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000
FXUS63 KFGF 192344
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
644 PM CDT SUN MAY 19 2013

.UPDATE...
ISSUED AT 643 PM CDT SUN MAY 19 2013

FOCUS ON SHORT TERM FORECAST WILL BE ON TWEAKING POPS FOR CURRENT
TRENDS. A WAVE OF THUNDERSTORMS INITIATING ALONG A LINE OF WEAK
SFC CONVERGENCE IN WEST CENTRAL MINNESOTA WILL LIFT NORTH OVER THE
NEXT THREE HOURS AND FILL IN MOST OF MY NORTH EAST. SHOWERS OVER
MY NORTHWEST WILL BEGIN TO DISSIPATE AS AREA OF ISENTROPIC LIFT
AND THETA E ADVECTION SHIFTS MORE OVER THE NORTH CENTRAL PORTION
OF THE STATE. ONE ISSUE IN THIS AREA WILL BE WINDS...AS A TIGHT
PRESSURE GRADIENT AND H850 WINDS IN THE 40 TO 45 KT RANGE. HEAVIER
RAIN SHOWERS ARE HELPING MIX SOME GUSTY WINDS TO SFC...BUT
SUSTAINED WINDS ABOUT ONE KNOT UNDER ADVISORY CRITERIA. WILL
CONTINUE TO MONITOR BUT CAN EXPECT GUSTS OF 35 KTS TO 40 KTS. WILL
KEEP LOWER POPS BUT STILL IN CHANCE CATEGORY FOR SOUTHEASTERN ND
(MY SW ZONES) AS SHOWER ACTIVITY AROUND SFC LOW IS MINIMAL. WOULD
EXPECT THIS TO FILL IN SOMEWHAT OVERNIGHT AS MORE ACTIVITY IN
SOUTHERN MN LIFTS NORTH AND BEGINS TO ROTATE AROUND THE LOW. WILL
BE HARDEST AREA TO NAIL DOWN TIMING ON.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 331 PM CDT SUN MAY 19 2013

TRICKY FORECAST FOR MOST OF THE SHORT TERM DUE TO THE LONG
DURATION PCPN EVENT. AS OF LATE AFTERNOON THE SFC LOW WAS STILL
JUST WEST OF KABR WITH A WARM FRONT ARCHING UP JUST NORTH OF KFAR
AND THEN OVER TOWARD KPKD. TEMPS SOUTH OF THE WARM FRONT HAVE
CLIMBED UP INTO THE MID 70S WITH DEW POINTS IN THE UPPER 50S AND
LOWER 60S. THIS IS GIVING SOME SFC BASED CAPE VALUES OF 500-1000
J/KG PER THE LATEST SPC MESO PAGE. BULK SHEAR VALUES ACROSS THIS
AREA AT THE MOMENT ARE PRETTY LOW THOUGH. DID HAVE A FEW CELLS
ALONG THE BOUNDARY ABOUT AN HOUR AGO THAT PRETTY MUCH FELL APART
AS THEY MOVED NORTHWARD. MODELS SHOW A STRONG UPPER LEVEL JET
DIGGING INTO THE CENTRAL PLAINS THRU 00Z MON WITH A BIT WEAKER
COMPONENT TRYING TO TURN NORTHWARD FROM THERE. THEREFORE THE
BETTER AREA OF CONVECTION WILL LIKELY BE SOUTH OF THE FA. THERE
IS A TORNADO WATCH OUT FOR BASICALLY THE SOUTHERN HALF OF MN AND
NORTHERN IOWA. CONVECTION HAS FIRED DOWN IN THIS WATCH AREA BUT SO
FAR NOTHING TOO ORGANIZED. HIGH RESOLUTION MODELS TRY TO LIFT SOME
OF THE CONVECTION WHICH FIRES DOWN ACROSS THIS WATCH AREA NORTH/NW
BY MID EVENING AND THEN WRAPPING IT AROUND THE LOW. THEREFORE WILL
KEEP HIGHEST PCPN CHANCES ACROSS WEST CENTRAL MN UP THRU THE
NORTHERN HALF OF THE FA. NOT SURE ABOUT SEVERE POTENTIAL BUT LIKE
THE LAST COUPLE OF NIGHTS THERE COULD BE A FEW STRAY SEVERE STORMS
BUT STILL A LOT OF UNCERTAINTY.

FOR MONDAY INTO MON NIGHT THE LOW PRESSURE SYSTEM DOES NOT MOVE
VERY MUCH. THEREFORE SHOULD BE A CONTINUAL PARADE OF PCPN BANDS
WRAPPING AROUND THE LOW. WITH THE LOW SOMEWHERE OVER NORTHEAST SD
THE MAIN PCPN BANDS WILL PROBABLY STAY WHERE THEY HAVE BEEN TODAY.
THIS KEEPS A BROAD STEADY RAIN OVER THE AREA BUT NOT THINKING IT
WILL BE HEAVY ENOUGH FOR FLASH FLOODING.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 331 PM CDT SUN MAY 19 2013

THE LOW WILL FINALLY START TO KICK EAST ON TUE AND TUE NIGHT. SOME
MODEL SOLUTIONS SHOW DRY WEATHER BY WED BUT WILL KEEP SOME LOW
CHANCES HANGING AROUND DUE TO THE OTHER SLOWER EXITING PCPN
SOLUTIONS.

12Z GFS/ECMWF/GEM IN REASONABLE AGREEMENT IN SHOWING UPPER LOW
DRIFTING SOUTH AND EAST WITH ANY LINGERING SHOWERS EXITING WCNTRL MN
WED NIGHT WITH DRY WEATHER THURSDAY INTO FRIDAY AS CANADIAN HIGH
MOVES SOUTH.  BUT FAST ON ITS HEELS WILL BE THE NEXT UPPER LOW WHICH
WILL MOVE FROM THE WEST COAST INTO THE ROCKIES AND NRN PLAINS THIS
NEXT WEEKEND.  ECMWF IS WEAKER AND SLOWER THAN GFS...AND THUS A BIT
LESS PRECIP CHANCES UNTIL JUST PAST NEXT WEEKEND WHEREAS GFS HAS
MORE PRECIP NEXT SAT-SUN.  GEM WOULD SEEM TO FOLLOW A BIT MORE GFS
SOLN.  NET RESULT USING AN ALL BLEND SOLN IS TO THROW IN 30-50 POPS
NEXT SAT-SUN FOR SHOWERS/STORMS.  TEMPS WILL RUN A BIT BELOW NORMAL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 643 PM CDT SUN MAY 19 2013

HAVE ADDED BRIEF PERIOD OF TSTMS TO BJI AND TVF AS LINE OF STORMS
INITIATING ALONG A WEAK SFC BOUNDARY OVER WEST CENTRAL MN BEGINS
TO LIFT NORTH. NOT SURE OF TSTMS WILL MAKE IT OVER TO GFK BUT
SHOWERS WILL. REMOVED MENTION OF TSTMS FOR FAR AS STORMS ARE
DEVELOPING WELL TO THE EAST. WILL ALSO NEED TO INCREASE NORTHEAST
WINDS OVER DVL AS SHOWERS ARE CREATING WIND GUSTS INTO THE 30+ KT
RANGE. SHOULD SEE A SLOW TRANSITION OVER TO MAINLY SHOWERS LATER
THIS EVENING AS SUN SETS ARE INSTABILITY DECREASES.

&&

.HYDROLOGY...
ISSUED AT 331 PM CDT SUN MAY 19 2013

RAINFALL AMOUNTS OVER THE AREA DURING THE LAST 24 HOURS ENDING AT
800 AM HAS RANGED FROM A TRACE TO NEARLY TWO INCHES IN ISOLATED
AREAS. HOWEVER...MOST AREAS SAW FROM ONE HALF TO ONE INCH. MORE
RAINFALL IS EXPECTED ACROSS THE AREA TODAY AND TONIGHT. EXPECT LIGHT
RAIN TO CONTINUE WITH THE POSSIBILITY OF ONE TO TWO INCHES OF RAIN
OVER THE NEXT 24 HOURS. IF THIS AMOUNT OF RAIN DOES FALL...IT MAY
PUSH SOME FORECAST POINTS IN THE RED RIVER BASIN BACK ABOVE FLOOD
STAGE. NCRFC MODEL INPUTS BRING SEVERAL FORECAST POINTS ABOVE
FLOOD STAGE. HOWEVER...THERE IS SOME UNCERTAINTY IN THE FORECAST
DEPENDING ON WHERE THE RAIN ACTUALLY FALLS AND RATE OF RAINFALL.
SOME OF THE RIVER POINTS HAVE BEEN DELAYED WITH RESPECT TO
ANTICIPATED TIMING OF RISES...AND HAVE BEEN COVERED BY A FLOOD
WATCH. THE NEW RIVER POINT FORECASTS ALSO BRING EAST GRAND
FORKS...OSLO AND CROOKSTON ABOVE FLOOD STAGE. SINCE THE FORECAST
DOES NOT BRING LEVELS TO FLOOD STAGE FOR ANOTHER THREE TO FOUR
DAYS...ISSUED A NEW RIVER FLOOD WATCH TO INCLUDE THOSE POINTS AS
WELL. WILL MONITOR RIVER STAGES CLOSELY AND WILL ISSUE APPROPRIATE
PRODUCTS AS REQUIRED.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

UPDATE...SPEICHER
SHORT TERM...GODON
LONG TERM...GODON/RIDDLE
AVIATION...SPEICHER
HYDROLOGY...HOPKINS