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Graphical depiction of the weather story for today.

Cloudy skies will make way for sunny conditions today as a slow moving upper level system to the east continues to pull away. With these clearing skies, temperatures will be able to rise to the 50s today. Clear skies will continue tonight before cloud cover increases once again on Tuesday as an upper level disturbance drops south into the region. As this passes through, a slight chance for showers will be possible Tuesday night, mainly across portions of west central Illinois.

000
FXUS63 KLOT 151111
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
611 AM CDT MON MAR 15 2010

.DISCUSSION...
401 AM CDT

AS WAS EXPECTED THIS PAST EVENING...THERE WERE SOME LINGERING
SCATTERED LIGHT RAIN SHOWERS OR SPRINKLES WHICH MOVED ACROSS THE
EASTERN TWO THIRDS OF THE CWA. THIS HAS SINCE ENDED WITH LATEST
RADAR TRENDS UPSTREAM SHOWING THIS MOISTURE DISSIPATING WITH ITS
WESTWARD PROGRESSION. EVEN WITH EXTENSIVE CLOUD COVER WRAPPING
CYCLONICALLY THROUGH THE CWA...DONT ANTICIPATE ANY MORE SPRINKLES
TO BE OBSERVED THIS MORNING WITH LATEST SATELLITE IMAGERY
INDICATING DRIER AIR TRYING TO MAKE ITS WAY INTO THE REGION.

TURNING TO CLOUD COVER...MOST OF THE CWA IS STILL OVERCAST THIS
MORNING WITH A FAIR AMOUNT OF EROSION OCCURRING OVER THE LAST
SEVERAL HOURS OVER PORTIONS OF WISCONSIN...EASTERN IOWA AND
NORTHWEST ILLINOIS. THIS IS ASSOCIATED WITH LARGE SCALE SUBSIDENCE
AND HEIGHT RISES ALOFT ACROSS MUCH OF THE UPPER MIDWEST. AS THIS
UPPER LEVEL RIDGE TRIES TO BUILD EAST ACROSS THE FA TODAY...IT
WILL BE RUNNING INTO THE STUBBORN UPPER LEVEL SYSTEM TO THE EAST.
THIS WILL HELP TO SLOW DOWN THE PROCESS OF FURTHER EROSION OF THIS
CLOUD DECK SOUTHEAST ACROSS THE REST OF THE CWA. ALTHOUGH IT WILL
BE SLOW...SKIES WILL CONTINUE TO SCATTER OUT BY THIS AFTERNOON
WITH SKIES BECOMING MOSTLY CLEAR BY TONIGHT. WORTHY TO NOTE IS THE
EXTENSIVE CLOUD DECK STRETCHED ACROSS MUCH OF THE CENTRAL PLAINS
THIS MORNING. WATER VAPOR IMAGERY SHOWS A COUPLE SMALLER SCALE
VORTICITY MAXIMUM SLOWLY MOVING THROUGH THE CENTRAL PLAINS. FOR
THE TIME BEING...EXPECT THIS CLOUD COVER TO REMAIN TO THE WEST.
WITH NO REAL STEERING FLOW ALOFT...THESE WEAKENING IMPULSES WILL
REMAIN IN THE CENTRAL PLAINS...FOR THE TIME BEING.

HAVE BUMPED UP HIGH TEMPS TO THE MID AND UPPER 50S ACROSS THE FA
FOR TODAY...WITH HIGHEST TEMPS BEING OBSERVED IN THE WESTERN HALF
OF THE CWA WITH MORE OF THE DAY BEING SPENT ABSORBING SOLAR
INSOLATION RATHER THAN SPENT UNDER CLOUD COVER. AFTER CLEAR SKIES
TONIGHT...CLOUD COVER WILL BEGIN TO INCREASE FROM THE NORTHWEST ON
TUESDAY AS PREVIOUSLY MENTIONED WEAK IMPULSES PHASE INTO A SHORT
WAVE TROUGH DROPPING SOUTH OUT OF CANADA. CURRENTLY THINK THAT
THIS CLOUD COVER WILL NOT MAKE MUCH PROGRESS EAST INTO THE ENTIRE
CWA...SO THE EASTERN PART OF THE CWA COULD OBSERVE ANOTHER SUNNY
DAY WITH FORECAST HIGH TEMPS IN THE UPPER 50S ON TUESDAY. DONT
ANTICIPATE MUCH IN TERMS OF PRECIPITATION...ONLY FORECASTING
SLIGHT CHANCE POPS TUESDAY NIGHT FOR OUR FAR WESTERN PART OF THE
CWA AS TROUGH AND BETTER FORCING STAY OFF TO THE WEST. ONCE THIS
WAVE DROPS SOUTH OUT OF THE AREA EARLY WEDNESDAY...UPPER LEVEL
RIDGE BUILDS BACK INTO THE REGION. SKIES CLEAR WITH TEMPS ALSO
WARMING ONCE AGAIN ON WEDNESDAY. AT THE SURFACE...RIDGE OF HIGH
PRESSURE DROPS SOUTH INTO THE SOUTHERN PLAINS. WINDS WILL BEGIN TO
BACK TO THE WEST...AND START A TREND OF WAA INTO THE CWA PAVING
THE WAY FOR A BEAUTIFUL THURSDAY.

RODRIGUEZ

&&

.AVIATION...

1200 UTC TAFS...NORTHWEST FRINGES OF STRATUS DECK FROM MASSIVE
STORM TO THE EAST CONTINUES TO BLANKET MUCH OF THE AREA WITH CIGS
DANCING RIGHT AROUND THE VFR/MVFR THRESHOLD. WRF-NAM AND TO LESSER
EXTENT GFS SHOW A TROUGH AT 925MB ROTATING THROUGH THE AREA EARLY
THIS AFTERNOON WITH A RESULTANT INCREASE IN LOWER LEVEL RH...SO
HAVE OPTED TO HANG ONTO MVFR CIGS A BIT LONGER THAN TYPICAL
DIURNAL TRENDS WOULD ARGUE FOR. SHOULD FINALLY SEE THIS CLOUD DECK
MOVE OUT FROM NW TO SE LATE THIS AFTERNOON/EARLY THIS EVENING WITH
CLEARING SKIES AND DIMINISHING WINDS TONIGHT. WET/COLD GROUND AND
NEARLY IDEAL RADIATIONAL COOLING WILL LIKELY RESULT IN SOME LIGHT
FOG DEVELOPING TONIGHT AWAY FROM URBAN HEAT AT DPA/RFD. MAV AND
MET BOTH SUGGEST GREATER THAN 60 PERCENT PROBABILITIES OF VSBYS
FALLING TO IFR OR LOWER...THOUGH MOS VSBY CAT WITH SINGLE HIGHEST
PROB IS MVFR. HAVE INTRODUCED MVFR VSBYS FOR NOW AND WILL ALLOW
LATER SHIFTS PONDER BRINGING VSBYS LOWER.

IZZI

&&

.MARINE...
255 AM CDT

NORTHERLY WINDS HAVE BEGUN TO SUBSIDE AND THIS TREND WILL CONTINUE
TODAY/TONIGHT AS EAST COAST LOW PULLS OUT TO SEA. A LARGE RIDGE OF
HIGH PRESSURE WILL BEGIN TO BULGE EASTWARD INTO THE GREAT LAKES BY
TUESDAY AND WEDNESDAY. AS THIS OCCURS THE PRESSURE GRADIENT WILL
GO LIMP AND ALLOW FOR DIURNAL LAND-SEA BREEZE CYCLE TO DOMINATE
WINDS OVER THE LAKE. RIDGE WILL SAG SOUTHWARD LATER IN THE WEEK
ALLOWING FOR A MORE ROBUST...THOUGH STILL NOT PARTICULARLY
STRONG...SOUTHWESTERLY WIND TO DEVELOP OVER THE LAKE BY THURSDAY.

IZZI

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

NWS LOT Office Area Forecast Discussion

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