FXUS63 KFGF 050827
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
227 AM CST SUN FEB 5 2012

.DISCUSSION...FORECAST CHALLENGE CONCERNS INITIAL FOG AND THEN
TEMPERATURES THROUGH THE PERIOD. THERMAL/MOISTURE PROFILES SIMILAR
BETWEEN MODELS THROUGH THE PERIOD WITH ONLY DIFFERENCE BEING
TIMING OF COLD FRONT WED NIGHT/THURSDAY. WILL USE BLEND FOR FORECAST.

FOG ACROSS FA MORE PATCHY WITH DENSE FOG ISOLATED. WILL BE
MONITORING TRENDS DURING THE OVERNIGHT AS RAPID REFRESH MESOSCALE
MODEL HINTING AT MORE WIDESPREAD DENSE FOG BUT CURRENTLY
OVERDOING LOWER VSBY. OTHERWISE TEMPERATURES WILL BE MAIN
CHALLENGE. SURFACE PRESSURE GRADIENT TO INCREASE TOWARDS MORNING
WHICH SHOULD HELP ERODE BR/ST. NOT MUCH CLOUD COVER ABOVE SHALLOW
STRATUS AND ONCE THAT GOES SHOULD SEE FAIR AMOUNT OF SOLAR.
THERMAL RIDGE AXIS DROPS OVER FA DURING THE DAY WITH +6C AIR OVER
FA THIS AFTERNOON. THIS COMBINED WITH SOLAR AND WESTERLY FLOW
SHOULD BOOST TEMPERATURES. CURRENT MAXIMUM TEMPERATURES IN THE 40S
SEEMS REASONABLE SO ONLY MINOR CHANGES PLANNED.

COLD FRONT REACHES NORTHERN FA LATE TONIGHT WITH COLD ADVECTION
SPREADING SOUTH DURING THE DAY MONDAY AS FRONT CLEARS SOUTHERN FA
MONDAY AM. NOT EXPECTING ANY SERIOUS COOL DOWN TONIGHT HOWEVER
RECOVERY MONDAY WILL BE MINIMAL. GFS LOOKS OVERDONE WITH QPF
HOWEVER CANNOT RULE OUT SOME FLURRIES AND WILL USE GFS/ECMWF COMPROMISE.

SURFACE HIGH JUST NORTH OF FA BY 12Z TUESDAY. LIGHT MIXING AND SKC
SHOULD ALLOW TEMPERATURES TO DROP BUT LACK OF SNOW COVER WILL HOLD
MINIMUMS TO SINGLE DIGITS ABOVE AND BLO ZERO.

HIGH PRESSURE OVER FA TUESDAY FOR LIGHT MIXING BUT PLENTY OF
SOLAR. THIS SHOULD ALLOW FOR TEMPERATURE TO RECOVER CLOSE TO
SEASONAL VALUES.

WEAK RETURN FLOW/WARM ADVECTION SETS UP AFT 06Z AS HIGH SAGS
SOUTHWARD.

WED LOOKS TO BE THE WARMEST DAY FOR A WHILE AS WARM
ADVECTION...FAVORED SW SURFACE MIXING AND SOLAR WORK TO GET
TEMPERATURES BACK ABOVE AVERAGE.

.LONG TERM... /THU THROUGH SUN/ LONG TERM MODELS CONTINUE TO SHOW A
POOL OF VERY COLD TEMPERATURES DIVING INTO HUDSON BAY AREA OUT OF
ALASKA. THE COLDEST AIR ARRIVES INTO NORTHEASTERN MB NEAR THE END
OF THE WEEK. AT THE CURRENT TIME...THE COLDEST AIR LOOKS TO ARRIVE
INTO THE CONUS OVER THE GRT LKS AND FAR NE US...WITH THE DAKOTAS
ON THE WESTERN EDGE. MODELS NOW SHOWING A COLD FRONT MOVE THROUGH
THE NORTHERN TIER WED NIGHT...INTRODUCING A SLIGHT CHANCE FOR SOME
LIGHT SNOW ACROSS THE NORTH. ECMWF...THE COLDEST MODEL...SHOWING
SFC TEMPS APPROACHING 20 BELOW FOR THU NIGHT. HOWEVER...SFC RIDGE
AT THE TIME WILL BE OVER WESTERN DAKOTAS...INDICATING SOME
WIND/LOW LEVEL MIXING. THUS CURRENT TEMPS LOOK REASONABLE...BUT
POTENTIAL IS THERE FOR SOME VERY COLD NIGHTS AT THE END OF NEXT
WEEK. MODEL BLENDS HAVE BEEN TRENDING TEMPS DOWN ACCORDINGLY. &&

&&

.AVIATION...
IFR ST COVERING SE HALF OF FA WITH SPOTTY IFR VSBY IN BR RANDOMLY
SPREAD ACROSS FA. EXPECT MIXING TO INCREASE THIS MORNING WHICH
SHOULD ERODE BR AND STRATUS BY EARLY AFTERNOON.

&&

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

$$
VOELKER/SPEICHER


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