000
FXUS63 KFGF 191755
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
1255 PM CDT SUN MAY 19 2013

.UPDATE...
ISSUED AT 1255 PM CDT SUN MAY 19 2013

STEADY RAIN HAS WORKED INTO THE FAR NORTHERN PORTIONS OF THE FA
NOW. THE COMBINATION OF RAIN AND CLOUDS ARE HOLDING TEMPS DOWN SO
WILL NUDGE HIGHS DOWN A BIT ALONG AND NORTH OF INTERSTATE 94.
OTHERWISE THE SFC LOW REMAINS JUST WEST OF KABR WITH A WARM FRONT
ARCHING UP TO SOUTH OF KFAR AND THEN SOUTHEAST DOWN TOWARD
STAPLES. THE WARMEST TEMPS ARE SOUTH OF THE WARM FRONT OF COURSE
WHERE THERE IS ALSO A LITTLE BIT OF SUN POKING THROUGH. HIGH
RESOLUTION MODELS SEEM TO INDICATE THE BEST CHANCES FOR ADDITIONAL
CONVECTION FORMING TO THE SOUTH/SE OF THE FA AND RIDING UP AND
AROUND THE LOW. THIS SHOULD KEEP GOOD CHANCES FOR PCPN OVER MOST
OF THE FA WITH THE EXCEPTION OF POSSIBLY THE SOUTHWEST.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT SUN MAY 19 2013

CHALLENGING FORECAST CONCERNING ADVERTISED HEAVY RAIN POTENTIAL.
GFS/ECMWF HAVE INITIALIZED BEST WITH SURFACE FEATURES BUT HAVE A
DIFFERENT SOLUTION ON TRACK OF CURRENT SURFACE LOW OVER E CENTRAL
SD WHICH WOULD AID IN ENHANCING LOW LEVEL FORCING. ECMWF LIFTS LOW
NORTHWARD ALONG INVERTED TROUGH THROUGH FA WHILE GFS KEEPS LOW
FAIRLY STATIONARY AS UPPER LOW APPROACHES. AND BOTH SOLUTIONS A
POSSIBILITY. MODELS CONTINUE TO SHOW DIFFERING QPF SOLUTIONS
AFTER THE CURRENT BAND OF CONVECTION LIFTS THROUGH TODAY.

WILL SEE SOMEWHAT SIMILAR SCENARIO TODAY AS YESTERDAY AS ARC OF
CONVECTION LIFTS NORTHWARD THROUGH FA. CONVECTION LOOKS STRONGER
THAN LAST NIGHT SO WILL LIKELY SEE BETTER BAND OF MODERATE/HEAVY
RAIN LIFTING THROUGH FA. WILL AGAIN SEE A BIG TEMPERATURE GRADIENT
FROM N-S AS FAR SOUTH STILL CURRENTLY AROUND 70 WITH 50 ALONG
INTERNATIONAL BORDER. PROBABLY NOT A LOT OF TEMPERATURE RECOVERY
WITH EXPECTED WITH CLOUDS AND RAIN.

CONCERNING HEAVY RAIN POTENTIAL SMALL CLUSTER OF CONVECTION ACROSS
FAR WEST CENTRAL FA INITIALLY PRODUCED HEAVY RAIN JUST WEST OF FA
HAVING STALLED OUT BUT BEGINNING TO PROPAGATE EASTWARD AND HAS
WEAKENED SOME. OF MORE CONCERN IS ARC OF DEEP CONVECTION LIFTING
NORTHWARD THROUGH SD INTO SOUTHERN FA. LINE IS PROGRESSIVE AT
30-40KTS HOWEVER DEPENDING HOW MUCH RAIN FALLS ACROSS THE
SOUTHERN FA THIS MORNING COULD BE SETTING STAGE FOR POSSIBLE FLASH
FLOODING.

LATER THIS AFTERNOON INTO THIS EVENING AS SURFACE LOW DEEPENS
ACROSS SD E-W BOUNDARY SETS UP AGAIN ALONG ND AND SD BORDER AREA.
THIS LOOKS TO BE THE FOCUS FOR ADDITIONAL CONVECTION. THIS SECOND
ROUND OF CONVECTION WHILE PROBABLY NOT SEVERE COULD PRODUCE ENOUGH
ADDITIONAL RAINFALL TO PRODUCE FLOOD ISSUES. AT THIS POINT WILL
HOLD OFF ON ANY FLASH FLOOD HEADLINES. WILL NEED TO MONITOR
RAIN AMOUNTS ACROSS THE SOUTHERN FA THIS MORNING.

WILL ALSO NEED TO MONITOR WINDS THIS EVENING ACROSS DVL BASIN AS
COULD SEE BORDERLINE ADVISORY WIND SPEEDS WITH TIGHTENING SURFACE
PRESSURE GRADIENT.

WITH LITTLE MOVEMENT OF SURFACE LOW MONDAY WILL CONTINUE TO SEE
RAIN BANDS ACROSS FA AND NON-SEVERE T POTENTIAL ACROSS SOUTH HALF
OF FA. WARMEST TEMPERATURES AGAIN WILL BE ALONG ND/SD/MN BORDER
AREA WITH COOL AND BREEZY CONDITIONS ELSEWHERE.

.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN MAY 19 2013

CUT OFF LOW MOVES VERY LITTLE THROUGH TUESDAY. WITH PRECIPITABLE
H2O VALUES REMAINING ABOVE AN INCH WILL CONTINUE TO SEE MODERATE
RAINFALL POTENTIAL WITH ANY IMPULSES ROTATING AROUND UPPER LOW.
SURFACE BOUNDARY ASSOCIATED WITH SD SURFACE LOW DRIFTS N AND S
THROUGH THE PERIOD CLOSE TO ND/SD BORDER AREA. WITH ENOUGH
INSTABILITY AND CAPE CANNOT RULE OUT THUNDER THIS AREA. GFS
QUICKEST IN SHIFTING LOW EASTWARD TUESDAY NIGHT WHICH WOULD
GRADUALLY BRING AN END TO MORE SIGNIFICANT RAINFALL. ALTHOUGH
COLUMN NOT PARTICULARLY COLD CLOUDS AND RAIN WILL HOLD
TEMPERATURES DOWN.

WEDNESDAY-SATURDAY...MODELS GENERALLY AGREE ON SHIFTING THE UPPER
LOW EASTWARD ACROSS THE UPPER MIDWEST INTO THE WESTERN GREAT LAKES
WEDNESDAY INTO THURSDAY. SHOWERS MAY LINGER INTO WEDNESDAY
ESPECIALLY ACROSS THE SOUTHEAST HALF OF THE AREA AS THE LOW SLOWLY
DRIFTS AWAY. BY THURSDAY AND FRIDAY...AMPLIFIED MID/UPPER RIDGING
WILL BUILD ACROSS THE NORTHERN PLAINS AS LONGWAVE TROUGHING
PROGRESSES INTO THE PACIFIC NORTHWEST. SFC HIGH PRESSURE PASSING OFF
TO THE NORTH WILL PROVIDE DRY EASTERLY LOW-LEVEL FLOW
THURSDAY/FRIDAY...WITH SEASONABLE TEMPS. CONFIDENCE IN DETAILS IS
LOW BY NEXT SATURDAY...BUT DID MAINTAIN LOW POPS...AS THE UPPER FLOW
GRADUALLY TRANSITIONS TO THE SOUTHWEST WITH THE WESTERN TROUGH
BEGINNING TO SHIFT EAST. TEMPS LOOK TO REMAIN NEAR NORMAL FOR NEXT
WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1255 PM CDT SUN MAY 19 2013

EXPECT CONTINUED WIDESPREAD IFR-LOW END MVFR CIGS OVER MOST OF THE
FORECAST AREA THROUGH MONDAY.  TRICKY PART IS TRYING TO SEE HOW FAR
NORTHWEST THE DRY SLOT WILL GET INTO WESTERN MN AND THE RED RIVER
VALLEY AS OBSERVATIONS CURRENTLY IN THE WAHPETON-FERGUS FALLS AREA
SHOW AREAS OF SCATTERED CLOUDS.  SOME OF THIS MAY MOVE INTO FARGO
AREA LATER THIS AFTN...BUT ALSO COULD LEAD TO SOME EVE TSTMS.  REST
OF THE AREA WILL STAY MVFR OR IFR CIGS AND VSBYS.  AS FOR PRECIP DO
EXPECT A BREAK IN PRECIP AT GFK-TVF-BJI IN THE AFTN AND PERHAPS INTO
THE EVENING BEFORE NEXT BATCH MOVES UP FROM THE SOUTH AND
SOUTHEAST.  BUT TIMING THE PRECIP BREAK ALWAYS SUSPECT.  DVL REGION
MOST PRONE TO REMAIN IN IFR AND RAIN THRU THE PERIOD...THOUGH A
PERIOD OF NO RAIN IS PSBL THERE LATE THIS AFTN/EVE BUT LESS
CERTAIN.  WINDS WILL BE EAST-NORTHEAST AT MOST SITES...BUT MAY TURN
A BIT MORE SOUTHEAST AT FARGO AND POINTS EAST AND SOUTH AS SFC LOW
WOBBLES TO ALONG THE ND/SD BORDER BTWN BIS/ABR.

&&

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

$$

UPDATE...GODON
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...RIDDLE