000
FXUS63 KBIS 190008
AFDBIS

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

.UPDATE...
ISSUED AT 708 PM CDT FRI APR 18 2014

SURFACE LOW PRESSURE NEAR BUFFALO SOUTH DAKOTA WITH STRONG
SOUTHEAST FLOW CONTINUING OVER THE EASTERN HALF OF NORTH DAKOTA.
SCATTERED TO NUMEROUS SHOWERS ARE CURRENTLY MOVING INTO WESTERN
NORTH DAKOTA. EXPECT THESE TO TRANSLATE EAST THROUGH THE EVENING.
HAVE UPDATED POP GRIDS BASED ON LATEST RADAR ANALYSIS. KEEPING
HIGHER POPS OUT OF THE CENTRAL PORTION OF THE STATE UNTIL MID
EVENING.

HAVE ALLOWED THE WIND ADVISORY TO EXPIRE AT MINOT AND BISMARCK.
AND EXTENDED IT THROUGH 10 PM OVER EASTERN PORTIONS OF CENTRAL
NORTH DAKOTA. THE JAMES RIVER VALLEY WAS ALREADY IN THE ADVISORY
THROUGH 10 PM.

UPDATE ISSUED AT 548 PM CDT FRI APR 18 2014

WILL LET THE WIND ADVISORY EXPIRE AT 7 PM OVER THE FAR WEST
PORTION OF THE ADVISORY...INCLUDING BISMARCK AND MINOT.
HOWEVER...LATEST RAP GUIDANCE SUGGESTS THAT STRONG SOUTHERLY
925-850MB WINDS WILL ACTUALLY INCREASE THIS EVENING OVER EASTERN
NORTH DAKOTA INCLUDING THE JAMES RIVER VALLEY INTO THE TURTLE
MOUNTAINS WITH THE MIXING LAYER REMAINING ELEVATED INTO THE MID TO
LATE EVENING HOURS. THE JAMES RIVER VALLEY GOES THROUGH 10 PM BUT
WILL EXTEND THIS NORTH THROUGH THE TURTLE MOUNTAINS AND ADD
ANOTHER LAYER COUNTIES TO THE WEST. OTHERWISE NO SIGNIFICANT
UPDATES AT THIS TIME. WILL SEND PRODUCTS OUT BY 6 PM CDT.

&&

.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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 708 PM CDT FRI APR 18 2014

LOW PRESSURE WILL MOVE ACROSS WESTERN AND CENTRAL NORTH DAKOTA
TONIGHT...WITH SCATTERED SHOWERS POSSIBLE AT ALL TAF SITES. WILL
MAINTAIN VFR CEILINGS AND VISIBILITIES THROUGH THE PERIOD WITH
LOWEST CEILINGS AROUND 5K FEET AND LOWEST VISIBILITIES ABOVE 6SM
DURING THE EVENING AND EARLY OVERNIGHT HOURS...THEN MAINLY CLEAR
CONDITIONS. STRONG SOUTHEAST FLOW WILL DIMINISH AT KBIS AND KMOT
EARLY THIS EVENING...AND CONTINUE THROUGH AROUND 03Z AT KJMS.
LIGHT FLOW AT KISN AND KDIK EARLY THIS EVENING WILL SHIFT WEST AND
INCREASE DURING THE EVENING...WESTERLY FLOW WILL MOVE INTO KMOT
AND KBIS AFTER MIDNIGHT AND KJMS TOWARD MORNING. BREEZY TO WINDY
WEST WINDS WILL CONTINUE THROUGH SATURDAY AFTERNOON.

&&

.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 10 PM CDT THIS EVENING FOR NDZ004-005-012-
013-022-023-025-036-037-047-048-050-051.

&&

$$

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