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000
FXUS63 KBIS 181951
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
251 PM CDT FRI APR 18 2014

.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 250 PM CDT FRI APR 18 2014

LOW PRESSURE OVER EASTERN MONTANA CONTINUES TO TIGHTEN THE
PRESSURE GRADIENT OVER WESTERN AND CENTRAL NORTH DAKOTA. SOLID
WIND ADVISORY CRITERIA IS BEING MET OVER THE ADVISED AREA...SO
WILL CONTINUE WITH THE WIND HEADLINE FOR THIS UPDATE.

RAIN SHOWERS ARE BEGINNING TO INCREASE IN COVERAGE OVER EASTERN
MONTANA THIS AFTERNOON AHEAD OF AN APPROACHING SHORTWAVE. THIS
ACTIVITY IS EXPECTED TO ENTER WESTERN AND CENTRAL NORTH DAKOTA
LATER THIS AFTERNOON AND TONIGHT. LAPSE RATES ALOFT DO NOT APPEAR
CONDUCIVE FOR THUNDERSTORM DEVELOP SOUTH LATER THIS AFTERNOON AND
EVENING. THEREFORE...REMOVED THUNDER WORDING FROM THE APPROPRIATE
ZONES IN THE FIRST PERIOD.

THE MAIN FORECAST CHALLENGE WILL BE DETERMINING THE GREATEST
POTENTIAL FOR RAIN SHOWERS TONIGHT. THE GFS/GEM/NAM KEEP THE
HIGHEST PRECIP CHANCES ALONG THE INTERNATIONAL BOUNDARY (PROXIMATE
TO THE MAIN UPPER LEVEL SHORTWAVE ENERGY) WHEREAS THE ECMWF HAS
HIGH PRECIP CHANCES OVER CENTRAL NORTH DAKOTA TONIGHT. FOR NOW
WILL FOLLOW A BLENDED APPROACH AND KEEP THE HIGHEST POPS NORTH AND
EXTEND THEM SOUTH INTO CENTRAL NORTH DAKOTA THIS EVENING.

AS THE SHORTWAVE MOVES THROUGH THE AREA...DRY WESTERLY FLOW WILL
DEVELOP WITH PRECIPITATION CHANCES ENDING FROM WEST TO EAST AFTER
MIDNIGHT.

DRY WESTERLY FLOW WILL CONTINUE SATURDAY WITH HIGHS EXPECTED TO
INCREASE INTO THE 60S. THERE COULD BE SOME FIRE WEATHER ISSUES
SATURDAY. SEE FIRE WEATHER DISCUSSION BELOW.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 250 PM CDT FRI APR 18 2014

THE HIGHLIGHTS OF THE EXTENDED FORECAST ARE A MILD EASTER FOLLOWED
BY A POTENTIAL SIGNIFICANT STORM SYSTEM TUESDAY NIGHT THROUGH
THURSDAY NIGHT.

WIDESPREAD HIGHS IN THE 60S TO LOWER 70S ARE FORECAST ACROSS
WESTERN AND CENTRAL NORTH DAKOTA EASTER SUNDAY IN THE WARM SECTOR
OF A WEAK SURFACE LOW ACROSS NORTHERN NORTH DAKOTA. ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE DURING THE
AFTERNOON WITH THE APPROACH OF AN UPPER LEVEL SHORTWAVE AND
SURFACE COLD FRONT. OVERALL INSTABILITY AND MOISTURE IS
LIMITED...THUS NOT EXPECTING A WASHOUT.

LOOKING AHEAD...THE 12 UTC GUIDANCE SUITE CONTINUES TO DEPICT A
SIGNIFICANT TROUGH COMING ONSHORE TO THE PACIFIC COAST
TUESDAY...PLACING THE NORTHERN PLAINS UNDER SOUTHWEST FLOW ALOFT
TUESDAY NIGHT INTO WEDNESDAY. WITH A STRONG LOW LEVEL JET POSSIBLE
TUESDAY NIGHT...AND CONTINUED LOW LEVEL WARM AIR ADVECTION AHEAD
OF THE SURFACE REFLECTION OF THE LOW INTO WEDNESDAY...THE CHANCE
FOR THUNDERSTORMS REMAINS. AT THIS TIME...SEVERE CONVECTION IS
NOT ANTICIPATED. FOR THE 12 UTC RUN TODAY...THE GFS AND ECMWF ARE
IN AGREEMENT ON CLOSING OFF AND PROPAGATING A STRONG UPPER LEVEL
LOW INTO THE NORTHERN PLAINS WEDNESDAY NIGHT INTO THURSDAY. THIS
WOULD SUGGEST THE POTENTIAL FOR ACCUMULATING SNOW THURSDAY NIGHT
INTO FRIDAY ON THE BACKSIDE OF THIS SYSTEM. UNCERTAINTY IN
PRECIPITATION TYPES...AMOUNTS AND PLACEMENT WILL LIKELY REMAIN
INTO EARLY NEXT WEEK. HOWEVER...SIGNIFICANT QPF IS POSSIBLE AND
HYDROLOGIC IMPACTS WILL HAVE TO BE MONITORED.


&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 250 PM CDT FRI APR 18 2014

VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE TAF PERIOD. WINDY CONDITIONS WILL ALSO CONTINUE
THROUGH EARLY EVENING...WITH GUSTS UP TO 40 KNOTS POSSIBLE. LIGHT
SHOWERS AND TEMPO MVFR CONDITIONS COULD IMPACT KISN-KMOT LATER
THIS AFTERNOON AND EVENING. HOWEVER...BRIEF RAIN SHOWER ACTIVITY
IS EXPECTED. BRIEF SCATTERED SHOWERS WILL ALSO BE POSSIBLE OVER
THE I-94 TERMINAL AERODROMES THIS AFTERNOON AND EVENING. THIS
ACTIVITY WILL TAPER OFF FROM WEST TO EAST AFTER MIDNIGHT TONIGHT.

&&

.FIRE WEATHER...
ISSUED AT 250 PM CDT FRI APR 18 2014

DRY WESTERLY FLOW WILL DEVELOP AFTER MIDNIGHT TONIGHT AND WILL
CONTINUE SATURDAY. WESTERLY WINDS WILL BE THE STRONGEST SATURDAY
MORNING...THEN SHOULD BEGIN TO WEAKEN BY THE AFTERNOON. SATURDAY
AFTERNOON MINIMUM RH VALUES ARE FORECAST TO RANGE FROM 20 TO 30
PERCENT.

SINCE THE STRONGEST WINDS WILL OCCUR IN THE MORNING...AND THE
LOWEST MINIMUM RH VALUES WILL OCCUR IN THE AFTERNOON...WILL HOLD
OFF ON ISSUING ANY FIRE WEATHER HEADLINES FOR NOW. HOWEVER...THE
GFDI HAS MOST OF WESTERN AND CENTRAL NORTH DAKOTA IN A LOW-END
"VERY HIGH" FIRE DANGER SATURDAY. FIRE MANAGERS SHOULD CONTINUE TO
MONITOR THE LATEST FORECASTS FOR ANY FIRE WEATHER HEADLINES
SATURDAY.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NDZ003>005-011>013-
021-022-035.

WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR NDZ023-025-036-
037-047-048-050-051.

&&

$$

SHORT TERM...TM
LONG TERM...AYD
AVIATION...TM
FIRE WEATHER...TM