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000
FXUS63 KBIS 200900
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
400 AM CDT SUN APR 20 2014

.SHORT TERM...(TODAY AND TONIGHT)

ISSUED AT 400 AM CDT SUN APR 20 2014

FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE WARM
TEMPERATURES TODAY...CHANCES FOR SHOWERS DURING THE DAYLIGHT
HOURS...AND ANOTHER DAY OF ELEVATED FIRE WEATHER CONCERNS THIS
AFTERNOON (SEE FIRE WEATHER DISCUSSION BELOW FOR DETAILS).

CURRENTLY...QUASI-ZONAL FLOW ALOFT WITH INCREASING RETURN FLOW
ACROSS THE DAKOTAS AHEAD OF A POTENT EMBEDDED S/WV TROUGH MOVING
OVER THE MONTANA ROCKIES. SURFACE HIGH PRESSURE MOVING EAST ACROSS
THE UPPER MISSISSIPPI VALLEY REGION WITH A LEE SIDE SFC TROUGH OFF
TO OUR WEST. A MOSTLY CLEAR SKY AT THE MOMENT...COUPLED WITH
LIGHT SFC WINDS AND DEWPOINT TEMPERATURES IN THE LOW 20S TO LOW
30S HAS ALLOWED TEMPERATURES TO DROP INTO THE UPPER 20S SOME
LOCATIONS DESPITE MID LEVEL WAA. CLOUDS WILL BE ON THE INCREASE
ACROSS MY WESTERN COUNTIES 9-12Z.

WILL SEE TEMPERATURES RAPIDLY WARM 14-18Z THIS MORNING AS MIXING
INCREASES ONCE THE LOW LEVEL INVERSION ERODES. VERY MILD TODAY
WITH FORECAST HIGHS IN THE LOW/MID 70S CENTRAL AND EAST AHEAD OF A
COLD FRONT AND 60S WEST BEHIND.

WILL MAINTAIN A CHANCE OF SHOWERS DURING THE DAYLIGHT HOURS TODAY
ALONG THE COLD FROPA. BEST CHANCES GENERALLY OVER MY NORTH CLOSE
TO THE TRACK OF THE MID LEVEL WAVE. WHILE SOME MODELS DO GENERATE
SOME WEAK CAPE ALONG THE COLD FRONT...LACK OF MOISTURE APPEARS TO
LIMIT THE THUNDER POTENTIAL SO KEPT THIS MENTION OUT OF THE
FORECAST WITH THIS ISSUANCE. CANNOT COMPLETELY RULE ISOLATED
THUNDERSTORMS OUT AS MID LEVEL FORCING WILL BE RATHER ROBUST. LACK
OF A DEEP MOISTURE PROFILE WILL ALSO LIMIT THE AMOUNT OF LIQUID
REACHING THE GROUND...A FEW HUNDREDTHS OF AN INCH AT BEST EXPECTED.
MAY SEE A FEW STRONGER WIND GUSTS WITH ANY SHOWER ACTIVITY...SO
WILL NEED TO KEEP AN EYE ON AREA OBS AS RADAR RETURNS DEVELOP AND
PROPAGATE EAST.

YET ANOTHER BREEZY DAY AS WESTERLY WINDS BEHIND THE COLD FRONT
WILL BE SUSTAINED AT AROUND 20-23KTS...MAINLY WEST AND CENTRAL.
NOT MUCH WIND GUST POTENTIAL WITH THE TOP OF THE FORECAST MIXING
LAYER INDICATING BELOW 30KTS FOR GUSTS. AS MENTIONED
ABOVE...SHOWER ACTIVITY MAY PRODUCE STRONGER GUSTS DUE TO
EVAPORATIONAL COOLING ACCELERATING DOWNWARD MOTION.

CLEAR SKIES AND LOW DEWPOINTS ONCE AGAIN TONIGHT ON THE BACKSIDE
OF THE COLD FRONT...BUT WINDS LOOK TO REMAIN 10-15KTS FOR MUCH OF
THE NIGHT...THUS I THINK WE WILL STAY MORE IN THE MID 30S TO LOW
40S FOR LOWS SUNDAY NIGHT/MONDAY MORNING THANKS TO STRONGER MIXING
COMPARED TO RIGHT NOW.


.LONG TERM...(MONDAY THROUGH SATURDAY)

ISSUED AT 400 AM CDT SUN APR 20 2014

THE LONG TERM PERIOD WILL START RELATIVELY QUIET WITH SURFACE HIGH
PRESSURE SLIDING ACROSS THE NORTHERN PLAINS ON MONDAY.  THIS WILL
BRING DRY WEATHER MONDAY INTO TUESDAY...HOWEVER THINGS CHANGE
QUICKLY TUESDAY NIGHT AS A LARGE TROUGH ACROSS THE WESTERN UNITED
STATES BEGINS TO APPROACH THE CENTRAL AND NORTHERN PLAINS. H85
WARM AIR ADVECTION TUESDAY NIGHT WITH AN INCREASING LOW LEVEL JET
WILL BRING A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS.

SOMEWHAT BETTER AGREEMENT CAN BE FOUND IN THE MEDIUM RANGE MODELS
THIS MORNING...BUT OVERALL CONFIDENCE IS STILL NOT HIGH DUE TO POOR
RUN TO RUN CONTINUITY.  THE GENERAL MESSAGE FROM THE MODELS APPEARS
TO BE THAT THERE COULD BE A BREAK IN THE PRECIPITATION ONCE THE
INITIAL ROUND OF WARM AIR ADVECTION MOVES THROUGH TUESDAY NIGHT
INTO WEDNESDAY. PRECIPITATION CHANCES INCREASE AGAIN AS THE
SURFACE LOW MOVES ACROSS THE REGION...WITH COLDER AIR AND A CHANCE
OF SNOW ARRIVING ON THE BACKSIDE OF THE LOW. THE GENERAL MESSAGE
REMAINS...TUESDAY NIGHT INTO FRIDAY COULD BE ACTIVE...BUT THE
MODELS NOW SUGGEST THE HIGHEST PRECIPITATION AMOUNTS MAY FALL IN
CANADA. THIS WILL HAVE TO BE WATCHED SINCE IT COULD HAVE HYDROLOGIC
IMPLICATIONS...ESPECIALLY ACROSS THE SOURIS BASIN.

ONCE THIS SYSTEM PASSES ON FRIDAY...THERE COULD BE A BRIEF BREAK IN
THE PRECIPITATION BEFORE ADDITIONAL WAVES WORK THEIR WAY ACROSS THE
NORTHERN PLAINS NEXT WEEKEND.


&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)

ISSUED AT 400 AM CDT SUN APR 20 2014

A DEVELOPING SURFACE TROUGH IN MONTANA WILL MOVE INTO NORTH
DAKOTA TODAY. AN ASSOCIATED COLD FRONT WILL ACCOMPANY THE SURFACE
TROUGH BRINGING A RETURN OF GUSTY WEST TO NORTHWEST WINDS 15 TO 30
KTS AND SCATTERED TO ISOLATED RAIN SHOWERS THIS AFTERNOON WEST
AND CENTRAL...AND EAST SUNDAY EVENING. THESE SHOWERS WILL HAVE
ONLY MINOR IMPACTS TO AVIATION...POSSIBLY LOCALLY GUSTIER WINDS IN
THEIR VICINITY.


&&

.FIRE WEATHER...

ISSUED AT 400 AM CDT SUN APR 20 2014

DRY WESTERLY FLOW WILL DEVELOP BEHIND A COLD FRONT OVER WESTERN
NORTH DAKOTA THIS SUNDAY AFTERNOON. THE COMBINATION OF WINDS 20
TO 25 MPH AND MINIMUM RH VALUES 25 TO 30 PERCENT IS FORECAST TO
GENERATE A GFDI IN A LOW-END "VERY HIGH" FIRE DANGER
TODAY...MAINLY WEST OF HIGHWAY 83. WILL NOT ISSUE ANY FIRE WEATHER
HEADLINES WITH THIS FORECAST ISSUANCE AS VALUES AT THIS TIME ARE
BELOW RED FLAG CRITERIA. FIRE MANAGERS SHOULD CONTINUE TO MONITOR
THE LATEST FORECASTS FOR ANY FIRE WEATHER HEADLINES TODAY.

&&

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

&&

$$

SHORT TERM...NH
LONG TERM...CK
AVIATION...NH
FIRE WEATHER...NH