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000
FXUS63 KGID 101152
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
552 AM CST WED FEB 10 2010

.AVIATION...12Z KGRI TAF. RELATIVELY QUIET WEATHER EXPECTED
TODAY. WINDS WILL BE LIGHT AND VARIABLE EARLY THIS MORNING AND
THEN BECOME SOUTHERLY BY LATE MORNING. LOW CLOUDS ARE ADVANCING
NORTHEAST ACROSS KANSAS AND SHOULD REACH KGRI AROUND 21 TO 22Z.
THE CEILINGS WILL THEN PROGRESSIVELY LOWER THROUGH THE EVENING
HOURS AND VISIBILITIES COULD ALSO BEGIN TO DROP OFF DURING THE
OVERNIGHT PERIOD. LIGHT FREEZING DRIZZLE MAY ALSO BE
POSSIBLE...BUT HAVE LEFT OUT OF THE TAF FOR NOW. THE FREEZING
DRIZZLE MAY NEED TO BE ADDED IF CONFIDENCE INCREASES.

&&

.PREV DISCUSSION... /ISSUED 418 AM CST WED FEB 10 2010/

DISCUSSION...MAIN FORECAST CONCERN IS THE POTENTIAL FOR FOG AND
SOME PATCHY LIGHT FREEZING DRIZZLE TONIGHT INTO THURSDAY MORNING.

ELONGATED RIDGE OF SURFACE HIGH PRESSURE EXTENDED FROM EASTERN
MANITOBA/WESTERN ONTARIO SOUTH THROUGH EASTERN TX EARLY THIS
MORNING. LIGHT WINDS AND MAINLY CLEAR SKIES ATTENDANT TO THE SURFACE
RIDGE WERE ALLOWING FOR GOOD RADIATIONAL COOLING ACROSS THE CWA
OVERNIGHT...WITH TEMPS HAVING DROPPED INTO THE SINGLE DIGITS IN MOST
LOCATIONS. WATER VAPOR IMAGERY REVEALED A NORTHWEST FLOW ALOFT IN
PLACE ACROSS THE FORECAST AREA...WITH A WEAK EMBEDDED RIPPLE
DROPPING SOUTHEAST THROUGH NORTHEAST WY/WESTERN SD AND A TRAILING
SLIGHTLY STRONGER SHORTWAVE SINKING THROUGH EASTERN MT. A FEW HIGH
CLOUDS WERE PUSHING INTO NORTHWEST NE AHEAD OF THE LEAD WAVE. A
CLOSED LOW WAS SPINNING OFF THE SOUTHERN CA COAST...WITH HIGH
CLOUDS ON THE INCREASE OVER THE SOUTHERN ROCKIES/PLAINS AS THIS
SYSTEM ADVECTED IN PACIFIC MOISTURE. BROAD SHIELD OF STRATUS HAS
BEEN STEADILY LIFTING NORTHEAST OUT OF NM AND THE TX PANHANDLE
THROUGH SOUTHWEST KS/EASTERN CO OVERNIGHT IN A ZONE OF ISENTROPIC
LIFT/WAA. SOME PATCHY STRATUS NORTHEAST OF THE CWA OVER NORTH
CENTRAL/NORTHEAST NE HAS BEEN DROPPING A FEW FLURRIES...BUT THIS
STRATUS CONTINUES TO DRIFT EAST/SOUTHEAST AND SHOULD JUST GRAZE
THE FAR NORTHEAST CWA BORDER.

THE SURFACE RIDGE WILL SHIFT EAST OF THE AREA TODAY...WITH SOUTHERLY
RETURN FLOW ENSUING. ISENTROPIC LIFT/WAA WILL CONTINUE IN THIS
REGIME...ALLOWING THE STRATUS DECK CURRENTLY TO OUR SOUTHWEST TO
CONTINUE TO LIFT NORTHEAST THROUGH THE DAY...EVENTUALLY ENCOMPASSING
MOST OF THE CWA BY LATE AFTERNOON. H85 TEMPS WARM CONSIDERABLY FROM
YESTERDAY...BUT DUE TO SHALLOWER MIXING AND THE INCREASING LOW
CLOUDS THROUGH THE DAY...HIGHS WILL END UP FAIRLY SIMILAR TO
YESTERDAY IN MOST SPOTS. THIS EVENING...THE DEPTH OF THE LOW-LEVEL
MOIST LAYER INCREASES AS THE BOUNDARY LAYER COOLS AND ISENTROPIC
LIFT PERSISTS AS INDICATED ON THE 280K SURFACE. MODELS HAVE BEEN
SHOWING SOME POTENTIAL FOR FZDZ OVER THE PAST FEW NIGHTS...AND
FORECAST SOUNDINGS FROM MOST RECENT MODEL RUNS ACTUALLY LOOK A
LITTLE MORE FAVORABLE THAN THEY HAVE BEEN...INDICATING A LITTLE
DEEPER SATURATED LAYER AT LOW LEVELS. GIVEN THIS FAIRLY CONSISTENT
AND SOMEWHAT HEIGHTENED SIGNAL OF A MOIST NEAR SURFACE LAYER BENEATH
VERY DRY MID LEVELS...HAVE INSERTED SOME PATCHY FZDZ INTO THE
FORECAST FROM MID EVENING INTO THURSDAY MORNING...ALONG WITH SOME
AREAS OF FOG. KEPT THE FZDZ OUT OF THE FAR NORTHWEST WHERE THE
MOISTURE APPEARS TO BE TOO SHALLOW FOR DRIZZLE AND MORE INDICATIVE
OF FOG. SIMILAR TO PREVIOUS THINKING...NOT EXPECTING THIS TO BE A
MAJOR DEAL BY ANY MEANS...BUT THE PATCHY FZDZ AND FOG COULD CREATE A
FEW SLICK SPOTS. THE CLOUDS AND WAA WILL KEEP LOWS TONIGHT CONSIDERABLY
WARMER THAN THE PREVIOUS COUPLE OF NIGHTS...WITH LOWS FORECAST TO
FALL INTO THE TEENS TO LOWER 20S.

THE LOW-LEVEL MOISTURE SHIFTS EAST OF THE CWA BY MIDDAY
THURSDAY...WHICH SHOULD BRING AN END TO ANY FOG AND FZDZ THAT
DEVELOPS. A WEAK SHORTWAVE SLIDES THROUGH THE NORTHWEST FLOW ALOFT
THURSDAY AFTERNOON...BUT WEAK NATURE OF THE FORCING COMBINED WITH
SPARSE MOISTURE TO WORK WITH MAKES EVEN FLURRIES LOOK UNLIKELY AT
THIS POINT. TEMPERATURES WILL REBOUND ON THURSDAY...WITH HIGHS
CLIMBING BACK INTO THE 30S. ANOTHER SLIGHTLY STRONGER SHORTWAVE
DROPS SOUTHEAST THURSDAY NIGHT INTO FRIDAY MORNING. THE FORCING
WITH THIS WAVE STAYS MAINLY EAST/NORTHEAST OF THE CWA AND THUS NO
PRECIP IS EXPECTED...ALTHOUGH PERHAPS IT WILL SQUEEZE OUT A FEW
FLURRIES. IT WILL PUSH A LITTLE COOLER AIR SOUTH HOWEVER...HALTING
THE WARMING TREND ON FRIDAY EXCEPT IN THE FAR SOUTH.

A COMPACT...BUT MUCH STRONGER CLOSED MID-LEVEL CIRCULATION THEN
DROPS SOUTH THROUGH THE DAKOTAS FRIDAY NIGHT AND THEN SOUTHEAST
ALONG THE NE/IA BORDER ON SATURDAY. IT WILL FORCE A PRETTY STRONG
COLD FRONT SOUTH THROUGH THE AREA ON SATURDAY...WITH GUSTY NORTH
WINDS DRIVING STRONG CAA BEHIND THE BOUNDARY. INSERTED SOME SMALL
POPS LATE FRIDAY NIGHT AND SATURDAY ACROSS THE NORTHEAST HALF TO TWO
THIRDS OF THE AREA FOR SOME LIGHT SNOW. ALSO COOLED TEMPS SATURDAY
AND SUNDAY ALTHOUGH MAYBE NOT ENOUGH.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$