000
FXUS63 KFGF 222032
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
332 PM CDT WED MAY 22 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 332 PM CDT WED MAY 22 2013

WITH NO ADDITIONAL RAINFALL EXPECTED THROUGH THURSDAY...PRIMARY
FORECAST CHALLENGE WILL BE TEMPERATURES. GFS/NAM/ECMWF/GEM ARE IN
GOOD AGREEMENT AND WILL USE A BLENDED SOLUTION.

20 UTC SATELLITE IMAGERY SHOWS LOW STRATUS/STRATOCU ALONG AND
SOUTH OF A LINE FROM LISBON TO PARK RAPIDS. SKIES WILL BECOME
MOSTLY CLEAR OVERNIGHT AS SURFACE HIGH PRESSURE BUILDS ACROSS THE
REGION...ALLOWING TEMPERATURES TO DROP INTO THE UPPER 30S TO LOW
40S. WITH CLEAR SKIES AND SOME LOW-LEVEL COLD AIR ADVECTION ACROSS
NORTHWEST AND NORTH CENTRAL MN OVERNIGHT...WILL NEED TO WATCH HOW
LOW INTO THE 30S TEMPERATURES DROP. CURRENT DEW POINTS ACROSS
NORTHWEST MN ARE AS LOW AS 34 DEGREES...SO DON/T THINK AIR
TEMPERATURES WILL FALL MUCH FURTHER.

THURSDAY WILL BE SUNNY AND DRY WITH THE SURFACE RIDGE AXIS ALONG
THE VALLEY FLOOR BY 18 UTC. BOUNDARY LAYER TEMPERATURES WILL BE
NEAR OR A FEW DEGREES COOLER THAN TODAY...SO DESPITE ABUNDANT
SUNSHINE...EXPECT DAYTIME HIGHS ONLY IN THE 60S. MOSTLY CLEAR
SKIES WILL CONTINUE THURSDAY NIGHT WITH TEMPERATURES SIMILAR TO
TONIGHT...FROM THE UPPER 30S TO MID 40S.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 332 PM CDT WED MAY 22 2013

PRECIPITATION CHANCES INCREASE FRIDAY AFTERNOON AND EVENING FROM
THE WEST AS A MID-LEVEL WARM FRONT BEGINS TO SLIDE ACROSS THE
DAKOTAS. ISENTROPIC LIFT ALONG THE 300 K SURFACE AND PRECIPITABLE
WATER NEAR ONE INCH WILL RESULT IN SOME SHOWERS AND PERHAPS A FEW
THUNDERSTORMS. NOT MUCH UPPER LEVEL SUPPORT AND MOST INSTABILITY
REMAINS ACROSS THE WESTERN DAKOTAS INTO EASTERN MT...BUT WILL
MAINTAIN ISOLATED THUNDER MENTION. STILL SOME PRECIPITATION
COVERAGE AND TIMING UNCERTAINTY...SO WILL KEEP POPS IN THE HIGH
CHANCE CATEGORY...LIKELY TO BE RAISED TO 60 PERCENT OR HIGHER
WHEN BETTER CONFIDENCE IS ACHIEVED.

SOME LINGERING SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO
SATURDAY...BUT DOES NOT APPEAR AT THIS TIME TO BE AN ALL DAY WASH
OUT. DESPITE WARM AIR ADVECTION ALOFT...THE BOUNDARY LAYER REMAINS
COOL WITH SURFACE TEMPERATURES FRIDAY AND ESPECIALLY SATURDAY
BELOW SEASONAL NORMALS WITH HIGHS IN THE 60S AND LOWS IN THE 40S
TO LOWER 50S.

FORECAST CHALLENGE SATURDAY NIGHT THROUGH WEDNESDAY WILL BE RW/T
CHANCES. MODELS IN REASONABLE AGREEMENT THROUGH THE LONG RANGE.
MID LEVEL RIDGE AXIS TO GRADUALLY SHIFT EAST PUTTING FA IN
INCREASING SW FLOW ALOFT BY FIRST HALF OF NEXT WEEK. FOR MOST OF
THE WEEKEND LOW LEVEL FORCING AND MOISTURE AXIS REMAINS ACROSS
WESTERN AND CENTRAL ND SO QUESTION WILL BE HOW FAR EAST CONVECTION
GETS AFTER DIURNAL INITIATION. BETTER CHANCES FOR PCPN NEXT WEEK
AS LOW PRESSURE AND ABOVE FORCING AND MOISTURE GRADUALLY SHIFTS
EAST. TEMPERATURES LIKELY TO HOLD AT OR A LITTLE BLO AVERAGE
THROUGH THE HOLIDAY WEEKEND THEN MODERATING TO AT OR ABOVE AVERAGE
TO START WORK WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 125 PM CDT WED MAY 22 2013

MVFR STRATUS DECK AND LIGHT RAIN SHOWERS HAVE MOVED JUST SOUTH OF
KBJI AND KFAR WITH CLEARING TO THE NORTH OF THIS LINE. EXPECT VFR
CONDITIONS TO PERSIST AT ALL TAF SITES THROUGH 18 UTC THURSDAY WITH
NORTHEAST WINDS GUSTING AT TIMES TO 25 KTS THIS AFTERNOON WEAKENING
AFTER SUNSET.

&&

.HYDROLOGY...
ISSUED AT 125 PM CDT WED MAY 22 2013

RIVER FLOOD WARNINGS REMAIN IN EFFECT AT WALHALLA AND NECHE ALONG
THE PEMBINA RIVER...WITH WALHALLA HAVING CRESTED EARLIER.

BIGGEST FORECAST CHANGE IS ALONG PARK RIVER AT GRAFTON WHERE THE
RECENT RAINFALL HAS TRIGGERED RAPID STAGE RISES TOWARD MAJOR AND
ULTIMATELY NEAR RECORD FLOOD LEVELS.

RIVER FLOOD WARNINGS ARE NOW IN EFFECT FOR MOST OF THE NORTHERN
MAINSTEM RED AS WELL AS THE SOUTHERN VALLEY MINNESOTA TRIBUTARIES
TO THE RED. THESE POINTS ARE ALL EXPECTED TO ACHIEVE MINOR FLOOD
STAGE EXCEPT FOR OSLO WHERE MODERATE FLOODING IS FORECAST.

AREAL FLOOD WARNINGS WILL BE IN EFFECT FOR PEMBINA...EASTERN
CAVALIER...AND WALSH COUNTIES THROUGH THURSDAY. BY THEN AREAL
FLOODING SHOULD BECOME LESS OF A CONCERN WITH LITTLE PRECIPITATION
AND THE CHANCE FOR SOME DRYING WITH WARMER TEMPERATURES.

A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY AFTERNOON FOR
AREAS DOWNSTREAM OF THE RENWICK DAM ON THE TONGUE RIVER. WATER
REMAINS VERY HIGH AT THE DAM SITE AND IS BEING HELD BACK BY A
CONSTRUCTED EARTHEN LEVEE ON TOP OF THE DAM STRUCTURE.  ALSO...
OFFICIALS ARE CONTINUING TO MONITOR SEVERAL RETENTION DAMS TO THE
WEST OF RENWICK DAM.

AT THIS TIME...OFFICIALS NOTE THE TEMPORARY LEVEE ON TOP OF THE
RENWICK DAM APPEARS TO BE STABLE AND WILL BE CONTINUALLY MONITORED.
HOWEVER...THE THREAT REMAINS AND FAILURE WOULD MEAN MAJOR FLOODING
WOULD BE IMMINENT FOR THE CITIES OF AKRA...CAVALIER...AND BATHGATE.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR NDZ008.

MN...NONE.
&&

$$

SHORT TERM...ROGERS
LONG TERM...ROGERS/VOELKER
AVIATION...ROGERS
HYDROLOGY...BH