Area Forecast Discussion Issued by NWS Grand Forks, ND
000
FXUS63 KFGF 250846
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
346 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 345 AM CDT SAT MAY 25 2013
CHALLENGE TODAY WILL BE TEMPS AND CLOUDS WITH CONVECTION TONIGHT.
MODELS IN FAIR AGREEMENT WITH THE SHORT TERM AND USED A BLEND FOR
THIS FORECAST. PERSISTENT SOUTHWEST FLOW THROUGH THE FORECAST
PERIOD WILL KEEP ACTIVE SHOWER...TSTORM PATTERN CONTINUING.
CHALLENGE WITH THE SHORT WAVE ENERGIES WILL BE PLACEMENT AND THE
TIME OF DAY WITH POTENTIAL TO TAP A MORE UNSTABLE AIRMASS IF WAVE
PASSAGE COINCIDES WITH PEAK HEATING.
CURRENTLY MODERATE WARM AIR ADVECTION LIKELY STILL PRODUCING
SCATTERED SHOWER ACTIVITY ACROSS MINNESOTA LAKES AND TREES THOUGH
RADAR TREND SHOWS DECREASING COVERAGE MAY JUST BE ARTIFACT OF
OVERSHOOTING AS THE ECHOS DRIFT FARTHER FROM THE KMVX RADAR.
295K ISENTROPIC SFC PROG SHOWS THE MOVEMENT OF THE SATURATED
LAYER ALIGNED WITH THE RADAR ECHOS. WEAK ASCENT WANES BY LATE
MORNING AND HAVE SLGT CHC POPS ENDING AT 18Z.
ATTENTION THEN TURNS TO THE WEST WHERE THE NEXT ROUND OF CONVECTION
WILL STRUGGLE EASTWARD FROM CNTRL ND. SHOWALTERS STAY POSITIVE
FOR MUCH OF THE NIGHT CWFA WIDE. KEPT ANY POP MENTION TO THE SW
HALF OF THE CWFA THROUGH SUNDAY 12Z...THOUGH THINK EVEN LESS OF
THE AREA WILL SEE SHOWER ACTIVITY...WITH THE SHOWER CHCS SLOWING
MOVING EAST SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 AM CDT SAT MAY 25 2013
SUNDAY NIGHT TO MONDAY NIGHT...INCREASING POPS INTO THE LIKELY
CATEGORY ACROSS THE SOUTHERN RRV WITH COMBINATION OF 500MB
SHORTWAVE ENERGY ATOP 850MB CONVERGENCE. 00Z GEM AND GFS A BIT
FASTER AND A TOUCH FARTHER NORTH THAN 00Z ECMWF BUT FAIRLY SIMILAR
SIGNALS FOR THE AREA. NEGATIVE SHOWALTERS WITH 200 TO 400 J/KG OF MU
CAPE EXPECTED AS SFC LOW TRACKS ACROSS THE SOUTHERN CWFA MONDAY
MORNING. CONVECTION WILL CONTINUE TO MOVE TO THE EAST NORTHEAST
AND AMOUNT OF TEMP RECOVERY WILL DEPEND ON SPEED OF SHORTWAVE AND
SUBSIDENCE IN ITS WAKE. HIGHS IN THE 60S WHERE THE CLOUDS LINGER
THE LONGEST AND 70S IN THE WEST MOST LIKELY.
TUESDAY-FRIDAY...MODELS IN GOOD AGREEMENT INDICATING SOUTHWEST FLOW
ALOFT AND THEN AN UPPER LOW CLOSING OFF SOMEWHERE IN THE VICINITY OF
THE FA TOWARD THE END OF THE PERIOD. THIS IS AN ACTIVE PATTERN...NOT
THAT DISSIMILAR FROM THE LAST HEAVY RAIN EVENT. THERE ARE STILL A
LOT OF DETAILS WITH LOW CONFIDENCE (LIKE WHERE THE UPPER LOW CLOSES
OFF...AND HOW QUICKLY IT THEN PROPAGATES TO THE EAST)...BUT THIS
WILL BE SOMETHING TO KEEP A CLOSE EYE ON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI MAY 24 2013
IFR CONDITIONS ARE MOVING INTO THE WESTERN AREAS AND SHOULD MOVE
INTO THE VALLEY OVERNIGHT. HAVE LOWERED CIGS SOME IN MOST AREAS
WITH SOME IMPROVEMENT INTO THE MVFR RANGE TOMORROW WITH SW WINDS
CONTINUING AND GUSTING OVER 20KT AT TIMES.
&&
.HYDROLOGY...
ISSUED AT 345 AM CDT SAT MAY 25 2013
MOST TRIBUTARIES OF THE RED RIVER WERE FALLING ACROSS THE FORECAST
AREA. THE EXCEPTION WAS THE BUFFALO RIVER AT DILWORTH WHICH IS
RISING AND IS FORECAST TO CREST JUST ABOVE MINOR FLOOD STAGE
THIS EVENING.
ON THE MAIN STEM OF THE RED RIVER...THE RIVER WAS FALLING IN THE
SOUTHERN PART OF THE VALLEY. AND IN THE NORTHERN VALLEY...THE RED
RIVER WAS RISING AS A RESPECTABLE AMOUNT OF WATER CONTINUES TO FLOW
INTO THE MAINSTEM RED. OSLO IS FORECAST TO CREST SATURDAY...DRAYTON
TO CREST ON MONDAY OR TUESDAY...AND PEMBINA TO CREST NEXT THURSDAY
OR FRIDAY.
RIVER FLOOD WARNINGS REMAIN IN EFFECT AT NECHE ON THE PEMBINA
RIVER. OTHER RIVER FLOOD WARNINGS REMAIN AT PEMBINA...DRAYTON AND
OSLO ON THE MAINSTEM RED...AS WELL AS HALLOCK...GRAFTON AND
DILWORTH.
THE PARK RIVER AT GRAFTON HAS CRESTED AND THE STAGE IS CURRENTLY
BELOW 14 FEET AND FALLING.
AREAL FLOOD WARNINGS REMAIN IN EFFECT FOR PEMBINA...WALSH...AND
EASTERN CAVALIER COUNTIES. WATER LEVELS ACROSS THIS AREA SHOULD
GRADUALLY DECREASE OVER THE NEXT FEW DAYS WITH MODEST ADDITIONAL
RAINFALL ANTICIPATED.
A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY 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. AT THIS
TIME...OFFICIALS NOTE THE TEMPORARY LEVEE ON TOP OF THE RENWICK DAM
REMAINS STABLE AND WILL STILL BE MONITORED. OTHERWISE...LAKE RENWICK
HAS BEEN SLOWLY RECEDING THE LAST COUPLE OF DAYS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FLASH FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR NDZ008.
MN...NONE.
&&
$$
SHORT TERM...JK
LONG TERM...TG
AVIATION...DK
HYDROLOGY...WJB