000
FXUS63 KBIS 141451
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
951 AM CDT TUE MAY 14 2013

.UPDATE...
ISSUED AT 942 AM CDT TUE MAY 14 2013

AT 9 AM COLD FRONT HAS MOVE THROUGH THE REGION. SUBSIDENCE BEHIND
THE FRONT ACROSS WEST AND CENTRAL NORTH DAKOTA CLEARING SKIES.
MODEL SOUNDINGS CONTINUE TO SHOW A HIGH RANGE WIND ADVISORY WITH
WIND GUSTS TO 50 MPH TODAY. CURRENT FORECAST TRENDS LOOK GOOD. THE
WINDS AND DRYING ARE GOING TO RAISE THE FIRE DANGER TO THE EXTREME
ACROSS THE STATE TODAY. CONTINUE THE WIND ADVISORY AND RED FLAG
WARNING.

UPDATE ISSUED AT 631 AM CDT TUE MAY 14 2013

ONLY UPDATE WAS TO SPEED UP THE END OF OUR PRECIPITATION WITH THE
SHOWERS AND SCATTERED THUNDERSTORMS VERY QUICKLY MOVING OFF TO OUR
EAST. WILL BE DRY BY 13Z OVER MY FAR EAST AT THE LATEST. ALSO
TRENDED SKY DOWN WITH CLEAR SKIES WEST INTO CENTRAL DEVELOPING
EAST.

&&

.SHORT TERM...(TODAY AND TONIGHT)

ISSUED AT 430 AM CDT TUE MAY 14 2013

WINDS AND FIRE WEATHER CONCERNS ARE THE HIGHLIGHT IN THE SHORT
TERM.

MODELS NOT IN COMPLETE AGREEMENT REGARDING THE MAX WIND POTENTIAL.
THEY SUGGEST A PRESSURE RISE BUBBLE BEHIND THE STRONG COLD
FRONT...WHICH EXTENDED FROM NEAR MINOT TO GARRISON TO JUST EAST OF
DICKINSON TO NEAR HETTINGER. THE STRONGEST PORTION OF THE BUBBLE IS
FORECAST ACROSS WESTERN/SOUTHWESTERN NORTH DAKOTA/EASTERN MONTANA AT
DAYBREAK...AND MOVING SOUTHEAST INTO EASTERN SOUTH DAKOTA. GETTING
HIGH GUSTS TO 50-60 MPH FOR A BRIEF TIME AT FRONTAL PASSAGE IN SOME
LOCALES...CONSIST WITH THE PRESSURE BUBBLE POSITION. MODELS WEAKEN
THE PRESSURE BUBBLE AS IT MOVES SOUTHEAST DURING THE MORNING...BUT
SURFACE WINDS SHOULD REMAIN STRONG AS SURFACE TEMPERATURES RISE
ENOUGH FOR LINKAGE ALOFT...AND THIS SHOULD KEEP WINDS STRONG THROUGH
THE AFTERNOON. THE QUESTION IS HOW STRONG WILL THE WINDS BE? THE GFS
SUGGESTS 40 MPH OR MORE SUSTAINED...WHILE THE NAM IS MORE IN THE 30
MPH RANGE OVERALL. EXPECT THAT SPEEDS WILL BE IN BETWEEN - THAT IS A
HIGH-END WIND ADVISORY CRITERIA OF WINDS 35 MPH WITH GUSTS TO 50
MPH. CENTRAL AND SOUTHERN PORTIONS (ESPECIALLY SOUTHWEST PORTIONS)
OF THE FORECAST AREA MAY SEE GUSTS TO 55 MPH AS STRONGEST WINDS
ALOFT AT H800 OR SO MAY TRANSLATE MOMENTUM TO THE SURFACE.

EXPECTING HIGHS RANGING FROM AROUND 70 NORTHWEST TO LOWER 80S IN THE
JAMES RIVER VALLEY TODAY. DRY AIR MOVING IN BEHIND THE COLD FRONT AS
WELL.

SEE FIRE WEATHER SECTION FOR DETAILS REGARDING RED FLAG WARNING.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)

ISSUED AT 430 AM CDT TUE MAY 14 2013

THE FOCUS IN THE LONG TERM WILL CONTINUE TO BE PRECIPITATION AMOUNTS
THURSDAY THROUGH THE WEEKEND...AND THE POTENTIAL FOR SEVERE WEATHER
THURSDAY THROUGH SATURDAY.

QUASI ZONAL FLOW ALOFT WEDNESDAY WILL TRANSITION TO RIDGING ALOFT
THURSDAY OVER THE CENTRAL CONUS. AN UPPER LEVEL TROUGH WILL DEVELOP
OVER THE WESTERN CONUS THURSDAY AND WILL DEEPEN INTO SATURDAY AS IT
SLOWLY MOVES EAST. THIS WILL NUDGE THE RIDGE EAST RESULTING IN
SOUTHWESTERLY FLOW ALOFT DEVELOPING OVER THE WESTERN DAKOTAS
THURSDAY AFTERNOON AND ACROSS THE ENTIRE REGION THURSDAY NIGHT. THIS
FLOW PATTERN IS THEN MAINTAINED INTO SATURDAY AS THE UPPER LEVEL
TROUGH PROPAGATES ACROSS THE ROCKIES AND INTO THE PLAINS STATES BY
SUNDAY. MODELS REMAIN IN GOOD AGREEMENT ON THIS PATTERN AND ON THE
ARRIVAL OF THE TROUGH OVER THE CENTRAL AND NORTHERN PLAINS. MODELS
DURING 12 UTC THURSDAY TO 12 UTC SUNDAY TIME FRAME SHOW SEVERAL
OPPORTUNITIES FOR PRECIPITATION OVER CENTRAL AND WESTERN NORTH
DAKOTA. THE LATEST 00Z GFS HAS TRENDED TOWARDS THE 00Z ECMWF...WITH
THE TROUGH STALLING OUT OVER THE CENTRAL AND NORTHERN
PLAINS...FOLLOWED BY A CLOSED LOW FORMING DIRECTLY OVER THE REGION.
THIS SUGGESTS PRECIPITATION CHANCES LINGERING THROUGH SUNDAY AND
MUCH OF MONDAY...BEFORE TRENDING MORE DRY FOR TUESDAY. WPC HAS
QPF VALUES JUST OVER AN INCH OVER NORTH DAKOTA FROM THURSDAY
THROUGH SUNDAY...AND WOULD SUSPECT SOME AREAS RECEIVING MORE THAN
AN INCH. THIS WOULD BE SUFFICIENT RAINFALL TO INCREASE GREENNESS
ACROSS THE STATE AND MINIMIZE FIRE WEATHER CONCERNS...IN ADDITION
TO EASE THE DRY CONDITIONS WHICH HAVE PLAGUED NORTH DAKOTA FOR
MUCH OF THE MONTH OF MAY.

REGARDING SEVERE WEATHER...THE FIRST CHANCE LOOKS TO BE THURSDAY
AFTERNOON WEST FROM A FRONTAL BOUNDARY MOVING IN FROM EASTERN
MONTANA...SPREADING EAST THURSDAY NIGHT. THERE WILL ALSO BE CHANCES
ON FRIDAY AND SATURDAY MAINLY ACROSS THE SOUTH FROM A SURFACE LOW
AND WARM FRONT SET UP IN SOUTH DAKOTA. OVER THIS TIME FRAME DEEP
LAYER BULK SHEAR VALUES WILL BE IN THE 40 TO 50 KT RANGE WITH MOST
UNSTABLE CAPE VALUES IN THE 1000 TO 2000 J/KG RANGE...AGAIN
ESPECIALLY ACROSS MY SOUTHERN COUNTIES. MAIN LIMIT FOR SEVERE
WEATHER WILL BE POTENTIAL CLOUD COVER AND THE WIDESPREAD SHOWER
ACTIVITY GOING ON DURING THIS TIME FRAME.

FOR TEMPERATURES...WE WILL TRANSITION FROM 70S THURSDAY AND
FRIDAY...TO 50S AND 60S SUNDAY THROUGH TUESDAY THANKS TO THE UPPER
TROUGH/CLOSED LOW DEVELOPING OVER THE REGION.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 942 AM CDT TUE MAY 14 2013

THE MAIN HAZARD TO AVIATION TODAY WILL BE STRONG NORTHWEST SURFACE
WINDS. AT 9 AM CDT...A STRONG COLD FRONT WAS MOVING EAST INTO
MINNESOTA. NORTHWEST SURFACE WINDS OF 25 TO 40 KTS EXPECTED AT
ALL TAF SITES THROUGH 00Z. WINDS WILL RAPIDLY DIMINISH AFTER 00Z.
VFR AT ALL TAF SITES THROUGH THE 12Z TAF PERIOD.

&&

.FIRE WEATHER...

ISSUED AT 430 AM CDT TUE MAY 14 2013

RED FLAG WARNING REMAINS IN EFFECT FOR TODAY FOR STRONG WINDS...LOW
RELATIVE HUMIDITY...AND DRY RANGELAND CONDITIONS. LOOKING AT MINIMUM
RELATIVE HUMIDITY RANGING FROM 15 PERCENT IN THE SOUTH WEST AND
SOUTH CENTRAL TO AROUND 25 PERCENT NORTH. HOWEVER STRONG WINDS OF UP
TO 35 MPH WITH GUSTS TO 50 MPH OR MORE WILL MAKE FOR CRITICAL FIRE
WEATHER CONDITIONS. ANY FIRES THAT IGNITE WOULD SPREAD VERY RAPIDLY.

FIRE WEATHER CONCERNS WILL BE LOW WEDNESDAY THROUGH THE COMING
WEEKEND. MUCH NEEDED MOISTURE WILL ARRIVE THURSDAY THROUGH SUNDAY
HELPING TO GREEN UP VEGETATION ACROSS THE AREA.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.

WIND ADVISORY UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NDZ001>004-009>012-017>022-031>035-040>046.

WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR NDZ005-013-023-025-
036-037-047-048-050-051.

&&

$$

UPDATE...WAA
SHORT TERM...JV
LONG TERM...NH
AVIATION...WAA
FIRE WEATHER...JV/NH