000
FXUS63 KBIS 181824
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
124 PM CDT SAT MAY 18 2013
.UPDATE...
ISSUED AT 105 PM CDT SAT MAY 18 2013
THE DISCUSSION FROM THE PREVIOUS UPDATE REMAINS VALID AS THE MAIN
FOCUS IS STILL LOCATION AND TIMING OF CONVECTIVE INITIATION THIS
AFTERNOON.
THE ONLY NEW INFORMATION TO ADD IS THE PRESENCE OF LOW LEVEL
CONVERGENCE STRETCHING FROM DICKINSON TO BUFFALO SD. VISIBLE
SATELLITE INDICATES SOME AGITATED CUMULUS THERE...AND 18 UTC SPC
MESOANALYSIS INDICATES A MARKED INCREASE IN MIXED LAYER CAPE OVER
THE PAST HOUR. SHOULD THIS TREND CONTINUE...STRONGER STORMS MAY BE
REALIZED BY 4 PM CDT.
UPDATE ISSUED AT 1024 AM CDT SAT MAY 18 2013
THE TIMING AND LOCATION OF CONVECTIVE INITIATION IN THIS COMPLEX
SCENARIO IS THE MAIN FOCUS TODAY. PRECIPITATION CHANCES ALONG THE
MISSOURI RIVER HAVE GENERALLY BEEN LOWERED FOR THIS MORNING AND
EARLY AFTERNOON AS LOW LEVEL STRATUS WILL HELP TO STABILIZE THE
ATMOSPHERE UNTIL THE NEXT MID LEVEL SHORTWAVE ARRIVES THIS
AFTERNOON.
THE 12 AND 13 UTC HRRR HAVE PICKED UP ON THE CLEARING OVER
NORTHWESTERN SOUTH DAKOTA THIS MORNING...AND NOW INITIATES
CONVECTION THERE AND IN SOUTHWESTERN NORTH DAKOTA BY 21 UTC. 12
UTC GFS THERMODYNAMIC PROFILES SUPPORT THIS IDEA ALONG WITH THE 00
UTC ECMWF AS CAPE IS FORECAST TO EXCEED 1000 J/KG THERE.
THE CURRENT THINKING IS THAT CONVECTION WILL SPREAD GENERALLY
EAST-NORTHEASTWARD UNTIL MID/LATE AFTERNOON DESTABILIZATION AND
MIDDLE LEVEL HEIGHT FALLS FINALLY INITIATE ADDITIONAL CONVECTION
BETWEEN THE MISSOURI AND JAMES RIVERS ALONG THE DAKOTA BORDER.
UPDATE ISSUED AT 644 AM CDT SAT MAY 18 2013
UPDATE MAINLY FOR POP TRENDS TODAY. SHOWERS AND ISOLATED STORMS
HAVE PUSHED INTO THE FAR NORTHEAST EARLY THIS MORNING. RECENT RUNS
OF THE RAP HAVE A GOOD HANDLE ON NEAR TERM TRENDS...AND HAVE
REDUCED POPS THROUGH THE MORNING INTO EARLY AFTERNOON. STILL
EXPECTING THE FOCUS OF AFTERNOON CONVECTION ALONG A BOUNDARY TO
THE SOUTHEAST...WITH POTENTIAL FOR SOME SEVERE STORMS TO DEVELOP
BY MID AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 18 2013
THE MAIN FOCUS IN THE SHORT TERM IS CONVECTIVE TRENDS AND
POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND TONIGHT. IN THE
NEAR TERM...THE 18/07Z RAP MODEL HAS A GOOD HANDLE ON THE LOCATION
OF THE CURRENT STORMS ACROSS THE NORTHEAST HALF OF THE FORECAST
AREA. STORMS SHOULD CONTINUE TO LIFT NORTH THROUGH THE MORNING
HOURS. AFTERNOON REDEVELOPMENT IS EXPECTED TO FOCUS ON THE TROUGH
EXTENDING ACROSS THE SOUTHEAST COUNTIES. ML CAPES AROUND 1500 TO
2000 J/KG ARE EXPECTED ALONG WITH DEEP LAYER SHEAR AT OR ABOVE 40
KTS...SUFFICIENT FOR SUPERCELL DEVELOPMENT WITH LARGE
HAIL/DAMAGING WIND THREAT. IN THE EXTREME SOUTHEAST...LOW
LCL`S...DECENT LOW LEVEL CAPE...AND A NARROW AREA OF FAVORABLE
0-1KM SHEAR SUGGEST THERE MAY ALSO BE A SEVERAL HOUR WINDOW OF
TORNADO THREAT THROUGH EARLY EVENING.
THE SOUTHEAST HALF OF THE FORECAST AREA LOOKS FAVORED FOR THE
HEAVIER RAINFALL AMOUNTS THROUGH TONIGHT. SIGNIFICANT RISES ON
MAINSTEM RIVERS ARE NOT EXPECTED...BUT WILL BE MONITORING FOR
LOCALIZED HEAVY RUNOFF AND ISOLATED SHORT TERM FLOODING DUE TO
EXTREME RAINFALL RATES OR MULTIPLE ROUNDS OF STORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 18 2013
A LARGE CLOSED H5 LOW IS FORECAST TO DRIFT THROUGH THE REGION
SUNDAY THROUGH TUESDAY. THE THREAT FOR SEVERE WEATHER WILL
DIMINISH DURING THIS PERIOD...BUT MODERATE TO LOCALLY HEAVY RAINFALL
WILL PERSIST. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE
POSSIBLE OVER THE WEEKEND THROUGH TUESDAY...WITH THE HIGHER TOTALS
TOWARD THE JAMES RIVER VALLEY. AGAIN...SIGNIFICANT RESPONSES ARE
NOT EXPECTED ON AREA RIVERS...BUT WILL BE WATCHING SMALLER CREEKS
AND STREAMS...AS WELL AS THE POTENTIAL FOR URBAN FLOODING. CLOUDS
AND RAIN WILL KEEP TEMPS DOWN IN THE 50S/LOWER 60S MONDAY AND
TUESDAY...BEFORE A WARMING TREND FROM MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 105 PM CDT SAT MAY 18 2013
LOW STRATUS HAS BEEN VERY DIFFICULT TO FORECAST TODAY...BUT
SHOULD LIFT AT ALL SITES BY 20 UTC. SHOWERS AND THUNDERSTORMS WILL
CAUSE MVFR CONDITIONS AT MOST TAF SITES TODAY...WITH BRIEF PERIODS
OF IFR POSSIBLE IN STRONGER STORMS. IFR/LIFR FOG AND LOW STRATUS
WILL LIKELY RETURN AFTER MIDNIGHT TONIGHT IN THE WAKE OF
PRECIPITATION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...SCHECK
SHORT TERM/LONG TERM...RP KINNEY
000
FXUS63 KBIS 181546
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1046 AM CDT SAT MAY 18 2013
.UPDATE...
ISSUED AT 1024 AM CDT SAT MAY 18 2013
THE TIMING AND LOCATION OF CONVECTIVE INITIATION IN THIS COMPLEX
SCENARIO IS THE MAIN FOCUS TODAY. PRECIPITATION CHANCES ALONG THE
MISSOURI RIVER HAVE GENERALLY BEEN LOWERED FOR THIS MORNING AND
EARLY AFTERNOON AS LOW LEVEL STRATUS WILL HELP TO STABILIZE THE
ATMOSPHERE UNTIL THE NEXT MID LEVEL SHORTWAVE ARRIVES THIS
AFTERNOON.
THE 12 AND 13 UTC HRRR HAVE PICKED UP ON THE CLEARING OVER
NORTHWESTERN SOUTH DAKOTA THIS MORNING...AND NOW INITIATES
CONVECTION THERE AND IN SOUTHWESTERN NORTH DAKOTA BY 21 UTC. 12
UTC GFS THERMODYNAMIC PROFILES SUPPORT THIS IDEA ALONG WITH THE 00
UTC ECMWF AS CAPE IS FORECAST TO EXCEED 1000 J/KG THERE.
THE CURRENT THINKING IS THAT CONVECTION WILL SPREAD GENERALLY
EAST-NORTHEASTWARD UNTIL MID/LATE AFTERNOON DESTABILIZATION AND
MIDDLE LEVEL HEIGHT FALLS FINALLY INITIATE ADDITIONAL CONVECTION
BETWEEN THE MISSOURI AND JAMES RIVERS ALONG THE DAKOTA BORDER.
UPDATE ISSUED AT 644 AM CDT SAT MAY 18 2013
UPDATE MAINLY FOR POP TRENDS TODAY. SHOWERS AND ISOLATED STORMS
HAVE PUSHED INTO THE FAR NORTHEAST EARLY THIS MORNING. RECENT RUNS
OF THE RAP HAVE A GOOD HANDLE ON NEAR TERM TRENDS...AND HAVE
REDUCED POPS THROUGH THE MORNING INTO EARLY AFTERNOON. STILL
EXPECTING THE FOCUS OF AFTERNOON CONVECTION ALONG A BOUNDARY TO
THE SOUTHEAST...WITH POTENTIAL FOR SOME SEVERE STORMS TO DEVELOP
BY MID AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 18 2013
THE MAIN FOCUS IN THE SHORT TERM IS CONVECTIVE TRENDS AND
POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND TONIGHT. IN THE
NEAR TERM...THE 18/07Z RAP MODEL HAS A GOOD HANDLE ON THE LOCATION
OF THE CURRENT STORMS ACROSS THE NORTHEAST HALF OF THE FORECAST
AREA. STORMS SHOULD CONTINUE TO LIFT NORTH THROUGH THE MORNING
HOURS. AFTERNOON REDEVELOPMENT IS EXPECTED TO FOCUS ON THE TROUGH
EXTENDING ACROSS THE SOUTHEAST COUNTIES. ML CAPES AROUND 1500 TO
2000 J/KG ARE EXPECTED ALONG WITH DEEP LAYER SHEAR AT OR ABOVE 40
KTS...SUFFICIENT FOR SUPERCELL DEVELOPMENT WITH LARGE
HAIL/DAMAGING WIND THREAT. IN THE EXTREME SOUTHEAST...LOW
LCL`S...DECENT LOW LEVEL CAPE...AND A NARROW AREA OF FAVORABLE
0-1KM SHEAR SUGGEST THERE MAY ALSO BE A SEVERAL HOUR WINDOW OF
TORNADO THREAT THROUGH EARLY EVENING.
THE SOUTHEAST HALF OF THE FORECAST AREA LOOKS FAVORED FOR THE
HEAVIER RAINFALL AMOUNTS THROUGH TONIGHT. SIGNIFICANT RISES ON
MAINSTEM RIVERS ARE NOT EXPECTED...BUT WILL BE MONITORING FOR
LOCALIZED HEAVY RUNOFF AND ISOLATED SHORT TERM FLOODING DUE TO
EXTREME RAINFALL RATES OR MULTIPLE ROUNDS OF STORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 18 2013
A LARGE CLOSED H5 LOW IS FORECAST TO DRIFT THROUGH THE REGION
SUNDAY THROUGH TUESDAY. THE THREAT FOR SEVERE WEATHER WILL
DIMINISH DURING THIS PERIOD...BUT MODERATE TO LOCALLY HEAVY RAINFALL
WILL PERSIST. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE
POSSIBLE OVER THE WEEKEND THROUGH TUESDAY...WITH THE HIGHER TOTALS
TOWARD THE JAMES RIVER VALLEY. AGAIN...SIGNIFICANT RESPONSES ARE
NOT EXPECTED ON AREA RIVERS...BUT WILL BE WATCHING SMALLER CREEKS
AND STREAMS...AS WELL AS THE POTENTIAL FOR URBAN FLOODING. CLOUDS
AND RAIN WILL KEEP TEMPS DOWN IN THE 50S/LOWER 60S MONDAY AND
TUESDAY...BEFORE A WARMING TREND FROM MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1024 AM CDT SAT MAY 18 2013
LOW STRATUS HAS BEEN VERY DIFFICULT TO FORECAST THIS MORNING...BUT
SHOULD IMPROVE BY 18 UTC. SHOWERS AND THUNDERSTORMS WILL CAUSE
MVFR CONDITIONS AT MOST TAF SITES TODAY...WITH BRIEF PERIODS OF
IFR POSSIBLE IN STRONGER STORMS. FOG AND LOW STRATUS WILL LIKELY
RETURN AFTER MIDNIGHT TONIGHT IN THE WAKE OF PRECIPITATION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...SCHECK
SHORT TERM/LONG TERM...RP KINNEY
000
FXUS63 KBIS 181144
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
644 AM CDT SAT MAY 18 2013
.UPDATE...
ISSUED AT 644 AM CDT SAT MAY 18 2013
UPDATE MAINLY FOR POP TRENDS TODAY. SHOWERS AND ISOLATED STORMS
HAVE PUSHED INTO THE FAR NORTHEAST EARLY THIS MORNING. RECENT RUNS
OF THE RAP HAVE A GOOD HANDLE ON NEAR TERM TRENDS...AND HAVE
REDUCED POPS THROUGH THE MORNING INTO EARLY AFTERNOON. STILL
EXPECTING THE FOCUS OF AFTERNOON CONVECTION ALONG A BOUNDARY TO
THE SOUTHEAST...WITH POTENTIAL FOR SOME SEVERE STORMS TO DEVELOP
BY MID AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 18 2013
THE MAIN FOCUS IN THE SHORT TERM IS CONVECTIVE TRENDS AND
POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND TONIGHT. IN THE
NEAR TERM...THE 18/07Z RAP MODEL HAS A GOOD HANDLE ON THE LOCATION
OF THE CURRENT STORMS ACROSS THE NORTHEAST HALF OF THE FORECAST
AREA. STORMS SHOULD CONTINUE TO LIFT NORTH THROUGH THE MORNING
HOURS. AFTERNOON REDEVELOPMENT IS EXPECTED TO FOCUS ON THE TROUGH
EXTENDING ACROSS THE SOUTHEAST COUNTIES. ML CAPES AROUND 1500 TO
2000 J/KG ARE EXPECTED ALONG WITH DEEP LAYER SHEAR AT OR ABOVE 40
KTS...SUFFICIENT FOR SUPERCELL DEVELOPMENT WITH LARGE
HAIL/DAMAGING WIND THREAT. IN THE EXTREME SOUTHEAST...LOW
LCL`S...DECENT LOW LEVEL CAPE...AND A NARROW AREA OF FAVORABLE
0-1KM SHEAR SUGGEST THERE MAY ALSO BE A SEVERAL HOUR WINDOW OF
TORNADO THREAT THROUGH EARLY EVENING.
THE SOUTHEAST HALF OF THE FORECAST AREA LOOKS FAVORED FOR THE
HEAVIER RAINFALL AMOUNTS THROUGH TONIGHT. SIGNIFICANT RISES ON
MAINSTEM RIVERS ARE NOT EXPECTED...BUT WILL BE MONITORING FOR
LOCALIZED HEAVY RUNOFF AND ISOLATED SHORT TERM FLOODING DUE TO
EXTREME RAINFALL RATES OR MULTIPLE ROUNDS OF STORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 18 2013
A LARGE CLOSED H5 LOW IS FORECAST TO DRIFT THROUGH THE REGION
SUNDAY THROUGH TUESDAY. THE THREAT FOR SEVERE WEATHER WILL
DIMINISH DURING THIS PERIOD...BUT MODERATE TO LOCALLY HEAVY RAINFALL
WILL PERSIST. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE
POSSIBLE OVER THE WEEKEND THROUGH TUESDAY...WITH THE HIGHER TOTALS
TOWARD THE JAMES RIVER VALLEY. AGAIN...SIGNIFICANT RESPONSES ARE
NOT EXPECTED ON AREA RIVERS...BUT WILL BE WATCHING SMALLER CREEKS
AND STREAMS...AS WELL AS THE POTENTIAL FOR URBAN FLOODING. CLOUDS
AND RAIN WILL KEEP TEMPS DOWN IN THE 50S/LOWER 60S MONDAY AND
TUESDAY...BEFORE A WARMING TREND FROM MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 430 AM CDT SAT MAY 18 2013
AREA OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUE TO PUSH
NORTH AND EAST AS A MID LEVEL DISTURBANCE LIFTS NORTHEAST ACROSS
CENTRAL NORTH DAKOTA EARLY THIS MORNING. PRECIPITATION HAS ENDED
AT KBIS-KDIK-KISN...AND WILL END BY 15Z FOR KMOT-KJMS. HIGH LOW
LEVEL MOISTURE WILL RESULT IN AREAS OF FOG AND POSSIBLE VLIFR
STRATUS THIS MORNING AT MOST IF NOT ALL TERMINALS. WHILE THE
STRATUS AND FOG SHOULD LIFT BY MID MORNING...IT MAY LINGER AT KMOT
INTO SATURDAY AFTERNOON...THEN DEVELOP OVER ALL TERMINALS ONCE
AGAIN SATURDAY NIGHT.
SHOWERS AND THUNDERSTORMS WILL REDEVELOP AFTER 18Z SATURDAY
AFTERNOON...DEVELOPING NORTH AND EAST INTO SATURDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/SHORT TERM/LONG TERM...RP KINNEY
AVIATION...NH
000
FXUS63 KBIS 180930
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
430 AM CDT SAT MAY 18 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 18 2013
THE MAIN FOCUS IN THE SHORT TERM IS CONVECTIVE TRENDS AND
POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND TONIGHT. IN THE
NEAR TERM...THE 18/07Z RAP MODEL HAS A GOOD HANDLE ON THE LOCATION
OF THE CURRENT STORMS ACROSS THE NORTHEAST HALF OF THE FORECAST
AREA. STORMS SHOULD CONTINUE TO LIFT NORTH THROUGH THE MORNING
HOURS. AFTERNOON REDEVELOPMENT IS EXPECTED TO FOCUS ON THE TROUGH
EXTENDING ACROSS THE SOUTHEAST COUNTIES. ML CAPES AROUND 1500 TO
2000 J/KG ARE EXPECTED ALONG WITH DEEP LAYER SHEAR AT OR ABOVE 40
KTS...SUFFICIENT FOR SUPERCELL DEVELOPMENT WITH LARGE
HAIL/DAMAGING WIND THREAT. IN THE EXTREME SOUTHEAST...LOW
LCL`S...DECENT LOW LEVEL CAPE...AND A NARROW AREA OF FAVORABLE
0-1KM SHEAR SUGGEST THERE MAY ALSO BE A SEVERAL HOUR WINDOW OF
TORNADO THREAT THROUGH EARLY EVENING.
THE SOUTHEAST HALF OF THE FORECAST AREA LOOKS FAVORED FOR THE
HEAVIER RAINFALL AMOUNTS THROUGH TONIGHT. SIGNIFICANT RISES ON
MAINSTEM RIVERS ARE NOT EXPECTED...BUT WILL BE MONITORING FOR
LOCALIZED HEAVY RUNOFF AND ISOLATED SHORT TERM FLOODING DUE TO
EXTREME RAINFALL RATES OR MULTIPLE ROUNDS OF STORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 18 2013
A LARGE CLOSED H5 LOW IS FORECAST TO DRIFT THROUGH THE REGION
SUNDAY THROUGH TUESDAY. THE THREAT FOR SEVERE WEATHER WILL
DIMINISH DURING THIS PERIOD...BUT MODERATE TO LOCALLY HEAVY RAINFALL
WILL PERSIST. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE
POSSIBLE OVER THE WEEKEND THROUGH TUESDAY...WITH THE HIGHER TOTALS
TOWARD THE JAMES RIVER VALLEY. AGAIN...SIGNIFICANT RESPONSES ARE
NOT EXPECTED ON AREA RIVERS...BUT WILL BE WATCHING SMALLER CREEKS
AND STREAMS...AS WELL AS THE POTENTIAL FOR URBAN FLOODING. CLOUDS
AND RAIN WILL KEEP TEMPS DOWN IN THE 50S/LOWER 60S MONDAY AND
TUESDAY...BEFORE A WARMING TREND FROM MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 430 AM CDT SAT MAY 18 2013
AREA OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUE TO PUSH
NORTH AND EAST AS A MID LEVEL DISTURBANCE LIFTS NORTHEAST ACROSS
CENTRAL NORTH DAKOTA EARLY THIS MORNING. PRECIPITATION HAS ENDED
AT KBIS-KDIK-KISN...AND WILL END BY 15Z FOR KMOT-KJMS. HIGH LOW
LEVEL MOISTURE WILL RESULT IN AREAS OF FOG AND POSSIBLE VLIFR
STRATUS THIS MORNING AT MOST IF NOT ALL TERMINALS. WHILE THE
STRATUS AND FOG SHOULD LIFT BY MID MORNING...IT MAY LINGER AT KMOT
INTO SATURDAY AFTERNOON...THEN DEVELOP OVER ALL TERMINALS ONCE
AGAIN SATURDAY NIGHT.
SHOWERS AND THUNDERSTORMS WILL REDEVELOP AFTER 18Z SATURDAY
AFTERNOON...DEVELOPING NORTH AND EAST INTO SATURDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/LONG TERM...RP KINNEY
AVIATION...NH
000
FXUS63 KBIS 180619
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
119 AM CDT SAT MAY 18 2013
.UPDATE...
ISSUED AT 114 AM CDT SAT MAY 18 2013
UPDATE MAINLY TO REFINE POPS FOR HIGHER COVERAGE OF STORMS
OVERNIGHT OVER MOST OF THE FORECAST AREA. THE NORTHERN HALF SHOULD
BECOME THE FOCUS FOR THE BULK OF THE SHOWERS AND STORMS TOWARD
DAYBREAK. CONVECTIVE INTENSITY HAS BEEN DOWNWARD OVER THE PAST
COUPLE OF HOURS...AND THE THREAT FOR ADDITIONAL SEVERE STORMS IS
LOW. HOWEVER...STRONGER STORMS COULD DUMP A QUICK INCH OF RAIN AND
CAUSE PONDING WATER.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 258 PM CDT FRI MAY 17 2013
THE MAIN SHORT TERM FOCUS IS PRECIPITATION THROUGH SATURDAY.
PRECIPITATION CHANCES HAVE GENERALLY BEEN LOWERED FROM CONTINUITY
BASED ON MODEL CONSENSUS AND COORDINATION WITH SURROUNDING
OFFICES. THEY NOW REFLECT THE BEST CHANCES FOR SHOWERS AND
THUNDERSTORMS. UNFORTUNATELY...THE AVAILABLE 12 UTC THROUGH 18 UTC
GUIDANCE DISAGREES WITH TIMING AND COVERAGE ACROSS MUCH OF THE
STATE FOR THIS AFTERNOON AND TONIGHT...BUT THERE IS GENERAL
AGREEMENT THAT AN AREA OF CONVECTION WILL DEVELOP OVER
SOUTHEASTERN MONTANA THIS AFTERNOON AND MOVE EAST-NORTHEAST.
WATER VAPOR SATELLITE IMAGERY INDICATES THE LEADING EDGE OF THE
NEXT MID LEVEL SHORTWAVE WILL NOSE INTO SOUTHWESTERN NORTH DAKOTA
AROUND 23 UTC. WHILE THAT WILL LIKELY BE THE BEST CHANCE FOR
STRONGER THUNDERSTORMS...CURRENT RADAR CONFIRMS THAT SHOWERS AHEAD
OF THAT FEATURE WILL ALSO SPREAD ACROSS THE MISSOURI SLOPE THIS
AFTERNOON...THOUGH NO LIGHTENING HAS BEEN OBSERVED THERE. LOOK
FOR THIS TREND TO CONTINUE AND FILL IN THROUGH THE AFTERNOON AS
MORE FAVORABLE DYNAMIC FORCING MOVES INTO THE REGION.
THERE IS A SPC SLIGHT RISK FOR SEVERE THUNDERSTORMS ON SATURDAY
AFTERNOON ASSOCIATED WITH A DEEPENING SURFACE LOW. NORTH DAKOTA
LOOKS TO BE ON THE NORTH SIDE OF THE WARM FRONT. WHILE LOW-LEVEL
WINDS WILL BE BACKED...FORECAST CLOUD COVER JUSTIFIED MODEL
SOUNDINGS NOT FAVORABLE FOR SURFACE-BASED CONVECTION. THUS...THE
MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS UNLESS CLEARING
MOVES INTO SOUTH CENTRAL NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 258 PM CDT FRI MAY 17 2013
THE MAIN FORECAST HIGHLIGHT FOR THE EXTENDED PERIOD CONTINUES TO BE
THE MODERATE TO HEAVY RAIN EVENT THROUGH EARLY TUESDAY.
THE 12Z DETERMINISTIC MODEL SUITE IS IN GOOD AGREEMENT EARLY IN THE
EXTENDED PERIOD BEFORE SOLUTIONS DIVERGE IN REGARDS OF THE FORMATION
AND MOVEMENT OF THE UPPER LEVEL LOW ACROSS THE NORTHERN PLAINS
MONDAY THROUGH WEDNESDAY. A BROAD WESTERN CONUS UPPER LEVEL TROUGH
IS PROGGED TO PUSH EAST AND OVER THE PLAINS SATURDAY AND
SUNDAY...CLOSE OFF OVER THE NORTHERN AND CENTRAL PLAINS LATE SUNDAY
AND MONDAY...AND THEN SLOWLY PUSH EAST AND WEAKEN THROUGH THURSDAY.
THE 12Z GFS REMAINS THE PROGRESSIVE SOLUTION MOVING AND WEAKENING
THE CLOSED OFF LOW AWAY FROM THE DAKOTAS BY WEDNESDAY...WHILE THE
12Z ECMWF/GEM KEEPS IT MEANDERING OVER THE DAKOTAS BEFORE PUSHING
EAST AND WEAKENING BY LATE NEXT WEEK. MEANWHILE...A REX BLOCKING
PATTERN OVER NORTHERN AMERICA WILL BEGIN TO SET UP AS UPPER LEVEL
RIDGING TAKES PLACE NORTH OF THE AFOREMENTIONED CLOSED OFF LOW AND
ANOTHER TROUGH DROPS SOUTH FROM THE NORTHEASTERN PACIFIC.
AS A RESULT IN THE DIFFERENCES IN THE POSITIONING AND MOVEMENT OF THE
AFOREMENTIONED LOW...PLACEMENT AND AMOUNT OF PRECIPITATION DIFFER
BETWEEN THE GFS AND THE GEM/ECMWF SOLUTIONS...MOST NOTABLY ON MONDAY
AND TUESDAY. THE ECMWF/GEM CONTINUE CHANCES FOR PRECIPITATION ON
THESE DAYS AS THE LOW HOVERS OVERHEAD...WHILE THE GFS KEEPS MOST OF
THE NORTH AND WEST DRY...WITH PRECIPITATION CHANCES FOR THE
SOUTHEAST PART OF THE STATE. HAVE DECIDED TO STICK CLOSE TO WPC
GUIDANCE FOR QPF...WHICH KEEPS THE JAMES RIVER VALLEY ON TRACK FOR
ONE TO TWO INCHES OF RAINFALL FROM SATURDAY EVENING THROUGH
TUESDAY...WITH LESSER AMOUNTS FURTHER NORTHWEST. IN REGARDS TO ANY
POTENTIAL FLOODING ISSUES...CONDITIONS ARE SUCH THAT SOILS CAN
ABSORB SIGNIFICANT RAINFALL. THUS...SIGNIFICANT RISES ON MAIN STEM
RIVERS SUCH AS THE SOURIS AND JAMES ARE NOT EXPECTED.
HOWEVER...ENHANCED RAINFALL RATES OR SEVERAL ROUNDS OF STORMS COULD
PRODUCE LOCALIZED RUNOFF...LEADING TO RISES ON SMALL CREEKS AND
STREAMS...AND POSSIBLY FLASH FLOODING.
PRECIPITATION CHANCES WILL BEGIN TO DIMINISH LATE TUESDAY AND INTO
WEDNESDAY AS DRY AND SEASONABLE CONDITIONS TAKE OVER....WITH AN
ADDITIONAL CHANCE FOR SHOWERS POSSIBLY THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1252 AM CDT SAT MAY 18 2013
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO SPREAD NORTH AND IMPACT
ALL TAF SITES OVERNIGHT. COVERAGE OF STORMS IS EXPECTED TO BE
RATHER LIMITED DURING THE MORNING HOURS SATURDAY...THEN INCREASE
AGAIN SATURDAY AFTERNOON AND EVENING WITH MAINLY MVFR CEILINGS
AND/OR VISIBILITIES DEVELOPING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RK
SHORT TERM...SCHECK
LONG TERM...LTH
AVIATION...RK
000
FXUS63 KBIS 180310
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1010 PM CDT FRI MAY 17 2013
.UPDATE...
ISSUED AT 1010 PM CDT FRI MAY 17 2013
A PERSISTENT SEVERE THUNDERSTORM CONTINUES TO MOVE EAST-NORTHEAST
ACROSS SOUTHWESTERN AND SOUTH CENTRAL NORTH DAKOTA. IT IS CURRENTLY
MOVING INTO WESTERN GRANT COUNTY AT THE TIME OF THIS WRITING. THIS
STORM HAS A HISTORY OF PRODUCING 60 MPH WINDS AND HEAVY RAIN.
HOWEVER...LITTLE TO NO HAIL HAS BEEN REPORTED.
UNCERTAINTY REMAINS HIGH FOR THE FORECAST FOR THE REMAINDER OF
THE NIGHT. FOR THE SAKE OF CONSISTENCY...CONTINUED TO FORECAST ALONG
THE LINES OF THE PREVIOUS UPDATE DISCUSSED BELOW. ONLY MODIFIED
HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS. THE
UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 717 PM CDT FRI MAY 17 2013
SHORT RANGE MODEL GUIDANCE CONTINUES TO STRUGGLE RESOLVING
CONVECTIVE ACTIVITY ACROSS PORTIONS OF THE NORTHERN PLAINS THIS
EVENING. THE ONLY EVENING CONVECTION AFFECTING WESTERN AND CENTRAL
NORTH DAKOTA IS JUST NOW NOSING ITS WAY INTO EXTREME SOUTHWESTERN
NORTH DAKOTA. THIS ACTIVITY SHOULD CONTINUE TO MOVE EAST-NORTHEAST
THROUGH THE EVENING HOURS ALONG THE 850MB-300MB MEAN WIND. AS A
RESULT...LOWERED EVENING POPS FOR ALL BUT SOUTHWESTERN AND SOUTH
CENTRAL NORTH DAKOTA.
AFTER MIDNIGHT...THE ECMWF AND NAM PROG A TIGHT THETA-E GRADIENT
DEVELOPING OVER CENTRAL NORTH DAKOTA (MAINLY ALONG AND NORTH OF
I-94). SUBSEQUENTLY...THESE MODELS PROG THIS HIGHEST QPF TO
DEVELOP THERE. ON THE OTHER HAND...THE GEM AND GFS ARE KEYING IN
ON AN UPSTREAM SHORTWAVE AND PROG THE HIGHEST QPF TO DEVELOP OVER
NORTHWESTERN NORTH DAKOTA. GIVEN THE MODEL TO MODEL
INCONSISTENCIES...MAINTAINED LIKELY POPS DEVELOPING AREAWIDE AFTER
MIDNIGHT. KEPT THE HIGHEST QPF NEAR THE I-94 CORRIDOR.
HOWEVER...CONFIDENCE IS LOW REGARDING THE PLACEMENT OF THE HIGHEST
QPF. WILL CONTINUE TO MONITOR EVENING TRENDS AND MODIFY AS NEEDED.
THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 258 PM CDT FRI MAY 17 2013
THE MAIN SHORT TERM FOCUS IS PRECIPITATION THROUGH SATURDAY.
PRECIPITATION CHANCES HAVE GENERALLY BEEN LOWERED FROM CONTINUITY
BASED ON MODEL CONSENSUS AND COORDINATION WITH SURROUNDING
OFFICES. THEY NOW REFLECT THE BEST CHANCES FOR SHOWERS AND
THUNDERSTORMS. UNFORTUNATELY...THE AVAILABLE 12 UTC THROUGH 18 UTC
GUIDANCE DISAGREES WITH TIMING AND COVERAGE ACROSS MUCH OF THE
STATE FOR THIS AFTERNOON AND TONIGHT...BUT THERE IS GENERAL
AGREEMENT THAT AN AREA OF CONVECTION WILL DEVELOP OVER
SOUTHEASTERN MONTANA THIS AFTERNOON AND MOVE EAST-NORTHEAST.
WATER VAPOR SATELLITE IMAGERY INDICATES THE LEADING EDGE OF THE
NEXT MID LEVEL SHORTWAVE WILL NOSE INTO SOUTHWESTERN NORTH DAKOTA
AROUND 23 UTC. WHILE THAT WILL LIKELY BE THE BEST CHANCE FOR
STRONGER THUNDERSTORMS...CURRENT RADAR CONFIRMS THAT SHOWERS AHEAD
OF THAT FEATURE WILL ALSO SPREAD ACROSS THE MISSOURI SLOPE THIS
AFTERNOON...THOUGH NO LIGHTENING HAS BEEN OBSERVED THERE. LOOK
FOR THIS TREND TO CONTINUE AND FILL IN THROUGH THE AFTERNOON AS
MORE FAVORABLE DYNAMIC FORCING MOVES INTO THE REGION.
THERE IS A SPC SLIGHT RISK FOR SEVERE THUNDERSTORMS ON SATURDAY
AFTERNOON ASSOCIATED WITH A DEEPENING SURFACE LOW. NORTH DAKOTA
LOOKS TO BE ON THE NORTH SIDE OF THE WARM FRONT. WHILE LOW-LEVEL
WINDS WILL BE BACKED...FORECAST CLOUD COVER JUSTIFIED MODEL
SOUNDINGS NOT FAVORABLE FOR SURFACE-BASED CONVECTION. THUS...THE
MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS UNLESS CLEARING
MOVES INTO SOUTH CENTRAL NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 258 PM CDT FRI MAY 17 2013
THE MAIN FORECAST HIGHLIGHT FOR THE EXTENDED PERIOD CONTINUES TO BE
THE MODERATE TO HEAVY RAIN EVENT THROUGH EARLY TUESDAY.
THE 12Z DETERMINISTIC MODEL SUITE IS IN GOOD AGREEMENT EARLY IN THE
EXTENDED PERIOD BEFORE SOLUTIONS DIVERGE IN REGARDS OF THE FORMATION
AND MOVEMENT OF THE UPPER LEVEL LOW ACROSS THE NORTHERN PLAINS
MONDAY THROUGH WEDNESDAY. A BROAD WESTERN CONUS UPPER LEVEL TROUGH
IS PROGGED TO PUSH EAST AND OVER THE PLAINS SATURDAY AND
SUNDAY...CLOSE OFF OVER THE NORTHERN AND CENTRAL PLAINS LATE SUNDAY
AND MONDAY...AND THEN SLOWLY PUSH EAST AND WEAKEN THROUGH THURSDAY.
THE 12Z GFS REMAINS THE PROGRESSIVE SOLUTION MOVING AND WEAKENING
THE CLOSED OFF LOW AWAY FROM THE DAKOTAS BY WEDNESDAY...WHILE THE
12Z ECWMF/GEM KEEPS IT MEANDERING OVER THE DAKOTAS BEFORE PUSHING
EAST AND WEAKENING BY LATE NEXT WEEK. MEANWHILE...A REX BLOCKING
PATTERN OVER NORTHERN AMERICA WILL BEGIN TO SET UP AS UPPER LEVEL
RIDGING TAKES PLACE NORTH OF THE AFOREMENTIONED CLOSED OFF LOW AND
ANOTHER TROUGH DROPS SOUTH FROM THE NORTHEASTERN PACIFIC.
AS A RESULT IN THE DIFFERENCES IN THE POSITIONING AND MOVEMENT OF THE
AFOREMENTIONED LOW...PLACEMENT AND AMOUNT OF PRECIPITATION DIFFER
BETWEEN THE GFS AND THE GEM/ECWMF SOLUTIONS...MOST NOTABLY ON MONDAY
AND TUESDAY. THE ECWMF/GEM CONTINUE CHANCES FOR PRECIPITATION ON
THESE DAYS AS THE LOW HOVERS OVERHEAD...WHILE THE GFS KEEPS MOST OF
THE NORTH AND WEST DRY...WITH PRECIPITATION CHANCES FOR THE
SOUTHEAST PART OF THE STATE. HAVE DECIDED TO STICK CLOSE TO WPC
GUIDANCE FOR QPF...WHICH KEEPS THE JAMES RIVER VALLEY ON TRACK FOR
ONE TO TWO INCHES OF RAINFALL FROM SATURDAY EVENING THROUGH
TUESDAY...WITH LESSER AMOUNTS FURTHER NORTHWEST. IN REGARDS TO ANY
POTENTIAL FLOODING ISSUES...CONDITIONS ARE SUCH THAT SOILS CAN
ABSORB SIGNIFICANT RAINFALL. THUS...SIGNIFICANT RISES ON MAIN STEM
RIVERS SUCH AS THE SOURIS AND JAMES ARE NOT EXPECTED.
HOWEVER...ENHANCED RAINFALL RATES OR SEVERAL ROUNDS OF STORMS COULD
PRODUCE LOCALIZED RUNOFF...LEADING TO RISES ON SMALL CREEKS AND
STREAMS...AND POSSIBLY FLASH FLOODING.
PRECIPITATION CHANCES WILL BEGIN TO DIMINISH LATE TUESDAY AND INTO
WEDNESDAY AS DRY AND SEASONABLE CONDITIONS TAKE OVER....WITH AN
ADDITIONAL CHANCE FOR SHOWERS POSSIBLY THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 24Z SATURDAY EVENING)
ISSUED AT 717 PM CDT FRI MAY 17 2013
VFR CONDITIONS AT ALL TAF SITES WILL EVENTUALLY BECOME MVFR
TONIGHT AS WIDESPREAD SHOWERS AND THUNDERSTORMS ACCOMPANY LOWER
CEILINGS. THE OFFENDING LARGE LOW PRESSURE SYSTEM WILL REMAIN OVER
THE NORTHERN PLAINS THROUGH AT LEAST MONDAY. THUNDERSTORMS WILL BE
MORE WIDESPREAD SATURDAY AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...SCHECK
LONG TERM...LTH
AVIATION...TM
000
FXUS63 KBIS 180016
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
716 PM CDT FRI MAY 17 2013
.UPDATE...
ISSUED AT 717 PM CDT FRI MAY 17 2013
SHORT RANGE MODEL GUIDANCE CONTINUES TO STRUGGLE RESOLVING
CONVECTIVE ACTIVITY ACROSS PORTIONS OF THE NORTHERN PLAINS THIS
EVENING. THE ONLY EVENING CONVECTION AFFECTING WESTERN AND CENTRAL
NORTH DAKOTA IS JUST NOW NOSING ITS WAY INTO EXTREME SOUTHWESTERN
NORTH DAKOTA. THIS ACTIVITY SHOULD CONTINUE TO MOVE EAST-NORTHEAST
THROUGH THE EVENING HOURS ALONG THE 850MB-300MB MEAN WIND. AS A
RESULT...LOWERED EVENING POPS FOR ALL BUT SOUTHWESTERN AND SOUTH
CENTRAL NORTH DAKOTA.
AFTER MIDNIGHT...THE ECMWF AND NAM PROG A TIGHT THETA-E GRADIENT
DEVELOPING OVER CENTRAL NORTH DAKOTA (MAINLY ALONG AND NORTH OF
I-94). SUBSEQUENTLY...THESE MODELS PROG THIS HIGHEST QPF TO
DEVELOP THERE. ON THE OTHER HAND...THE GEM AND GFS ARE KEYING IN
ON AN UPSTREAM SHORTWAVE AND PROG THE HIGHEST QPF TO DEVELOP OVER
NORTHWESTERN NORTH DAKOTA. GIVEN THE MODEL TO MODEL
INCONSISTENCIES...MAINTAINED LIKELY POPS DEVELOPING AREAWIDE AFTER
MIDNIGHT. KEPT THE HIGHEST QPF NEAR THE I-94 CORRIDOR.
HOWEVER...CONFIDENCE IS LOW REGARDING THE PLACEMENT OF THE HIGHEST
QPF. WILL CONTINUE TO MONITOR EVENING TRENDS AND MODIFY AS NEEDED.
THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 258 PM CDT FRI MAY 17 2013
THE MAIN SHORT TERM FOCUS IS PRECIPITATION THROUGH SATURDAY.
PRECIPITATION CHANCES HAVE GENERALLY BEEN LOWERED FROM CONTINUITY
BASED ON MODEL CONSENSUS AND COORDINATION WITH SURROUNDING
OFFICES. THEY NOW REFLECT THE BEST CHANCES FOR SHOWERS AND
THUNDERSTORMS. UNFORTUNATELY...THE AVAILABLE 12 UTC THROUGH 18 UTC
GUIDANCE DISAGREES WITH TIMING AND COVERAGE ACROSS MUCH OF THE
STATE FOR THIS AFTERNOON AND TONIGHT...BUT THERE IS GENERAL
AGREEMENT THAT AN AREA OF CONVECTION WILL DEVELOP OVER
SOUTHEASTERN MONTANA THIS AFTERNOON AND MOVE EAST-NORTHEAST.
WATER VAPOR SATELLITE IMAGERY INDICATES THE LEADING EDGE OF THE
NEXT MID LEVEL SHORTWAVE WILL NOSE INTO SOUTHWESTERN NORTH DAKOTA
AROUND 23 UTC. WHILE THAT WILL LIKELY BE THE BEST CHANCE FOR
STRONGER THUNDERSTORMS...CURRENT RADAR CONFIRMS THAT SHOWERS AHEAD
OF THAT FEATURE WILL ALSO SPREAD ACROSS THE MISSOURI SLOPE THIS
AFTERNOON...THOUGH NO LIGHTENING HAS BEEN OBSERVED THERE. LOOK
FOR THIS TREND TO CONTINUE AND FILL IN THROUGH THE AFTERNOON AS
MORE FAVORABLE DYNAMIC FORCING MOVES INTO THE REGION.
THERE IS A SPC SLIGHT RISK FOR SEVERE THUNDERSTORMS ON SATURDAY
AFTERNOON ASSOCIATED WITH A DEEPENING SURFACE LOW. NORTH DAKOTA
LOOKS TO BE ON THE NORTH SIDE OF THE WARM FRONT. WHILE LOW-LEVEL
WINDS WILL BE BACKED...FORECAST CLOUD COVER JUSTIFIED MODEL
SOUNDINGS NOT FAVORABLE FOR SURFACE-BASED CONVECTION. THUS...THE
MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS UNLESS CLEARING
MOVES INTO SOUTH CENTRAL NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 258 PM CDT FRI MAY 17 2013
THE MAIN FORECAST HIGHLIGHT FOR THE EXTENDED PERIOD CONTINUES TO BE
THE MODERATE TO HEAVY RAIN EVENT THROUGH EARLY TUESDAY.
THE 12Z DETERMINISTIC MODEL SUITE IS IN GOOD AGREEMENT EARLY IN THE
EXTENDED PERIOD BEFORE SOLUTIONS DIVERGE IN REGARDS OF THE FORMATION
AND MOVEMENT OF THE UPPER LEVEL LOW ACROSS THE NORTHERN PLAINS
MONDAY THROUGH WEDNESDAY. A BROAD WESTERN CONUS UPPER LEVEL TROUGH
IS PROGGED TO PUSH EAST AND OVER THE PLAINS SATURDAY AND
SUNDAY...CLOSE OFF OVER THE NORTHERN AND CENTRAL PLAINS LATE SUNDAY
AND MONDAY...AND THEN SLOWLY PUSH EAST AND WEAKEN THROUGH THURSDAY.
THE 12Z GFS REMAINS THE PROGRESSIVE SOLUTION MOVING AND WEAKENING
THE CLOSED OFF LOW AWAY FROM THE DAKOTAS BY WEDNESDAY...WHILE THE
12Z ECWMF/GEM KEEPS IT MEANDERING OVER THE DAKOTAS BEFORE PUSHING
EAST AND WEAKENING BY LATE NEXT WEEK. MEANWHILE...A REX BLOCKING
PATTERN OVER NORTHERN AMERICA WILL BEGIN TO SET UP AS UPPER LEVEL
RIDGING TAKES PLACE NORTH OF THE AFOREMENTIONED CLOSED OFF LOW AND
ANOTHER TROUGH DROPS SOUTH FROM THE NORTHEASTERN PACIFIC.
AS A RESULT IN THE DIFFERENCES IN THE POSITIONING AND MOVEMENT OF THE
AFOREMENTIONED LOW...PLACEMENT AND AMOUNT OF PRECIPITATION DIFFER
BETWEEN THE GFS AND THE GEM/ECWMF SOLUTIONS...MOST NOTABLY ON MONDAY
AND TUESDAY. THE ECWMF/GEM CONTINUE CHANCES FOR PRECIPITATION ON
THESE DAYS AS THE LOW HOVERS OVERHEAD...WHILE THE GFS KEEPS MOST OF
THE NORTH AND WEST DRY...WITH PRECIPITATION CHANCES FOR THE
SOUTHEAST PART OF THE STATE. HAVE DECIDED TO STICK CLOSE TO WPC
GUIDANCE FOR QPF...WHICH KEEPS THE JAMES RIVER VALLEY ON TRACK FOR
ONE TO TWO INCHES OF RAINFALL FROM SATURDAY EVENING THROUGH
TUESDAY...WITH LESSER AMOUNTS FURTHER NORTHWEST. IN REGARDS TO ANY
POTENTIAL FLOODING ISSUES...CONDITIONS ARE SUCH THAT SOILS CAN
ABSORB SIGNIFICANT RAINFALL. THUS...SIGNIFICANT RISES ON MAIN STEM
RIVERS SUCH AS THE SOURIS AND JAMES ARE NOT EXPECTED.
HOWEVER...ENHANCED RAINFALL RATES OR SEVERAL ROUNDS OF STORMS COULD
PRODUCE LOCALIZED RUNOFF...LEADING TO RISES ON SMALL CREEKS AND
STREAMS...AND POSSIBLY FLASH FLOODING.
PRECIPITATION CHANCES WILL BEGIN TO DIMINISH LATE TUESDAY AND INTO
WEDNESDAY AS DRY AND SEASONABLE CONDITIONS TAKE OVER....WITH AN
ADDITIONAL CHANCE FOR SHOWERS POSSIBLY THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 24Z SATURDAY EVENING)
ISSUED AT 717 PM CDT FRI MAY 17 2013
VFR CONDITIONS AT ALL TAF SITES WILL EVENTUALLY BECOME MVFR
TONIGHT AS WIDESPREAD SHOWERS AND THUNDERSTORMS ACCOMPANY LOWER
CEILINGS. THE OFFENDING LARGE LOW PRESSURE SYSTEM WILL REMAIN OVER
THE NORTHERN PLAINS THROUGH AT LEAST MONDAY. THUNDERSTORMS WILL BE
MORE WIDESPREAD SATURDAY AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...SCHECK
LONG TERM...LTH
AVIATION...TM
000
FXUS63 KBIS 171959
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
259 PM CDT FRI MAY 17 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 258 PM CDT FRI MAY 17 2013
THE MAIN SHORT TERM FOCUS IS PRECIPITATION THROUGH SATURDAY.
PRECIPITATION CHANCES HAVE GENERALLY BEEN LOWERED FROM CONTINUITY
BASED ON MODEL CONSENSUS AND COORDINATION WITH SURROUNDING
OFFICES. THEY NOW REFLECT THE BEST CHANCES FOR SHOWERS AND
THUNDERSTORMS. UNFORTUNATELY...THE AVAILABLE 12 UTC THROUGH 18 UTC
GUIDANCE DISAGREES WITH TIMING AND COVERAGE ACROSS MUCH OF THE
STATE FOR THIS AFTERNOON AND TONIGHT...BUT THERE IS GENERAL
AGREEMENT THAT AN AREA OF CONVECTION WILL DEVELOP OVER
SOUTHEASTERN MONTANA THIS AFTERNOON AND MOVE EAST-NORTHEAST.
WATER VAPOR SATELLITE IMAGERY INDICATES THE LEADING EDGE OF THE
NEXT MID LEVEL SHORTWAVE WILL NOSE INTO SOUTHWESTERN NORTH DAKOTA
AROUND 23 UTC. WHILE THAT WILL LIKELY BE THE BEST CHANCE FOR
STRONGER THUNDERSTORMS...CURRENT RADAR CONFIRMS THAT SHOWERS AHEAD
OF THAT FEATURE WILL ALSO SPREAD ACROSS THE MISSOURI SLOPE THIS
AFTERNOON...THOUGH NO LIGHTENING HAS BEEN OBSERVED THERE. LOOK
FOR THIS TREND TO CONTINUE AND FILL IN THROUGH THE AFTERNOON AS
MORE FAVORABLE DYNAMIC FORCING MOVES INTO THE REGION.
THERE IS A SPC SLIGHT RISK FOR SEVERE THUNDERSTORMS ON SATURDAY
AFTERNOON ASSOCIATED WITH A DEEPENING SURFACE LOW. NORTH DAKOTA
LOOKS TO BE ON THE NORTH SIDE OF THE WARM FRONT. WHILE LOW-LEVEL
WINDS WILL BE BACKED...FORECAST CLOUD COVER JUSTIFIED MODEL
SOUNDINGS NOT FAVORABLE FOR SURFACE-BASED CONVECTION. THUS...THE
MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS UNLESS CLEARING
MOVES INTO SOUTH CENTRAL NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 258 PM CDT FRI MAY 17 2013
THE MAIN FORECAST HIGHLIGHT FOR THE EXTENDED PERIOD CONTINUES TO BE
THE MODERATE TO HEAVY RAIN EVENT THROUGH EARLY TUESDAY.
THE 12Z DETERMINISTIC MODEL SUITE IS IN GOOD AGREEMENT EARLY IN THE
EXTENDED PERIOD BEFORE SOLUTIONS DIVERGE IN REGARDS OF THE FORMATION
AND MOVEMENT OF THE UPPER LEVEL LOW ACROSS THE NORTHERN PLAINS
MONDAY THROUGH WEDNESDAY. A BROAD WESTERN CONUS UPPER LEVEL TROUGH
IS PROGGED TO PUSH EAST AND OVER THE PLAINS SATURDAY AND
SUNDAY...CLOSE OFF OVER THE NORTHERN AND CENTRAL PLAINS LATE SUNDAY
AND MONDAY...AND THEN SLOWLY PUSH EAST AND WEAKEN THROUGH THURSDAY.
THE 12Z GFS REMAINS THE PROGRESSIVE SOLUTION MOVING AND WEAKENING
THE CLOSED OFF LOW AWAY FROM THE DAKOTAS BY WEDNESDAY...WHILE THE
12Z ECWMF/GEM KEEPS IT MEANDERING OVER THE DAKOTAS BEFORE PUSHING
EAST AND WEAKENING BY LATE NEXT WEEK. MEANWHILE...A REX BLOCKING
PATTERN OVER NORTHERN AMERICA WILL BEGIN TO SET UP AS UPPER LEVEL
RIDGING TAKES PLACE NORTH OF THE AFOREMENTIONED CLOSED OFF LOW AND
ANOTHER TROUGH DROPS SOUTH FROM THE NORTHEASTERN PACIFIC.
AS A RESULT IN THE DIFFERENCES IN THE POSITIONING AND MOVEMENT OF THE
AFOREMENTIONED LOW...PLACEMENT AND AMOUNT OF PRECIPITATION DIFFER
BETWEEN THE GFS AND THE GEM/ECWMF SOLUTIONS...MOST NOTABLY ON MONDAY
AND TUESDAY. THE ECWMF/GEM CONTINUE CHANCES FOR PRECIPITATION ON
THESE DAYS AS THE LOW HOVERS OVERHEAD...WHILE THE GFS KEEPS MOST OF
THE NORTH AND WEST DRY...WITH PRECIPITATION CHANCES FOR THE
SOUTHEAST PART OF THE STATE. HAVE DECIDED TO STICK CLOSE TO WPC
GUIDANCE FOR QPF...WHICH KEEPS THE JAMES RIVER VALLEY ON TRACK FOR
ONE TO TWO INCHES OF RAINFALL FROM SATURDAY EVENING THROUGH
TUESDAY...WITH LESSER AMOUNTS FURTHER NORTHWEST. IN REGARDS TO ANY
POTENTIAL FLOODING ISSUES...CONDITIONS ARE SUCH THAT SOILS CAN
ABSORB SIGNIFICANT RAINFALL. THUS...SIGNIFICANT RISES ON MAIN STEM
RIVERS SUCH AS THE SOURIS AND JAMES ARE NOT EXPECTED.
HOWEVER...ENHANCED RAINFALL RATES OR SEVERAL ROUNDS OF STORMS COULD
PRODUCE LOCALIZED RUNOFF...LEADING TO RISES ON SMALL CREEKS AND
STREAMS...AND POSSIBLY FLASH FLOODING.
PRECIPITATION CHANCES WILL BEGIN TO DIMINISH LATE TUESDAY AND INTO
WEDNESDAY AS DRY AND SEASONABLE CONDITIONS TAKE OVER....WITH AN
ADDITIONAL CHANCE FOR SHOWERS POSSIBLY THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 227 PM CDT FRI MAY 17 2013
VFR CONDITIONS AT ALL TAF SITES WILL EVENTUALLY BECOME MVFR
TONIGHT AS WIDESPREAD SHOWERS AND THUNDERSTORMS ACCOMPANY LOWER
CEILINGS. THE OFFENDING LARGE LOW PRESSURE SYSTEM WILL REMAIN OVER
THE NORTHERN PLAINS THROUGH AT LEAST MONDAY. THUNDERSTORMS WILL BE
MORE WIDESPREAD SATURDAY AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SCHECK
LONG TERM...LTH
AVIATION...SCHECK
000
FXUS63 KBIS 171833
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
133 PM CDT FRI MAY 17 2013
.UPDATE...
ISSUED AT 114 PM CDT FRI MAY 17 2013
THE MAIN FOCUS THIS UPDATE WAS PRECIPITATION CHANCES TODAY AND
TONIGHT.
BASED ON MODEL CONSENSUS AND COORDINATION WITH SURROUNDING
OFFICES...PROBABILITIES WERE SCALED BACK TO BETTER REFLECT THE
BEST CHANCES FOR SHOWERS AND THUNDERSTORMS. UNFORTUNATELY...THE
AVAILABLE 12 UTC THROUGH 16 UTC GUIDANCE DISAGREES WITH
TIMING...BUT THERE IS GENERAL AGREEMENT THAT AN AREA OF CONVECTION
WILL DEVELOP OVER SOUTHEASTERN MONTANA THIS AFTERNOON AND MOVE
NORTHEASTWARD. TIMING THE NEXT MID-LEVEL SHORTWAVE USING WATER
VAPOR SATELLITE IMAGERY INDICATES THE LEADING EDGE OF DYNAMIC
FORCING WILL SPREAD INTO SOUTHWESTERN NORTH DAKOTA AROUND 23 UTC.
WHILE THAT WILL LIKELY BE THE BEST CHANCE FOR STRONGER
THUNDERSTORMS...CURRENT RADAR AND VISIBLE SATELLITE SHOW THAT SOME
DESTABILIZATION HAS ALREADY OCCURRED...THOUGH NO LIGHTENING HAS
BEEN OBSERVED.
LOOK FOR THIS TREND TO CONTINUE AND FILL IN THROUGH THE AFTERNOON
AS MORE FAVORABLE DYNAMIC FORCING MOVES INTO THE REGION.
UPDATE ISSUED AT 1001 AM CDT FRI MAY 17 2013
THE MAIN FOCUS TODAY WILL BE SEEMINGLY UNENDING PRECIPITATION
CHANCES. THIS UPDATE MADE SIMPLE ADJUSTMENTS TO PRECIPITATION
PROBABILITIES TODAY. WHILE THERE LOOKS TO BE A BREAK THAT WILL
LAST SEVERAL HOURS OVER MUCH OF THE MISSOURI SLOPE AND JAMES RIVER
VALLEYS THROUGH EARLY AFTERNOON...ECHOES ON SOUTH DAKOTA RADARS
INDICATE AT LEAST LIGHT SHOWER ACTIVITY MOVING NORTHEASTWARD FAST.
THE NEXT FEW HOURS SHOULD GIVE A BETTER FEEL FOR FORCING
MECHANISMS AND LIKELIHOOD OF INTENSIFICATION.
PREVIOUS FORECASTS OF SUB-SEVERE CONVECTION OVER SOUTHWESTERN NORTH
DAKOTA LOOK TO BE ON TRACK FOR LATER TODAY/TONIGHT.
UPDATE ISSUED AT 637 AM CDT FRI MAY 17 2013
UPDATE FOR MINOR CHANGES TO POPS ACROSS THE NORTH THIS MORNING AS
BATCH OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES TO HEAD
NORTHEAST. OTHERWISE...MAINTAINED GENERALLY INCREASING POPS
THROUGH LATE AFTERNOON AND EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT FRI MAY 17 2013
THE MAIN CONCERN FOR TODAY INTO TONIGHT WILL BE THE CHANCE OF
THUNDERSTORMS AND POTENTIAL SEVERE WEATHER. EARLY MORNING RADAR
MOSAIC SHOWED ISOLATED SHOWERS FROM SOUTHWEST NORTH DAKOTA INTO
NORTHWEST MINNESOTA. MUCH OF THIS ACTIVITY DEVELOPED IN AN AREA OF
H85 WARM AIR ADVECTION THAT HAS BEEN MOVING FROM SOUTH TO NORTH
ACROSS THE REGION. THE STRONGEST WARM AIR ADVECTION SHIFTS NORTH BY
AFTERNOON AS SOUTHWESTERLY FLOW ALOFT BRINGS A SERIES OF WAVES ACROSS
THE STATE. WILL MAINTAIN FAIRLY HIGH POPS TODAY...ESPECIALLY IN
THE NORTH AND WEST WHERE THE MAJORITY OF MODEL SOLUTIONS FAVOR THE
HIGHER PRECIPITATION CHANCES.
THE FOCUS THEN TURNS FARTHER SOUTH AS SURFACE LOW PRESSURE GATHERS
IN EAST CENTRAL WYOMING. A WARM FRONT STRETCHING OUT OF THE LOW
INTO SOUTHERN SOUTH DAKOTA IS EXPECTED TO LIFT NORTH TONIGHT...BRINGING
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS TO CENTRAL AND
WESTERN NORTH DAKOTA. CAN NOT RULE OUT AN ISOLATED SEVERE STORM
LATE THIS AFTERNOON / EVENING ACROSS THE SOUTHERN PART OF THE
FORECAST AREA WHERE INSTABILITY WILL BE GREATEST. THE SPC DAY 1
SEVERE WEATHER OUTLOOK KEEPS THE SLIGHT RISK SOUTH OF THE FORECAST
AREA...HOWEVER THE 5 PERCENT PROBABILITIES FOR SEVERE HAIL / WIND
ARE DRAWN SOUTH OF I-94 INTO SOUTHERN NORTH DAKOTA WHICH APPEARS
REASONABLE.
TEMPERATURES TODAY WILL BE TRICKY DUE TO THE CLOUDS AND RAIN. WILL
GENERALLY STAY ON THE COOL SIDE OF GUIDANCE WHICH SUGGESTS MID
60S NORTH TO LOWER 70S SOUTH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CDT FRI MAY 17 2013
THE MAIN FORECAST ISSUES THROUGH THE LONG TERM PERIOD ARE CONVECTIVE
TRENDS...AND POTENTIAL FOR PROLONGED MODERATE TO HEAVY RAIN AND
SOME SEVERE WEATHER ON SATURDAY. THE LATEST 17/00Z MODEL RUNS HAVE
SOME SIGNIFICANT DIFFERENCE IN THE PROGRESSION OF A CLOSED UPPER
LOW THROUGH THE REGION THROUGH EARLY NEXT WEEK. THE NAM IS AMONG
THE FARTHEST WEST...WHILE THE GFS FAVORS A FASTER...MORE EASTERLY
PATH. THE ECMWF REPRESENTS A REASONABLE COMPROMISE...AND WOULD
KEEP SHOWERS AROUND INTO TUESDAY BEFORE PUSHING EAST. THE FAVORED
PERIOD FOR SEVERE WEATHER WILL BE SATURDAY...WITH SOUTHWEST FLOW
ALOFT AND A WARM FRONT NOSING INTO THE SOUTHEAST PORTION OF THE
FORECAST AREA. SPC CONTINUES TO HAVE THE SOUTHEAST OUTLOOKED IN
SLIGHT RISK FOR DAY 2. BUFR SOUNDINGS SUGGEST STORMS WILL DEVELOP
RELATIVELY EARLY IN THE DAY. AM EXPECTING SOME STRONG TO SEVERE
STORMS WITH LARGE HAIL/STRONG WIND GUSTS THE PRIMARY THREATS.
STRONG MOISTURE TRANSPORT INTO THE BOUNDARY WILL CONTINUE THROUGH
SATURDAY NIGHT AS A DECENT SHORT WAVE TROUGH MOVES THROUGH EASTERN
NORTH DAKOTA. THE SEVERE WEATHER THREAT DIMINISHES SUNDAY...BUT
MODERATE TO LOCALLY HEAVY RAIN IS EXPECTED TO CONTINUE OVER MUCH
OF WESTERN AND CENTRAL NORTH DAKOTA. THIS SCENARIO WILL LIKELY
CONTINUE MONDAY...BEFORE SHOWERS TAPER OFF IN COVERAGE AND
INTENSITY ON TUESDAY. TOTAL RAINFALL AMOUNTS OF 1 TO 3 ARE
EXPECTED THROUGH THE PERIOD...WITH AMOUNTS AROUND 4 INCHES
POSSIBLE...ESPECIALLY IN THE JAMES RIVER VALLEY. CONDITIONS ARE
SUCH THAT SOILS CAN ABSORB SIGNIFICANT RAINFALL. THUS...SIGNIFICANT
RISES ON MAIN STEM RIVERS SUCH AS THE SOURIS AND JAMES ARE NOT
EXPECTED. HOWEVER...ENHANCED RAINFALL RATES OR SEVERAL ROUNDS OF
STORMS COULD PRODUCE LOCALIZED RUNOFF...LEADING TO RISES ON SMALL
CREEKS AND STREAMS...AND POSSIBLY FLASH FLOODING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 114 PM CDT FRI MAY 17 2013
VFR CONDITIONS AT ALL TAF SITES WILL EVENTUALLY BECOME MVFR
TONIGHT AS WIDESPREAD SHOWERS AND THUNDERSTORMS ACCOMPANY LOWER
CEILINGS. THE OFFENDING LARGE LOW PRESSURE SYSTEM WILL REMAIN OVER
THE NORTHERN PLAINS THROUGH AT LEAST MONDAY. THUNDERSTORMS WILL BE
MORE WIDESPREAD SATURDAY AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...SCHECK
SHORT TERM...CK
LONG TERM...RP KINNEY
000
FXUS63 KBIS 171506
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1006 AM CDT FRI MAY 17 2013
.UPDATE...
ISSUED AT 1001 AM CDT FRI MAY 17 2013
THE MAIN FOCUS TODAY WILL BE SEEMINGLY UNENDING PRECIPITATION
CHANCES. THIS UPDATE MADE SIMPLE ADJUSTMENTS TO PRECIPITATION
PROBABILITIES TODAY. WHILE THERE LOOKS TO BE A BREAK THAT WILL
LAST SEVERAL HOURS OVER MUCH OF THE MISSOURI SLOPE AND JAMES RIVER
VALLEYS THROUGH EARLY AFTERNOON...ECHOES ON SOUTH DAKOTA RADARS
INDICATE AT LEAST LIGHT SHOWER ACTIVITY MOVING NORTHEASTWARD FAST.
THE NEXT FEW HOURS SHOULD GIVE A BETTER FEEL FOR FORCING
MECHANISMS AND LIKELIHOOD OF INTENSIFICATION.
PREVIOUS FORECASTS OF SUB-SEVERE CONVECTION OVER SOUTHWESTERN NORTH
DAKOTA LOOK TO BE ON TRACK FOR LATER TODAY/TONIGHT.
UPDATE ISSUED AT 637 AM CDT FRI MAY 17 2013
UPDATE FOR MINOR CHANGES TO POPS ACROSS THE NORTH THIS MORNING AS
BATCH OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES TO HEAD
NORTHEAST. OTHERWISE...MAINTAINED GENERALLY INCREASING POPS
THROUGH LATE AFTERNOON AND EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT FRI MAY 17 2013
THE MAIN CONCERN FOR TODAY INTO TONIGHT WILL BE THE CHANCE OF
THUNDERSTORMS AND POTENTIAL SEVERE WEATHER. EARLY MORNING RADAR
MOSAIC SHOWED ISOLATED SHOWERS FROM SOUTHWEST NORTH DAKOTA INTO
NORTHWEST MINNESOTA. MUCH OF THIS ACTIVITY DEVELOPED IN AN AREA OF
H85 WARM AIR ADVECTION THAT HAS BEEN MOVING FROM SOUTH TO NORTH
ACROSS THE REGION. THE STRONGEST WARM AIR ADVECTION SHIFTS NORTH BY
AFTERNOON AS SOUTHWESTERLY FLOW ALOFT BRINGS A SERIES OF WAVES ACROSS
THE STATE. WILL MAINTAIN FAIRLY HIGH POPS TODAY...ESPECIALLY IN
THE NORTH AND WEST WHERE THE MAJORITY OF MODEL SOLUTIONS FAVOR THE
HIGHER PRECIPITATION CHANCES.
THE FOCUS THEN TURNS FARTHER SOUTH AS SURFACE LOW PRESSURE GATHERS
IN EAST CENTRAL WYOMING. A WARM FRONT STRETCHING OUT OF THE LOW
INTO SOUTHERN SOUTH DAKOTA IS EXPECTED TO LIFT NORTH TONIGHT...BRINGING
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS TO CENTRAL AND
WESTERN NORTH DAKOTA. CAN NOT RULE OUT AN ISOLATED SEVERE STORM
LATE THIS AFTERNOON / EVENING ACROSS THE SOUTHERN PART OF THE
FORECAST AREA WHERE INSTABILITY WILL BE GREATEST. THE SPC DAY 1
SEVERE WEATHER OUTLOOK KEEPS THE SLIGHT RISK SOUTH OF THE FORECAST
AREA...HOWEVER THE 5 PERCENT PROBABILITIES FOR SEVERE HAIL / WIND
ARE DRAWN SOUTH OF I-94 INTO SOUTHERN NORTH DAKOTA WHICH APPEARS
REASONABLE.
TEMPERATURES TODAY WILL BE TRICKY DUE TO THE CLOUDS AND RAIN. WILL
GENERALLY STAY ON THE COOL SIDE OF GUIDANCE WHICH SUGGESTS MID
60S NORTH TO LOWER 70S SOUTH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CDT FRI MAY 17 2013
THE MAIN FORECAST ISSUES THROUGH THE LONG TERM PERIOD ARE CONVECTIVE
TRENDS...AND POTENTIAL FOR PROLONGED MODERATE TO HEAVY RAIN AND
SOME SEVERE WEATHER ON SATURDAY. THE LATEST 17/00Z MODEL RUNS HAVE
SOME SIGNIFICANT DIFFERENCE IN THE PROGRESSION OF A CLOSED UPPER
LOW THROUGH THE REGION THROUGH EARLY NEXT WEEK. THE NAM IS AMONG
THE FARTHEST WEST...WHILE THE GFS FAVORS A FASTER...MORE EASTERLY
PATH. THE ECMWF REPRESENTS A REASONABLE COMPROMISE...AND WOULD
KEEP SHOWERS AROUND INTO TUESDAY BEFORE PUSHING EAST. THE FAVORED
PERIOD FOR SEVERE WEATHER WILL BE SATURDAY...WITH SOUTHWEST FLOW
ALOFT AND A WARM FRONT NOSING INTO THE SOUTHEAST PORTION OF THE
FORECAST AREA. SPC CONTINUES TO HAVE THE SOUTHEAST OUTLOOKED IN
SLIGHT RISK FOR DAY 2. BUFR SOUNDINGS SUGGEST STORMS WILL DEVELOP
RELATIVELY EARLY IN THE DAY. AM EXPECTING SOME STRONG TO SEVERE
STORMS WITH LARGE HAIL/STRONG WIND GUSTS THE PRIMARY THREATS.
STRONG MOISTURE TRANSPORT INTO THE BOUNDARY WILL CONTINUE THROUGH
SATURDAY NIGHT AS A DECENT SHORT WAVE TROUGH MOVES THROUGH EASTERN
NORTH DAKOTA. THE SEVERE WEATHER THREAT DIMINISHES SUNDAY...BUT
MODERATE TO LOCALLY HEAVY RAIN IS EXPECTED TO CONTINUE OVER MUCH
OF WESTERN AND CENTRAL NORTH DAKOTA. THIS SCENARIO WILL LIKELY
CONTINUE MONDAY...BEFORE SHOWERS TAPER OFF IN COVERAGE AND
INTENSITY ON TUESDAY. TOTAL RAINFALL AMOUNTS OF 1 TO 3 ARE
EXPECTED THROUGH THE PERIOD...WITH AMOUNTS AROUND 4 INCHES
POSSIBLE...ESPECIALLY IN THE JAMES RIVER VALLEY. CONDITIONS ARE
SUCH THAT SOILS CAN ABSORB SIGNIFICANT RAINFALL. THUS...SIGNIFICANT
RISES ON MAIN STEM RIVERS SUCH AS THE SOURIS AND JAMES ARE NOT
EXPECTED. HOWEVER...ENHANCED RAINFALL RATES OR SEVERAL ROUNDS OF
STORMS COULD PRODUCE LOCALIZED RUNOFF...LEADING TO RISES ON SMALL
CREEKS AND STREAMS...AND POSSIBLY FLASH FLOODING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 637 AM CDT FRI MAY 17 2013
SHOWERS AND ISOLATED THUNDERSTORMS MOVING NORTHEAST ACROSS WESTERN
NORTH DAKOTA COULD APPROACH KMOT DURING THE FIRST FEW HOURS OF THE
TAF. THE REMAINDER OF THE TAF SITES SHOULD STAY DRY THIS
MORNING...THOUGH THE CHANCES OF SHOWERS AND A FEW THUNDERSTORMS WILL
INCREASE LATE THIS AFTERNOON INTO TONIGHT.
CEILINGS IN PARTICULAR ARE A CHALLENGE RIGHT FROM THE BEGINNING WITH
PARTS OF CENTRAL AND WESTERN NORTH DAKOTA ALREADY SHOWING LOCATIONS
WITH MVFR / IFR CONDITIONS. KMOT BRIEFLY FELL TO IFR...WHILE KISN
AND KDIK ARE CURRENTLY MVFR. FORECAST SOUNDINGS SUGGEST CEILINGS
SHOULD IMPROVE LATER THIS MORNING BEFORE THEY DECLINE AGAIN TONIGHT
IN THE RAIN. GENERALLY STAYED MVFR WITH CEILINGS / VISIBILITIES IN
THE RAIN...BUT COULD SEE THOSE BEING DROPPED LOWER ONCE MORE
CONFIDENCE IN THE TIMING CAN BE ESTABLISHED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SCHECK
SHORT TERM/AVIATION...CK
LONG TERM...RP KINNEY
000
FXUS63 KBIS 171138
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
638 AM CDT FRI MAY 17 2013
.UPDATE...
ISSUED AT 637 AM CDT FRI MAY 17 2013
UPDATE FOR MINOR CHANGES TO POPS ACROSS THE NORTH THIS MORNING AS
BATCH OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES TO HEAD
NORTHEAST. OTHERWISE...MAINTAINED GENERALLY INCREASING POPS
THROUGH LATE AFTERNOON AND EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT FRI MAY 17 2013
THE MAIN CONCERN FOR TODAY INTO TONIGHT WILL BE THE CHANCE OF
THUNDERSTORMS AND POTENTIAL SEVERE WEATHER. EARLY MORNING RADAR
MOSAIC SHOWED ISOLATED SHOWERS FROM SOUTHWEST NORTH DAKOTA INTO
NORTHWEST MINNESOTA. MUCH OF THIS ACTIVITY DEVELOPED IN AN AREA OF
H85 WARM AIR ADVECTION THAT HAS BEEN MOVING FROM SOUTH TO NORTH
ACROSS THE REGION. THE STRONGEST WARM AIR ADVECTION SHIFTS NORTH BY
AFTERNOON AS SOUTHWESTERLY FLOW ALOFT BRINGS A SERIES OF WAVES ACROSS
THE STATE. WILL MAINTAIN FAIRLY HIGH POPS TODAY...ESPECIALLY IN
THE NORTH AND WEST WHERE THE MAJORITY OF MODEL SOLUTIONS FAVOR THE
HIGHER PRECIPITATION CHANCES.
THE FOCUS THEN TURNS FARTHER SOUTH AS SURFACE LOW PRESSURE GATHERS
IN EAST CENTRAL WYOMING. A WARM FRONT STRETCHING OUT OF THE LOW
INTO SOUTHERN SOUTH DAKOTA IS EXPECTED TO LIFT NORTH TONIGHT...BRINGING
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS TO CENTRAL AND
WESTERN NORTH DAKOTA. CAN NOT RULE OUT AN ISOLATED SEVERE STORM
LATE THIS AFTERNOON / EVENING ACROSS THE SOUTHERN PART OF THE
FORECAST AREA WHERE INSTABILITY WILL BE GREATEST. THE SPC DAY 1
SEVERE WEATHER OUTLOOK KEEPS THE SLIGHT RISK SOUTH OF THE FORECAST
AREA...HOWEVER THE 5 PERCENT PROBABILITIES FOR SEVERE HAIL / WIND
ARE DRAWN SOUTH OF I-94 INTO SOUTHERN NORTH DAKOTA WHICH APPEARS
REASONABLE.
TEMPERATURES TODAY WILL BE TRICKY DUE TO THE CLOUDS AND RAIN. WILL
GENERALLY STAY ON THE COOL SIDE OF GUIDANCE WHICH SUGGESTS MID
60S NORTH TO LOWER 70S SOUTH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CDT FRI MAY 17 2013
THE MAIN FORECAST ISSUES THROUGH THE LONG TERM PERIOD ARE CONVECTIVE
TRENDS...AND POTENTIAL FOR PROLONGED MODERATE TO HEAVY RAIN AND
SOME SEVERE WEATHER ON SATURDAY. THE LATEST 17/00Z MODEL RUNS HAVE
SOME SIGNIFICANT DIFFERENCE IN THE PROGRESSION OF A CLOSED UPPER
LOW THROUGH THE REGION THROUGH EARLY NEXT WEEK. THE NAM IS AMONG
THE FARTHEST WEST...WHILE THE GFS FAVORS A FASTER...MORE EASTERLY
PATH. THE ECMWF REPRESENTS A REASONABLE COMPROMISE...AND WOULD
KEEP SHOWERS AROUND INTO TUESDAY BEFORE PUSHING EAST. THE FAVORED
PERIOD FOR SEVERE WEATHER WILL BE SATURDAY...WITH SOUTHWEST FLOW
ALOFT AND A WARM FRONT NOSING INTO THE SOUTHEAST PORTION OF THE
FORECAST AREA. SPC CONTINUES TO HAVE THE SOUTHEAST OUTLOOKED IN
SLIGHT RISK FOR DAY 2. BUFR SOUNDINGS SUGGEST STORMS WILL DEVELOP
RELATIVELY EARLY IN THE DAY. AM EXPECTING SOME STRONG TO SEVERE
STORMS WITH LARGE HAIL/STRONG WIND GUSTS THE PRIMARY THREATS.
STRONG MOISTURE TRANSPORT INTO THE BOUNDARY WILL CONTINUE THROUGH
SATURDAY NIGHT AS A DECENT SHORT WAVE TROUGH MOVES THROUGH EASTERN
NORTH DAKOTA. THE SEVERE WEATHER THREAT DIMINISHES SUNDAY...BUT
MODERATE TO LOCALLY HEAVY RAIN IS EXPECTED TO CONTINUE OVER MUCH
OF WESTERN AND CENTRAL NORTH DAKOTA. THIS SCENARIO WILL LIKELY
CONTINUE MONDAY...BEFORE SHOWERS TAPER OFF IN COVERAGE AND
INTENSITY ON TUESDAY. TOTAL RAINFALL AMOUNTS OF 1 TO 3 ARE
EXPECTED THROUGH THE PERIOD...WITH AMOUNTS AROUND 4 INCHES
POSSIBLE...ESPECIALLY IN THE JAMES RIVER VALLEY. CONDITIONS ARE
SUCH THAT SOILS CAN ABSORB SIGNIFICANT RAINFALL. THUS...SIGNIFICANT
RISES ON MAIN STEM RIVERS SUCH AS THE SOURIS AND JAMES ARE NOT
EXPECTED. HOWEVER...ENHANCED RAINFALL RATES OR SEVERAL ROUNDS OF
STORMS COULD PRODUCE LOCALIZED RUNOFF...LEADING TO RISES ON SMALL
CREEKS AND STREAMS...AND POSSIBLY FLASH FLOODING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 637 AM CDT FRI MAY 17 2013
SHOWERS AND ISOLATED THUNDERSTORMS MOVING NORTHEAST ACROSS WESTERN
NORTH DAKOTA COULD APPROACH KMOT DURING THE FIRST FEW HOURS OF THE
TAF. THE REMAINDER OF THE TAF SITES SHOULD STAY DRY THIS
MORNING...THOUGH THE CHANCES OF SHOWERS AND A FEW THUNDERSTORMS WILL
INCREASE LATE THIS AFTERNOON INTO TONIGHT.
CEILINGS IN PARTICULAR ARE A CHALLENGE RIGHT FROM THE BEGINNING WITH
PARTS OF CENTRAL AND WESTERN NORTH DAKOTA ALREADY SHOWING LOCATIONS
WITH MVFR / IFR CONDITIONS. KMOT BRIEFLY FELL TO IFR...WHILE KISN
AND KDIK ARE CURRENTLY MVFR. FORECAST SOUNDINGS SUGGEST CEILINGS
SHOULD IMPROVE LATER THIS MORNING BEFORE THEY DECLINE AGAIN TONIGHT
IN THE RAIN. GENERALLY STAYED MVFR WITH CEILINGS / VISIBILITIES IN
THE RAIN...BUT COULD SEE THOSE BEING DROPPED LOWER ONCE MORE
CONFIDENCE IN THE TIMING CAN BE ESTABLISHED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/LONG TERM...RP KINNEY
SHORT TERM/AVIATION...CK
000
FXUS63 KBIS 170850
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
350 AM CDT FRI MAY 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT FRI MAY 17 2013
THE MAIN CONCERN FOR TODAY INTO TONIGHT WILL BE THE CHANCE OF
THUNDERSTORMS AND POTENTIAL SEVERE WEATHER. EARLY MORNING RADAR
MOSAIC SHOWED ISOLATED SHOWERS FROM SOUTHWEST NORTH DAKOTA INTO
NORTHWEST MINNESOTA. MUCH OF THIS ACTIVITY DEVELOPED IN AN AREA OF
H85 WARM AIR ADVECTION THAT HAS BEEN MOVING FROM SOUTH TO NORTH
ACROSS THE REGION. THE STRONGEST WARM AIR ADVECTION SHIFTS NORTH BY
AFTERNOON AS SOUTHWESTERLY FLOW ALOFT BRINGS A SERIES OF WAVES ACROSS
THE STATE. WILL MAINTAIN FAIRLY HIGH POPS TODAY...ESPECIALLY IN
THE NORTH AND WEST WHERE THE MAJORITY OF MODEL SOLUTIONS FAVOR THE
HIGHER PRECIPITATION CHANCES.
THE FOCUS THEN TURNS FARTHER SOUTH AS SURFACE LOW PRESSURE GATHERS
IN EAST CENTRAL WYOMING. A WARM FRONT STRETCHING OUT OF THE LOW
INTO SOUTHERN SOUTH DAKOTA IS EXPECTED TO LIFT NORTH TONIGHT...BRINGING
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS TO CENTRAL AND
WESTERN NORTH DAKOTA. CAN NOT RULE OUT AN ISOLATED SEVERE STORM
LATE THIS AFTERNOON / EVENING ACROSS THE SOUTHERN PART OF THE
FORECAST AREA WHERE INSTABILITY WILL BE GREATEST. THE SPC DAY 1
SEVERE WEATHER OUTLOOK KEEPS THE SLIGHT RISK SOUTH OF THE FORECAST
AREA...HOWEVER THE 5 PERCENT PROBABILITIES FOR SEVERE HAIL / WIND
ARE DRAWN SOUTH OF I-94 INTO SOUTHERN NORTH DAKOTA WHICH APPEARS
REASONABLE.
TEMPERATURES TODAY WILL BE TRICKY DUE TO THE CLOUDS AND RAIN. WILL
GENERALLY STAY ON THE COOL SIDE OF GUIDANCE WHICH SUGGESTS MID
60S NORTH TO LOWER 70S SOUTH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CDT FRI MAY 17 2013
THE MAIN FORECAST ISSUES THROUGH THE LONG TERM PERIOD ARE CONVECTIVE
TRENDS...AND POTENTIAL FOR PROLONGED MODERATE TO HEAVY RAIN AND
SOME SEVERE WEATHER ON SATURDAY. THE LATEST 17/00Z MODEL RUNS HAVE
SOME SIGNIFICANT DIFFERENCE IN THE PROGRESSION OF A CLOSED UPPER
LOW THROUGH THE REGION THROUGH EARLY NEXT WEEK. THE NAM IS AMONG
THE FARTHEST WEST...WHILE THE GFS FAVORS A FASTER...MORE EASTERLY
PATH. THE ECMWF REPRESENTS A REASONABLE COMPROMISE...AND WOULD
KEEP SHOWERS AROUND INTO TUESDAY BEFORE PUSHING EAST. THE FAVORED
PERIOD FOR SEVERE WEATHER WILL BE SATURDAY...WITH SOUTHWEST FLOW
ALOFT AND A WARM FRONT NOSING INTO THE SOUTHEAST PORTION OF THE
FORECAST AREA. SPC CONTINUES TO HAVE THE SOUTHEAST OUTLOOKED IN
SLIGHT RISK FOR DAY 2. BUFR SOUNDINGS SUGGEST STORMS WILL DEVELOP
RELATIVELY EARLY IN THE DAY. AM EXPECTING SOME STRONG TO SEVERE
STORMS WITH LARGE HAIL/STRONG WIND GUSTS THE PRIMARY THREATS.
STRONG MOISTURE TRANSPORT INTO THE BOUNDARY WILL CONTINUE THROUGH
SATURDAY NIGHT AS A DECENT SHORT WAVE TROUGH MOVES THROUGH EASTERN
NORTH DAKOTA. THE SEVERE WEATHER THREAT DIMINISHES SUNDAY...BUT
MODERATE TO LOCALLY HEAVY RAIN IS EXPECTED TO CONTINUE OVER MUCH
OF WESTERN AND CENTRAL NORTH DAKOTA. THIS SCENARIO WILL LIKELY
CONTINUE MONDAY...BEFORE SHOWERS TAPER OFF IN COVERAGE AND
INTENSITY ON TUESDAY. TOTAL RAINFALL AMOUNTS OF 1 TO 3 ARE
EXPECTED THROUGH THE PERIOD...WITH AMOUNTS AROUND 4 INCHES
POSSIBLE...ESPECIALLY IN THE JAMES RIVER VALLEY. CONDITIONS ARE
SUCH THAT SOILS CAN ABSORB SIGNIFICANT RAINFALL. THUS...SIGNIFICANT
RISES ON MAIN STEM RIVERS SUCH AS THE SOURIS AND JAMES ARE NOT
EXPECTED. HOWEVER...ENHANCED RAINFALL RATES OR SEVERAL ROUNDS OF
STORMS COULD PRODUCE LOCALIZED RUNOFF...LEADING TO RISES ON SMALL
CREEKS AND STREAMS...AND POSSIBLY FLASH FLOODING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1244 AM CDT FRI MAY 17 2013
MVFR / IFR CEILINGS CONTINUE TO SPREAD INTO PARTS OF CENTRAL AND
WESTERN NORTH DAKOTA EARLY THIS MORNING. THE WESTERN PART OF THE
STATE APPEARS FAVORED FOR THE LOWEST CEILINGS WITH THE 17.00Z NAM
SHOWING THE BEST LOW LEVEL SATURATION IN THAT REGION.
RAIN CHANCES REMAIN DIFFICULT TO PINPOINT WITH ENOUGH SPREAD IN
MODEL SOLUTIONS TO KEEP CONFIDENCE FAIRLY LOW IN SPECIFIC TIMING.
THE 17.03Z RAP STILL FAVORS THE NORTH THIS MORNING IN AN AREA OF
H85 WARM AIR ADVECTION. THIS IS GENERALLY IN LINE WITH CURRENT
RADAR TRENDS...SO WILL CONFINE ANY SHOWERS THIS MORNING TO KMOT
AND KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION...CK
LONG TERM...RP KINNEY
000
FXUS63 KBIS 170546
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1246 AM CDT FRI MAY 17 2013
.UPDATE...
ISSUED AT 1244 AM CDT FRI MAY 17 2013
REGIONAL RADAR MOSAIC SHOWS ISOLATED TO SCATTERED SHOWERS ACROSS
NORTH CENTRAL AND NORTHEAST NORTH DAKOTA. THIS APPEARS TO LINE UP
WITH AN AREA OF H85 WARM AIR ADVECTION SHOWN BY THE 17.03Z RAP.
THE STRONGEST WARM AIR ADVECTION IS FORECAST TO BE ACROSS NORTHERN
PARTS OF THE STATE EARLY THIS MORNING...SO WILL HAVE THE HIGHEST
POPS IN THAT REGION. INSTABILITY REMAINS LIMITED THIS
MORNING...SO ANY THUNDER CHANCES SHOULD BE ISOLATED AT BEST.
UPDATE ISSUED AT 1016 PM CDT THU MAY 16 2013
ADJUSTED EVENING POPS DOWNWARD BASED ON CURRENT RADAR OBS/TRENDS.
OTHERWISE...NOT TOO MANY CHANGES WERE MADE TO THE ONGOING
FORECAST. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 718 PM CDT THU MAY 16 2013
REGIONAL RADAR TRENDS INDICATE NUMEROUS SHOWERS ACROSS THE JAMES
RIVER BASIN CONTINUING TO PUSH EAST OF THE CWA THIS EVENING. WITH
THE ATMOSPHERE PRETTY WELL WORKED OVER...DECREASED POPS WEST AND
CENTRAL THROUGH THE REMAINDER OF THE EVENING HOURS.
HOWEVER...SHORT RANGE MODEL GUIDANCE CONTINUES TO PROG INCREASING PRECIP
CHANCES AFTER MIDNIGHT AS AN UPPER WAVE APPROACHES FROM THE
SOUTHWEST. SHOWALTER INDICES INDICATE THUNDER POTENTIAL DEVELOPING
ACROSS SOUTHWESTERN NORTH DAKOTA AFTER MIDNIGHT. AS A
RESULT...REMOVED THUNDER AREAWIDE TONIGHT AND ONLY INDICATED
ISOLATED THUNDER SOUTHWEST DEVELOPING AFTER MIDNIGHT.
UPDATED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 300 PM CDT THU MAY 16 2013
LATEST WATER VAPOR IMAGERY SHOWS A SOUTHWEST FLOW INTO NORTH DAKOTA
AHEAD OF AN UPPER TROUGH WHICH IS SLIDING INTO THE NORTHWEST COAST.
FOR THE NEAR TERM...THROUGH THURSDAY EVENING...CATEGORICAL POPS
WILL CONTINUE FROM BLAT TO MCCLUSKY INTO BISMARCK AND AREAS TO
THE EAST AS A SHORTWAVE PROPAGATES THROUGH. THERE IS A BREAK IN
THE CLOUDS AND PRECIPITATION IN THE FAR WEST WITH MORE SHORTWAVES
MOVING INTO CENTRAL MONTANA. THESE WILL MOVE THROUGH TONIGHT INTO
FRIDAY GENERATING ISOLATED TO SCATTERED SHOWERS. BEST CHANCE FOR
AN ISOLATED THUNDERSTORM WILL RESIDE IN THE WEST AND SOUTH INTO
TONIGHT. LATEST VISIBLE IMAGERY SHOWS SOME CLEARING IN THE WEST
WITH CLOUDS BEGINNING TO BILLOW UP IN NORTHEAST MONTANA. FOR
FRIDAY...SOME INSTABILITY CONTINUES IN THE SOUTHWEST AND FAR SOUTH
CENTRAL FOR A MENTION OF THUNDERSTORMS...OTHERWISE SCATTERED
SHOWERS WILL GENERALLY BE THE RULE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CDT THU MAY 16 2013
A BROADENING UPPER LEVEL LOW POSITIONED OVER THE WESTERN CONUS EARLY
THE EXTENDED WILL ALLOW FOR MOIST SOUTHWESTERLY FLOW TO CONTINUE
ACROSS THE NORTHERN PLAINS SATURDAY INTO SUNDAY. AS THIS BROAD UPPER
LEVEL TROUGH SLOWLY SHIFTS EAST AND OVER THE REGION LATE SUNDAY AND
EARLY MONDAY THE FLOW WILL BECOME SOUTHERLY AS THE UPPER LEVEL
TROUGH CLOSES OFF OVER THE DAKOTAS. IT WILL REMAIN OVERHEAD MONDAY
AND TUESDAY BEFORE MOVING EAST THEREAFTER. 12Z GFS/GEM/NAM/ECWMF ARE
IN GOOD AGREEMENT REGARDING THIS PATTERN...BEFORE SOLUTIONS DIVERGE
LATE IN THE EXTENDED AS THE UPPER LEVEL LOW MOVES EAST.
THE MAIN ISSUE FOR THE EXTENDED WILL BE THE POTENTIAL FOR HEAVY RAIN
THROUGH EARLY NEXT WEEK. THERE IS DECENT AGREEMENT BETWEEN THE 12Z
MODEL RUNS REGARDING THE PLACEMENT AND AMOUNT OF PRECIPITATION
ACROSS THE AREA...WITH THE HEAVIEST AMOUNTS FOCUSED ON THE JAMES
RIVER VALLEY AND POINTS EAST. A SECOND AREA OF HEAVY PRECIPITATION
MAY BE POSSIBLE ACROSS THE NORTHWEST. HOWEVER...THERE IS A BIT
MORE UNCERTAINTY FOR THE NORTHWEST AREA. IN ADDITION...THE 12Z
GFS AND NAM CONTINUE TO PLACE PRECIPITABLE WATER VALUES OF 1.30 TO
1.50 INCHES ACROSS THE EASTERN TWO THIRDS OF NORTH DAKOTA SATURDAY
THROUGH EARLY SUNDAY MORNING. ACCORDING TO PW CLIMATOLOGY...THESE
FORECAST VALUES WILL BE IN THE 99TH PERCENTILE TO THE HIGHEST EVER
OBSERVED FOR THE MONTH OF MAY. CONFIDENCE IS INCREASING FOR 1 TO 2
INCHES (WITH LOCALLY HIGHER AMOUNTS ACROSS THE JAMES RIVER VALLEY)
OF RAINFALL THROUGH SUNDAY EVENING. ADDITIONAL LIGHT TO MODERATE
RAIN WILL CONTINUE THROUGH TUESDAY AS THE UPPER LEVEL LOW IS
OVERHEAD...BRINGING POTENTIAL RAINFALL TOTALS THROUGH TUESDAY INTO
THE 2 TO 4 INCH RANGE. THIS WILL HAVE TO BE MONITORED CLOSELY OVER
THE NEXT FEW DAYS AS POTENTIAL HYDRO ISSUES FOR THE JAMES RIVER
MAY COME INTO PLAY. ALSO...THIS HEAVY RAIN EVENT WILL POTENTIALLY
ALLEVIATE THE RAINFALL DEFICITS OBSERVED SO FAR FOR MAY.
REGARDING THE POTENTIAL FOR SEVERE WEATHER...THE BEST CHANCES FOR
ANY SEVERE WEATHER WILL COME SATURDAY AFTERNOON THROUGH EARLY SUNDAY
MORNING FOR LOCATIONS EAST OF STATE HIGHWAY 83 AND SOUTH OF
INTERSTATE 94. ISOLATED SEVERE MAY BE POSSIBLE FOR THE SOUTHWEST
LATE SATURDAY AFTERNOON AND EARLY EVENING. SUFFICIENT MOISTURE
WILL BE PRESENT DUE TO PREVIOUS MOISTURE RECEIVED ON THURSDAY AND
FRIDAY. BULK SHEAR VALUES WILL BE IN THE 40 TO 50 KT RANGE DURING
THIS PERIOD...WITH ML CAPE IN THE 1000 TO 2000 J/KG RANGE FOR THE
FAR SOUTH CENTRAL...AND 2000 TO 3000 J/LG VALUES ACROSS THE
SOUTHERN JAMES RIVER VALLEY. MU CAPE VALUES WILL BE IN THE 1200 TO
3000 J/KG RANGE AS WELL. HOWEVER...THE MAIN LIMITING FACTOR WILL
BE THE WARM AIR ALOFT...AS THE NAM/GFS BUFR SOUNDINGS FOR JMS/BIS
DEPICT A DECENT CAP INVERSION. THIS MAY BE OVERCOME BY DAYTIME
HEATING AND LARGE SCALE ASCENT ASSOCIATED WITH THE AFOREMENTIONED
UPPER LEVEL TROUGH.
BEYOND TUESDAY...THE UPPER LEVEL LOW WILL MOVE EAST AND IN ITS
WAKE...UPPER LEVEL RIDING WILL COMMENCE. A PERIOD OF DRIER AND
SEASONABLE TEMPERATURES ARE FORECAST FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1244 AM CDT FRI MAY 17 2013
MVFR / IFR CEILINGS CONTINUE TO SPREAD INTO PARTS OF CENTRAL AND
WESTERN NORTH DAKOTA EARLY THIS MORNING. THE WESTERN PART OF THE
STATE APPEARS FAVORED FOR THE LOWEST CEILINGS WITH THE 17.00Z NAM
SHOWING THE BEST LOW LEVEL SATURATION IN THAT REGION.
RAIN CHANCES REMAIN DIFFICULT TO PINPOINT WITH ENOUGH SPREAD IN
MODEL SOLUTIONS TO KEEP CONFIDENCE FAIRLY LOW IN SPECIFIC TIMING.
THE 17.03Z RAP STILL FAVORS THE NORTH THIS MORNING IN AN AREA OF
H85 WARM AIR ADVECTION. THIS IS GENERALLY IN LINE WITH CURRENT
RADAR TRENDS...SO WILL CONFINE ANY SHOWERS THIS MORNING TO KMOT
AND KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...KS
LONG TERM...LTH
AVIATION...CK
000
FXUS63 KBIS 170316
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1016 PM CDT THU MAY 16 2013
.UPDATE...
ISSUED AT 1016 PM CDT THU MAY 16 2013
ADJUSTED EVENING POPS DOWNWARD BASED ON CURRENT RADAR OBS/TRENDS.
OTHERWISE...NOT TOO MANY CHANGES WERE MADE TO THE ONGOING
FORECAST. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 718 PM CDT THU MAY 16 2013
REGIONAL RADAR TRENDS INDICATE NUMEROUS SHOWERS ACROSS THE JAMES
RIVER BASIN CONTINUING TO PUSH EAST OF THE CWA THIS EVENING. WITH
THE ATMOSPHERE PRETTY WELL WORKED OVER...DECREASED POPS WEST AND
CENTRAL THROUGH THE REMAINDER OF THE EVENING HOURS.
HOWEVER...SHORT RANGE MODEL GUIDANCE CONTINUES TO PROG INCREASING PRECIP
CHANCES AFTER MIDNIGHT AS AN UPPER WAVE APPROACHES FROM THE
SOUTHWEST. SHOWALTER INDICES INDICATE THUNDER POTENTIAL DEVELOPING
ACROSS SOUTHWESTERN NORTH DAKOTA AFTER MIDNIGHT. AS A
RESULT...REMOVED THUNDER AREAWIDE TONIGHT AND ONLY INDICATED
ISOLATED THUNDER SOUTHWEST DEVELOPING AFTER MIDNIGHT.
UPDATED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 300 PM CDT THU MAY 16 2013
LATEST WATER VAPOR IMAGERY SHOWS A SOUTHWEST FLOW INTO NORTH DAKOTA
AHEAD OF AN UPPER TROUGH WHICH IS SLIDING INTO THE NORTHWEST COAST.
FOR THE NEAR TERM...THROUGH THURSDAY EVENING...CATEGORICAL POPS
WILL CONTINUE FROM BLAT TO MCCLUSKY INTO BISMARCK AND AREAS TO
THE EAST AS A SHORTWAVE PROPAGATES THROUGH. THERE IS A BREAK IN
THE CLOUDS AND PRECIPITATION IN THE FAR WEST WITH MORE SHORTWAVES
MOVING INTO CENTRAL MONTANA. THESE WILL MOVE THROUGH TONIGHT INTO
FRIDAY GENERATING ISOLATED TO SCATTERED SHOWERS. BEST CHANCE FOR
AN ISOLATED THUNDERSTORM WILL RESIDE IN THE WEST AND SOUTH INTO
TONIGHT. LATEST VISIBLE IMAGERY SHOWS SOME CLEARING IN THE WEST
WITH CLOUDS BEGINNING TO BILLOW UP IN NORTHEAST MONTANA. FOR
FRIDAY...SOME INSTABILITY CONTINUES IN THE SOUTHWEST AND FAR SOUTH
CENTRAL FOR A MENTION OF THUNDERSTORMS...OTHERWISE SCATTERED
SHOWERS WILL GENERALLY BE THE RULE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CDT THU MAY 16 2013
A BROADENING UPPER LEVEL LOW POSITIONED OVER THE WESTERN CONUS EARLY
THE EXTENDED WILL ALLOW FOR MOIST SOUTHWESTERLY FLOW TO CONTINUE
ACROSS THE NORTHERN PLAINS SATURDAY INTO SUNDAY. AS THIS BROAD UPPER
LEVEL TROUGH SLOWLY SHIFTS EAST AND OVER THE REGION LATE SUNDAY AND
EARLY MONDAY THE FLOW WILL BECOME SOUTHERLY AS THE UPPER LEVEL
TROUGH CLOSES OFF OVER THE DAKOTAS. IT WILL REMAIN OVERHEAD MONDAY
AND TUESDAY BEFORE MOVING EAST THEREAFTER. 12Z GFS/GEM/NAM/ECWMF ARE
IN GOOD AGREEMENT REGARDING THIS PATTERN...BEFORE SOLUTIONS DIVERGE
LATE IN THE EXTENDED AS THE UPPER LEVEL LOW MOVES EAST.
THE MAIN ISSUE FOR THE EXTENDED WILL BE THE POTENTIAL FOR HEAVY RAIN
THROUGH EARLY NEXT WEEK. THERE IS DECENT AGREEMENT BETWEEN THE 12Z
MODEL RUNS REGARDING THE PLACEMENT AND AMOUNT OF PRECIPITATION
ACROSS THE AREA...WITH THE HEAVIEST AMOUNTS FOCUSED ON THE JAMES
RIVER VALLEY AND POINTS EAST. A SECOND AREA OF HEAVY PRECIPITATION
MAY BE POSSIBLE ACROSS THE NORTHWEST. HOWEVER...THERE IS A BIT
MORE UNCERTAINTY FOR THE NORTHWEST AREA. IN ADDITION...THE 12Z
GFS AND NAM CONTINUE TO PLACE PRECIPITABLE WATER VALUES OF 1.30 TO
1.50 INCHES ACROSS THE EASTERN TWO THIRDS OF NORTH DAKOTA SATURDAY
THROUGH EARLY SUNDAY MORNING. ACCORDING TO PW CLIMATOLOGY...THESE
FORECAST VALUES WILL BE IN THE 99TH PERCENTILE TO THE HIGHEST EVER
OBSERVED FOR THE MONTH OF MAY. CONFIDENCE IS INCREASING FOR 1 TO 2
INCHES (WITH LOCALLY HIGHER AMOUNTS ACROSS THE JAMES RIVER VALLEY)
OF RAINFALL THROUGH SUNDAY EVENING. ADDITIONAL LIGHT TO MODERATE
RAIN WILL CONTINUE THROUGH TUESDAY AS THE UPPER LEVEL LOW IS
OVERHEAD...BRINGING POTENTIAL RAINFALL TOTALS THROUGH TUESDAY INTO
THE 2 TO 4 INCH RANGE. THIS WILL HAVE TO BE MONITORED CLOSELY OVER
THE NEXT FEW DAYS AS POTENTIAL HYDRO ISSUES FOR THE JAMES RIVER
MAY COME INTO PLAY. ALSO...THIS HEAVY RAIN EVENT WILL POTENTIALLY
ALLEVIATE THE RAINFALL DEFICITS OBSERVED SO FAR FOR MAY.
REGARDING THE POTENTIAL FOR SEVERE WEATHER...THE BEST CHANCES FOR
ANY SEVERE WEATHER WILL COME SATURDAY AFTERNOON THROUGH EARLY SUNDAY
MORNING FOR LOCATIONS EAST OF STATE HIGHWAY 83 AND SOUTH OF
INTERSTATE 94. ISOLATED SEVERE MAY BE POSSIBLE FOR THE SOUTHWEST
LATE SATURDAY AFTERNOON AND EARLY EVENING. SUFFICIENT MOISTURE
WILL BE PRESENT DUE TO PREVIOUS MOISTURE RECEIVED ON THURSDAY AND
FRIDAY. BULK SHEAR VALUES WILL BE IN THE 40 TO 50 KT RANGE DURING
THIS PERIOD...WITH ML CAPE IN THE 1000 TO 2000 J/KG RANGE FOR THE
FAR SOUTH CENTRAL...AND 2000 TO 3000 J/LG VALUES ACROSS THE
SOUTHERN JAMES RIVER VALLEY. MU CAPE VALUES WILL BE IN THE 1200 TO
3000 J/KG RANGE AS WELL. HOWEVER...THE MAIN LIMITING FACTOR WILL
BE THE WARM AIR ALOFT...AS THE NAM/GFS BUFR SOUNDINGS FOR JMS/BIS
DEPICT A DECENT CAP INVERSION. THIS MAY BE OVERCOME BY DAYTIME
HEATING AND LARGE SCALE ASCENT ASSOCIATED WITH THE AFOREMENTIONED
UPPER LEVEL TROUGH.
BEYOND TUESDAY...THE UPPER LEVEL LOW WILL MOVE EAST AND IN ITS
WAKE...UPPER LEVEL RIDING WILL COMMENCE. A PERIOD OF DRIER AND
SEASONABLE TEMPERATURES ARE FORECAST FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 24Z FRIDAY EVENING)
ISSUED AT 718 PM CDT THU MAY 16 2013
MVFR CIGS ACROSS SOUTHWESTERN NORTH DAKOTA WILL GRADUALLY SPREAD
NORTHEAST OVER THE STATE TONIGHT. IFR CIGS ARE EXPECTED TO DEVELOP
OVER KDIK AROUND MIDNIGHT...THEN IMPROVE TO MVFR MIDDAY FRIDAY.
AN UNSETTLED WEATHER PATTERN WILL GENERATE CHANCES FOR SHOWERS AND
POSSIBLE THUNDERSTORMS PRIMARILY AFTER SUNRISE FRIDAY. THE THREAT
FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE REMAINDER
OF THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...LTH
AVIATION...TM
000
FXUS63 KBIS 170018
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
718 PM CDT THU MAY 16 2013
.UPDATE...
ISSUED AT 718 PM CDT THU MAY 16 2013
REGIONAL RADAR TRENDS INDICATE NUMEROUS SHOWERS ACROSS THE JAMES
RIVER BASIN CONTINUING TO PUSH EAST OF THE CWA THIS EVENING. WITH
THE ATMOSPHERE PRETTY WELL WORKED OVER...DECREASED POPS WEST AND
CENTRAL THROUGH THE REMAINDER OF THE EVENING HOURS.
HOWEVER...SHORT RANGE MODEL GUIDANCE CONTINUES TO PROG INCREASING PRECIP
CHANCES AFTER MIDNIGHT AS AN UPPER WAVE APPROACHES FROM THE
SOUTHWEST. SHOWALTER INDICES INDICATE THUNDER POTENTIAL DEVELOPING
ACROSS SOUTHWESTERN NORTH DAKOTA AFTER MIDNIGHT. AS A
RESULT...REMOVED THUNDER AREAWIDE TONIGHT AND ONLY INDICATED
ISOLATED THUNDER SOUTHWEST DEVELOPING AFTER MIDNIGHT.
UPDATED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 300 PM CDT THU MAY 16 2013
LATEST WATER VAPOR IMAGERY SHOWS A SOUTHWEST FLOW INTO NORTH DAKOTA
AHEAD OF AN UPPER TROUGH WHICH IS SLIDING INTO THE NORTHWEST COAST.
FOR THE NEAR TERM...THROUGH THURSDAY EVENING...CATEGORICAL POPS
WILL CONTINUE FROM BALTA TO MCCLUSKY INTO BISMARCK AND AREAS TO
THE EAST AS A SHORTWAVE PROPAGATES THROUGH. THERE IS A BREAK IN
THE CLOUDS AND PRECIPITATION IN THE FAR WEST WITH MORE SHORTWAVES
MOVING INTO CENTRAL MONTANA. THESE WILL MOVE THROUGH TONIGHT INTO
FRIDAY GENERATING ISOLATED TO SCATTERED SHOWERS. BEST CHANCE FOR
AN ISOLATED THUNDERSTORM WILL RESIDE IN THE WEST AND SOUTH INTO
TONIGHT. LATEST VISIBLE IMAGERY SHOWS SOME CLEARING IN THE WEST
WITH CLOUDS BEGINNING TO BILLOW UP IN NORTHEAST MONTANA. FOR
FRIDAY...SOME INSTABILITY CONTINUES IN THE SOUTHWEST AND FAR SOUTH
CENTRAL FOR A MENTION OF THUNDERSTORMS...OTHERWISE SCATTERED
SHOWERS WILL GENERALLY BE THE RULE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CDT THU MAY 16 2013
A BROADENING UPPER LEVEL LOW POSITIONED OVER THE WESTERN CONUS EARLY
THE EXTENDED WILL ALLOW FOR MOIST SOUTHWESTERLY FLOW TO CONTINUE
ACROSS THE NORTHERN PLAINS SATURDAY INTO SUNDAY. AS THIS BROAD UPPER
LEVEL TROUGH SLOWLY SHIFTS EAST AND OVER THE REGION LATE SUNDAY AND
EARLY MONDAY THE FLOW WILL BECOME SOUTHERLY AS THE UPPER LEVEL
TROUGH CLOSES OFF OVER THE DAKOTAS. IT WILL REMAIN OVERHEAD MONDAY
AND TUESDAY BEFORE MOVING EAST THEREAFTER. 12Z GFS/GEM/NAM/ECWMF ARE
IN GOOD AGREEMENT REGARDING THIS PATTERN...BEFORE SOLUTIONS DIVERGE
LATE IN THE EXTENDED AS THE UPPER LEVEL LOW MOVES EAST.
THE MAIN ISSUE FOR THE EXTENDED WILL BE THE POTENTIAL FOR HEAVY RAIN
THROUGH EARLY NEXT WEEK. THERE IS DECENT AGREEMENT BETWEEN THE 12Z
MODEL RUNS REGARDING THE PLACEMENT AND AMOUNT OF PRECIPITATION
ACROSS THE AREA...WITH THE HEAVIEST AMOUNTS FOCUSED ON THE JAMES
RIVER VALLEY AND POINTS EAST. A SECOND AREA OF HEAVY PRECIPITATION
MAY BE POSSIBLE ACROSS THE NORTHWEST. HOWEVER...THERE IS A BIT
MORE UNCERTAINITY FOR THE NORTHWEST AREA. IN ADDITION...THE 12Z
GFS AND NAM CONTINUE TO PLACE PRECIPITABLE WATER VALUES OF 1.30 TO
1.50 INCHES ACROSS THE EASTERN TWO THIRDS OF NORTH DAKOTA SATURDAY
THROUGH EARLY SUNDAY MORNING. ACCORDING TO PW CLIMATOLOGY...THESE
FORECAST VALUES WILL BE IN THE 99TH PERCENTILE TO THE HIGHEST EVER
OBSERVED FOR THE MONTH OF MAY. CONFIDENCE IS INCREASING FOR 1 TO 2
INCHES (WITH LOCALLY HIGHER AMOUNTS ACROSS THE JAMES RIVER VALLEY)
OF RAINFALL THROUGH SUNDAY EVENING. ADDITIONAL LIGHT TO MODERATE
RAIN WILL CONTINUE THROUGH TUESDAY AS THE UPPER LEVEL LOW IS
OVERHEAD...BRINGING POTENTIAL RAINFALL TOTALS THROUGH TUESDAY INTO
THE 2 TO 4 INCH RANGE. THIS WILL HAVE TO BE MONITORED CLOSELY OVER
THE NEXT FEW DAYS AS POTENTIAL HYDRO ISSUES FOR THE JAMES RIVER
MAY COME INTO PLAY. ALSO...THIS HEAVY RAIN EVENT WILL POTENTIALLY
ALLEVIATE THE RAINFALL DEFICITS OBSERVED SO FAR FOR MAY.
REGARDING THE POTENTIAL FOR SEVERE WEATHER...THE BEST CHANCES FOR
ANY SEVERE WEATHER WILL COME SATURDAY AFTERNOON THROUGH EARLY SUNDAY
MORNING FOR LOCATIONS EAST OF STATE HIGHWAY 83 AND SOUTH OF
INTERSTATE 94. ISOLATED SEVERE MAY BE POSSIBLE FOR THE SOUTHWEST
LATE SATURDAY AFTERNOON AND EARLY EVENING. SUFFICIENT MOISTURE
WILL BE PRESENT DUE TO PREVIOUS MOISTURE RECEIVED ON THURSDAY AND
FRIDAY. BULK SHEAR VALUES WILL BE IN THE 40 TO 50 KT RANGE DURING
THIS PERIOD...WITH ML CAPE IN THE 1000 TO 2000 J/KG RANGE FOR THE
FAR SOUTH CENTRAL...AND 2000 TO 3000 J/LG VALUES ACROSS THE
SOUTHERN JAMES RIVER VALLEY. MU CAPE VALUES WILL BE IN THE 1200 TO
3000 J/KG RANGE AS WELL. HOWEVER...THE MAIN LIMITING FACTOR WILL
BE THE WARM AIR ALOFT...AS THE NAM/GFS BUFR SOUNDINGS FOR JMS/BIS
DEPICT A DECENT CAP INVERSION. THIS MAY BE OVERCOME BY DAYTIME
HEATING AND LARGE SCALE ASCENT ASSOCIATED WITH THE AFOREMENTIONED
UPPER LEVEL TROUGH.
BEYOND TUESDAY...THE UPPER LEVEL LOW WILL MOVE EAST AND IN ITS
WAKE...UPPER LEVEL RIDING WILL COMMENCE. A PERIOD OF DRIER AND
SEASONABLE TEMPERATURES ARE FORECAST FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 24Z FRIDAY EVENING)
ISSUED AT 718 PM CDT THU MAY 16 2013
MVFR CIGS ACROSS SOUTHWESTERN NORTH DAKOTA WILL GRADAULLY SPREAD
NORTHEAST OVER THE STATE TONIGHT. IFR CIGS ARE EXPECTED TO DEVELOP
OVER KDIK AROUND MIDNIGHT...THEN IMPROVE TO MVFR MIDDAY FRIDAY.
AN UNSETTLED WEATHER PATTERN WILL GENERATE CHANCES FOR SHOWERS AND
POSSIBLE THUNDERSTORMS PRIMARILY AFTER SUNRISE FRIDAY. THE THREAT
FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE REMAINDER
OF THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...LTH
AVIATION...TM
000
FXUS63 KBIS 162003
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
303 PM CDT THU MAY 16 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 300 PM CDT THU MAY 16 2013
LATEST WATER VAPOR IMAGERY SHOWS A SOUTHWEST FLOW INTO NORTH DAKOTA
AHEAD OF AN UPPER TROUGH WHICH IS SLIDING INTO THE NORTHWEST COAST.
FOR THE NEAR TERM...THROUGH THURSDAY EVENING...CATEGORICAL POPS
WILL CONTINUE FROM BALTA TO MCCLUSKY INTO BISMARCK AND AREAS TO
THE EAST AS A SHORTWAVE PROPAGATES THROUGH. THERE IS A BREAK IN
THE CLOUDS AND PRECIPITATION IN THE FAR WEST WITH MORE SHORTWAVES
MOVING INTO CENTRAL MONTANA. THESE WILL MOVE THROUGH TONIGHT INTO
FRIDAY GENERATING ISOLATED TO SCATTERED SHOWERS. BEST CHANCE FOR
AN ISOLATED THUNDERSTORM WILL RESIDE IN THE WEST AND SOUTH INTO
TONIGHT. LATEST VISIBLE IMAGERY SHOWS SOME CLEARING IN THE WEST
WITH CLOUDS BEGINNING TO BILLOW UP IN NORTHEAST MONTANA. FOR
FRIDAY...SOME INSTABILITY CONTINUES IN THE SOUTHWEST AND FAR SOUTH
CENTRAL FOR A MENTION OF THUNDERSTORMS...OTHERWISE SCATTERED
SHOWERS WILL GENERALLY BE THE RULE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CDT THU MAY 16 2013
A BROADENING UPPER LEVEL LOW POSITIONED OVER THE WESTERN CONUS EARLY
THE EXTENDED WILL ALLOW FOR MOIST SOUTHWESTERLY FLOW TO CONTINUE
ACROSS THE NORTHERN PLAINS SATURDAY INTO SUNDAY. AS THIS BROAD UPPER
LEVEL TROUGH SLOWLY SHIFTS EAST AND OVER THE REGION LATE SUNDAY AND
EARLY MONDAY THE FLOW WILL BECOME SOUTHERLY AS THE UPPER LEVEL
TROUGH CLOSES OFF OVER THE DAKOTAS. IT WILL REMAIN OVERHEAD MONDAY
AND TUESDAY BEFORE MOVING EAST THEREAFTER. 12Z GFS/GEM/NAM/ECWMF ARE
IN GOOD AGREEMENT REGARDING THIS PATTERN...BEFORE SOLUTIONS DIVERGE
LATE IN THE EXTENDED AS THE UPPER LEVEL LOW MOVES EAST.
THE MAIN ISSUE FOR THE EXTENDED WILL BE THE POTENTIAL FOR HEAVY RAIN
THROUGH EARLY NEXT WEEK. THERE IS DECENT AGREEMENT BETWEEN THE 12Z
MODEL RUNS REGARDING THE PLACEMENT AND AMOUNT OF PRECIPITATION
ACROSS THE AREA...WITH THE HEAVIEST AMOUNTS FOCUSED ON THE JAMES
RIVER VALLEY AND POINTS EAST. A SECOND AREA OF HEAVY PRECIPITATION
MAY BE POSSIBLE ACROSS THE NORTHWEST. HOWEVER...THERE IS A BIT
MORE UNCERTAINITY FOR THE NORTHWEST AREA. IN ADDITION...THE 12Z
GFS AND NAM CONTINUE TO PLACE PRECIPITABLE WATER VALUES OF 1.30 TO
1.50 INCHES ACROSS THE EASTERN TWO THIRDS OF NORTH DAKOTA SATURDAY
THROUGH EARLY SUNDAY MORNING. ACCORDING TO PW CLIMATOLOGY...THESE
FORECAST VALUES WILL BE IN THE 99TH PERCENTILE TO THE HIGHEST EVER
OBSERVED FOR THE MONTH OF MAY. CONFIDENCE IS INCREASING FOR 1 TO 2
INCHES (WITH LOCALLY HIGHER AMOUNTS ACROSS THE JAMES RIVER VALLEY)
OF RAINFALL THROUGH SUNDAY EVENING. ADDITIONAL LIGHT TO MODERATE
RAIN WILL CONTINUE THROUGH TUESDAY AS THE UPPER LEVEL LOW IS
OVERHEAD...BRINGING POTENTIAL RAINFALL TOTALS THROUGH TUESDAY INTO
THE 2 TO 4 INCH RANGE. THIS WILL HAVE TO BE MONITORED CLOSELY OVER
THE NEXT FEW DAYS AS POTENTIAL HYDRO ISSUES FOR THE JAMES RIVER
MAY COME INTO PLAY. ALSO...THIS HEAVY RAIN EVENT WILL POTENTIALLY
ALLEVIATE THE RAINFALL DEFICITS OBSERVED SO FAR FOR MAY.
REGARDING THE POTENTIAL FOR SEVERE WEATHER...THE BEST CHANCES FOR
ANY SEVERE WEATHER WILL COME SATURDAY AFTERNOON THROUGH EARLY SUNDAY
MORNING FOR LOCATIONS EAST OF STATE HIGHWAY 83 AND SOUTH OF
INTERSTATE 94. ISOLATED SEVERE MAY BE POSSIBLE FOR THE SOUTHWEST
LATE SATURDAY AFTERNOON AND EARLY EVENING. SUFFICIENT MOISTURE
WILL BE PRESENT DUE TO PREVIOUS MOISTURE RECEIVED ON THURSDAY AND
FRIDAY. BULK SHEAR VALUES WILL BE IN THE 40 TO 50 KT RANGE DURING
THIS PERIOD...WITH ML CAPE IN THE 1000 TO 2000 J/KG RANGE FOR THE
FAR SOUTH CENTRAL...AND 2000 TO 3000 J/LG VALUES ACROSS THE
SOUTHERN JAMES RIVER VALLEY. MU CAPE VALUES WILL BE IN THE 1200 TO
3000 J/KG RANGE AS WELL. HOWEVER...THE MAIN LIMITING FACTOR WILL
BE THE WARM AIR ALOFT...AS THE NAM/GFS BUFR SOUNDINGS FOR JMS/BIS
DEPICT A DECENT CAP INVERSION. THIS MAY BE OVERCOME BY DAYTIME
HEATING AND LARGE SCALE ASCENT ASSOCIATED WITH THE AFOREMENTIONED
UPPER LEVEL TROUGH.
BEYOND TUESDAY...THE UPPER LEVEL LOW WILL MOVE EAST AND IN ITS
WAKE...UPPER LEVEL RIDING WILL COMMENCE. A PERIOD OF DRIER AND
SEASONABLE TEMPERATURES ARE FORECAST FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 300 PM CDT THU MAY 16 2013
MOIST FLOW WILL CONTINUE THROUGH TAF PERIOD WITH SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS. THE MAIN AREA OF PRECIPITATION THROUGH
00Z FRIDAY WILL OCCUR FROM KBIS TO KJMS...WITH ISOLATED SHOWERS
FURTHER NORTH AND WEST. EXPECT MAINLY VFR CIGS/VSBYS...HOWEVER
MVFR/IFR CIGS POSSIBLE IN ANY OF THE HEAVIER RAIN SHOWERS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...LTH
AVIATION...KS
000
FXUS63 KBIS 161820
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
120 PM CDT THU MAY 16 2013
.UPDATE...
ISSUED AT 120 PM CDT THU MAY 16 2013
CURRENT LOCAL RADAR SHOWS A LARGE AREA OF LIGHT TO MODERATE RAIN
SHOWERS FROM NEAR VELVA...TO BEULAH...AND SOUTH TO HETTINGER. THIS
IS MOVING EAST/NORTHEAST AND HAVE BUMPED POPS TO CATEGORICAL FOR THE
AFTERNOON...TAPERING FROM WEST TO EAST. LOWERED MAX TEMPS A BIT DUE
TO CLOUDS AND RAIN OVER SOUTH CENTRAL/SOUTHEAST NORTH DAKOTA.
SATELLITE IMAGERY SHOWS A BREAK IN THE WEST BUT EXPECT CLOUDS TO
REGAIN MOMENTUM THIS AFTERNOON WITH SCATTERED SHOWERS DEVELOPING.
CURRENT SHOWERS ARE IN CENTRAL MONTANA AND WILL ARRIVE THIS EVENING
INTO TONIGHT.
UPDATE ISSUED AT 935 AM CDT THU MAY 16 2013
LATEST LOCAL RADAR SHOWS BANDS OF LIGHT TO MODERATE RAIN SHOWERS
MOVING FROM SOUTHWEST NORTH DAKOTA...INTO OUR SOUTH CENTRAL ZONES.
MULTIPLE UPSTREAM SHORTWAVES NOTED ON THE WATER VAPOR IMAGERY
WITH LARGE SCALE ASCENT/OMEGA CONTINUING FOR MOST OF THE
DAY...BUT ALSO SHIFTING FURTHER TO THE NORTHEAST AND INTO THE
JAMES RIVER BASIN. POPS OVERALL LOOK GOOD WITH ONLY MINOR
ADJUSTMENTS NECESSARY. REST OF FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 654 AM CDT THU MAY 16 2013
UPDATE TO REFINE POPS FOR MORNING RADAR TRENDS...OTHERWISE
PREVIOUS FORECAST IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT THU MAY 16 2013
MAIN CONCERN THIS SHORT TERM PERIOD WILL BE THE CHANCE OF SHOWERS
AND THUNDERSTORMS.
CURRENTLY...SURFACE HIGH PRESSURE WAS OVER MANITOBA WITH LOW
PRESSURE OVER WYOMING. AT UPPER LEVELS...THE LEADING EDGE OF A
SERIES OF SHORTWAVE ENERGY IMPULSES WAS MOVING INTO SOUTHWESTERN
NORTH DAKOTA FROM THE WEST.
THE MODELS INDICATE THAT H850 WINDS SHOULD BE INCREASING FROM A
SOUTHEASTERLY DIRECTION ACROSS WESTERN SOUTH DAKOTA INTO THE
SOUTHWEST CORNER OF NORTH DAKOTA. MEANWHILE SOUTHWESTERLY WINDS AT
H700 AND FINALLY WESTERLY WINDS AROUND H500 WERE SETTING UP AN
OVERRUNNING PRECIPITATION SCENARIO THIS MORNING. THE STRONGER H850
WINDS WERE EVIDENT IN THAT A LINE OF ELEVATED CONVECTION SEEN ON
REGIONAL RADARS EXTENDED FROM NEAR BEACH TO BEULAH. THESE HIGH-BASED
SHOWERS AND ISOLATED THUNDERSHOWERS WERE MOVING EASTWARD WITH THE
UPPER LEVEL WIND FIELD.
THE MODELS ARE IN GOOD AGREEMENT IN BRINGING IN GOOD MOISTURE...WITH
INCREASING LOW LEVEL DEWPOINTS AS WELL AS H850 AND H700 MOISTURE
FIELDS...WITH OVERRUNNING PRECIPITATION CONTINUING INTO TONIGHT.
INSTABILITY IS MARGINAL AS BEST CAPE VALUES OF 200-400 J/KG REMAIN
ACROSS THE SOUTHWEST TODAY AND ACROSS THE WEST AND SOUTH TONIGHT.
THUS KEPT THE MENTION OF RAIN SHOWERS WITH ISOLATED THUNDERSTORMS
MAINLY SOUTH AND WEST DURING THE DAY TODAY AND EXPANDED THE MENTION
OF THUNDER A BIT NORTH AND EAST TONIGHT. WENT WITH HIGHS IN TE 60S
MOST AREAS IN THE WEST AND PARTS OF CENTRAL NORTH DAKOTA WITH FAIRLY
WIDESPREAD RAIN SHOWERS. THE RAIN AND BETTER MOISTURE WILL KEEP THE
FIRE DANGER IN THE LOW TO MEDIUM TODAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 352 AM CDT THU MAY 16 2013
THE MAIN FORECAST ISSUES THROUGH THE LONG TERM PERIOD ARE CONVECTIVE
TRENDS...AND POTENTIAL FOR HEAVY RAIN AND SOME SEVERE WEATHER.
SOUTHWEST FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE NORTHERN
PLAINS FRIDAY AND SATURDAY. HAVE INCREASED POPS BOTH DAYS. THE FAR
SOUTHWEST IS STILL OUTLOOKED IN THE SPC 5 PERCENT RISK
AREA...COINCIDENT WITH THE MAIN INSTABILITY AXIS. SIGNIFICANT WARM
AIR ALOFT SHOULD LIMIT THE COVERAGE OF SEVERE STORMS. SPC HAS ALSO
INCLUDED THE FAR SOUTH/SOUTHEAST IN SLIGHT RISK FOR SATURDAY...NEAR
THE SURFACE BOUNDARY. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES
ARE EXPECTED...AND THE GFS IS SUGGESTING SB CAPE AROUND 2000 J/KG.
WIDESPREAD 1 TO 2 INCH RAINFALL AMOUNTS ARE EXPECTED THROUGH
SATURDAY NIGHT. THE FAR SOUTHEAST IS NOT OUT OF THE WOODS CONCERNING
SEVERE WEATHER POTENTIAL SUNDAY. A LARGE UPPER LOW WILL MOVE INTO
THE REGION SUNDAY AND MONDAY...BRINGING ADDITIONAL MODERATE TO
LOCALLY HEAVY RAIN...WHICH WILL LIKELY LINGER THROUGH AT LEAST
TUESDAY. TOTAL RAINFALL AMOUNTS THROUGH THE ENTIRE PERIOD COULD
REACH 3 TO 4 INCHES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA.
RENEWED HYDRO CONCERNS ARE LIKELY...ESPECIALLY IN THE SOURIS AND
JAMES RIVER BASINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 120 PM CDT THU MAY 16 2013
MOIST FLOW WILL CONTINUE THROUGH TAF PERIOD WITH SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS. THE MAIN AREA OF PRECIPITATION THURSDAY
AFTERNOON WILL OCCUR FROM KBIS TO KJMS WITH LESSER ACTIVITY FURTHER
NORTH AND WEST. HOWEVER MORE SHOWERS DEVELOPING OVER CENTRAL MONTANA
WILL PROPAGATE EAST AND ARRIVE IN THE WESTERN AERODROMES THURSDAY
NIGHT. MAINLY VFR CIGS/VSBYS...HOWEVER MVFR/IFR CIGS POSSIBLE IN THE
HEAVIER RAIN SHOWERS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...JV
LONG TERM...RP KINNEY
AVIATION...KS
000
FXUS63 KBIS 161435
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
935 AM CDT THU MAY 16 2013
.UPDATE...
ISSUED AT 935 AM CDT THU MAY 16 2013
LATEST LOCAL RADAR SHOWS BANDS OF LIGHT TO MODERATE RAIN SHOWERS
MOVING FROM SOUTHWEST NORTH DAKOTA...INTO OUR SOUTH CENTRAL ZONES.
MULTIPLE UPSTREAM SHORTWAVES NOTED ON THE WATER VAPOR IMAGERY
WITH LARGE SCALE ASCENT/OMEGA CONTINUING FOR MOST OF THE
DAY...BUT ALSO SHIFTING FURTHER TO THE NORTHEAST AND INTO THE
JAMES RIVER BASIN. POPS OVERALL LOOK GOOD WITH ONLY MINOR
ADJUSTMENTS NECESSARY. REST OF FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 654 AM CDT THU MAY 16 2013
UPDATE TO REFINE POPS FOR MORNING RADAR TRENDS...OTHERWISE
PREVIOUS FORECAST IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT THU MAY 16 2013
MAIN CONCERN THIS SHORT TERM PERIOD WILL BE THE CHANCE OF SHOWERS
AND THUNDERSTORMS.
CURRENTLY...SURFACE HIGH PRESSURE WAS OVER MANITOBA WITH LOW
PRESSURE OVER WYOMING. AT UPPER LEVELS...THE LEADING EDGE OF A
SERIES OF SHORTWAVE ENERGY IMPULSES WAS MOVING INTO SOUTHWESTERN
NORTH DAKOTA FROM THE WEST.
THE MODELS INDICATE THAT H850 WINDS SHOULD BE INCREASING FROM A
SOUTHEASTERLY DIRECTION ACROSS WESTERN SOUTH DAKOTA INTO THE
SOUTHWEST CORNER OF NORTH DAKOTA. MEANWHILE SOUTHWESTERLY WINDS AT
H700 AND FINALLY WESTERLY WINDS AROUND H500 WERE SETTING UP AN
OVERRUNNING PRECIPITATION SCENARIO THIS MORNING. THE STRONGER H850
WINDS WERE EVIDENT IN THAT A LINE OF ELEVATED CONVECTION SEEN ON
REGIONAL RADARS EXTENDED FROM NEAR BEACH TO BEULAH. THESE HIGH-BASED
SHOWERS AND ISOLATED THUNDERSHOWERS WERE MOVING EASTWARD WITH THE
UPPER LEVEL WIND FIELD.
THE MODELS ARE IN GOOD AGREEMENT IN BRINGING IN GOOD MOISTURE...WITH
INCREASING LOW LEVEL DEWPOINTS AS WELL AS H850 AND H700 MOISTURE
FIELDS...WITH OVERRUNNING PRECIPITATION CONTINUING INTO TONIGHT.
INSTABILITY IS MARGINAL AS BEST CAPE VALUES OF 200-400 J/KG REMAIN
ACROSS THE SOUTHWEST TODAY AND ACROSS THE WEST AND SOUTH TONIGHT.
THUS KEPT THE MENTION OF RAIN SHOWERS WITH ISOLATED THUNDERSTORMS
MAINLY SOUTH AND WEST DURING THE DAY TODAY AND EXPANDED THE MENTION
OF THUNDER A BIT NORTH AND EAST TONIGHT. WENT WITH HIGHS IN TE 60S
MOST AREAS IN THE WEST AND PARTS OF CENTRAL NORTH DAKOTA WITH FAIRLY
WIDESPREAD RAIN SHOWERS. THE RAIN AND BETTER MOISTURE WILL KEEP THE
FIRE DANGER IN THE LOW TO MEDIUM TODAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 352 AM CDT THU MAY 16 2013
THE MAIN FORECAST ISSUES THROUGH THE LONG TERM PERIOD ARE CONVECTIVE
TRENDS...AND POTENTIAL FOR HEAVY RAIN AND SOME SEVERE WEATHER.
SOUTHWEST FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE NORTHERN
PLAINS FRIDAY AND SATURDAY. HAVE INCREASED POPS BOTH DAYS. THE FAR
SOUTHWEST IS STILL OUTLOOKED IN THE SPC 5 PERCENT RISK
AREA...COINCIDENT WITH THE MAIN INSTABILITY AXIS. SIGNIFICANT WARM
AIR ALOFT SHOULD LIMIT THE COVERAGE OF SEVERE STORMS. SPC HAS ALSO
INCLUDED THE FAR SOUTH/SOUTHEAST IN SLIGHT RISK FOR SATURDAY...NEAR
THE SURFACE BOUNDARY. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES
ARE EXPECTED...AND THE GFS IS SUGGESTING SB CAPE AROUND 2000 J/KG.
WIDESPREAD 1 TO 2 INCH RAINFALL AMOUNTS ARE EXPECTED THROUGH
SATURDAY NIGHT. THE FAR SOUTHEAST IS NOT OUT OF THE WOODS CONCERNING
SEVERE WEATHER POTENTIAL SUNDAY. A LARGE UPPER LOW WILL MOVE INTO
THE REGION SUNDAY AND MONDAY...BRINGING ADDITIONAL MODERATE TO
LOCALLY HEAVY RAIN...WHICH WILL LIKELY LINGER THROUGH AT LEAST
TUESDAY. TOTAL RAINFALL AMOUNTS THROUGH THE ENTIRE PERIOD COULD
REACH 3 TO 4 INCHES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA.
RENEWED HYDRO CONCERNS ARE LIKELY...ESPECIALLY IN THE SOURIS AND
JAMES RIVER BASINS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 654 AM CDT THU MAY 16 2013
SURFACE HIGH OVER MANITOBA AND SURFACE LOW WAS OVER WYOMING. WINDS
WERE GENERALLY LIGHT AND VARIABLE OVER NORTH DAKOTA BETWEEN THESE
TWO SURFACE PRESSURE SYSTEMS. LATER THIS MORNING AS THE LOW DEVELOPS
FARTHER EAST...WINDS SHOULD BECOME EAST/SOUTHEAST AT TAF SITES.
ELEVATED CONVECTION...WITH CLOUD BASES AT AROUND 8000 FEET...WAS
OCCURRING OVER SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA - NEAR KDIK
AND KBIS. EXPECT CONVECTION TO BECOME MORE WIDESPREAD DURING THE
MORNING AND CONTINUE SPREADING NORTH AND EAST ACROSS THE STATE.
SHOWERS MORE LIKELY AT KDIK AFT 15Z AND AT KBIS AND KISN AFT 18Z.
AFTER 00Z CONVECTION MORE LIKELY AT NORTHERN TAF SITES KISN/KMOT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
AVIATION...JV
000
FXUS63 KBIS 161155
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
655 AM CDT THU MAY 16 2013
.UPDATE...
ISSUED AT 654 AM CDT THU MAY 16 2013
UPDATE TO REFINE POPS FOR MORNING RADAR TRENDS...OTHERWISE
PREVIOUS FORECAST IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT THU MAY 16 2013
MAIN CONCERN THIS SHORT TERM PERIOD WILL BE THE CHANCE OF SHOWERS
AND THUNDERSTORMS.
CURRENTLY...SURFACE HIGH PRESSURE WAS OVER MANITOBA WITH LOW
PRESSURE OVER WYOMING. AT UPPER LEVELS...THE LEADING EDGE OF A
SERIES OF SHORTWAVE ENERGY IMPULSES WAS MOVING INTO SOUTHWESTERN
NORTH DAKOTA FROM THE WEST.
THE MODELS INDICATE THAT H850 WINDS SHOULD BE INCREASING FROM A
SOUTHEASTERLY DIRECTION ACROSS WESTERN SOUTH DAKOTA INTO THE
SOUTHWEST CORNER OF NORTH DAKOTA. MEANWHILE SOUTHWESTERLY WINDS AT
H700 AND FINALLY WESTERLY WINDS AROUND H500 WERE SETTING UP AN
OVERRUNNING PRECIPITATION SCENARIO THIS MORNING. THE STRONGER H850
WINDS WERE EVIDENT IN THAT A LINE OF ELEVATED CONVECTION SEEN ON
REGIONAL RADARS EXTENDED FROM NEAR BEACH TO BEULAH. THESE HIGH-BASED
SHOWERS AND ISOLATED THUNDERSHOWERS WERE MOVING EASTWARD WITH THE
UPPER LEVEL WIND FIELD.
THE MODELS ARE IN GOOD AGREEMENT IN BRINGING IN GOOD MOISTURE...WITH
INCREASING LOW LEVEL DEWPOINTS AS WELL AS H850 AND H700 MOISTURE
FIELDS...WITH OVERRUNNING PRECIPITATION CONTINUING INTO TONIGHT.
INSTABILITY IS MARGINAL AS BEST CAPE VALUES OF 200-400 J/KG REMAIN
ACROSS THE SOUTHWEST TODAY AND ACROSS THE WEST AND SOUTH TONIGHT.
THUS KEPT THE MENTION OF RAIN SHOWERS WITH ISOLATED THUNDERSTORMS
MAINLY SOUTH AND WEST DURING THE DAY TODAY AND EXPANDED THE MENTION
OF THUNDER A BIT NORTH AND EAST TONIGHT. WENT WITH HIGHS IN TE 60S
MOST AREAS IN THE WEST AND PARTS OF CENTRAL NORTH DAKOTA WITH FAIRLY
WIDESPREAD RAIN SHOWERS. THE RAIN AND BETTER MOISTURE WILL KEEP THE
FIRE DANGER IN THE LOW TO MEDIUM TODAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 352 AM CDT THU MAY 16 2013
THE MAIN FORECAST ISSUES THROUGH THE LONG TERM PERIOD ARE CONVECTIVE
TRENDS...AND POTENTIAL FOR HEAVY RAIN AND SOME SEVERE WEATHER.
SOUTHWEST FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE NORTHERN
PLAINS FRIDAY AND SATURDAY. HAVE INCREASED POPS BOTH DAYS. THE FAR
SOUTHWEST IS STILL OUTLOOKED IN THE SPC 5 PERCENT RISK
AREA...COINCIDENT WITH THE MAIN INSTABILITY AXIS. SIGNIFICANT WARM
AIR ALOFT SHOULD LIMIT THE COVERAGE OF SEVERE STORMS. SPC HAS ALSO
INCLUDED THE FAR SOUTH/SOUTHEAST IN SLIGHT RISK FOR SATURDAY...NEAR
THE SURFACE BOUNDARY. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES
ARE EXPECTED...AND THE GFS IS SUGGESTING SB CAPE AROUND 2000 J/KG.
WIDESPREAD 1 TO 2 INCH RAINFALL AMOUNTS ARE EXPECTED THROUGH
SATURDAY NIGHT. THE FAR SOUTHEAST IS NOT OUT OF THE WOODS CONCERNING
SEVERE WEATHER POTENTIAL SUNDAY. A LARGE UPPER LOW WILL MOVE INTO
THE REGION SUNDAY AND MONDAY...BRINGING ADDITIONAL MODERATE TO
LOCALLY HEAVY RAIN...WHICH WILL LIKELY LINGER THROUGH AT LEAST
TUESDAY. TOTAL RAINFALL AMOUNTS THROUGH THE ENTIRE PERIOD COULD
REACH 3 TO 4 INCHES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA.
RENEWED HYDRO CONCERNS ARE LIKELY...ESPECIALLY IN THE SOURIS AND
JAMES RIVER BASINS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 654 AM CDT THU MAY 16 2013
SURFACE HIGH OVER MANITOBA AND SURFACE LOW WAS OVER WYOMING. WINDS
WERE GENERALLY LIGHT AND VARIABLE OVER NORTH DAKOTA BETWEEN THESE
TWO SURFACE PRESSURE SYSTEMS. LATER THIS MORNING AS THE LOW DEVELOPS
FARTHER EAST...WINDS SHOULD BECOME EAST/SOUTHEAST AT TAF SITES.
ELEVATED CONVECTION...WITH CLOUD BASES AT AROUND 8000 FEET...WAS
OCCURRING OVER SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA - NEAR KDIK
AND KBIS. EXPECT CONVECTION TO BECOME MORE WIDESPREAD DURING THE
MORNING AND CONTINUE SPREADING NORTH AND EAST ACROSS THE STATE.
SHOWERS MORE LIKELY AT KDIK AFT 15Z AND AT KBIS AND KISN AFT 18Z.
AFTER 00Z CONVECTION MORE LIKELY AT NORTHERN TAF SITES KISN/KMOT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/LONG TERM...RP KINNEY
AVIATION...JV
000
FXUS63 KBIS 160858
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
358 AM CDT THU MAY 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT THU MAY 16 2013
MAIN CONCERN THIS SHORT TERM PERIOD WILL BE THE CHANCE OF SHOWERS
AND THUNDERSTORMS.
CURRENTLY...SURFACE HIGH PRESSURE WAS OVER MANITOBA WITH LOW
PRESSURE OVER WYOMING. AT UPPER LEVELS...THE LEADING EDGE OF A
SERIES OF SHORTWAVE ENERGY IMPULSES WAS MOVING INTO SOUTHWESTERN
NORTH DAKOTA FROM THE WEST.
THE MODELS INDICATE THAT H850 WINDS SHOULD BE INCREASING FROM A
SOUTHEASTERLY DIRECTION ACROSS WESTERN SOUTH DAKOTA INTO THE
SOUTHWEST CORNER OF NORTH DAKOTA. MEANWHILE SOUTHWESTERLY WINDS AT
H700 AND FINALLY WESTERLY WINDS AROUND H500 WERE SETTING UP AN
OVERRUNNING PRECIPITATION SCENARIO THIS MORNING. THE STRONGER H850
WINDS WERE EVIDENT IN THAT A LINE OF ELEVATED CONVECTION SEEN ON
REGIONAL RADARS EXTENDED FROM NEAR BEACH TO BEULAH. THESE HIGH-BASED
SHOWERS AND ISOLATED THUNDERSHOWERS WERE MOVING EASTWARD WITH THE
UPPER LEVEL WIND FIELD.
THE MODELS ARE IN GOOD AGREEMENT IN BRINGING IN GOOD MOISTURE...WITH
INCREASING LOW LEVEL DEWPOINTS AS WELL AS H850 AND H700 MOISTURE
FIELDS...WITH OVERRUNNING PRECIPITATION CONTINUING INTO TONIGHT.
INSTABILITY IS MARGINAL AS BEST CAPE VALUES OF 200-400 J/KG REMAIN
ACROSS THE SOUTHWEST TODAY AND ACROSS THE WEST AND SOUTH TONIGHT.
THUS KEPT THE MENTION OF RAIN SHOWERS WITH ISOLATED THUNDERSTORMS
MAINLY SOUTH AND WEST DURING THE DAY TODAY AND EXPANDED THE MENTION
OF THUNDER A BIT NORTH AND EAST TONIGHT. WENT WITH HIGHS IN TE 60S
MOST AREAS IN THE WEST AND PARTS OF CENTRAL NORTH DAKOTA WITH FAIRLY
WIDESPREAD RAIN SHOWERS. THE RAIN AND BETTER MOISTURE WILL KEEP THE
FIRE DANGER IN THE LOW TO MEDIUM TODAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 352 AM CDT THU MAY 16 2013
THE MAIN FORECAST ISSUES THROUGH THE LONG TERM PERIOD ARE CONVECTIVE
TRENDS...AND POTENTIAL FOR HEAVY RAIN AND SOME SEVERE WEATHER.
SOUTHWEST FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE NORTHERN
PLAINS FRIDAY AND SATURDAY. HAVE INCREASED POPS BOTH DAYS. THE FAR
SOUTHWEST IS STILL OUTLOOKED IN THE SPC 5 PERCENT RISK
AREA...COINCIDENT WITH THE MAIN INSTABILITY AXIS. SIGNIFICANT WARM
AIR ALOFT SHOULD LIMIT THE COVERAGE OF SEVERE STORMS. SPC HAS ALSO
INCLUDED THE FAR SOUTH/SOUTHEAST IN SLIGHT RISK FOR SATURDAY...NEAR
THE SURFACE BOUNDARY. PRECIPITABLE WATER VALUES AROUND 1.5 INCHES
ARE EXPECTED...AND THE GFS IS SUGGESTING SB CAPE AROUND 2000 J/KG.
WIDESPREAD 1 TO 2 INCH RAINFALL AMOUNTS ARE EXPECTED THROUGH
SATURDAY NIGHT. THE FAR SOUTHEAST IS NOT OUT OF THE WOODS CONCERNING
SEVERE WEATHER POTENTIAL SUNDAY. A LARGE UPPER LOW WILL MOVE INTO
THE REGION SUNDAY AND MONDAY...BRINGING ADDITIONAL MODERATE TO
LOCALLY HEAVY RAIN...WHICH WILL LIKELY LINGER THROUGH AT LEAST
TUESDAY. TOTAL RAINFALL AMOUNTS THROUGH THE ENTIRE PERIOD COULD
REACH 3 TO 4 INCHES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA.
RENEWED HYDRO CONCERNS ARE LIKELY...ESPECIALLY IN THE SOURIS AND
JAMES RIVER BASINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1258 AM CDT THU MAY 16 2013
SURFACE HIGH OVER MANITOBA AND SURFACE LOW WAS OVER WYOMING. WINDS
WERE GENERALLY LIGHT AND VARIABLE OVER NORTH DAKOTA BETWEEN THESE
TWO SURFACE PRESSURE SYSTEMS. LATER TONIGHT AS THE LOW DEVELOPS
FARTHER EAST...WINDS SHOULD BECOME EAST/SOUTHEAST AT TAF SITES.
LEADING EDGE OF UPPER LEVEL ENERGY EXPECTED TO BE APPROACHING KDIK
AFTER 11Z...AND MORE LIKELY AFT 15Z. THIS CONVECTION WITH MVFR
CIGS EXPECTED TO SPREAD NORTH AND EAST LATER THURSDAY
MORNING...WITH SHOWERS AND THUNDERSHOWERS MORE LIKELY AT KBIS AND
KISN AROUND/AFT 18Z. AFTER 00Z CONVECTION MORE LIKELY AT NORTHERN
TAF SITES KISN/KMOT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION...JV
LONG TERM...RP KINNEY
000
FXUS63 KBIS 160558
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1258 AM CDT THU MAY 16 2013
.UPDATE...
ISSUED AT 1258 AM CDT THU MAY 16 2013
ADJUSTED HOURLY TEMPERATURES AND DEWPOINTS WITH TEMPERATURE TREND A
TAD COOLER THAN EXPECTED...AND DEWPOINTS A BIT LOWER IN THE WEST.
EXPECT DEWPOINTS TO BEGIN RISING IN THE SOUTHWEST LATER TONIGHT AS
WINDS BECOME EAST/SOUTHEAST AND AS EXPECTED INCREASED LOWER LEVEL
CLOUDS AND POSSIBLE CONVECTION ARRIVES FROM THE SOUTHWEST.
OTHERWISE NO OTHER UPDATES WERE NEEDED TO THE ONGOING FORECAST FOR
THE OVERNIGHT TIME PERIOD.
UPDATE ISSUED AT 1003 PM CDT WED MAY 15 2013
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. OTHERWISE...NO MAJOR UPDATES WERE REQUIRED TO THE
ONGOING FORECAST. THE FRESHENED UP PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 716 PM CDT WED MAY 15 2013
LAPS ANALYSIS CONTINUES TO INDICATE DECREASING CAPE ACROSS THE
REGION EARLY THIS EVENING. FURTHERMORE...RADAR TRENDS OF
SPRINKLES ARE DECREASING WITH THE LOSS OF DAYTIME HEATING. AS A
RESULT...UPDATED THE FORECAST TO REMOVE EVENING SPRINKLES. ALSO
MADE A FEW DOWNWARD ADJUSTMENTS TO OVERNIGHT LOWS AS WINDS SHOULD
BECOME LIGHT AND VARIABLE TONIGHT. OTHERWISE...THE REMAINING
WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED GRIDDED AND TEXT
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 250 PM CDT WED MAY 15 2013
MAIN CONCERN THIS SHORT TERM PERIOD WILL BE THE CHANCE OF
THUNDERSTORMS LATE TONIGHT AND THURSDAY. MODELS ARE IN GOOD
AGREEMENT IN BRINGING IN GOOD MOISTURE...WITH OVERRUNNING
PRECIPITATION OVER A WARM FRONTAL BOUNDARY DEVELOPING ACROSS
NEBRASKA AND SOUTH DAKOTA ON THURSDAY. INSTABILITY IS MARGINAL AS
BEST CAPE VALUES REMAIN ACROSS THE SOUTH AND WEST. SO BELIEVE
THERE WILL BE RAIN SHOWERS WITH ISOLATED THUNDERSTORMS MAINLY
SOUTH AND WEST ON THURSDAY. WITH FAIRLY WIDESPREAD RAIN SHOWERS
ACROSS WEST AND CENTRAL...LOWERED THE HIGH TEMPERATURES INTO THE
60S FOR THE MOST PART. THE RAIN AND BETTER MOISTURE WILL KEEP THE
FIRE DANGER IN THE LOW TO MEDIUM ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 250 CDT WED MAY 15 2013
THE FOCUS IN THE LONG TERM WILL BE ON PRECIPITATION SUNDAY INTO
EARLY NEXT WEEK.
MODEL AGREEMENT ON THE DEVELOPING RIDGE OVER THE CENTRAL CONUS AND
TROUGH OVER THE WESTERN CONUS CONTINUES THURSDAY INTO SATURDAY.
DURING THIS TIME FRAME SOUTHWEST FLOW ALOFT WILL DOMINATE AND SHORT
WAVE ENERGY WITH AMPLE MOISTURE WILL PROVIDE NUMEROUS CHANCES FOR
RAINFALL THURSDAY INTO THE WEEKEND. UNCERTAINTY IN THE LONG TERM
BEGINS LATE SUNDAY INTO EARLY NEXT WEEK...WITH THE PLACEMENT OF THE
TROUGH AND CUT OFF UPPER LEVEL LOW AND HOW LONG THESE FEATURES
LINGER OVER THE REGION. GFS AND GEM GLOBAL 12 UTC RUNS PLACE THE CUT
OFF LOW OVER THE DAKOTAS AND KEEP IT OVER THE AREA INTO TUESDAY.
THIS SOLUTION HAS COMMA HEAD PRECIPITATION OVER WESTERN AND CENTRAL
NORTH DAKOTA INTO EARLY NEXT WEEK. THE ECMWF ON THE OTHER HAND
PLACES THE CUT OFF LOW FURTHER EAST OVER THE DAKOTA MINNESOTA
BORDER...WHICH WOULD KEEP COMMA HEAD PRECIPITATION EAST OF CENTRAL
NORTH DAKOTA. THIS IS LESS MODEL VARIANCE THAN THE PAST FEW DAYS
HAVE SHOWN WITH THE CUT OFF LOW PLACEMENT...HOWEVER THE SLIGHTEST
SHIFT WILL PLAY A LARGE ROLE IN WHETHER OR NOT CENTRAL AND
POSSIBLY WESTERN NORTH DAKOTA HAVE A TROWAL SET UP OVER HEAD
PROVIDING RAINFALL EARLY NEXT WEEK. REGARDLESS OF WHETHER OR NOT A
TROWAL SETS UP OVER CENTRAL AND WESTERN NORTH DAKOTA INTO EARLY
NEXT WEEK...I WOULD EXPECT SEASONABLY COOL...DAMP...AND CLOUDY
CONDITIONS.
RAINFALL TOTALS THROUGH THE WEEKEND ARE GENERALLY IN THE INCH TO
INCH AND HALF RANGE. THIS WOULD BE MORE THAN ENOUGH TO GREEN UP
CENTRAL AND WESTERN NORTH DAKOTA...MINIMIZING FIRE WEATHER ISSUES.
AS FOR RAINFALL TOTALS INTO EARLY NEXT WEEK IT SEEMS WPC IS RELYING
ON THE ECMWF AND ESSENTIALLY ENDING ANY REAL ACCUMULATIONS AFTER
SUNDAY FOR BOTH CENTRAL AND WESTERN NORTH DAKOTA...HOWEVER THIS WILL BE
MONITORED CLOSELY THROUGH THE WEEK.
THIS SET UP WILL PROVIDE CHANCES FOR SEVERE WEATHER. THURSDAY INTO
SATURDAY. MODELS HAVE DECREASED CAPE VALUES THURSDAY NIGHT AND
FRIDAY OVER THE LAST FEW DAYS...HOWEVER BULK SHEAR VALUES STILL IN
THE 40 TO 50 KT RANGE MAY PROVIDE A CHANCE FOR THUNDERSTORMS AND
SEVERE WEATHER. THE BEST OPPORTUNITY FOR SEVERE WEATHER LOOKS TO BE
SATURDAY ACROSS SOUTH CENTRAL AND SOUTHWESTERN NORTH DAKOTA WITH
CAPE VALUES AROUND 1000 TO 3000 J/KG AND DEEP LAYER BULK SHEAR
AROUND 50 KTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1258 AM CDT THU MAY 16 2013
SURFACE HIGH OVER MANITOBA AND SURFACE LOW WAS OVER WYOMING. WINDS
WERE GENERALLY LIGHT AND VARIABLE OVER NORTH DAKOTA BETWEEN THESE
TWO SURFACE PRESSURE SYSTEMS. LATER TONIGHT AS THE LOW DEVELOPS
FARTHER EAST...WINDS SHOULD BECOME EAST/SOUTHEAST AT TAF SITES.
LEADING EDGE OF UPPER LEVEL ENERGY EXPECTED TO BE APPROACHING KDIK
AFTER 11Z...AND MORE LIKELY AFT 15Z. THIS CONVECTION WITH MVFR
CIGS EXPECTED TO SPREAD NORTH AND EAST LATER THURSDAY
MORNING...WITH SHOWERS AND THUNDERSHOWERS MORE LIKELY AT KBIS AND
KISN AROUND/AFT 18Z. AFTER 00Z CONVECTION MORE LIKELY AT NORTHERN
TAF SITES KISN/KMOT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...WAA
LONG TERM...MM/KS
AVIATION...JV
000
FXUS63 KBIS 160303
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1003 PM CDT WED MAY 15 2013
.UPDATE...
ISSUED AT 1003 PM CDT WED MAY 15 2013
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. OTHERWISE...NO MAJOR UPDATES WERE REQUIRED TO THE
ONGOING FORECAST. THE FRESHENED UP PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 716 PM CDT WED MAY 15 2013
LAPS ANALYSIS CONTINUES TO INDICATE DECREASING CAPE ACROSS THE
REGION EARLY THIS EVENING. FURTHERMORE...RADAR TRENDS OF
SPRINKLES ARE DECREASING WITH THE LOSS OF DAYTIME HEATING. AS A
RESULT...UPDATED THE FORECAST TO REMOVE EVENING SPRINKLES. ALSO
MADE A FEW DOWNWARD ADJUSTMENTS TO OVERNIGHT LOWS AS WINDS SHOULD
BECOME LIGHT AND VARIABLE TONIGHT. OTHERWISE...THE REMAINING
WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED GRIDDED AND TEXT
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 250 PM CDT WED MAY 15 2013
MAIN CONCERN THIS SHORT TERM PERIOD WILL BE THE CHANCE OF
THUNDERSTORMS LATE TONIGHT AND THURSDAY. MODELS ARE IN GOOD
AGREEMENT IN BRINGING IN GOOD MOISTURE...WITH OVERRUNNING
PRECIPITATION OVER A WARM FRONTAL BOUNDARY DEVELOPING ACROSS
NEBRASKA AND SOUTH DAKOTA ON THURSDAY. INSTABILITY IS MARGINAL AS
BEST CAPE VALUES REMAIN ACROSS THE SOUTH AND WEST. SO BELIEVE
THERE WILL BE RAIN SHOWERS WITH ISOLATED THUNDERSTORMS MAINLY
SOUTH AND WEST ON THURSDAY. WITH FAIRLY WIDESPREAD RAIN SHOWERS
ACROSS WEST AND CENTRAL...LOWERED THE HIGH TEMPERATURES INTO THE
60S FOR THE MOST PART. THE RAIN AND BETTER MOISTURE WILL KEEP THE
FIRE DANGER IN THE LOW TO MEDIUM ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 250 CDT WED MAY 15 2013
THE FOCUS IN THE LONG TERM WILL BE ON PRECIPITATION SUNDAY INTO
EARLY NEXT WEEK.
MODEL AGREEMENT ON THE DEVELOPING RIDGE OVER THE CENTRAL CONUS AND
TROUGH OVER THE WESTERN CONUS CONTINUES THURSDAY INTO SATURDAY.
DURING THIS TIME FRAME SOUTHWEST FLOW ALOFT WILL DOMINATE AND SHORT
WAVE ENERGY WITH AMPLE MOISTURE WILL PROVIDE NUMEROUS CHANCES FOR
RAINFALL THURSDAY INTO THE WEEKEND. UNCERTAINTY IN THE LONG TERM
BEGINS LATE SUNDAY INTO EARLY NEXT WEEK...WITH THE PLACEMENT OF THE
TROUGH AND CUT OFF UPPER LEVEL LOW AND HOW LONG THESE FEATURES
LINGER OVER THE REGION. GFS AND GEM GLOBAL 12 UTC RUNS PLACE THE CUT
OFF LOW OVER THE DAKOTAS AND KEEP IT OVER THE AREA INTO TUESDAY.
THIS SOLUTION HAS COMMA HEAD PRECIPITATION OVER WESTERN AND CENTRAL
NORTH DAKOTA INTO EARLY NEXT WEEK. THE ECMWF ON THE OTHER HAND
PLACES THE CUT OFF LOW FURTHER EAST OVER THE DAKOTA MINNESOTA
BORDER...WHICH WOULD KEEP COMMA HEAD PRECIPITATION EAST OF CENTRAL
NORTH DAKOTA. THIS IS LESS MODEL VARIANCE THAN THE PAST FEW DAYS
HAVE SHOWN WITH THE CUT OFF LOW PLACEMENT...HOWEVER THE SLIGHTEST
SHIFT WILL PLAY A LARGE ROLE IN WHETHER OR NOT CENTRAL AND
POSSIBLY WESTERN NORTH DAKOTA HAVE A TROWAL SET UP OVER HEAD
PROVIDING RAINFALL EARLY NEXT WEEK. REGARDLESS OF WHETHER OR NOT A
TROWAL SETS UP OVER CENTRAL AND WESTERN NORTH DAKOTA INTO EARLY
NEXT WEEK...I WOULD EXPECT SEASONABLY COOL...DAMP...AND CLOUDY
CONDITIONS.
RAINFALL TOTALS THROUGH THE WEEKEND ARE GENERALLY IN THE INCH TO
INCH AND HALF RANGE. THIS WOULD BE MORE THAN ENOUGH TO GREEN UP
CENTRAL AND WESTERN NORTH DAKOTA...MINIMIZING FIRE WEATHER ISSUES.
AS FOR RAINFALL TOTALS INTO EARLY NEXT WEEK IT SEEMS WPC IS RELYING
ON THE ECMWF AND ESSENTIALLY ENDING ANY REAL ACCUMULATIONS AFTER
SUNDAY FOR BOTH CENTRAL AND WESTERN NORTH DAKOTA...HOWEVER THIS WILL BE
MONITORED CLOSELY THROUGH THE WEEK.
THIS SET UP WILL PROVIDE CHANCES FOR SEVERE WEATHER. THURSDAY INTO
SATURDAY. MODELS HAVE DECREASED CAPE VALUES THURSDAY NIGHT AND
FRIDAY OVER THE LAST FEW DAYS...HOWEVER BULK SHEAR VALUES STILL IN
THE 40 TO 50 KT RANGE MAY PROVIDE A CHANCE FOR THUNDERSTORMS AND
SEVERE WEATHER. THE BEST OPPORTUNITY FOR SEVERE WEATHER LOOKS TO BE
SATURDAY ACROSS SOUTH CENTRAL AND SOUTHWESTERN NORTH DAKOTA WITH
CAPE VALUES AROUND 1000 TO 3000 J/KG AND DEEP LAYER BULK SHEAR
AROUND 50 KTS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 24Z THURSDAY EVENING)
ISSUED AT 716 PM CDT WED MAY 15 2013
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
TONIGHT. A CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BEGIN TO
DEVELOP NEAR KDIK AFTER SUNRISE...THEN SLOWLY PUSH NORTH AND EAST
ACROSS NORTH DAKOTA THROUGH THURSDAY AFTERNOON. DUE TO THE EXPECTED
COVERAGE...ONLY INDICATED VCTS IN THE AFFECTED TAFS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...WAA
LONG TERM...MM/KS
AVIATION...TM
000
FXUS63 KBIS 160016
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
716 PM CDT WED MAY 15 2013
.UPDATE...
ISSUED AT 716 PM CDT WED MAY 15 2013
LAPS ANALYSIS CONTINUES TO INDICATE DECREASING CAPE ACROSS THE
REGION EARLY THIS EVENING. FURTHERMORE...RADAR TRENDS OF
SPRINKLES ARE DECREASING WITH THE LOSS OF DAYTIME HEATING. AS A
RESULT...UPDATED THE FORECAST TO REMOVE EVENING SPRINKLES. ALSO
MADE A FEW DOWNWARD ADJUSTMENTS TO OVERNIGHT LOWS AS WINDS SHOULD
BECOME LIGHT AND VARIABLE TONIGHT. OTHERWISE...THE REMAINING
WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED GRIDDED AND TEXT
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 250 PM CDT WED MAY 15 2013
MAIN CONCERN THIS SHORT TERM PERIOD WILL BE THE CHANCE OF
THUNDERSTORMS LATE TONIGHT AND THURSDAY. MODELS ARE IN GOOD
AGREEMENT IN BRINGING IN GOOD MOISTURE...WITH OVERRUNNING
PRECIPITATION OVER A WARM FRONTAL BOUNDARY DEVELOPING ACROSS
NEBRASKA AND SOUTH DAKOTA ON THURSDAY. INSTABILITY IS MARGINAL AS
BEST CAPE VALUES REMAIN ACROSS THE SOUTH AND WEST. SO BELIEVE
THERE WILL BE RAIN SHOWERS WITH ISOLATED THUNDERSTORMS MAINLY
SOUTH AND WEST ON THURSDAY. WITH FAIRLY WIDESPREAD RAIN SHOWERS
ACROSS WEST AND CENTRAL...LOWERED THE HIGH TEMPERATURES INTO THE
60S FOR THE MOST PART. THE RAIN AND BETTER MOISTURE WILL KEEP THE
FIRE DANGER IN THE LOW TO MEDIUM ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 250 CDT WED MAY 15 2013
THE FOCUS IN THE LONG TERM WILL BE ON PRECIPITATION SUNDAY INTO
EARLY NEXT WEEK.
MODEL AGREEMENT ON THE DEVELOPING RIDGE OVER THE CENTRAL CONUS AND
TROUGH OVER THE WESTERN CONUS CONTINUES THURSDAY INTO SATURDAY.
DURING THIS TIME FRAME SOUTHWEST FLOW ALOFT WILL DOMINATE AND SHORT
WAVE ENERGY WITH AMPLE MOISTURE WILL PROVIDE NUMEROUS CHANCES FOR
RAINFALL THURSDAY INTO THE WEEKEND. UNCERTAINTY IN THE LONG TERM
BEGINS LATE SUNDAY INTO EARLY NEXT WEEK...WITH THE PLACEMENT OF THE
TROUGH AND CUT OFF UPPER LEVEL LOW AND HOW LONG THESE FEATURES
LINGER OVER THE REGION. GFS AND GEM GLOBAL 12 UTC RUNS PLACE THE CUT
OFF LOW OVER THE DAKOTAS AND KEEP IT OVER THE AREA INTO TUESDAY.
THIS SOLUTION HAS COMMA HEAD PRECIPITATION OVER WESTERN AND CENTRAL
NORTH DAKOTA INTO EARLY NEXT WEEK. THE ECMWF ON THE OTHER HAND
PLACES THE CUT OFF LOW FURTHER EAST OVER THE DAKOTA MINNESOTA
BORDER...WHICH WOULD KEEP COMMA HEAD PRECIPITATION EAST OF CENTRAL
NORTH DAKOTA. THIS IS LESS MODEL VARIANCE THAN THE PAST FEW DAYS
HAVE SHOWN WITH THE CUT OFF LOW PLACEMENT...HOWEVER THE SLIGHTEST
SHIFT WILL PLAY A LARGE ROLE IN WHETHER OR NOT CENTRAL AND
POSSIBLY WESTERN NORTH DAKOTA HAVE A TROWAL SET UP OVER HEAD
PROVIDING RAINFALL EARLY NEXT WEEK. REGARDLESS OF WHETHER OR NOT A
TROWAL SETS UP OVER CENTRAL AND WESTERN NORTH DAKOTA INTO EARLY
NEXT WEEK...I WOULD EXPECT SEASONABLY COOL...DAMP...AND CLOUDY
CONDITIONS.
RAINFALL TOTALS THROUGH THE WEEKEND ARE GENERALLY IN THE INCH TO
INCH AND HALF RANGE. THIS WOULD BE MORE THAN ENOUGH TO GREEN UP
CENTRAL AND WESTERN NORTH DAKOTA...MINIMIZING FIRE WEATHER ISSUES.
AS FOR RAINFALL TOTALS INTO EARLY NEXT WEEK IT SEEMS WPC IS RELYING
ON THE ECMWF AND ESSENTIALLY ENDING ANY REAL ACCUMULATIONS AFTER
SUNDAY FOR BOTH CENTRAL AND WESTERN NORTH DAKOTA...HOWEVER THIS WILL BE
MONITORED CLOSELY THROUGH THE WEEK.
THIS SET UP WILL PROVIDE CHANCES FOR SEVERE WEATHER. THURSDAY INTO
SATURDAY. MODELS HAVE DECREASED CAPE VALUES THURSDAY NIGHT AND
FRIDAY OVER THE LAST FEW DAYS...HOWEVER BULK SHEAR VALUES STILL IN
THE 40 TO 50 KT RANGE MAY PROVIDE A CHANCE FOR THUNDERSTORMS AND
SEVERE WEATHER. THE BEST OPPORTUNITY FOR SEVERE WEATHER LOOKS TO BE
SATURDAY ACROSS SOUTH CENTRAL AND SOUTHWESTERN NORTH DAKOTA WITH
CAPE VALUES AROUND 1000 TO 3000 J/KG AND DEEP LAYER BULK SHEAR
AROUND 50 KTS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 24Z THURSDAY EVENING)
ISSUED AT 716 PM CDT WED MAY 15 2013
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
TONIGHT. A CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BEGIN TO
DEVELOP NEAR KDIK AFTER SUNRISE...THEN SLOWLY PUSH NORTH AND EAST
ACROSS NORTH DAKOTA THROUGH THURSDAY AFTERNOON. DUE TO THE EXPECTED
COVERAGE...ONLY INDICATED VCTS IN THE AFFECTED TAFS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...WAA
LONG TERM...MM/KS
AVIATION...TM
000
FXUS63 KBIS 151953
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
253 PM CDT WED MAY 15 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 250 PM CDT WED MAY 15 2013
MAIN CONCERN THIS SHORT TERM PERIOD WILL BE THE CHANCE OF
THUNDERSTORMS LATE TONIGHT AND THURSDAY. MODELS ARE IN GOOD
AGREEMENT IN BRINGING IN GOOD MOISTURE...WITH OVERRUNNING
PRECIPITATION OVER A WARM FRONTAL BOUNDARY DEVELOPING ACROSS
NEBRASKA AND SOUTH DAKOTA ON THURSDAY. INSTABILITY IS MARGINAL AS
BEST CAPE VALUES REMAIN ACROSS THE SOUTH AND WEST. SO BELIEVE
THERE WILL BE RAIN SHOWERS WITH ISOLATED THUNDERSTORMS MAINLY
SOUTH AND WEST ON THURSDAY. WITH FAIRLY WIDESPREAD RAIN SHOWERS
ACROSS WEST AND CENTRAL...LOWERED THE HIGH TEMPERATURES INTO THE
60S FOR THE MOST PART. THE RAIN AND BETTER MOISTURE WILL KEEP THE
FIRE DANGER IN THE LOW TO MEDIUM ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 250 CDT WED MAY 15 2013
THE FOCUS IN THE LONG TERM WILL BE ON PRECIPITATION SUNDAY INTO
EARLY NEXT WEEK.
MODEL AGREEMENT ON THE DEVELOPING RIDGE OVER THE CENTRAL CONUS AND
TROUGH OVER THE WESTERN CONUS CONTINUES THURSDAY INTO SATURDAY.
DURING THIS TIME FRAME SOUTHWEST FLOW ALOFT WILL DOMINATE AND SHORT
WAVE ENERGY WITH AMPLE MOISTURE WILL PROVIDE NUMEROUS CHANCES FOR
RAINFALL THURSDAY INTO THE WEEKEND. UNCERTAINTY IN THE LONG TERM
BEGINS LATE SUNDAY INTO EARLY NEXT WEEK...WITH THE PLACEMENT OF THE
TROUGH AND CUT OFF UPPER LEVEL LOW AND HOW LONG THESE FEATURES
LINGER OVER THE REGION. GFS AND GEM GLOBAL 12 UTC RUNS PLACE THE CUT
OFF LOW OVER THE DAKOTAS AND KEEP IT OVER THE AREA INTO TUESDAY.
THIS SOLUTION HAS COMMA HEAD PRECIPITATION OVER WESTERN AND CENTRAL
NORTH DAKOTA INTO EARLY NEXT WEEK. THE ECMWF ON THE OTHER HAND
PLACES THE CUT OFF LOW FURTHER EAST OVER THE DAKOTA MINNESOTA
BORDER...WHICH WOULD KEEP COMMA HEAD PRECIPITATION EAST OF CENTRAL
NORTH DAKOTA. THIS IS LESS MODEL VARIANCE THAN THE PAST FEW DAYS
HAVE SHOWN WITH THE CUT OFF LOW PLACEMENT...HOWEVER THE SLIGHTEST
SHIFT WILL PLAY A LARGE ROLE IN WHETHER OR NOT CENTRAL AND
POSSIBLY WESTERN NORTH DAKOTA HAVE A TROWAL SET UP OVER HEAD
PROVIDING RAINFALL EARLY NEXT WEEK. REGARDLESS OF WHETHER OR NOT A
TROWAL SETS UP OVER CENTRAL AND WESTERN NORTH DAKOTA INTO EARLY
NEXT WEEK...I WOULD EXPECT SEASONABLY COOL...DAMP...AND CLOUDY
CONDITIONS.
RAINFALL TOTALS THROUGH THE WEEKEND ARE GENERALLY IN THE INCH TO
INCH AND HALF RANGE. THIS WOULD BE MORE THAN ENOUGH TO GREEN UP
CENTRAL AND WESTERN NORTH DAKOTA...MINIMIZING FIRE WEATHER ISSUES.
AS FOR RAINFALL TOTALS INTO EARLY NEXT WEEK IT SEEMS WPC IS RELYING
ON THE ECMWF AND ESSENTIALLY ENDING ANY REAL ACCUMULATIONS AFTER
SUNDAY FOR BOTH CENTRAL AND WESTERN NORTH DAKOTA...HOWEVER THIS WILL BE
MONITORED CLOSELY THROUGH THE WEEK.
THIS SET UP WILL PROVIDE CHANCES FOR SEVERE WEATHER. THURSDAY INTO
SATURDAY. MODELS HAVE DECREASED CAPE VALUES THURSDAY NIGHT AND
FRIDAY OVER THE LAST FEW DAYS...HOWEVER BULK SHEAR VALUES STILL IN
THE 40 TO 50 KT RANGE MAY PROVIDE A CHANCE FOR THUNDERSTORMS AND
SEVERE WEATHER. THE BEST OPPORTUNITY FOR SEVERE WEATHER LOOKS TO BE
SATURDAY ACROSS SOUTH CENTRAL AND SOUTHWESTERN NORTH DAKOTA WITH
CAPE VALUES AROUND 1000 TO 3000 J/KG AND DEEP LAYER BULK SHEAR
AROUND 50 KTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 250 PM CDT WED MAY 15 2013
HIGH PRESSURE CONTINUES ACROSS NORTH DAKOTA THIS AFTERNOON. LOW
PRESSURE WILL DEVELOP ALONG THE LEE OF THE ROCKIES LATE TONIGHT
ACROSS WYOMING AND MONTANA. THIS WILL BRING AN INCREASING CHANCE
FOR SHOWERS AND POSSIBLY A THUNDERSTORMS THURSDAY. VFR AT ALL TAF
SITES THROUGH THE 18Z PERIOD. SHOWERS AND SCATTERED THUNDERSTORMS
ARE POSSIBLE FROM KDIK-KBIS AFTER 12Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WAA
LONG TERM...MM/KS
AVIATION...WAA
| 
