000
FXUS63 KLOT 152340
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
640 PM CDT MON MAR 15 2010
.DISCUSSION...
316 PM CDT
TONIGHT...THE CLOUDS WILL DECREASE. SOME DRIER AIR WAS MOVING
INTO THE NORTHERN ILLINOIS. THIS WAS SEEN ON THE SURFACE DATA.
THE VISIBLE SATELLITE IMAGERY SHOWS A CLEARING SKY THIS AFTERNOON.
SOME LIGHT FOG MAY DEVELOP LATE TONIGHT. WE WILL NOT FORECAST FOG
AT THIS TIME. THE FOG MAY BE PATCHY AT BEST. THE EVENING SHIFT MAY
UPDATE LATER THIS EVENING.
TUESDAY THROUGH WEDNESDAY...A WEAK 500 MB TROUGH IS FORECAST TO
MOVE THROUGH TUESDAY NIGHT. WE USED THE ECMWF MODELS FOR THE
FORECAST OF TROUGH MOVEMENT. THE SHOWERS MAY OCCUR WEST OF
INTERSTATE 39. SO WE WILL ADD A CHANCE OF SHOWERS IN OUR WESTERN
COUNTIES. THE HIGH TEMPERATURES ARE EXPECTED TO BE IN THE UPPER
50S. A LARGE HIGH IS EXPECTED TO MOVE SOUTH FROM THE NORTHERN
PLAINS TO TEXAS BY THURSDAY MORNING.
THURSDAY THROUGH MONDAY...THE ECMWF AND GFS MODELS ARE FORECASTING
A COLD FRONT WILL MOVE THROUGH NORTHERN ILLINOIS FRIDAY AND
FRIDAY EVENING. THEN A LOW WILL DEVELOP IN TEXAS FRIDAY NIGHT AND
WILL MOVE INTO ILLINOIS BY FRIDAY. THE MODELS ARE NOT CONSISTENT
IN THE FORECAST TRACK OF THE LOW. SO WE WILL FORECAST RAIN SHOWERS
FOR NOW AND WAIT UNTIL WE GET MORE CONSISTENT FORECASTS FROM THE
MODELS.
&&
.AVIATION...
00Z TAFS...CIGS ONLY FORECAST CONCERN THIS PERIOD. MVFR CIGS
CONTINUE TO SLOWLY LIFT TO 3KFT OR BETTER LATE THIS AFTERNOON.
CLEARING LINE SLOWLY PUSHING SOUTH ACROSS FAR NORTHEAST IL AND
HAVE THIS ROUGHLY TIMED THRU RFD/DPA/ORD BY 02Z...MDW/GYY BY 03Z.
CONCERNED THIS MAY SLOW SOME WITH SUNSET BUT WILL MONITOR TRENDS
THRU THE EVENING. OTHERWISE...SOME THIN CIRRUS TONIGHT AND SOME
MID CLOUDS TUESDAY AFTERNOON/EVENING. NORTHEAST WINDS 10KTS OR
LESS WILL SLOWLY DIMINISH THRU THE EVENING TO 5KTS OR LESS
OVERNIGHT. SOME LOCATIONS MAY DROP OFF TO VRB OR CALM. AND WITH
THE LIGHTER WINDS AND CLEARING SKIES...COULD BE SOME GROUND FOG
IN THE TYPICAL LOCATIONS BY MORNING. CMS
&&
.MARINE...
304 PM CDT
LIGHT NORTHERLY FLOW WILL PERSIST OVER THE LAKE DURING THE NEXT
COUPLE OF DAYS AS A LOW PRESSURE SYSTEM DEPARTS THE ATLANTIC
COAST AND A BROAD RIDGE BUILDS OVER THE CENTRAL UNITED STATES.
WAVES ON THE SOUTH HALF SHOULD NOT BE A PROBLEM DESPITE THE LONG
NORTHERLY FETCH...MAINLY DUE TO THE LIGHT WINDS WHICH WILL
DIMINISH EVEN MORE OVER THE NEXT DAY...AND THE PERSISTENT
INVERSION SET UP BY THE RELATIVE WARMTH OF THE AIR OVER THE VERY
COLD LAKE.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
