000
FXUS63 KFGF 150833
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
333 AM CDT WED MAY 15 2013

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT WED MAY 15 2013

FORECAST CHALLENGE CONCERNS MAINLY TEMPERATURES THROUGH THE SHORT
TERM. WEAK RIDGE OF SURFACE HIGH PRESSURE WILL COVER THE FA TODAY.
SURFACE PRESSURE GRADIENT WEAK HOWEVER MIXED LAYER TO 700MB WITH
15-20KTS THROUGH THE LAYER. THIS COULD RESULT IN SOME WIND GUSTS TO 20
MPH HOWEVER OVERALL LIGHTER WINDS TODAY SHOULD AID EFFORTS BY
REGIONAL WILD LAND FIRE FIGHTERS. SHORTWAVE CURRENTLY MOVING INTO
WESTERN SD TO PROPAGATE ESE. ASSOCIATED CONVECTION CURRENTLY
ACROSS W SD SHOULD PROPAGATE ESE AND REMAIN S OF FA HOWEVER
ASSOCIATED CLOUDS MAY PROVIDE SOME MID/UPPER LEVEL CLOUD COVER TO
THE REGION. THERMAL ADVECTION NEUTRAL BUT AT LEAST PARTIAL SOLAR
SHOULD ALLOW TEMPERATURES TO RECOVER TO ABOVE AVERAGE.

HIGH PRESSURE REMAINS ACROSS FA TONIGHT. WEAK DRY EASTERLY FLOW
...LITTLE IN THE WAY OF CLOUD COVER AND WEAK COLD ADVECTION SHOULD
ALLOW TEMPERATURES TO DROP OFF CLOSE TO AVERAGE.

MID LEVEL SHORT WAVE RIDGE AXIS BUILDS OVER FA THURSDAY. SURFACE
LOW PRESSURE DEVELOPS OVER HIGH PLAINS IN RESPONSE TO SHORT WAVE
MOVING INTO NORTHERN ROCKIES. MOIST AXIS BECOMES ORIENTED FROM
CENTRAL PLAINS NW TO NORTHERN HIGH PLAINS ALONG WITH LOW LEVEL
FORCING. WITH DRIER LOW LEVEL E-SE FLOW WILL KEEP FORECAST DRY
THROUGH THE DAY MOST AREAS. WILL MAINTAIN LOW END POPS ACROSS THE
FAR WEST IN CASE CONVECTION CAN PROPAGATE FAR ENOUGH EAST.

.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 15 2013

WILL MAINTAIN SOME MODEST POPS ROUGHLY ACROSS WEST HALF OF FA
THURSDAY NIGHT AS WEAK WAVE CRESTS RIDGE.

LOW LEVEL BOUNDARY SLOWLY SHIFTS FRIDAY ALONG WITH AN INCREASE IN
LOW LEVEL MOISTURE AND RELATED INSTABILITY. BEST LOW LEVEL
CONVERGENCE REMAINS TO OUR WEST WHICH WILL KEEP ME FROM ANY
INCREASE IN POPS. TEMPERATURE WILL HINGE ON CLOUDS BUT WITH
EXPECTED WARM ADVECTION AND ELEVATED MOISTURE CLOUDS MAY LIMIT
TEMPERATURE CLIMB.

AS WESTERN TROUGH/SURFACE BOUNDARY APPROACHES AND REGION COMES UNDER
INCREASINGLY SW MID LEVEL FLOW MID RANGE POPS SEEM REASONABLE SO
MINIMAL CHANGES TO POPS IN LATER PERIODS.

SATURDAY THROUGH TUESDAY NIGHT...00 UTC GFS/ECMWF 500 HPA HEIGHT
PATTERN IN GOOD AGREEMENT. BOTH SHOW A BROAD OPEN PACIFIC WAVE
MOVING VERY SLOWLY INTO THE NATION/S MIDSECTION THROUGH THE
WEEKEND...THEN FORMING A CLOSED LOW SOMEWHERE ACROSS THE NORTHERN
PLAINS MONDAY INTO TUESDAY. WITH PRECIPITABLE WATER VALUES FROM 1.0
TO 1.5 INCHES AND PERSISTENT ENHANCED MID-LEVEL CONVERGENCE...EXPECT
A PROLONGED PERIOD OF SHOWERS AND THUNDERSTORMS THIS WEEKEND INTO
EARLY NEXT WEEK. RAW MODEL QPF SUGGESTS ANYWHERE FROM 1 TO 3 INCHES
OF RAIN THROUGH TUESDAY MORNING REGION-WIDE. WITH CLOUD COVER AND
RAIN...TEMPERATURES WILL FALL BELOW NORMAL SUNDAY INTO EARLY NEXT
WEEK WITH AFTERNOON HIGHS FROM THE UPPER 50S TO MID 60S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1144 PM CDT TUE MAY 14 2013

VFR CONDITIONS WILL CONTINUE WITH ONLY CIRRUS CLOUDS MOVING ACROSS
THE AREA. WINDS WILL BE FROM THE WEST LESS THAN 12 KTS TONIGHT
WITH A FEW SITES GOING LIGHT AND VARIABLE. WINDS WILL PICK UP A
BIT WITH GUSTS TO AROUND 20 KTS TOMORROW AFTERNOON BUT WILL NOT BE
AS STRONG AS TUESDAY. NORTHWEST WINDS WILL DROP BELOW 10 KTS AGAIN
LATE IN THE PERIOD.



&&

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

$$

SHORT TERM...VOELKER
LONG TERM...ROGERS/VOELKER
AVIATION...JR