Area Forecast Discussion
Issued by NWS Bismarck, ND

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KBIS 270520
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1220 AM CDT WED MAY 27 2015

.UPDATE...
ISSUED AT 1215 AM CDT WED MAY 27 2015

FOR THIS UPDATE REMOVED PRECIPITATION CHANCES FOR TONIGHT. LATEST
OBSERVATIONS AND SHORT TERM MODEL GUIDANCE DO NOT SUGGEST ANYTHING
WILL FORM. OTHERWISE...LOWERED TEMPERATURES BY A DEGREE OR TWO.
LATEST OBSERVATIONS SHOWED TEMPERATURES TRENDING COOLER THAN
PREVIOUSLY FORECAST.

UPDATE ISSUED AT 943 PM CDT TUE MAY 26 2015

MOST OF THE EVENING CONVECTION HAS DIED. STILL A FEW SHOWERS
REMAINING OVER THE NORTHWEST AND FROM AROUND MINOT TO JUST WEST OF
JAMESTOWN...BUT ARE FADING FAST. WILL REMOVE THE MENTION OF
THUNDER FOR THIS EVENING. MESOSCALE MODELS AND NEW NAM ARE STILL
HINTING AT SOME SHOWER ACTIVITY LATE TONIGHT AROUND THE TURTLE
MOUNTAINS. COULD BE ENOUGH INSTABILITY ALOFT FOR AN ELEVATED
THUNDER SO WILL KEEP A MENTION OF ISOLATED THUNDERSTORMS IN THIS
AREA AFTER MIDNIGHT. OTHERWISE NO SIGNIFICANT UPDATES NEEDED.

UPDATE ISSUED AT 648 PM CDT TUE MAY 26 2015

INSTABILITY SHOWERS AND SCATTERED THUNDERSTORMS CONTINUE TO
DIMINISH IN COVERAGE THIS EVENING. ADJUSTED POPS DOWNWARD A BIT
WITH JUST A MENTION OF ISOLATED THUNDER EARLY THIS EVENING. FOR
NOW DID KEEP A MENTION OF ISOLATED THUNDERSHOWERS ACROSS THE NORTH
LATER TONIGHT AS PREVIOUSLY FORECAST. OTHERWISE NO SIGNIFICANT
CHANGES TO THE GOING FORECAST.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 316 PM CDT TUE MAY 26 2015

THUNDERSTORM CHANCES THIS AFTERNOON AND EVENING...AND AGAIN ON
WEDNESDAY AFTERNOON HIGHLIGHT THE SHORT TERM FORECAST.

AS OF 2030 UTC...SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO
DEVELOP ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA. THIS
TREND IS EXPECTED INTO THE EARLY EVENING....WITH A DIURNAL DOWN
TREND WITH SUNSET. GIVEN ML CAPE VALUES OF 500-700 J/KG AND VERY
WEAK DEEP LAYER SHEAR...NO SEVERE WEATHER IS EXPECTED.

FOR TONIGHT...THE 12 UTC WRF-ARW/NMM AND 16-18 UTC HRRR
ITERATIONS CONTINUE TO SUGGEST ISOLATED CONVECTION ACROSS
NORTHWEST NORTH DAKOTA WITH WEAK IMPULSES EJECTING OUT OF THE
UPPER LEVEL LOW ACROSS WASHINGTON AND IDAHO. ADDITIONAL ISOLATED
SHOWERS AND STORMS ARE POSSIBLE ACROSS THE TURTLE
MOUNTAINS...AGAIN WITH WEAK IMPULSES PROPAGATING SOUTHEAST IN THE
NORTHERN STREAM.

ON WEDNESDAY...A MORE POTENT UPPER LEVEL WAVE IS FORECAST TO
PROPAGATE INTO WESTERN NORTH DAKOTA DURING THE AFTERNOON. 12 UTC
NAM/GFS BUFR SOUNDINGS SUGGEST RATHER WEAK ML CAPE IN THE 200-500
J/KG RANGE...WITH SEVERE CONVECTION AS A RESULT NOT EXPECTED.
HOWEVER....PRECIPITABLE  WATER VALUES OF 1.00 TO 1.25 INCHES
POINTS TO ANOTHER ROUND OF POTENTIAL WIDESPREAD MODERATE RAINFALL
AMOUNTS IN THE 0.30 TO 0.50 INCH RANGE WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS WEDNESDAY AFTERNOON INTO THURSDAY.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 316 PM CDT TUE MAY 26 2015

FORECAST ISSUES THIS PERIOD INCLUDE INCREASING CHANCES FOR SHOWERS
AND THUNDERSTORMS WEDNESDAY NIGHT AND THURSDAY WITH A SIGNIFICANT
COOL DOWN FRIDAY INTO SATURDAY. SOME PATCHY FROST WILL BE POSSIBLE
SATURDAY MORNING.

MODELS ARE IN GENERAL AGREEMENT IN BRINGING AN H500 TROUGH FROM THE
NORTHWEST US INTO THE NORTHERN PLAINS WEDNESDAY NIGHT AND
THURSDAY. THIS WILL BRING INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS WEST AND CENTRAL NORTH DAKOTA WEDNESDAY NIGHT
AND CONTINUING CENTRAL AND EASTERN NORTH DAKOTA THURSDAY. AS THE
H500 TROUGH MERGES INTO A COOL UPPER LOW OVER CENTRAL CANADA...THE
ASSOCIATED H850 FLOW WITH THIS COLD UPPER FLOW BRINGS IN PRETTY
UNSEASONABLY COOL AIR WITH EVEN A 1030MB SURFACE HIGH ACROSS THE
MANITOBA/SASKATCHEWAN BORDER. FRIDAYS HIGHS WILL BE IN THE 50S
NORTH AND 60S SOUTH AND BY SATURDAY MORNING WIDESPREAD TEMPERATURES
IN THE MID TO UPPER 30S WITH PATCHY FROST POSSIBLE. TEMPERATURES
WILL RETURN TO MORE NORMAL BY MONDAY AND TUESDAY WITH HIGHS INTO
THE 70S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1215 AM CDT WED MAY 27 2015

VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THE TAF
PERIOD. SHOWERS AND THUNDERSTORMS ARE POSSIBLE TOWARD THE END OF
THE PERIOD...BEGINNING ACROSS WESTERN NORTH DAKOTA AND SPREADING
EAST THROUGH THE EVENING.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...AJ
SHORT TERM...AYD
LONG TERM...WAA
AVIATION...AJ



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.