000
FXUS63 KBIS 140001
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
701 PM CDT MON MAY 13 2013

.UPDATE...
ISSUED AT 701 PM CDT MON MAY 13 2013

A CLUSTER OF THUNDERSTORMS CONTINUES TO SLOWLY INCREASE BETWEEN
GLASGOW AND LEWISTOWN MONTANA...AND ARE PROGGED TO APPROACH THE
BORDER WITH NORTHWEST NORTH DAKOTA AROUND 03-04 UTC. GIVEN THE
HIGH BASES...EVAPORATIVE POTENTIAL AND STEEP LAPSE RATES THROUGH
MUCH OF THE TROPOSPHERE...ISOLATED SEVERE WIND GUSTS CANNOT BE
RULED OUT...ALONG WITH HEAT BURSTS AS THESE STORMS PROPAGATE
GENERALLY ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA TONIGHT.
GIVEN THE LATEST 18 UTC NAM AND GFS...IT APPEARS THAT MUCH OF THE
AREA WILL HAVE A TOUGH TIME APPROACHING HIGH WIND WARNING
SUSTAINED OR GUST CRITERIA ON TUESDAY AND MAY REPLACE MOST OR
ALL OF THE WATCH WITH A WIND ADVISORY AT THE 10 PM UPDATE SHOULD
TRENDS CONTINUE WITH THE 00 UTC RUNS.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 345 PM CDT MON MAY 13 2013

SEVERAL CONCERNS THIS AFTERNOON REGARDING WINDS AND FIRE WEATHER.
WELL MIXED ATMOSPHERE THIS AFTERNOON ACROSS WEST AND CENTRAL NORTH
DAKOTA. DEBATED ABOUT ISSUING HIGH WIND WARNING ACROSS THE
SOUTHWEST FOR LATE TONIGHT AND TUESDAY. MODELS NOT IN COMPLETE
AGREEMENT ON THE MAX WIND POTENTIAL. NAM BRINGS IN A 9 MB PRESSURE
RISE BUBBLE ACROSS THE SOUTHWEST AROUND 12Z ASSOCIATED WITH A COLD
FRONTAL PASSAGE. GEOSTROPHIC 1000 MB AND H850 WINDS INDICATE
MARGINAL HIGH WIND WARNING...BUT BOUNDARY LAYER WINDS SUGGEST HIGH
END WIND ADVISORY. GFS INDICATING SOMEWHAT LOWER WINDS AND HIGH END
WIND ADVISORY WOULD BE APPROPRIATE FOLLOWING THE GFS. FOR NOW WILL
CONTINUE WITH THE HIGH WIND WATCH DUE TO THE UNCERTAINTY.

TONIGHT...STRONG ARM ADVECTION WILL SUPPORT SHOWERS AND SCATTERED
THUNDERSTORMS MAINLY NORTH. THERE COULD BE SOME GUSTY WINDS WITH
THE THUNDERSTORMS NORTHWEST DUE TO STRONG MID LEVEL WINDS. AT THIS
TIME DID NOT MENTION SEVERE AS BELIEVE TO ISOLATED THREAT.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 CDT MON MAY 13 2013

THE FOCUS IN THE LONG TERM WILL BE ON THE TOTAL PRECIPITATION
THURSDAY THROUGH THE WEEKEND...AND THE POTENTIAL FOR SEVERE WEATHER
THURSDAY THROUGH SATURDAY.

QUASI ZONAL FLOW ALOFT TUESDAY AND WEDNESDAY WILL TRANSITION TO
RIDGING ALOFT THURSDAY OVER THE CENTRAL CONUS. LIKEWISE A TROUGH
WILL DEVELOP OVER THE WESTERN CONUS THURSDAY AND WILL DEEPEN INTO
SATURDAY. THIS WILL PROVIDE SOUTHWEST FLOW ALOFT FOR WESTERN AND
CENTRAL NORTH DAKOTA THURSDAY INTO SATURDAY...AS THE UPPER LEVEL
TROUGH PROPAGATES ACROSS THE ROCKIES AND INTO THE PLAIN STATES BY
SUNDAY. MODELS ARE IN GOOD AGREEMENT ON THIS PATTERN AND ON THE
ARRIVAL OF THE TROUGH OVER THE CENTRAL AND NORTHERN PLAINS. MODELS
DURING THE 18 UTC THURSDAY TO 06 UTC SUNDAY TIME FRAME SHOW SEVERAL
OPPORTUNITIES FOR PRECIPITATION OVER CENTRAL AND WESTERN NORTH
DAKOTA. BEGINNING SUNDAY THE GFS AND EURO DIVERGE ON THE POSITION OF
THE TROUGH. THE EURO HAS THE TROUGH STALLING OUT OVER THE CENTRAL
AND NORTHERN PLAINS...WITH A CLOSED LOW FORMING DIRECTLY OVER
NORTHERN NORTH DAKOTA. THIS SOLUTION KEEPS CHANCES FOR MODERATE
RAINFALL OVER NORTHERN AND EASTERN NORTH DAKOTA INTO MONDAY NIGHT.
THE GFS ON THE OTHER HAND PUSHES THE TROUGH FURTHER EAST BEFORE
DEVELOPING A CLOSED LOW JUST NORTH OF MINNESOTA...WHICH HAS CENTRAL
AND WESTERN NORTH DAKOTA ESSENTIALLY RAIN FREE FROM SUNDAY 18 UTC
ON. THIS WILL BE CLOSELY MONITORED MOVING FORWARD...AS WPC HAS QPF
VALUES JUST OVER AN INCH OVER NORTH DAKOTA FROM THURSDAY
THROUGH SUNDAY. THIS WOULD BE SUFFICIENT RAINFALL TO INCREASE
GREENNESS ACROSS THE STATE AND MINIMIZE FIRE WEATHER CONCERNS.

AS FOR SEVERE WEATHER...THE FIRST CHANCE LOOKS TO BE THURSDAY
AFTERNOON WEST FROM A FRONTAL BOUNDARY MOVING IN FROM EASTERN
MONTANA. THERE WILL ALSO BE CHANCES ON FRIDAY AND SATURDAY SOUTH
CENTRAL AND SOUTHWEST 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. THIS IS CERTAINLY ENOUGH FOR THUNDERSTORMS
TO DEVELOP OVER WESTERN AND SOUTH CENTRAL NORTH DAKOTA...HOWEVER
SEVERE WEATHER WILL ALMOST CERTAINLY BE LIMITED IN SOME RESPECT BY
CLOUD COVER AND THE WIDESPREAD SHOWER ACTIVITY GOING ON DURING THIS
TIME FRAME.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 701 CDT MON MAY 13 2013

AS OF 2350 UTC...A CLUSTER OF THUNDERSTORMS NEAR KGGW AND KLWT ARE
EXPECTED TO APPROACH THE KISN TERMINAL BETWEEN BY THE 03-04 UTC
TIMEFRAME AND POSSIBLY INTO KMOT BY 06-07 UTC. STRONG WIND GUSTS
IN EXCESS OF 35 KTS ARE POSSIBLE WITH THESE STORMS. A STRONG COLD
FRONT WILL MOVE THROUGH THE AREA TUESDAY MORNING. STRONG WESTERLY
WIND GUSTS OF 35-40 KTS ARE POSSIBLE AT ALL TAF SITES BEHIND THE
FRONT.


&&

.FIRE WEATHER...
ISSUED AT 345 PM CDT MON MAY 13 2013

RED FLAG WARNING CONTINUES THIS AFTERNOON AND EARLY EVENING FOR
LOW RELATIVE HUMIDITY...GUSTY WINDS AND DRY PASTURES.

UPGRADED FIRE WEATHER WATCH TO RED FLAG WARNING FOR TUESDAY FOR
STRONG WINDS...LOW RELATIVE HUMIDITY...AND DRY RANGELAND
CONDITIONS.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT /7 PM MDT/ THIS EVENING FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.

RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TO 9 PM CDT /8 PM
MDT/ TUESDAY FOR NDZ001>005-009>013-017>023-025-031>037-040>048-
050-051.

HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
NDZ003-004-011-012-019>022-034-035-042-045-046.

HIGH WIND WATCH FROM 6 AM CDT /5 AM MDT/ TUESDAY THROUGH TUESDAY
EVENING FOR NDZ001-002-009-010-017-018-031>033-040-041-043-044.

HIGH WIND WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING
FOR NDZ005-013-023-025-036-037-047.

&&

$$

UPDATE...AYD
SHORT TERM...WAA
LONG TERM...MM/KS
AVIATION...WAA
FIRE WEATHER...WAA