOUGH DID KEEP THUNDER MENTION OUT OF THE MORNING
WITH ONLY ISOLATED MENTION IN THE AFTERNOON AS SOUNDINGS LOOK RATHER
STABLE AND SREF INDICATES LITTLE OR NO MUCAPE.  BY LATE
EVENING/OVERNIGHT...BETTER INSTABILITY SHOULD BEGIN TO SLIP INTO THE
CWA...WITH SHOWERS LIKELY TO CONTINUE THROUGH FRIDAY NIGHT.

FROM SATURDAY THROUGH WEDNESDAY...FORECAST UNCERTAINTY INCREASES.
UPPER-LEVEL RIDGE WILL SLOWLY FLATTEN THROUGH THE WEEKEND...THEN
SLIDE EASTWARD EARLY IN THE WORK WEEK...ALLOWING SOUTHWESTERLY UPPER-
LEVEL FLOW ACROSS THE CENTRAL US.  THE SPEED OF THIS TRANSITION
VARIES AMONG MODELS AND MODEL RUNS...AND ALSO...THE TIMING OF
TRANSIENT WAVES AROUND THE RIDGING AND THROUGH THE SOUTHWESTERLY
FLOW ALSO VARIES FROM MODEL TO MODEL.  OVERALL...THE PERIOD APPEARS
ACTIVE...BUT DETERMINING WHICH PERIODS WILL BE MORE LIKELY TO SEE
SHOWERS AND THUNDERSTORMS IS A LITTLE HIT OR MISS RIGHT NOW.  THINK
THAT EARLY IN THE PERIOD...DEVELOPMENT MAY FOCUS IN THE HIGH
PLAINS...WITH MORE OF A NOCTURNAL STORM THREAT AS CONVECTION MOVES
OFF THE HIGH PLAINS.  AS THE PATTERN TRANSITIONS...THE DEVELOPMENT
REGION WOULD TRANSITION EASTWARD...WITH A LATE AFTERNOON/EVENING
THUNDERSTORM RISK AND LIKELY A GREATER RISK FOR SEVERE WEATHER.
FOR NOW...HAVE PAINFULLY KEPT SLIGHT CHANCE TO CHANCE POPS
SPRAYED THROUGHOUT THE EXTENDED FORECAST.

MAYES

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

FOBERT

000
FXUS63 KLBF 221804
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
104 PM CDT WED MAY 22 2013

.UPDATE...
ISSUED AT 949 AM CDT WED MAY 22 2013

UPDATED THE FORECAST FOR TRENDS IN CLOUD COVER AND PRECIPITATION.
THE SURFACE LOW WHICH HAS THE MOISTURE ROTATING AROUND IT IS NOW
OVER NORTHEAST IOWA AS OF 14Z...WHILE HIGH PRESSURE BUILDS INTO
THE PANHANDLE AND WESTERN NEBRASKA. THE CLOUD COVER WAS STARTING
TO BREAK UP THIS MORNING...MAINLY OVER THE SOUTHWEST PARTS OF THE
FORECAST AREA. THERE IS A NARROW BAND FROM APPROXIMATELY KOGA TO
KCDR THAT MAY PERSIST A BIT LONGER...BUT EXPECTING THIS AREA TO
MIX OUT AND DISSIPATE BY THE NOON HOUR. GOING FURTHER EAST...THE
CLOUDS WILL LIKELY PERSIST THROUGH MUCH OF THE DAY...OR AT LEAST
THROUGH MID AFTERNOON AS A THICKER LAYER OF MOISTURE WILL REMAIN.
THE SHOWERS HAVE DECREASED IN AREA AND INTENSITY BY LATE THIS
MORNING...WITH THE STRONGER ECHOES NOW OVER EASTERN NEBRASKA AND
EASTERN SOUTH DAKOTA...CLOSER TO THE SURFACE LOW. WILL KEEP
MENTION OF SHOWERS AND SPRINKLES ACROSS NORTH CENTRAL AND CENTRAL
NEBRASKA THROUGH THE MORNING...THEN DRY CONDITIONS EXPECTED FOR
THE AFTERNOON.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT WED MAY 22 2013

WRAP AROUND CLOUDINESS WILL CONTINUE TODAY ACROSS NRN NEB. THE LIGHT
RAIN SHOULD END BY NOON. THERE IS ONE MORE IMPULSE ACROSS ERN SD
WHICH WILL DROP SOUTH BEFORE THE SFC LOW DRIFTS EAST INTO THE
MIDWEST THIS AFTERNOON. THIS LEAVES MUCH OF THE SRN HALF OF THE FCST
AREA IN PARTLY CLOUDY SKIES WITH HIGHS IN THE 60S WHILE OVERCAST
SKIES KEEP THE NORTH IN THE 50S.

TONIGHT...AN INVERTED SFC LOW PRESSURE TROF WILL SHARPEN UP ACROSS
THE NRN AND CNTL ROCKIES. THIS WILL SET UP A BROAD BELT OF
EASTERLIES ACROSS THE FCST AREA WHICH COULD TRAP LOW LEVEL MOISTURE
AND PRODUCE UPSLOPE FOG AND STRATUS ACROSS WRN NEB. PRESUMABLY...DRY
AIR COULD MOVE INTO NCNTL NEB CLEARING SKIES THERE. GIVEN THE POOR
MODEL PERFORMANCE OF THE NAM IN THESE TYPES OF SITUATIONS...THE RAP
MODEL MIGHT BE THE BEST HANDLE FOR TONIGHTS SKY FORECAST.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT WED MAY 22 2013

SFC HIGH PRESSURE WILL MOVE EAST OF THE REGION THURSDAY...WITH EAST
TO SOUTHEAST WINDS KEEPING CONDITIONS RATHER COOL...WITH HIGHS IN
THE 60S TO PERHAPS 70 IN A FEW LOCALS. INCREASING LOW LEVEL MOISTURE
COULD LEAD TO SOME STRATUS DEVELOPMENT...ESPECIALLY ACROSS SOUTHWEST
NEB AND THE PANHANDLE...WHICH COULD HOLD HIGHS DOWN FURTHER. A
SOUTHERLY LLJ CRACKS UP TO AROUND 45 KTS...ADVECTING MORE MOISTURE
AND BETTER CHANCES FOR STRATUS CLOUDS INTO THE AREA. WILL MAINTAIN A
SLIGHT CHANCE FOR SHOWERS/TSTMS ACROSS SOUTHWEST NEBRASKA...WHERE
WARM AIR ADVECTION WILL BE MAXIMIZED.

FRIDAY THROUGH TUESDAY APPEARS TO BE QUITE ACTIVE IN TERMS OF
CONVECTIVE POTENTIAL. A LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL
BECOME ANCHORED ACROSS THE PACIFIC NORTHWEST...PROVIDING A SOUTHWEST
FLOW ALOFT ACROSS THE CENTRAL CONUS. THIS FLOW DOESN/T APPEAR OVERLY
STRONG...BUT ADEQUATE ENOUGH TO SUPPORT SOME SEVERE TSTM POTENTIAL
FROM TIME TO TIME. MEANWHILE...PLENTY OF LOW LEVEL MOISTURE AND
STEEP MID LEVEL LAPSE RATES...WILL RESULT IN STRONG INSTABILITY
DURING THE AFTERNOON AND EVENING HOURS. IT APPEARS THAT A LEEWARD
TROUGH/DRY LINE WILL BE ESTABLISHED EACH AFTERNOON ACROSS WESTERN
NEB/KS...AND COULD SERVE AS A FOCUS FOR CONVECTIVE INITIATION AS
SHORTWAVE TROUGHS EJECT EASTWARD FROM THE WESTERN UPPER LOW. OF
COURSE TIMING OF THESE TROUGHS WILL BE A FACTOR...AND LATER
FORECASTS WILL REFINE THE TIMING AND INTENSITY OF ANY TSTMS.

TEMPERATURES THROUGH THE PERIOD COULD BE A CHALLENGE...ESPECIALLY
HIGH TEMPERATURES...AS POTENTIAL EXISTS FOR QUITE A BIT IN THE WAY
OF STRATUS CLOUDS DUE TO INCREASED GULF OF MEXICO MOISTURE...AND ANY
CONVECTIVE DEBRIS CLOUDINESS. FOR NOW WILL GO WITH HIGHS MAINLY IN
THE LOWER 70S TO LOWER 80S...WITH THE WARMEST READINGS ACROSS THE
WESTERN PORTIONS OF THE AREA. LOWS WILL BE MILD...MID 50S TO LOWER
60S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 103 PM CDT WED MAY 22 2013

FORECAST THROUGH THURSDAY IS PLAGUED BY CLOUD COVER WITH PASSAGE
OF BACKDOOR COLD FRONT TONIGHT. SHOULD GET STRATUS IN THE VICINITY
OF THE FRONT...WHICH WOULD OCCUR ACROSS ALL OF WESTERN AND NORTH
CENTRAL NEBRASKA. MODELS WOULD SUGGEST THE STRATUS MOVING OUT OF
NORTH CENTRAL NEBRASKA BY 12Z...BUT WITH INVERSION SET UP...KEPT
THE STRATUS IN THROUGH MID MORNING AT KVTN AND KLBF. WINDS WILL
SWITCH OVER TO THE EAST BY THURSDAY MORNING...AND COULD GET SOME
GUSTS TO 20 MPH BY LATE MORNING. SHOULD THE STRATUS NOT DEVELOP AS
ANTICIPATED...FORECAST WILL IMPROVE GREATLY.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...BROOKS
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...BROOKS

000
FXUS63 KGID 221748
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1248 PM CDT WED MAY 22 2013

.UPDATE...
ISSUED AT 625 AM CDT WED MAY 22 2013

AS DISCUSSED EARLIER...ENDED UP MAKING A FEW ADJUSTMENTS TO VERY
SHORT TERM GRIDS BASED ON LATEST RADAR TRENDS...AND WITH SUPPORT
FROM THE LATEST RAP13/HRRR QPF/REFLECTIVITY. ALTHOUGH CANNOT RULE
OUT A FEW SPOTS REPORTING LIGHT MEASURABLE RAIN WITH THIS
ACTIVITY...ESPECIALLY IN THE NANCE/POLK COUNTY AREA...THINK THAT
NON-MEASURABLE SPRINKLES WILL BE THE DOMINANT STORY FOR MOST OF
THE AFFECTED AREA...AND THUS LEFT OUT A MEASURABLE POP.
HOWEVER...BEEFED UP SPRINKLE WORDING TO WIDESPREAD IN SEVERAL FAR
NORTHEAST COUNTIES THROUGH NOON 17Z...AND EXPANDED AN ISOLATED
SPRINKLE MENTION AS FAR SOUTH AS A LOUP CITY-GENEVA LINE. IT MAY
TURN OUT THAT THIS LIGHT PRECIP MAY BE OUT OF THE PICTURE WELL
BEFORE NOON...BUT GIVEN THE VERY SLOW MOVING NATURE OF THE PARENT
MID LEVEL LOW TO THE EAST ANYTHING IS POSSIBLE. ALSO BEEFED UP SKY
COVER PERCENTAGES FROM MOSTLY CLOUDY TO OUTRIGHT CLOUDY ACROSS
ROUGHLY THE NORTHEAST 1/2 OF THE CWA THROUGH MID-DAY...WHILE
LEAVING A MORE OPTIMISTIC TREND IN PLACE FARTHER SOUTHWEST. THE
LATEST HRRR IS NOW SPORTING A ROUGHLY 20 DEGREE HIGH-TEMP GRADIENT
ACROSS THE CWA THIS AFTERNOON FROM ONLY LOW-MID 50S NORTHEAST TO
MID 70S SOUTHWEST. OTHER SHORT TERM MODELS SUCH AS THE RAP13 ARE
NOT AS COOL IN THE NORTHEAST AS THE HRRR...AND THUS WILL RESIST
THE URGE TO MODIFY AFTERNOON HIGHS AT THIS TIME...BUT FOR SURE ITS
POSSIBLE THAT SOME NORTHEAST AREAS COULD STRUGGLE TO REACH THE
MID-UPPER 50S AND NEXT SHIFT WILL HAVE MONITOR TRENDS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM CDT WED MAY 22 2013

WHILE THERE IS CERTAINLY NO HIGH-IMPACT WEATHER DURING THE NEXT
24 HOURS...THERE ARE AT LEAST A FEW TRICKY ELEMENTS AT
HAND...INCLUDING THE EXTENT OF LOW STRATUS AND ITS POSSIBLE
INFLUENCE ON A FAIRLY DECENT SOUTHWEST-NORTHEAST TEMP
GRADIENT...AND ALSO THE EXTENT OF SPRINKLES/LIGHT RAIN SHOWERS
MAINLY THIS MORNING IN THE NORTHEAST.

08Z OBJECTIVE SURFACE ANALYSIS REVEALS NO MAJOR FEATURES ACROSS
THE CENTRAL PLAINS...WITH THE CWA POSITIONED BETWEEN A MODEST 1004
MILLIBAR LOW OVER EASTERN IA...AND A 1014MB HIGH OVER THE NEB
PANHANDLE...A SOUTHWARD EXTENSION OF A STRONGER...BROADER HIGH
WELL TO THE NORTH IN CANADA. WITHIN THE MODEST PRESSURE GRADIENT
BETWEEN THESE FEATURES...A FAIRLY STEADY NORTH-NORTHWEST BREEZE OF
10-15 MPH HAS PREVAILED THROUGH THE NIGH IN MOST AREAS...WITH
OCCASIONAL GUSTS OVER 20 MPH. TEMPERATURES WILL START OUT THE
MORNING SEASONABLY COOL...WITH EVENTUAL LOWS AIMED INTO THE MID-
UPPER 40S ALL AREAS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM
MODEL DATA FEATURES A CLOSED 500MB LOW DRIFTING SLOWLY
EAST...CENTERED NEAR THE IA/SD/NEB BORDER...AND A FAIRLY SHARP MID
LEVEL TROUGH AXIS THEN TRAILING SOUTH-SOUTHEAST INTO THE MID-SOUTH
STATES. OFF TO THE WEST OF THE LOCAL AREA...A LOW AMPLITUDE MID
LEVEL RIDGE IS ALIGNED NORTH-SOUTH THROUGH THE ROCKIES...WITH A
FAIRLY VIGOROUS...EXPANSIVE CLOSED LOW SPINNING OVER THE PACIFIC
NORTHWEST. WHILE IT HAS TAKEN ITS TIME FORMING...11-3.9 MICRON
SATELLITE IMAGERY AND AUTOMATED OBS HAVE FINALLY REVEALED THE
FORMATION OF FAIRLY WIDESPREAD LOW STRATUS MAINLY IN THE 1500-2500
FT RANGE OVER MUCH OF THE CWA...ALTHOUGH SOME BREAKS IN THE CLOUDS
DO STILL EXIST. ALSO JUST WITHIN THE PAST 90 MINUTES OR SO...AN
INCREASING FLARE-UP OF LIGHT RAIN/SPRINKLES HAS TAKEN PLACE MAINLY
OVER THE FAR NORTHERN/NORTHEAST CWA...WITH UPSTREAM OBS AT PLACES
SUCH AS ONEILL AND ALBION CONFIRMING AT LEAST TRACE AMOUNTS ARE
FALLING.

TODAY...THE MAIN STORY ALOFT INVOLVES THE CONTINUED SLOW DEPARTURE
OF THE CLOSED MID LEVEL LOW...WITH THE CENTER OF THIS FEATURE
PROGGED TO ONLY REACH NORTHEAST IA BY 00Z. AT THE SURFACE...A
MODEST PRESSURE GRADIENT WILL REMAIN IN PLACE AS HIGH PRESSURE TO
THE NORTH NOSES SOUTHWARD...AND THIS IN COMBINATION WITH MIXING TO
AT LEAST 850MB IN MOST AREAS WILL RESULT IN SOMEWHAT BREEZY
CONDITIONS ESPECIALLY WITHIN THE NORTHEAST 2/3 OF THE CWA...WITH
SUSTAINED NORTHWEST WINDS 15 TO POSSIBLY 20 MPH...AND SOME HIGHER
GUSTS. THE REAL CHALLENGE TODAY LIES INITIALLY WITH THE EXTENT AND
INTENSITY OF RAINFALL...AND ALSO JUST HOW STUBBORN THE LOW STRATUS
DECK WILL BE...AND WHETHER OR NOT IT RETREATS SLOW NORTHEAST
DURING THE AFTERNOON. STARTING OUT EARLY THIS MORNING THROUGH MID-
DAY...HAVE INTRODUCED A MENTION OF SPRINKLES TO A PREVIOUSLY
PRECIP-FREE FORECAST FOR FAR NORTHEAST AREAS MAINLY NORTH OF A
GREELEY-POLK LINE...AS DECENT LOW-MID LEVEL SATURATION UP TO
AROUND 600MB RESIDES MAINLY IN THIS ZONE AND POINTS
NORTHEAST...ASSOCIATED WITH A BATCH OF MID LEVEL MOISTURE FOCUSED
IN THE DEFORMATION ZONE ON THE BACK-SIDE OF THE DEPARTING LOW. THE
VERY SHORT TERM QUESTION THAT WILL NEED PONDERED OVER THE NEXT FEW
HOURS IS WHETHER TO EXPAND THIS SPRINKLE MENTION SOUTHWESTWARD
CLOSER TO I-80 PER SUGGESTION OF THE LATEST HRRR REFLECTIVITY
PROG...AND ALSO WHETHER TO UP THE ANTE TO A MEASURABLE POP. WILL
GIVE IT SOME TIME TO SEE IF AREA OBSERVATIONS SUPPORT A FEW
HUNDREDTHS OF ACCUMULATIONS BEFORE POSSIBLY MAKING THIS MOVE. AT
ANY RATE...ANY LIGHT RAINFALL IN THE NORTHEAST...ESPECIALLY OF THE
POTENTIALLY MEASURABLE VARIETY...IS EXPECTED TO BE OUT OF THE
PICTURE BY NOON...AS THE MID LEVELS START TO DRY OUT FROM WEST TO
EAST. CLOUD-WISE...HAVE LEANED TOWARD A COMBINATION OF THE NAM AND
HRRR...WITH THE EXPECTATION OF A RATHER SHARP SOUTHWEST-NORTHEAST
GRADIENT RANGING FROM MOSTLY SUNNY-PARTLY CLOUDY SOUTHWEST TO
MOSTLY CLOUDY AT BEST IN THE NORTHEAST. SHAKY CONFIDENCE IN THESE
CLOUD DETAILS LEAD TO SOMEWHAT SHAKY CONFIDENCE IN HIGH TEMPS. AT
LEAST FOR NOW...NUDGED SOUTHWEST AREAS UP A FEW DEGREES AND
NORTHEAST AREAS DOWN A FEW DEGREES VERSUS PREVIOUS...WHILE LEAVING
THE CENTRAL RATHER UNCHANGED. AS A RESULT...AM AIMING FROM UPPER
50S-LOW 60S FAR NORTH/NORTHEAST TO MID 60S TRI-CITIES TO MID 70S
SOUTHWEST. HOWEVER...AM STARTING TO WONDER IF THE HRRR MIGHT BE
ONTO SOMETHING...KEEPING MUCH OF THE NORTHEAST 1/2 OF THE CWA WELL
DOWN IN THE MID-50S AT BEST UNDER THE LONGEST-LASTING STRATUS.
THIS WILL BEAR WATCHING FOR LATER UPDATES...BUT DON/T WANT TO GO
QUITE THIS COOL YET.

TURNING TO THE TONIGHT PERIOD...00Z-12Z...CONFIDENCE REMAINS
RATHER HIGH IN A LEGITIMATELY DRY NIGHT...WITH THE SOLE POSSIBLE
EXCEPTION OF SOME PATCHY LIGHT DRIZZLE IN THE EVENING IN THE NORTH
UNDER A LOW STRATUS DECK...BUT THIS SCENARIO IS TOO UNCERTAIN TO
INSERT AT THIS TIME. IN THE MID-UPPER LEVELS...THE DEPARTING LOW
FINALLY SLIPS FAR ENOUGH EAST TO ALLOW THE RIDGE TO THE WEST TO
START BUILDING INTO NEB/KS. ALTHOUGH THERE WILL BE A MODEST
NORTHWEST-SOUTHEAST ORIENTED WING OF MID LEVEL MOISTURE
ADVECTION/ISENTROPIC LIFT THAT SETS UP FROM SOUTHWEST NEB TO
SOUTHEAST KS MAINLY AFTER MIDNIGHT AS EVIDENT ON THE 310K
SURFACE...SOUNDINGS SUGGEST THAT LIFT/MOISTURE SHOULD BE
INSUFFICIENT FOR PRECIP OVER THE CWA...ALTHOUGH A FEW SHOWERS OR
EVEN WEAK STORMS COULD FLARE UP WITHIN A FEW COUNTIES JUST TO THE
SOUTH/SOUTHWEST BY SUNRISE. AT THE SURFACE...HIGH PRESSURE WILL
CONTINUE OOZING DOWN FROM THE NORTH...KEEPING FAIRLY LIGHT BUT
STEADY NORTHERLY BREEZES AROUND 10 MPH IN PLACE. DESPITE THE
PRESENCE OF POTENTIALLY DECENT LOW LEVEL SATURATION...THESE
BREEZES SHOULD KEEP ANYTHING MORE THAN HAZE/LIGHT FOG AT BAY. THE
REAL QUESTION MARK AT THIS POINT TONIGHT AGAIN LIES WITH LOW
STRATUS TRENDS. WHILE THE PREVIOUS FORECAST HAD NO WORSE THAN
PARTLY CLOUDY SKIES...THE LATEST NAM RUNS AND ASSOCIATED MET
GUIDANCE FAIRLY AGGRESSIVELY BRING A BATCH OF LOW STRATUS BACK
SOUTHWARD ACROSS MOST OF THE CWA AS THE NIGHT WEARS ON...WITH THIS
ESPECIALLY EVIDENT AT 900MB. FOR NOW...HAVE STARTED AN UPWARD
TREND IN SKY COVER...BUT VERY WELL MAY NOT BE HIGH ENOUGH
ESPECIALLY POST-MIDNIGHT. EVEN IF STRATUS DOES END UP BEING MORE
WIDESPREAD THAN CURRENTLY SUGGESTED...CONFIDENCE IS DECENT THAT
LOW TEMPS WILL END UP SIMILAR TO THOSE OF THIS MORNING...AND USED
A BLEND OF MET/MAV GUIDANCE...AIMING FOR ANOTHER COOL ONE WITH MID
40S MOST SPOTS.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 509 AM CDT WED MAY 22 2013

MODELS ARE IN GOOD AGREEMENT TRANSITIONING A RIDGE OF HIGH PRESSURE
ACROSS THE PLAINS ON THURSDAY IN WAKE OF THE DEPARTING UPPER LEVEL
LOW. WHILE HEIGHTS ALOFT WILL BE RISING...EXPECT ONLY A MODESTLY
WARMER AFTERNOON ON THURSDAY AS 850MB TEMPS ARE EXPECTED TO ONLY
REBOUND A COUPLE OF DEGREES AND PLENTY OF CLOUD COVER IS EXPECTED IN
EASTERLY UPSLOPE FLOW.

AS THE WINDS SHIFT MORE SOUTHEASTERLY THURSDAY NIGHT AND
FRIDAY...EXPECT ADDITIONAL MOISTURE TO SURGE NORTHWARD...AND FOR
INCREASING INSTABILITY ACROSS THE REGION. THIS BUILDING INSTABILITY
COMBINED WITH SOME FORCING FROM THE LOW LEVEL JET...WILL LIKELY
RESULT IN A CHANCE OF THUNDERSTORMS THURSDAY NIGHT ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...WHICH WILL BE IN CLOSER
PROXIMITY TO THE JET. WITH THE NOSE OF THE NOCTURNAL JET MORE
FOCUSED ACROSS THE HEART OF LOCAL AREA FRIDAY AND FRIDAY
NIGHT...CANNOT RULE OUT ADDITIONAL ELEVATED SHOWER AND THUNDERSTORM
ACTIVITY ACROSS THE ENTIRE FORECAST AREA...WITH THE BEST CHANCES FOR
PRECIPITATION COMING DURING THE LATE EVENING AND OVERNIGHT HOURS.

THEREAFTER THE MID LEVEL CAP IS EXPECTED TO WEAKEN SUBSTANTIALLY BY
SATURDAY AFTERNOON... AND WITH SEVERAL THOUSAND JOULES OF CAPE TO
WORK WITH THROUGH THE REMAINDER OF THE LONG TERM PERIODS...WILL
LIKELY SEE THUNDERSTORMS AROUND EACH DAY AS PERIODIC VORTICITY
MAXIMA EJECT OUT OF THE LONGWAVE TROUGH ACROSS THE WEST COAST.
ADDITIONALLY...WITH THESE SUBSTANTIAL CAPE VALUES AND MARGINALLY
SUPPORTIVE SHEAR PROFILES...WILL HAVE THE POTENTIAL FOR SOME SEVERE
THUNDERSTORMS DEVELOP FROM TIME TO TIME SATURDAY ONWARD...WITH LARGE
HAIL AND STRONG THUNDERSTORM WIND GUSTS BEING THE PRIMARY THREATS.
TEMPERATURES THROUGH THE PERIOD ARE NOT EXPECTED TO FLUCTUATE A
WHOLE LOT AS THERE WILL BE LITTLE CHANGE IN THE UNDERLYING AIRMASS
SATURDAY ONWARD...WITH LOWER TO MIDDLE 80S EXPECTED EACH AFTERNOON
AND LOWER 60S EXPECTED AT NIGHT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1248 PM CDT WED MAY 22 2013

MVFR CONDITIONS FORECAST THROUGH 20Z...VFR 20-02Z...THEN MVFR
CONDITIONS 02-15Z.

AS OF MIDDAY A STRATUS DECK...WITH A CEILING NEAR 2000FT
AGL...PERSISTS AT KGRI. THIS CEILING IS EXPECTED TO CONTINUE
THROUGH ANOTHER COUPLE HOURS...BUT IS THEN EXPECTED TO SCATTER OUT
BY MID AFTERNOON...THUS THE VFR FORECAST BEGINNING 20Z. VFR
CONDITIONS ARE THEN FORECAST THROUGH THIS EVENING...HOWEVER
GUIDANCE SUGGESTS AN MVFR DECK WILL ONCE AGAIN INFILTRATE THE AREA
THIS EVENING AND INTO THE OVERNIGHT HOURS. IT IS WORTH NOTING THAT
SOME GUIDANCE SUGGESTS IFR CEILINGS...OR LOWER...WILL BE REALIZED
TONIGHT THROUGH EARLY THURSDAY MORNING...BUT AT THIS TIME
CONFIDENCE IS NOT HIGH ENOUGH TO INSERT SUCH CONDITIONS IN THE
TAF. FUTURE SHIFTS WILL WANT TO CONTINUE MONITORING FOR THE
POSSIBLE INSERTION OF A LOWER CEILING IN FUTURE TAFS. WHAT CEILING
DOES DEVELOP OVERNIGHT TONIGHT SHOULD SCATTER OUT POST- SUNRISE
THURSDAY. THE SURFACE WIND WILL TRANSITION FROM THE NORTHWEST TO
MORE OF A NORTH/NORTHEAST DIRECTION THROUGH THE NEXT 24
HOURS...SUSTAINED AT AROUND 14KTS AND GUSTING NEAR 20KTS THROUGH
THIS EVENING. VISIBILITY RESTRICTION IS NOT CURRENTLY EXPECTED AT
KGRI THROUGH THE NEXT 24 HOURS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...SAR
AVIATION...BRYANT/BRUM