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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KBIS 212026
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
326 PM CDT TUE MAY 21 2013

.SHORT TERM...
-- Changed Discussion --
(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 327 PM CDT TUE MAY 21 2013

THE HIGHLIGHT OF THE SHORT TERM IS THE END OF THE LONG DURATION
RAINFALL EVENT ACROSS THE AREA.

FOR TONIGHT...THE RAP THROUGHOUT THE DAY HAS HAD A GOOD HANDLE ON
THE STRATUS DECK ACROSS THE AREA..AND FOLLOWED ITS LATEST 19 UTC
RUN FOR CLOUD COVER THROUGH THE NIGHT WHICH ADVECTS DRIER AIR
SOUTHWEST AND SCOURS OUT THE STRATUS. DID ADD A MENTION OF FOG TO
THE NORTHWEST AND NORTH CENTRAL WHERE SKIES FIRST CLEAR TONIGHT
AND WINDS BECOME LIGHT...ALLOWING FOR GOOD RADIATIONAL COOLING
INTO THE UPPER 30S AND SATURATION IN LIGHT OF THE RECENT RAINFALL.

A QUIET WEDNESDAY IS FORECAST WITH A SURFACE RIDGE AXIS ACROSS THE
AREA. GIVEN GOOD MODEL AGREEMENT...USED A BLEND OF THE 12 UTC
GEM/GFS/NAM/ECMWF AND 15 UTC SREF FOR ALL FIELDS...WITH GENERALLY
SUNNY SKIES AND HIGHS IN THE 60S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 327 PM CDT TUE MAY 21 2013

BY WEDNESDAY NIGHT AN UPPER LEVEL SHORTWAVE RIDGE BETWEEN THE
EXITING LOW PRESSURE SYSTEM TO THE EAST...AND THE ESTABLISHED UPPER
LEVEL LOW OVER THE WEST COAST/ROCKIES...WILL BE SITUATED OVER THE
PLAINS OF NORTH AMERICA. AT THE SURFACE...COOL HIGH PRESSURE RIDGE
MOVING SOUTH FROM CANADA NOSES INTO THE DAKOTAS.

BY THURSDAY THE SURFACE PRESSURE GRADIENT INCREASES AS THE
INTENSIFYING SURFACE LOW OVER THE ROCKIES/LEE OF THE ROCKIES SETS UP
A STRONGER SOUTHERLY/SOUTHEASTERLY WIND FLOW ACROSS THE WESTERN
PLAINS. SOUTHEAST WINDS 20 TO 30 MPH CAN BE EXPECTED OVER THE
WESTERN THIRD OF NORTH DAKOTA.

FRIDAY THROUGH THE MEMORIAL DAY WEEKEND...THE LARGE UPPER LEVEL LOW
OVER THE ROCKIES SETS UP A SOUTHWEST FLOW ALOFT OVER NORTH
DAKOTA...AND A SERIES OF UPPER LEVEL IMPULSES WILL TRAVERSE
NORTHEASTWARD ACROSS THE DAKOTAS. THUS A CHANCE OF THUNDERSTORMS
THROUGHOUT THIS PERIOD.

FAIRLY SEASONABLE TEMPERATURES IN THE LONG TERM...WITH HIGHS IN THE
60S AND 70S AND LOWS IN THE 40S AND 50S.
-- End Changed Discussion --

&&

.AVIATION...
-- Changed Discussion --
(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 327 PM CDT TUE MAY 21 2013

MVFR STRATUS WITH OCCASIONAL LIGHT RAIN WILL CONTINUE TO IMPACT
KMOT...KBIS...KJMS AND KDIK THIS AFTERNOON AND EVENING...WITH A
CLEARING TREND FROM NORTH TO SOUTH TONIGHT. HOWEVER...WITH
SUNSET...THE STRATUS DECK MAY LOWER TO IFR BEFORE CLEARING. KISN
SHOULD REMAIN OUTSIDE OF THIS DECK FOR THE 18 UTC TAF CYCLE WITH
VFR CONDITIONS EXPECTED. THERE IS A CHANCE OF FOG TONIGHT AT KMOT
AS SKIES CLEAR WITH RECENT RAINFALL...HOWEVER...IMPACTS ARE STILL
UNCERTAIN AT THIS TIME AND WILL CODE AS VCFG FOR NOW.
-- End Changed Discussion --

&&

.HYDROLOGY...
-- Changed Discussion --
ISSUED AT 327 PM CDT TUE MAY 21 2013

FLOOD WARNINGS CONTINUE FOR THE PIPESTEM CREEK NEAR PINGREE AND
THE FORECAST POINTS OF TOWNER...BANTRY AND WESTHOPE ON THE SOURIS.
CONTINUING TO MONITOR THE WINTERING RIVER NEAR KARLSRUHE AND THE
WILLOW CREEK NEAR WILLOW CITY WHICH MAY APPROACH FLOOD STAGE IN
THE NEXT 24-48 HOURS. HAVE HELD OFF ON A FLOOD WARNING FOR
NOW...AND WILL WATCH HOW THESE WATERWAYS RESPOND TO RUNOFF.
-- End Changed Discussion --

&&

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

$$

SHORT TERM...AYD
LONG TERM...JV
AVIATION...AYD
HYDROLOGY...AYD