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 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 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 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 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 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 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 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
000
FXUS63 KGID 221127
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
627 AM 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 REFLECTITY
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 12Z KGRI TAF THROUGH 12Z THURSDAY MORNING)
ISSUED AT 625 AM CDT WED MAY 22 2013
ALTHOUGH CONFIDENCE IS HIGH IN VFR VISIBILITY THROUGH THE
PERIOD...CEILING TRENDS CONTINUE TO BE TRICKY AS PLENTY OF LOWER
STRATUS HANGS AROUND THE AREA ON THE BACK SIDE OF A DEPARTING MID
LEVEL LOW. STARTING OFF THROUGH THE MORNING INTO THE MID-AFTERNOON
HOURS...HAVE CONTINUED A PREVAILING MVFR CEILING...ALTHOUGH JUST
WITHIN THE PAST HOUR CLOUDS AT THE MVFR LEVEL HAVE SCATTERED A
BIT...DIMINISHING CONFIDENCE SOMEWHAT AND SUGGESTING THAT MVFR
MAY BE MORE OFF-AND-ON. ALSO THIS MORNING...A FEW SPRINKLES CANNOT
BE RULED OUT AT KGRI...BUT GIVEN SUCH LOW IMPACT WILL OMIT ANY
PRECIP MENTION. THROUGH THE LATE AFTERNOON AND EVENING
HOURS...KEPT TREND FROM PREVIOUS FORECAST BY RAISING PREVAILING
CEILING TO LOW-END VFR. HOWEVER...CONFIDENCE IN THE DETAILS REALLY
DECREASES BY THE LAST 6 HOURS OR SO LATE TONIGHT...AS SOME
MODELS/GUIDANCE SUGGEST A LOW-MVFR AND POSSIBLY EVEN IFR DECK
COULD MATERIALIZE...WHILE OTHER MODELS KEEP CEILING VFR. AS A
COMPROMISE BETWEEN THE WIDE POSSIBILITIES AT THIS TIME
RANGE...WILL INTRODUCE A SCATTERED LOW-END MVFR CLOUD GROUP.
WIND-WISE...A STEADY NORTH-NORTHWEST BREEZE WILL PREVAIL MUCH OF
THE DAY WITH GUST POTENTIAL TO AROUND 22KT...BEFORE SLACKENING THIS
EVENING AND AVERAGING UNDER 10KT OVERNIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...SAR
AVIATION...PFANNKUCH
000
FXUS63 KGID 221010
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
510 AM CDT WED MAY 22 2013
.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 REFLECTITY
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 06Z KGRI TAF THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1250 AM CDT WED MAY 22 2013
ALTHOUGH CONFIDENCE IS HIGH IN VFR VISIBILITY THROUGH THE
PERIOD...ALONG WITH LITTLE IF ANY RISK OF PRECIPITATION...CEILING
TRENDS APPEAR TO BE SOMEWHAT TRICKY AS PLENTY OF LOWER STRATUS
HANGS AROUND THE AREA ON THE BACK SIDE OF A DEPARTING MID LEVEL
LOW. STARTING OFF EARLY THIS MORNING...HAVE CONTINUED TO DELAY THE
ONSET OF PREVAILING MVFR CEILING UNTIL 09Z...ALTHOUGH AT LEAST
BRIEF INSTANCES OF MVFR MAY BE OBSERVED BEFORE THEN. LEANING
HEAVILY TOWARD LATEST CEILING TRENDS FROM 00Z NAM AND 05Z GFS LAMP
GUIDANCE...KEPT A BROKEN MVFR DECK IN PLACE THROUGH MID-
AFTERNOON...WHICH IS SEVERAL HOURS LATER THAN PREVIOUS FORECAST
INDICATED. CONFIDENCE STARTS TO WANE ESPECIALLY DURING THE FINAL 9
HOURS OR SO...BUT FOR NOW WILL AIM FOR A RETURN TO AT LEAST LOW-
END VFR CEILING BY LATE AFTERNOON. WILL CONTINUE THIS LOW-END VFR
THROUGH THE EVENING HOURS...BUT ITS WORTH NOTING THAT THE LATEST
NAM/MET GUIDANCE ACTUALLY RE-ESTABLISHES A SOLID MVFR DECK AFTER
SUNSET...SO THIS TREND WILL BEAR WATCHING. WIND-WISE...A STEADY
NORTH-NORTHWEST BREEZE WILL PREVAIL...WITH GUST POTENTIAL OF
18-22KT THROUGH LATE AFTERNOON BEFORE SLACKENING SOMEWHAT DURING
THE EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...SAR
AVIATION...PFANNKUCH
000
FXUS63 KGID 220605
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
105 AM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 655 PM CDT TUE MAY 21 2013
MADE MINOR ADJUSTMENTS TO HOURLY WEATHER FOR THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 319 PM CDT TUE MAY 21 2013
MORNING UPPER AIR ANALYSIS INDICATES A MID TO UPPER LEVEL LOW OVER
NORTHERN PORTIONS OF THE MISSOURI RIVER VALLEY...WITH LONGWAVE
TROUGHING OVER CENTRAL PORTIONS OF THE CONUS...RIDGING OVER THE
EASTERN CONUS...AND ANOTHER MID TO UPPER LEVEL LOW APPROACHING THE
NORTHWESTERN CONUS. MID AND UPPER LEVEL JET ENERGY SURROUNDS THE
MISSOURI VALLEY MID TO UPPER LEVEL LOW...AND ALSO EXTENDS FROM THE
WEST-CENTRAL CONUS INTO THE SOUTHERN CONUS. ALL THAT BEING
SAID...MID TO UPPER LEVEL FLOW IS FAIRLY WEAK OVER OUR
AREA...MAXING OUT AT AROUND 35KTS NEAR 500MB PER 12Z SOUNDING DATA
FROM KLBF AND KOAX. THE STRONGEST TROPOSPHERIC FLOW OVER OUR AREA
IS ACTUALLY LOCATED WITHIN THE LOWEST ~8000FT AGL...WITH A WIND
NEAR 50KTS INDICATED BETWEEN 700 AND 800MB. WATER VAPOR IMAGERY
CLEARLY SHOWS THE MID LEVEL LOW OVER THE MISSOURI RIVER
VALLEY...AS WELL AS THE MID LEVEL LOW NEARING THE NORTHWESTERN
CONUS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS
OVER THE NORTHERN MISSOURI RIVER VALLEY...AND A COLD FRONT EXTENDS
FROM NORTHEASTERN MISSOURI INTO THE OKLAHOMA AND TEXAS. THE LOW
LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE NORTHWEST AS A
RESULT.
A FAIRLY STRONG LOW LEVEL PRESSURE GRADIENT...WORKING IN CONCERT
WITH BOUNDARY LAYER MIXING TO AROUND 800MB...HAS PROMOTED A FAIRLY
BREEZY DAY ACROSS OUR CWA TODAY. A FEW LOCATIONS...PRIMARILY NORTH
OF HIGHWAY 6 AND WEST OF HIGHWAY 281...HAVE PERIODICALLY HIT WIND
ADVISORY CRITERIA. THAT BEING SAID...SUCH OBSERVATIONS HAVE BEEN
FLEETING AND NO HEADLINE IS EXPECTED THROUGH THE REMAINDER OF THIS
AFTERNOON GIVEN THAT THE WIND SPEED FOR THESE LOCATIONS IS SO
MARGINAL WITH RESPECT TO WIND ADVISORY CRITERIA.
DRY CONDITIONS ARE FORECAST ACROSS THE AREA THROUGH THE NEXT 24
HOURS WITH NOTHING IN THE WAY OF HIGH IMPACT WEATHER ANTICIPATED.
GUIDANCE SUGGESTS THE MID LEVEL LOW...CURRENTLY OVER THE NORTHERN
MISSOURI RIVER VALLEY...WILL CONTINUE MOVING EAST OUT OF OUR AREA.
THIS SHOULD BRING AN END TO ANY PRECIPITATION CHANCES AS UPPER
LEVEL RIDGING AND AN OVERALL LACK IN KINEMATIC FORCING SETTLES IN
OVER THE AREA HEADING INTO THE DAY WEDNESDAY. THE CLOUD COVER WILL
ALSO BE ON THE DECREASE FROM SOUTHWEST TO NORTHEAST ACROSS OUR CWA
THROUGH THE NEXT 24 HOURS. FINALLY...A DECREASING LOW LEVEL
PRESSURE GRADIENT SHOULD PROMOTE A WEAKER LOW LEVEL WIND FIELD
ACROSS OUR AREA THROUGH THE NEXT 24 HOURS.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS WOULD OTHERWISE PROVIDE A
SIMILAR LOW TEMPERATURE EARLY TOMORROW MORNING WHEN COMPARED TO
THIS MORNING...BUT WITH CLOUD COVER ON THE DECREASE...ESPECIALLY
ACROSS OUR SOUTHWEST...IT WILL MORE THAN LIKELY BE A TOUCH COOLER.
GIVEN ALL THIS...WENT AHEAD WITH AN OVERNIGHT LOW TEMPERATURE IN
THE MID TO UPPER 40S ACROSS OUR CWA. WE HAVE REALLY STRUGGLED TO
SEE ANY SUNSHINE ACROSS MUCH OF OUR AREA TODAY...BUT WITH
DECREASING CLOUD COVER AND AN INCREASE IN DIABATIC HEATING DURING
THE DAY WEDNESDAY...IT SEEMS LOGICAL THAT WE OUGHT TO BE SOMEWHAT
WARMER DURING ON WEDNESDAY. AN AFTERNOON HIGH TEMPERATURE RANGING
FROM THE 60S TO LOW 70S IS CURRENTLY FORECAST ACROSS OUR CWA FOR
WEDNESDAY AS A RESULT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 319 PM CDT TUE MAY 21 2013
WEDNESDAY NIGHT THROUGH TUESDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS THURSDAY NIGHT THROUGH TUESDAY AND
TEMPERATURES THROUGH THE PERIOD.
SHORT WAVE RIDGING ALOFT AND A SURFACE HIGH PRESSURE SYSTEM TRYING
TO NOSE INTO THE AREA WILL ALLOW FOR DRY CONDITIONS FOR WEDNESDAY
NIGHT INTO THURSDAY. THE SURFACE HIGH IS A LITTLE ON THE COOLER
SIDE AND LOW TEMPERATURES WEDNESDAY NIGHT WILL BE REFLECTIVE OF
THAT WITH READINGS ONLY IN THE MID TO UPPER 40S. BY THURSDAY THE
SURFACE HIGH WILL BE MOVING TO THE EAST AND WINDS WILL TURN TO THE
SOUTH. WITH SOME SUNSHINE...EXPECT TEMPERATURES TO WARM TO AROUND
70 DEGREES.
AN UNSETTLED WEATHER PATTERN WILL START TO AFFECT THE AREA
THURSDAY NIGHT AND CONTINUE THROUGH THE PERIOD. THE UPPER LEVEL
SHORT WAVE RIDGE WILL BE BATTERED BY SEVERAL SHORT WAVES SPINNING
OFF FROM AN UPPER LEVEL LOW IN THE WESTERN CONUS. MODELS HAVE SOME
DIFFERENCES IN THE STRENGTH AND LOCATION OF THE UPPER LEVEL LOW IN
THE WESTERN CONUS...ESPECIALLY IN THE MONDAY AND TUESDAY TIME
FRAME.
THE FIRST OF THE WAVES TO AFFECT THE AREA MOVES IN THURSDAY NIGHT.
WITH THE SOUTH WINDS THE MOISTURE INCREASES ESPECIALLY ON THE HIGH
PLAINS AND SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN THE
SOUTHWEST PART OF THE FORECAST AREA THURSDAY NIGHT. THE UPPER WAVE
AND THE LOW LEVEL MOISTURE MOVE OFF TO THE EAST FRIDAY AND FRIDAY
NIGHT AND BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA.
BY SATURDAY A STRONGER WAVE MOVES INTO THE AREA AND WITH WARMER
AIR PUSHING INTO THE AREA THE ATMOSPHERE DESTABILIZES AND MUCAPES
APPROACH 4500 J/KG. THIS COULD LEAD TO SOME STRONGER
THUNDERSTORMS. ANOTHER WAVE MOVES INTO THE AREA ON SUNDAY AND A
WARM FRONT LIFTS NORTH ACROSS THE AREA. THE WARM AIR HELPS TO
DESTABILIZE THINGS FURTHER AND MUCAPES OVER 5000 J/KG ARE EXPECTED
ON SUNDAY. WILL CONTINUE THE THREAT OF SEVERE WEATHER ON SUNDAY.
THE MODELS HAVE A FEW MORE DIFFERENCES BY MONDAY AND TUESDAY. THE
GFS HAS A STRONGER UPPER LEVEL LOW IN THE WEST THAN THE ECMWF DOES
AND HAS SOME STRONGER WAVES THAT MOVE INTO THE PLAINS. WITH THE
MODELS HAVING DIFFERENT SOLUTIONS THEY STILL HAVE SOME
PRECIPITATION AROUND THE AREA FOR MONDAY AND TUESDAY. HAVE KEPT IN
SOME LOWER POPS. IT CERTAINLY WILL NOT BE RAINING ALL THE
TIME...BUT THERE IS SOME CHANCES. THE OTHER CONSISTENCY BETWEEN
THE MODELS IS THAT THERE IS GENERALLY A BROAD RIDGE ACROSS THE
REGION AND TEMPERATURES WILL BE ON THE WARMER SIDE.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1250 AM CDT WED MAY 22 2013
ALTHOUGH CONFIDENCE IS HIGH IN VFR VISIBILITY THROUGH THE
PERIOD...ALONG WITH LITTLE IF ANY RISK OF PRECIPITATION...CEILING
TRENDS APPEAR TO BE SOMEWHAT TRICKY AS PLENTY OF LOWER STRATUS
HANGS AROUND THE AREA ON THE BACK SIDE OF A DEPARTING MID LEVEL
LOW. STARTING OFF EARLY THIS MORNING...HAVE CONTINUED TO DELAY THE
ONSET OF PREVAILING MVFR CEILING UNTIL 09Z...ALTHOUGH AT LEAST
BRIEF INSTANCES OF MVFR MAY BE OBSERVED BEFORE THEN. LEANING
HEAVILY TOWARD LATEST CEILING TRENDS FROM 00Z NAM AND 05Z GFS LAMP
GUIDANCE...KEPT A BROKEN MVFR DECK IN PLACE THROUGH MID-
AFTERNOON...WHICH IS SEVERAL HOURS LATER THAN PREVIOUS FORECAST
INDICATED. CONFIDENCE STARTS TO WANE ESPECIALLY DURING THE FINAL 9
HOURS OR SO...BUT FOR NOW WILL AIM FOR A RETURN TO AT LEAST LOW-
END VFR CEILING BY LATE AFTERNOON. WILL CONTINUE THIS LOW-END VFR
THROUGH THE EVENING HOURS...BUT ITS WORTH NOTING THAT THE LATEST
NAM/MET GUIDANCE ACTUALLY RE-ESTABLISHES A SOLID MVFR DECK AFTER
SUNSET...SO THIS TREND WILL BEAR WATCHING. WIND-WISE...A STEADY
NORTH-NORTHWEST BREEZE WILL PREVAIL...WITH GUST POTENTIAL OF
18-22KT THROUGH LATE AFTERNOON BEFORE SLACKENING SOMEWHAT DURING
THE EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...BRYANT
LONG TERM...JCB
AVIATION...PFANNKUCH
000
FXUS63 KGID 212359
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
659 PM CDT TUE MAY 21 2013
.UPDATE...
ISSUED AT 655 PM CDT TUE MAY 21 2013
MADE MINOR ADJUSTMENTS TO HOURLY WEATHER FOR THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 319 PM CDT TUE MAY 21 2013
MORNING UPPER AIR ANALYSIS INDICATES A MID TO UPPER LEVEL LOW OVER
NORTHERN PORTIONS OF THE MISSOURI RIVER VALLEY...WITH LONGWAVE
TROUGHING OVER CENTRAL PORTIONS OF THE CONUS...RIDGING OVER THE
EASTERN CONUS...AND ANOTHER MID TO UPPER LEVEL LOW APPROACHING THE
NORTHWESTERN CONUS. MID AND UPPER LEVEL JET ENERGY SURROUNDS THE
MISSOURI VALLEY MID TO UPPER LEVEL LOW...AND ALSO EXTENDS FROM THE
WEST-CENTRAL CONUS INTO THE SOUTHERN CONUS. ALL THAT BEING
SAID...MID TO UPPER LEVEL FLOW IS FAIRLY WEAK OVER OUR
AREA...MAXING OUT AT AROUND 35KTS NEAR 500MB PER 12Z SOUNDING DATA
FROM KLBF AND KOAX. THE STRONGEST TROPOSPHERIC FLOW OVER OUR AREA
IS ACTUALLY LOCATED WITHIN THE LOWEST ~8000FT AGL...WITH A WIND
NEAR 50KTS INDICATED BETWEEN 700 AND 800MB. WATER VAPOR IMAGERY
CLEARLY SHOWS THE MID LEVEL LOW OVER THE MISSOURI RIVER
VALLEY...AS WELL AS THE MID LEVEL LOW NEARING THE NORTHWESTERN
CONUS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS
OVER THE NORTHERN MISSOURI RIVER VALLEY...AND A COLD FRONT EXTENDS
FROM NORTHEASTERN MISSOURI INTO THE OKLAHOMA AND TEXAS. THE LOW
LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE NORTHWEST AS A
RESULT.
A FAIRLY STRONG LOW LEVEL PRESSURE GRADIENT...WORKING IN CONCERT
WITH BOUNDARY LAYER MIXING TO AROUND 800MB...HAS PROMOTED A FAIRLY
BREEZY DAY ACROSS OUR CWA TODAY. A FEW LOCATIONS...PRIMARILY NORTH
OF HIGHWAY 6 AND WEST OF HIGHWAY 281...HAVE PERIODICALLY HIT WIND
ADVISORY CRITERIA. THAT BEING SAID...SUCH OBSERVATIONS HAVE BEEN
FLEETING AND NO HEADLINE IS EXPECTED THROUGH THE REMAINDER OF THIS
AFTERNOON GIVEN THAT THE WIND SPEED FOR THESE LOCATIONS IS SO
MARGINAL WITH RESPECT TO WIND ADVISORY CRITERIA.
DRY CONDITIONS ARE FORECAST ACROSS THE AREA THROUGH THE NEXT 24
HOURS WITH NOTHING IN THE WAY OF HIGH IMPACT WEATHER ANTICIPATED.
GUIDANCE SUGGESTS THE MID LEVEL LOW...CURRENTLY OVER THE NORTHERN
MISSOURI RIVER VALLEY...WILL CONTINUE MOVING EAST OUT OF OUR AREA.
THIS SHOULD BRING AN END TO ANY PRECIPITATION CHANCES AS UPPER
LEVEL RIDGING AND AN OVERALL LACK IN KINEMATIC FORCING SETTLES IN
OVER THE AREA HEADING INTO THE DAY WEDNESDAY. THE CLOUD COVER WILL
ALSO BE ON THE DECREASE FROM SOUTHWEST TO NORTHEAST ACROSS OUR CWA
THROUGH THE NEXT 24 HOURS. FINALLY...A DECREASING LOW LEVEL
PRESSURE GRADIENT SHOULD PROMOTE A WEAKER LOW LEVEL WIND FIELD
ACROSS OUR AREA THROUGH THE NEXT 24 HOURS.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS WOULD OTHERWISE PROVIDE A
SIMILAR LOW TEMPERATURE EARLY TOMORROW MORNING WHEN COMPARED TO
THIS MORNING...BUT WITH CLOUD COVER ON THE DECREASE...ESPECIALLY
ACROSS OUR SOUTHWEST...IT WILL MORE THAN LIKELY BE A TOUCH COOLER.
GIVEN ALL THIS...WENT AHEAD WITH AN OVERNIGHT LOW TEMPERATURE IN
THE MID TO UPPER 40S ACROSS OUR CWA. WE HAVE REALLY STRUGGLED TO
SEE ANY SUNSHINE ACROSS MUCH OF OUR AREA TODAY...BUT WITH
DECREASING CLOUD COVER AND AN INCREASE IN DIABATIC HEATING DURING
THE DAY WEDNESDAY...IT SEEMS LOGICAL THAT WE OUGHT TO BE SOMEWHAT
WARMER DURING ON WEDNESDAY. AN AFTERNOON HIGH TEMPERATURE RANGING
FROM THE 60S TO LOW 70S IS CURRENTLY FORECAST ACROSS OUR CWA FOR
WEDNESDAY AS A RESULT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 319 PM CDT TUE MAY 21 2013
WEDNESDAY NIGHT THROUGH TUESDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS THURSDAY NIGHT THROUGH TUESDAY AND
TEMPERATURES THROUGH THE PERIOD.
SHORT WAVE RIDGING ALOFT AND A SURFACE HIGH PRESSURE SYSTEM TRYING
TO NOSE INTO THE AREA WILL ALLOW FOR DRY CONDITIONS FOR WEDNESDAY
NIGHT INTO THURSDAY. THE SURFACE HIGH IS A LITTLE ON THE COOLER
SIDE AND LOW TEMPERATURES WEDNESDAY NIGHT WILL BE REFLECTIVE OF
THAT WITH READINGS ONLY IN THE MID TO UPPER 40S. BY THURSDAY THE
SURFACE HIGH WILL BE MOVING TO THE EAST AND WINDS WILL TURN TO THE
SOUTH. WITH SOME SUNSHINE...EXPECT TEMPERATURES TO WARM TO AROUND
70 DEGREES.
AN UNSETTLED WEATHER PATTERN WILL START TO AFFECT THE AREA
THURSDAY NIGHT AND CONTINUE THROUGH THE PERIOD. THE UPPER LEVEL
SHORT WAVE RIDGE WILL BE BATTERED BY SEVERAL SHORT WAVES SPINNING
OFF FROM AN UPPER LEVEL LOW IN THE WESTERN CONUS. MODELS HAVE SOME
DIFFERENCES IN THE STRENGTH AND LOCATION OF THE UPPER LEVEL LOW IN
THE WESTERN CONUS...ESPECIALLY IN THE MONDAY AND TUESDAY TIME
FRAME.
THE FIRST OF THE WAVES TO AFFECT THE AREA MOVES IN THURSDAY NIGHT.
WITH THE SOUTH WINDS THE MOISTURE INCREASES ESPECIALLY ON THE HIGH
PLAINS AND SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN THE
SOUTHWEST PART OF THE FORECAST AREA THURSDAY NIGHT. THE UPPER WAVE
AND THE LOW LEVEL MOISTURE MOVE OFF TO THE EAST FRIDAY AND FRIDAY
NIGHT AND BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA.
BY SATURDAY A STRONGER WAVE MOVES INTO THE AREA AND WITH WARMER
AIR PUSHING INTO THE AREA THE ATMOSPHERE DESTABILIZES AND MUCAPES
APPROACH 4500 J/KG. THIS COULD LEAD TO SOME STRONGER
THUNDERSTORMS. ANOTHER WAVE MOVES INTO THE AREA ON SUNDAY AND A
WARM FRONT LIFTS NORTH ACROSS THE AREA. THE WARM AIR HELPS TO
DESTABILIZE THINGS FURTHER AND MUCAPES OVER 5000 J/KG ARE EXPECTED
ON SUNDAY. WILL CONTINUE THE THREAT OF SEVERE WEATHER ON SUNDAY.
THE MODELS HAVE A FEW MORE DIFFERENCES BY MONDAY AND TUESDAY. THE
GFS HAS A STRONGER UPPER LEVEL LOW IN THE WEST THAN THE ECMWF DOES
AND HAS SOME STRONGER WAVES THAT MOVE INTO THE PLAINS. WITH THE
MODELS HAVING DIFFERENT SOLUTIONS THEY STILL HAVE SOME
PRECIPITATION AROUND THE AREA FOR MONDAY AND TUESDAY. HAVE KEPT IN
SOME LOWER POPS. IT CERTAINLY WILL NOT BE RAINING ALL THE
TIME...BUT THERE IS SOME CHANCES. THE OTHER CONSISTENCY BETWEEN
THE MODELS IS THAT THERE IS GENERALLY A BROAD RIDGE ACROSS THE
REGION AND TEMPERATURES WILL BE ON THE WARMER SIDE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 655 PM CDT TUE MAY 21 2013
BIGGEST ISSUE WILL BE CEILING HEIGHTS TONIGHT. CEILINGS ARE
CURRENTLY VFR...BUT BARELY...AND UPSTREAM...CEILINGS DIP TO MVFR.
ANTICIPATE THAT OVERNIGHT WILL BE MAINLY MVFR...BUT COULD BE VFR
AT TIMES. CEILINGS SHOULD BECOME VFR ONCE AGAIN FOR WEDNESDAY WITH
WIND BEING A BIT GUSTY ONCE AGAIN...BUT NOT AS GUSTY AS TODAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...BRYANT
LONG TERM...JCB
AVIATION...HEINLEIN
000
FXUS63 KGID 212019
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
319 PM CDT TUE MAY 21 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 319 PM CDT TUE MAY 21 2013
MORNING UPPER AIR ANALYSIS INDICATES A MID TO UPPER LEVEL LOW OVER
NORTHERN PORTIONS OF THE MISSOURI RIVER VALLEY...WITH LONGWAVE
TROUGHING OVER CENTRAL PORTIONS OF THE CONUS...RIDGING OVER THE
EASTERN CONUS...AND ANOTHER MID TO UPPER LEVEL LOW APPROACHING THE
NORTHWESTERN CONUS. MID AND UPPER LEVEL JET ENERGY SURROUNDS THE
MISSOURI VALLEY MID TO UPPER LEVEL LOW...AND ALSO EXTENDS FROM THE
WEST-CENTRAL CONUS INTO THE SOUTHERN CONUS. ALL THAT BEING
SAID...MID TO UPPER LEVEL FLOW IS FAIRLY WEAK OVER OUR
AREA...MAXING OUT AT AROUND 35KTS NEAR 500MB PER 12Z SOUNDING DATA
FROM KLBF AND KOAX. THE STRONGEST TROPOSPHERIC FLOW OVER OUR AREA
IS ACTUALLY LOCATED WITHIN THE LOWEST ~8000FT AGL...WITH A WIND
NEAR 50KTS INDICATED BETWEEN 700 AND 800MB. WATER VAPOR IMAGERY
CLEARLY SHOWS THE MID LEVEL LOW OVER THE MISSOURI RIVER
VALLEY...AS WELL AS THE MID LEVEL LOW NEARING THE NORTHWESTERN
CONUS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS
OVER THE NORTHERN MISSOURI RIVER VALLEY...AND A COLD FRONT EXTENDS
FROM NORTHEASTERN MISSOURI INTO THE OKLAHOMA AND TEXAS. THE LOW
LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE NORTHWEST AS A
RESULT.
A FAIRLY STRONG LOW LEVEL PRESSURE GRADIENT...WORKING IN CONCERT
WITH BOUNDARY LAYER MIXING TO AROUND 800MB...HAS PROMOTED A FAIRLY
BREEZY DAY ACROSS OUR CWA TODAY. A FEW LOCATIONS...PRIMARILY NORTH
OF HIGHWAY 6 AND WEST OF HIGHWAY 281...HAVE PERIODICALLY HIT WIND
ADVISORY CRITERIA. THAT BEING SAID...SUCH OBSERVATIONS HAVE BEEN
FLEETING AND NO HEADLINE IS EXPECTED THROUGH THE REMAINDER OF THIS
AFTERNOON GIVEN THAT THE WIND SPEED FOR THESE LOCATIONS IS SO
MARGINAL WITH RESPECT TO WIND ADVISORY CRITERIA.
DRY CONDITIONS ARE FORECAST ACROSS THE AREA THROUGH THE NEXT 24
HOURS WITH NOTHING IN THE WAY OF HIGH IMPACT WEATHER ANTICIPATED.
GUIDANCE SUGGESTS THE MID LEVEL LOW...CURRENTLY OVER THE NORTHERN
MISSOURI RIVER VALLEY...WILL CONTINUE MOVING EAST OUT OF OUR AREA.
THIS SHOULD BRING AN END TO ANY PRECIPITATION CHANCES AS UPPER
LEVEL RIDGING AND AN OVERALL LACK IN KINEMATIC FORCING SETTLES IN
OVER THE AREA HEADING INTO THE DAY WEDNESDAY. THE CLOUD COVER WILL
ALSO BE ON THE DECREASE FROM SOUTHWEST TO NORTHEAST ACROSS OUR CWA
THROUGH THE NEXT 24 HOURS. FINALLY...A DECREASING LOW LEVEL
PRESSURE GRADIENT SHOULD PROMOTE A WEAKER LOW LEVEL WIND FIELD
ACROSS OUR AREA THROUGH THE NEXT 24 HOURS.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS WOULD OTHERWISE PROVIDE A
SIMILAR LOW TEMPERATURE EARLY TOMORROW MORNING WHEN COMPARED TO
THIS MORNING...BUT WITH CLOUD COVER ON THE DECREASE...ESPECIALLY
ACROSS OUR SOUTHWEST...IT WILL MORE THAN LIKELY BE A TOUCH COOLER.
GIVEN ALL THIS...WENT AHEAD WITH AN OVERNIGHT LOW TEMPERATURE IN
THE MID TO UPPER 40S ACROSS OUR CWA. WE HAVE REALLY STRUGGLED TO
SEE ANY SUNSHINE ACROSS MUCH OF OUR AREA TODAY...BUT WITH
DECREASING CLOUD COVER AND AN INCREASE IN DIABATIC HEATING DURING
THE DAY WEDNESDAY...IT SEEMS LOGICAL THAT WE OUGHT TO BE SOMEWHAT
WARMER DURING ON WEDNESDAY. AN AFTERNOON HIGH TEMPERATURE RANGING
FROM THE 60S TO LOW 70S IS CURRENTLY FORECAST ACROSS OUR CWA FOR
WEDNESDAY AS A RESULT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 319 PM CDT TUE MAY 21 2013
WEDNESDAY NIGHT THROUGH TUESDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS THURSDAY NIGHT THROUGH TUESDAY AND
TEMPERATURES THROUGH THE PERIOD.
SHORT WAVE RIDGING ALOFT AND A SURFACE HIGH PRESSURE SYSTEM TRYING
TO NOSE INTO THE AREA WILL ALLOW FOR DRY CONDITIONS FOR WEDNESDAY
NIGHT INTO THURSDAY. THE SURFACE HIGH IS A LITTLE ON THE COOLER
SIDE AND LOW TEMPERATURES WEDNESDAY NIGHT WILL BE REFLECTIVE OF
THAT WITH READINGS ONLY IN THE MID TO UPPER 40S. BY THURSDAY THE
SURFACE HIGH WILL BE MOVING TO THE EAST AND WINDS WILL TURN TO THE
SOUTH. WITH SOME SUNSHINE...EXPECT TEMPERATURES TO WARM TO AROUND
70 DEGREES.
AN UNSETTLED WEATHER PATTERN WILL START TO AFFECT THE AREA
THURSDAY NIGHT AND CONTINUE THROUGH THE PERIOD. THE UPPER LEVEL
SHORT WAVE RIDGE WILL BE BATTERED BY SEVERAL SHORT WAVES SPINNING
OFF FROM AN UPPER LEVEL LOW IN THE WESTERN CONUS. MODELS HAVE SOME
DIFFERENCES IN THE STRENGTH AND LOCATION OF THE UPPER LEVEL LOW IN
THE WESTERN CONUS...ESPECIALLY IN THE MONDAY AND TUESDAY TIME
FRAME.
THE FIRST OF THE WAVES TO AFFECT THE AREA MOVES IN THURSDAY NIGHT.
WITH THE SOUTH WINDS THE MOISTURE INCREASES ESPECIALLY ON THE HIGH
PLAINS AND SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN THE
SOUTHWEST PART OF THE FORECAST AREA THURSDAY NIGHT. THE UPPER WAVE
AND THE LOW LEVEL MOISTURE MOVE OFF TO THE EAST FRIDAY AND FRIDAY
NIGHT AND BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA.
BY SATURDAY A STRONGER WAVE MOVES INTO THE AREA AND WITH WARMER
AIR PUSHING INTO THE AREA THE ATMOSPHERE DESTABILIZES AND MUCAPES
APPROACH 4500 J/KG. THIS COULD LEAD TO SOME STRONGER
THUNDERSTORMS. ANOTHER WAVE MOVES INTO THE AREA ON SUNDAY AND A
WARM FRONT LIFTS NORTH ACROSS THE AREA. THE WARM AIR HELPS TO
DESTABILIZE THINGS FURTHER AND MUCAPES OVER 5000 J/KG ARE EXPECTED
ON SUNDAY. WILL CONTINUE THE THREAT OF SEVERE WEATHER ON SUNDAY.
THE MODELS HAVE A FEW MORE DIFFERENCES BY MONDAY AND TUESDAY. THE
GFS HAS A STRONGER UPPER LEVEL LOW IN THE WEST THAN THE ECMWF DOES
AND HAS SOME STRONGER WAVES THAT MOVE INTO THE PLAINS. WITH THE
MODELS HAVING DIFFERENT SOLUTIONS THEY STILL HAVE SOME
PRECIPITATION AROUND THE AREA FOR MONDAY AND TUESDAY. HAVE KEPT IN
SOME LOWER POPS. IT CERTAINLY WILL NOT BE RAINING ALL THE
TIME...BUT THERE IS SOME CHANCES. THE OTHER CONSISTENCY BETWEEN
THE MODELS IS THAT THERE IS GENERALLY A BROAD RIDGE ACROSS THE
REGION AND TEMPERATURES WILL BE ON THE WARMER SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1215 PM CDT TUE MAY 21 2013
VFR CONDITIONS FORECAST UNTIL 02Z...WITH MVFR CONDITIONS
THEREAFTER.
BROKEN TO OVERCAST SKIES WILL CONTINUE AT KGRI THROUGH MUCH OF THE
TAF PERIOD...WITH GUIDANCE SUGGESTING AN MVFR CEILING WILL BE
REALIZED STARTING THIS EVENING AND LASTING INTO THE MORNING HOURS
WEDNESDAY...THUS THE MVFR FORECAST 02Z ONWARD. THE SURFACE WIND
WILL REMAIN FROM THE WEST/NORTHWEST THROUGH THE TAF
PERIOD...SUSTAINED NEAR 19KTS AND GUSTING AROUND 27KTS THIS
AFTERNOON INTO THIS EVENING BEFORE DECREASING TO AROUND 12KTS
TONIGHT INTO WEDNESDAY MORNING. 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...JCB
AVIATION...BRYANT
000
FXUS63 KGID 211715
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1215 PM CDT TUE MAY 21 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT TUE MAY 21 2013
UNDER THE INFLUENCE OF AN UPPER LOW PRESSURE SYSTEM...CONDITIONS
WILL BE CLOUDY AND COOL THROUGH THE SHORT TERM PERIODS. WATER VAPOR
IMAGERY PLACED THE UPPER LOW CENTER ACROSS THE EASTERN DAKOTAS EARLY
THIS MORNING...WITH LOBES OF ENERGY ROTATING AROUND THE BACK SIDE OF
THE SYSTEM INTO NORTHERN NEBRASKA. THE UPPER LOW IS PROGGED TO REACH
NORTHEAST NEBRASKA THIS EVENING AND TRANSLATE SOUTH ALONG THE
MISSOURI RIVER TONIGHT. AS THE SYSTEM MOVES SOUTH...OUR REGION WILL
SEE COLDER AIR ADVECTING SOUTH AND A FAIR AMOUNT OF CLOUD COVER
TODAY. CONVECTIVE TEMPS ARE PROGGED IN THE MID/UPPER 50S IN OUR
NORTHERN ZONES AND IN THE UPPER 60S IN THE SOUTH...WHICH ARE
EXPECTED TO BE REACHED THIS AFTN. ALTHOUGH NOT WIDESPREAD...CANNOT
RULE OUT ISOLATED SHOWERS OR SPRINKLES THIS AFTN WITH BETTER CHCS
NORTH OF INTERSTATE 80 IN NEB IN PROXIMITY TO THE UPPER LOW/DYNAMICS
WHILE FARTHER SOUTH FORECAST SOUNDINGS INDICATE DRIER LLVLS. NORMAL
HIGHS THIS TIME OF YEAR ARE IN THE MID 70S...AND WE WILL FALL SHORT
OF THIS TODAY WITH HIGHS RANGING FM NEAR 60F IN OUR NORTH TO NEAR
70F IN THE SOUTH.
HEADING INTO TONIGHT...THE UPPER LOW REACHES IOWA AND A WRAPAROUND
SHOWER/SPRINKLE COULD LINGER ACROSS OUR NORTHERN/NORTHEAST ZONES BUT
CONFIDENCE IS LOW AND HAVE WENT WITH SILENT POPS. CLOUD COVER AND
STEADY WINDS TONIGHT SHLD HOLD LOWS IN THE MID 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 430 AM CDT TUE MAY 21 2013
A RIDGE OF HIGH PRESSURE WILL BEGIN BUILDING IN ACROSS THE PLAINS
ON WEDNESDAY IN WAKE OF THE DEPARTING UPPER LEVEL LOW. THIS WILL
RESULT IN A GRADUAL WARMING TREND WEDNESDAY AND THURSDAY...WITH
HIGH TEMPERATURES TRYING TO CLIMB BACK TOWARDS NORMAL THURSDAY AS
A BIT MORE SUNSHINE CAN BE EXPECTED BEHIND THE DEPARTING LOW.
WEDNESDAY WILL STILL REMAIN FAIRLY COOL FOR THE END OF MAY...WITH
HIGH TEMPERATURES GENERALLY RUNNING ABOUT 10 DEGREES BELOW
CLIMATOLOGICAL NORMS.
AS THE LOW LEVEL FLOW BECOMES MORE SOUTHERLY LATE THURSDAY...
EXPECT MOISTURE TO BE ADVECTED NORTHWARD ACROSS THE REGION AND FOR
INSTABILITY TO BUILD. THIS BUILDING INSTABILITY SHOULD MARK A
RETURN TO A MORE UNSETTLED WEATHER PATTERN THAT WILL CONTINUE INTO
AT LEAST MONDAY OF NEXT WEEK. AT THE SAME TIME...TEMPERATURES WILL
BEGIN TO CLIMB BACK ABOVE NORMAL...WITH GENERALLY 80S EXPECTED OVER
THE UPCOMING HOLIDAY WEEKEND.
WHILE THERE WILL BE ADEQUATE INSTABILITY FOR THUNDERSTORMS
BEGINNING LATE THURSDAY NIGHT...THE BEST CHANCE FOR SEVERE STORMS
CONTINUES TO REMAIN OVER THE WEEKEND...WITH FORECAST SOUNDING
INDICATING THE CAP WILL BE FAIRLY WEAK WITH SEVERAL THOUSAND
JOULES OF CAPE TO WORK WITH. WHILE THERE WILL BE SOME LOW LEVEL
SHEAR...AT THIS POINT THE MAIN THREATS APPEAR TO BE GUSTY
THUNDERSTORM WINDS AND THE POTENTIAL FOR LARGE HAIL. THE EUROPEAN
COMPUTER MODEL IS DEFINITELY A BIT MORE BULLISH WITH PRECIP THAN
THE 00Z GFS ALONG A STALLED OUT FRONT BOUNDARY BOTH SATURDAY AND
SUNDAY...BUT EITHER WAY...EXPECT SHOWERS AND THUNDERSTORMS TO BE
AROUND BOTH DAYS...WITH THE CAPABILITY TO PRODUCE SOME BENEFICIAL
RAINFALL TOTALS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1215 PM CDT TUE MAY 21 2013
VFR CONDITIONS FORECAST UNTIL 02Z...WITH MVFR CONDITIONS
THEREAFTER.
BROKEN TO OVERCAST SKIES WILL CONTINUE AT KGRI THROUGH MUCH OF THE
TAF PERIOD...WITH GUIDANCE SUGGESTING AN MVFR CEILING WILL BE
REALIZED STARTING THIS EVENING AND LASTING INTO THE MORNING HOURS
WEDNESDAY...THUS THE MVFR FORECAST 02Z ONWARD. THE SURFACE WIND
WILL REMAIN FROM THE WEST/NORTHWEST THROUGH THE TAF
PERIOD...SUSTAINED NEAR 19KTS AND GUSTING AROUND 27KTS THIS
AFTERNOON INTO THIS EVENING BEFORE DECREASING TO AROUND 12KTS
TONIGHT INTO WEDNESDAY MORNING. VISIBILITY RESTRICTION IS NOT
EXPECTED AT KGRI THROUGH THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...SAR
AVIATION...BRYANT
000
FXUS63 KGID 211121
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
621 AM CDT TUE MAY 21 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT TUE MAY 21 2013
UNDER THE INFLUENCE OF AN UPPER LOW PRESSURE SYSTEM...CONDITIONS
WILL BE CLOUDY AND COOL THROUGH THE SHORT TERM PERIODS. WATER VAPOR
IMAGERY PLACED THE UPPER LOW CENTER ACROSS THE EASTERN DAKOTAS EARLY
THIS MORNING...WITH LOBES OF ENERGY ROTATING AROUND THE BACK SIDE OF
THE SYSTEM INTO NORTHERN NEBRASKA. THE UPPER LOW IS PROGGED TO REACH
NORTHEAST NEBRASKA THIS EVENING AND TRANSLATE SOUTH ALONG THE
MISSOURI RIVER TONIGHT. AS THE SYSTEM MOVES SOUTH...OUR REGION WILL
SEE COLDER AIR ADVECTING SOUTH AND A FAIR AMOUNT OF CLOUD COVER
TODAY. CONVECTIVE TEMPS ARE PROGGED IN THE MID/UPPER 50S IN OUR
NORTHERN ZONES AND IN THE UPPER 60S IN THE SOUTH...WHICH ARE
EXPECTED TO BE REACHED THIS AFTN. ALTHOUGH NOT WIDESPREAD...CANNOT
RULE OUT ISOLATED SHOWERS OR SPRINKLES THIS AFTN WITH BETTER CHCS
NORTH OF INTERSTATE 80 IN NEB IN PROXIMITY TO THE UPPER LOW/DYNAMICS
WHILE FARTHER SOUTH FORECAST SOUNDINGS INDICATE DRIER LLVLS. NORMAL
HIGHS THIS TIME OF YEAR ARE IN THE MID 70S...AND WE WILL FALL SHORT
OF THIS TODAY WITH HIGHS RANGING FM NEAR 60F IN OUR NORTH TO NEAR
70F IN THE SOUTH.
HEADING INTO TONIGHT...THE UPPER LOW REACHES IOWA AND A WRAPAROUND
SHOWER/SPRINKLE COULD LINGER ACROSS OUR NORTHERN/NORTHEAST ZONES BUT
CONFIDENCE IS LOW AND HAVE WENT WITH SILENT POPS. CLOUD COVER AND
STEADY WINDS TONIGHT SHLD HOLD LOWS IN THE MID 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 430 AM CDT TUE MAY 21 2013
A RIDGE OF HIGH PRESSURE WILL BEGIN BUILDING IN ACROSS THE PLAINS
ON WEDNESDAY IN WAKE OF THE DEPARTING UPPER LEVEL LOW. THIS WILL
RESULT IN A GRADUAL WARMING TREND WEDNESDAY AND THURSDAY...WITH
HIGH TEMPERATURES TRYING TO CLIMB BACK TOWARDS NORMAL THURSDAY AS
A BIT MORE SUNSHINE CAN BE EXPECTED BEHIND THE DEPARTING LOW.
WEDNESDAY WILL STILL REMAIN FAIRLY COOL FOR THE END OF MAY...WITH
HIGH TEMPERATURES GENERALLY RUNNING ABOUT 10 DEGREES BELOW
CLIMATOLOGICAL NORMS.
AS THE LOW LEVEL FLOW BECOMES MORE SOUTHERLY LATE THURSDAY...
EXPECT MOISTURE TO BE ADVECTED NORTHWARD ACROSS THE REGION AND FOR
INSTABILITY TO BUILD. THIS BUILDING INSTABILITY SHOULD MARK A
RETURN TO A MORE UNSETTLED WEATHER PATTERN THAT WILL CONTINUE INTO
AT LEAST MONDAY OF NEXT WEEK. AT THE SAME TIME...TEMPERATURES WILL
BEGIN TO CLIMB BACK ABOVE NORMAL...WITH GENERALLY 80S EXPECTED OVER
THE UPCOMING HOLIDAY WEEKEND.
WHILE THERE WILL BE ADEQUATE INSTABILITY FOR THUNDERSTORMS
BEGINNING LATE THURSDAY NIGHT...THE BEST CHANCE FOR SEVERE STORMS
CONTINUES TO REMAIN OVER THE WEEKEND...WITH FORECAST SOUNDING
INDICATING THE CAP WILL BE FAIRLY WEAK WITH SEVERAL THOUSAND
JOULES OF CAPE TO WORK WITH. WHILE THERE WILL BE SOME LOW LEVEL
SHEAR...AT THIS POINT THE MAIN THREATS APPEAR TO BE GUSTY
THUNDERSTORM WINDS AND THE POTENTIAL FOR LARGE HAIL. THE EUROPEAN
COMPUTER MODEL IS DEFINITELY A BIT MORE BULLISH WITH PRECIP THAN
THE 00Z GFS ALONG A STALLED OUT FRONT BOUNDARY BOTH SATURDAY AND
SUNDAY...BUT EITHER WAY...EXPECT SHOWERS AND THUNDERSTORMS TO BE
AROUND BOTH DAYS...WITH THE CAPABILITY TO PRODUCE SOME BENEFICIAL
RAINFALL TOTALS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 621 AM CDT TUE MAY 21 2013
AN AREA OF LOW PRESSURE OVER SOUTH DAKOTA WILL KEEP MVFR TO VFR CEILINGS
OVER GRI THROUGH THE FORECAST PERIOD. THE WINDS WILL BE WESTERLY
TO NORTHWESTERLY WITH GUSTS TO AROUND 25KTS BY EARLY AFTERNOON. A
FEW RAIN SHOWERS WILL BE POSSIBLE THIS AFTERNOON BUT CONFIDENCE
ISN`T HIGH ENOUGH TO INCLUDE THEM IN THE TAF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...SAR
AVIATION...BEDA
000
FXUS63 KGID 210957
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
457 AM CDT TUE MAY 21 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT TUE MAY 21 2013
UNDER THE INFLUENCE OF AN UPPER LOW PRESSURE SYSTEM...CONDITIONS
WILL BE CLOUDY AND COOL THROUGH THE SHORT TERM PERIODS. WATER VAPOR
IMAGERY PLACED THE UPPER LOW CENTER ACROSS THE EASTERN DAKOTAS EARLY
THIS MORNING...WITH LOBES OF ENERGY ROTATING AROUND THE BACK SIDE OF
THE SYSTEM INTO NORTHERN NEBRASKA. THE UPPER LOW IS PROGGED TO REACH
NORTHEAST NEBRASKA THIS EVENING AND TRANSLATE SOUTH ALONG THE
MISSOURI RIVER TONIGHT. AS THE SYSTEM MOVES SOUTH...OUR REGION WILL
SEE COLDER AIR ADVECTING SOUTH AND A FAIR AMOUNT OF CLOUD COVER
TODAY. CONVECTIVE TEMPS ARE PROGGED IN THE MID/UPPER 50S IN OUR
NORTHERN ZONES AND IN THE UPPER 60S IN THE SOUTH...WHICH ARE
EXPECTED TO BE REACHED THIS AFTN. ALTHOUGH NOT WIDESPREAD...CANNOT
RULE OUT ISOLATED SHOWERS OR SPRINKLES THIS AFTN WITH BETTER CHCS
NORTH OF INTERSTATE 80 IN NEB IN PROXIMITY TO THE UPPER LOW/DYNAMICS
WHILE FARTHER SOUTH FORECAST SOUNDINGS INDICATE DRIER LLVLS. NORMAL
HIGHS THIS TIME OF YEAR ARE IN THE MID 70S...AND WE WILL FALL SHORT
OF THIS TODAY WITH HIGHS RANGING FM NEAR 60F IN OUR NORTH TO NEAR
70F IN THE SOUTH.
HEADING INTO TONIGHT...THE UPPER LOW REACHES IOWA AND A WRAPAROUND
SHOWER/SPRINKLE COULD LINGER ACROSS OUR NORTHERN/NORTHEAST ZONES BUT
CONFIDENCE IS LOW AND HAVE WENT WITH SILENT POPS. CLOUD COVER AND
STEADY WINDS TONIGHT SHLD HOLD LOWS IN THE MID 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 430 AM CDT TUE MAY 21 2013
A RIDGE OF HIGH PRESSURE WILL BEGIN BUILDING IN ACROSS THE PLAINS
ON WEDNESDAY IN WAKE OF THE DEPARTING UPPER LEVEL LOW. THIS WILL
RESULT IN A GRADUAL WARMING TREND WEDNESDAY AND THURSDAY...WITH
HIGH TEMPERATURES TRYING TO CLIMB BACK TOWARDS NORMAL THURSDAY AS
A BIT MORE SUNSHINE CAN BE EXPECTED BEHIND THE DEPARTING LOW.
WEDNESDAY WILL STILL REMAIN FAIRLY COOL FOR THE END OF MAY...WITH
HIGH TEMPERATURES GENERALLY RUNNING ABOUT 10 DEGREES BELOW
CLIMATOLOGICAL NORMS.
AS THE LOW LEVEL FLOW BECOMES MORE SOUTHERLY LATE THURSDAY...
EXPECT MOISTURE TO BE ADVECTED NORTHWARD ACROSS THE REGION AND FOR
INSTABILITY TO BUILD. THIS BUILDING INSTABILITY SHOULD MARK A
RETURN TO A MORE UNSETTLED WEATHER PATTERN THAT WILL CONTINUE INTO
AT LEAST MONDAY OF NEXT WEEK. AT THE SAME TIME...TEMPERATURES WILL
BEGIN TO CLIMB BACK ABOVE NORMAL...WITH GENERALLY 80S EXPECTED OVER
THE UPCOMING HOLIDAY WEEKEND.
WHILE THERE WILL BE ADEQUATE INSTABILITY FOR THUNDERSTORMS
BEGINNING LATE THURSDAY NIGHT...THE BEST CHANCE FOR SEVERE STORMS
CONTINUES TO REMAIN OVER THE WEEKEND...WITH FORECAST SOUNDING
INDICATING THE CAP WILL BE FAIRLY WEAK WITH SEVERAL THOUSAND
JOULES OF CAPE TO WORK WITH. WHILE THERE WILL BE SOME LOW LEVEL
SHEAR...AT THIS POINT THE MAIN THREATS APPEAR TO BE GUSTY
THUNDERSTORM WINDS AND THE POTENTIAL FOR LARGE HAIL. THE EUROPEAN
COMPUTER MODEL IS DEFINITELY A BIT MORE BULLISH WITH PRECIP THAN
THE 00Z GFS ALONG A STALLED OUT FRONT BOUNDARY BOTH SATURDAY AND
SUNDAY...BUT EITHER WAY...EXPECT SHOWERS AND THUNDERSTORMS TO BE
AROUND BOTH DAYS...WITH THE CAPABILITY TO PRODUCE SOME BENEFICIAL
RAINFALL TOTALS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1141 PM CDT MON MAY 20 2013
CLOUD COVER WITH VARYING HEIGHTS BETWEEN MVFR AND VFR WILL IMPACT
KGRI THRU THE TAF PERIOD UNDER THE INFLUENCE OF AN UPPER LOW
PRESSURE SYSTEM ACROSS THE NORTHERN AND CENTRAL PLAINS REGION. A
FEW SPRINKLES OR ISOLATED RAIN SHOWERS ARE POSSIBLE MAINLY TUESDAY
AFTN BUT CHCS ARE NOT GREAT ENOUGH TO INCLUDE IN TAF. WINDS WILL
BE STEADY FM THE W/NW WITH GUSTS AROUND 25KTS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...SAR
AVIATION...FAY
000
FXUS63 KGID 210453
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1153 PM CDT MON MAY 20 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 349 PM CDT MON MAY 20 2013
MAIN FORECAST CONCERNS WILL BE CHANCES FOR SHOWERS AND
THUNDERSTORMS TONIGHT AND TUESDAY AND TEMPERATURES.
SATELLITE AND OBSERVATIONS SHOW CUMULUS HAVE DEVELOPED ACROSS THE
AREA THIS AFTERNOON. RADAR SHOWS A BAND OF SHOWERS TO THE SOUTHEAST
OF THE FORECAST AREA WHICH SHOULD STAY OUT OF THE AREA. A FEW MORE
SHOWERS OR EVEN SPRINKLES HAVE DEVELOPED TO THE NORTHWEST AND WEST.
WITH THE UPPER LEVEL LOW IN THE NORTHERN PLAINS THESE SHOWERS SHOULD
MOVE INTO THE FORECAST AREA LATER THIS AFTERNOON AND THIS EVENING.
THE UPPER LEVEL LOW IN THE NORTHERN PLAINS WILL BE THE MAIN
WEATHER FEATURE DURING THE PERIOD. WITH THIS UPPER LOW SPINNING IN
THE NORTHERN PLAINS...SMALL LOBES OF ENERGY GET PUSHED INTO THE
FORECAST AREA. WITH THE CUMULUS THAT IS ACROSS THE AREA...AS SOME
OF THAT ENERGY MOVES INTO THE AREA SOME SHOWERS COULD DEVELOP. THE
SMALL BAND OF SHOWERS TO THE NORTHWEST WILL BE THE MAIN AREA THAT
WILL AFFECT THE FORECAST AREA THIS AFTERNOON INTO THIS EVENING.
EXPECT THAT MOST OF THESE WILL BE SHOWERS...BUT IN THE SOUTHEAST
PART OF THE FORECAST AREA LATE THIS AFTERNOON THERE IS SOME MUCAPE
AROUND 1200 J/KG. THIS COULD MAKE FOR A FEW THUNDERSTORMS IF THE
SHOWERS GET TO THE SOUTHEAST. DURING THE EVENING THE MUCAPE DROPS
OFF QUICKLY AND THE CHANCE FOR THUNDERSTORMS DIMINISHES NOT TOO
LONG AFTER SUNSET. DURING THE EVENING THE CHANCE FOR SHOWERS ALSO
DIMINISHES AND IS CONFINED TO THE NORTHWEST PART OF THE AREA
CLOSER TO THE UPPER LOW AND THE LOBES OF ENERGY MOVING THROUGH
NORTHERN NEBRASKA.
THE CHANCES FOR SHOWERS CONTINUES LATE TONIGHT AND DURING THE DAY
ON TUESDAY BUT SHOULD BE SLIGHT CHANCES AND SPOTTY SHOWERS. ALSO
THE SHOWERS WILL BE MAINLY IN THE NORTHERN PART OF THE FORECAST
AREA.
ANOTHER CONSEQUENCE OF THE UPPER LEVEL LOW IS THAT COOLER AIR IS
SPUN INTO THE AREA FROM THE NORTH. LOW TEMPERATURES TONIGHT WILL BE
AROUND 50 DEGREES AND HIGHS TOMORROW WILL BE MOSTLY IN THE 60S TO
AROUND 70.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 349 PM CDT MON MAY 20 2013
GUIDANCE SUGGESTS THE LONG-TERM FORECAST PERIOD SHOULD START OFF
DRY AS THE MID LEVEL LOW...CURRENTLY OVER THE CENTRAL
PLAINS...BEGINS MOVING EAST...OUT OF OUR AREA. THE RESULTANT LACK
IN KINEMATIC FORCING AS A MID TO UPPER LEVEL RIDGE AXIS MOVES
OVERHEAD SUGGESTS LITTLE IN THE WAY OF PRECIPITATION WILL BE
REALIZED ACROSS OUR AREA WEDNESDAY AND THURSDAY. STARTING THURSDAY
NIGHT HOWEVER...IT APPEARS AS THOUGH THE MID TO UPPER LEVEL RIDGE
WILL BREAK DOWN SOMEWHAT AS SEVERAL MID LEVEL PERTURBATIONS BEGIN
EJECTING FROM A WESTERN-CONUS LONG WAVE TROUGH. PERIODS OF
INCREASED DPVA AND MID LEVEL THERMAL ADVECTION MAY BRING PERIODIC
PRECIPITATION TO OUR AREA THURSDAY NIGHT ONWARD. IN
ADDITION...INCREASED LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF
AN ~850MB JET STREAK MAY ALLOW FOR ENHANCED CHANCES FOR MEASURABLE
PRECIPITATION DURING THE OVERNIGHT HOURS. ALLBLEND RESPONDED BY
PROVIDING POPS TO MOST ALL OF OUR CWA THURSDAY NIGHT ONWARD AND
THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART.
LOW LEVEL RETURN FLOW AND RESULTANT LOW LEVEL MOISTURE FLUX INTO
THE CENTRAL PLAINS SHOULD ALLOW FOR INCREASING POTENTIAL
INSTABILITY ACROSS OUR AREA THURSDAY NIGHT ONWARD. THE OPERATIONAL
GFS AND EC BOTH SUGGEST DEEP LAYER MUCAPE VALUES OF
2000-3000J/KG...ALONG WITH DEEP LAYER BULK SHEAR VALUES OF
20-30KTS...WILL OVERTAKE OUR AREA SATURDAY THROUGH THE END OF THE
FORECAST PERIOD. GIVEN THE APPARENT POTENTIAL FOR STRONG UPDRAFT
PRODUCTION DURING THIS TIME PERIOD...WILL GO AHEAD AND OUTLOOK
SEVERE WEATHER IN THE HWO SATURDAY ONWARD.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS A SIMILAR HIGH
AND LOW TEMPERATURE WILL BE REALIZED WEDNESDAY THROUGH FRIDAY FOR
MOST LOCATIONS ACROSS OUR CWA. LOW LEVEL RETURN FLOW AND RESULTANT
LOW LEVEL WARM AIR ADVECTION SHOULD THEN ALLOW FOR WARMER WEATHER
TO FINISH OUT THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1141 PM CDT MON MAY 20 2013
CLOUD COVER WITH VARYING HEIGHTS BETWEEN MVFR AND VFR WILL IMPACT
KGRI THRU THE TAF PERIOD UNDER THE INFLUENCE OF AN UPPER LOW
PRESSURE SYSTEM ACROSS THE NORTHERN AND CENTRAL PLAINS REGION. A
FEW SPRINKLES OR ISOLATED RAIN SHOWERS ARE POSSIBLE MAINLY TUESDAY
AFTN BUT CHCS ARE NOT GREAT ENOUGH TO INCLUDE IN TAF. WINDS WILL
BE STEADY FM THE W/NW WITH GUSTS AROUND 25KTS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...FAY
000
FXUS63 KGID 202316
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
616 PM CDT MON MAY 20 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 349 PM CDT MON MAY 20 2013
MAIN FORECAST CONCERNS WILL BE CHANCES FOR SHOWERS AND
THUNDERSTORMS TONIGHT AND TUESDAY AND TEMPERATURES.
SATELLITE AND OBSERVATIONS SHOW CUMULUS HAVE DEVELOPED ACROSS THE
AREA THIS AFTERNOON. RADAR SHOWS A BAND OF SHOWERS TO THE SOUTHEAST
OF THE FORECAST AREA WHICH SHOULD STAY OUT OF THE AREA. A FEW MORE
SHOWERS OR EVEN SPRINKLES HAVE DEVELOPED TO THE NORTHWEST AND WEST.
WITH THE UPPER LEVEL LOW IN THE NORTHERN PLAINS THESE SHOWERS SHOULD
MOVE INTO THE FORECAST AREA LATER THIS AFTERNOON AND THIS EVENING.
THE UPPER LEVEL LOW IN THE NORTHERN PLAINS WILL BE THE MAIN
WEATHER FEATURE DURING THE PERIOD. WITH THIS UPPER LOW SPINNING IN
THE NORTHERN PLAINS...SMALL LOBES OF ENERGY GET PUSHED INTO THE
FORECAST AREA. WITH THE CUMULUS THAT IS ACROSS THE AREA...AS SOME
OF THAT ENERGY MOVES INTO THE AREA SOME SHOWERS COULD DEVELOP. THE
SMALL BAND OF SHOWERS TO THE NORTHWEST WILL BE THE MAIN AREA THAT
WILL AFFECT THE FORECAST AREA THIS AFTERNOON INTO THIS EVENING.
EXPECT THAT MOST OF THESE WILL BE SHOWERS...BUT IN THE SOUTHEAST
PART OF THE FORECAST AREA LATE THIS AFTERNOON THERE IS SOME MUCAPE
AROUND 1200 J/KG. THIS COULD MAKE FOR A FEW THUNDERSTORMS IF THE
SHOWERS GET TO THE SOUTHEAST. DURING THE EVENING THE MUCAPE DROPS
OFF QUICKLY AND THE CHANCE FOR THUNDERSTORMS DIMINISHES NOT TOO
LONG AFTER SUNSET. DURING THE EVENING THE CHANCE FOR SHOWERS ALSO
DIMINISHES AND IS CONFINED TO THE NORTHWEST PART OF THE AREA
CLOSER TO THE UPPER LOW AND THE LOBES OF ENERGY MOVING THROUGH
NORTHERN NEBRASKA.
THE CHANCES FOR SHOWERS CONTINUES LATE TONIGHT AND DURING THE DAY
ON TUESDAY BUT SHOULD BE SLIGHT CHANCES AND SPOTTY SHOWERS. ALSO
THE SHOWERS WILL BE MAINLY IN THE NORTHERN PART OF THE FORECAST
AREA.
ANOTHER CONSEQUENCE OF THE UPPER LEVEL LOW IS THAT COOLER AIR IS
SPUN INTO THE AREA FROM THE NORTH. LOW TEMPERATURES TONIGHT WILL BE
AROUND 50 DEGREES AND HIGHS TOMORROW WILL BE MOSTLY IN THE 60S TO
AROUND 70.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 349 PM CDT MON MAY 20 2013
GUIDANCE SUGGESTS THE LONG-TERM FORECAST PERIOD SHOULD START OFF
DRY AS THE MID LEVEL LOW...CURRENTLY OVER THE CENTRAL
PLAINS...BEGINS MOVING EAST...OUT OF OUR AREA. THE RESULTANT LACK
IN KINEMATIC FORCING AS A MID TO UPPER LEVEL RIDGE AXIS MOVES
OVERHEAD SUGGESTS LITTLE IN THE WAY OF PRECIPITATION WILL BE
REALIZED ACROSS OUR AREA WEDNESDAY AND THURSDAY. STARTING THURSDAY
NIGHT HOWEVER...IT APPEARS AS THOUGH THE MID TO UPPER LEVEL RIDGE
WILL BREAK DOWN SOMEWHAT AS SEVERAL MID LEVEL PERTURBATIONS BEGIN
EJECTING FROM A WESTERN-CONUS LONG WAVE TROUGH. PERIODS OF
INCREASED DPVA AND MID LEVEL THERMAL ADVECTION MAY BRING PERIODIC
PRECIPITATION TO OUR AREA THURSDAY NIGHT ONWARD. IN
ADDITION...INCREASED LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF
AN ~850MB JET STREAK MAY ALLOW FOR ENHANCED CHANCES FOR MEASURABLE
PRECIPITATION DURING THE OVERNIGHT HOURS. ALLBLEND RESPONDED BY
PROVIDING POPS TO MOST ALL OF OUR CWA THURSDAY NIGHT ONWARD AND
THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART.
LOW LEVEL RETURN FLOW AND RESULTANT LOW LEVEL MOISTURE FLUX INTO
THE CENTRAL PLAINS SHOULD ALLOW FOR INCREASING POTENTIAL
INSTABILITY ACROSS OUR AREA THURSDAY NIGHT ONWARD. THE OPERATIONAL
GFS AND EC BOTH SUGGEST DEEP LAYER MUCAPE VALUES OF
2000-3000J/KG...ALONG WITH DEEP LAYER BULK SHEAR VALUES OF
20-30KTS...WILL OVERTAKE OUR AREA SATURDAY THROUGH THE END OF THE
FORECAST PERIOD. GIVEN THE APPARENT POTENTIAL FOR STRONG UPDRAFT
PRODUCTION DURING THIS TIME PERIOD...WILL GO AHEAD AND OUTLOOK
SEVERE WEATHER IN THE HWO SATURDAY ONWARD.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS A SIMILAR HIGH
AND LOW TEMPERATURE WILL BE REALIZED WEDNESDAY THROUGH FRIDAY FOR
MOST LOCATIONS ACROSS OUR CWA. LOW LEVEL RETURN FLOW AND RESULTANT
LOW LEVEL WARM AIR ADVECTION SHOULD THEN ALLOW FOR WARMER WEATHER
TO FINISH OUT THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 607 PM CDT MON MAY 20 2013
KGRI WILL SEE INTERMITTENT CLOUD COVER THRU THE TAF PERIOD UNDER
THE UNFLUENCE OF AN UPPER LOW PRESSURE SYSTEM CROSSING THE CENTRAL
PLAINS. CLOUDS MAY SCATTER FOR A TIME THIS EVENING...WITH CLOUD
COVER INCREASING AGAIN TONIGHT AND PERSISTING THRU TUESDAY AS THE
UPPER SYSTEM TRANSLATES FARTHER SOUTHEAST. FOR THE MOST
PART...CLOUDS ARE EXPECTED TO BE IN THE VFR CATEGORY BUT MAY DROP
TO MVFR AT TIMES. RAIN SHOWERS OR SPRINKLES WILL BE HIT OR MISS
AND DID NOT MENTION JUST YET.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...FAY
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