Forecast Discussions mentioning "ACARS", "MDCRS", or "AIRCRAFT" received at FSL on 01/27/02

AFTER EXAMINING THE LATEST ACARS AND RAOB SOUNDINGS TEMPERATURES LOOK TO BE ON TRACK FOR THIS AFTERNOON DUE TO A WARMER START. LATEST SFC ANALYSIS SHOWS THE HIGH ACROSS LOUISIANA WITH A WEAK LEE SIDE TROF IN EASTERN CO. THE GRADIENT BETWEEN THESE TWO FEATURES LOOKS TO BE A LITTLE STRONGER TODAY THAN YESTERDAY. WE MAY BUMP UP WINDS A CATEGORY TO REFLECT THIS.

ISC GRIDS HAVE BEEN SENT.

.ICT...NONE. COX



ONE AND A HALF MORE APRIL-LIKE DAYS ON TAP FOR CWFA, THEN AN UNSETTLED PERIOD ON THE COOL SIDE OF THE CANADIAN FRONT.

FOR TODAY TIME SECTIONS AND SATELLITE TRENDS SUGGEST JUST THIN CIRRUS WHICH SHOULD NOT IMPACT TEMPS MUCH, UNLIKE YESTERDAY MORNING'S THICK DECK. YESTERDAY FOR A CHANGE FWC #S PERFORMED PRETTY WELL TO OUR WEST. LATE EVENING ACARS SOUNDINGS AROUND 12-13C AT 900 MB WHICH WOULD YIELD WELL INTO THE 60S. BUT WE'RE NOT LIKELY TO MIX TO THAT LEVEL. WILL ADD A FEW DEGREES TO MOS BUT TRIM BACK TEMPS A CATEGORY OR SO FROM PREVIOUS FORECAST.

FRONT NOW FORECAST BY ALL MODELS TO SLIP ACROSS MUCH OF CWFA DURING MONDAY. GIVEN THE CENTRAL PRESSURE OF THE HIGH TO THE NORTH AND THAT OVER THE SOUTHEAST AND THE DEVELOPING SOUTHWEST FLOW ALOFT, WOULD PREFER THE VERY SLIGHTLY SLOWER AVN FORECAST FOR 00Z. ACTUALLY WHILE AVN WIND SHIFT IS A TAD SLOWER, ETA TEMPS WHICH OFTEN BETTER DEFINE FRONTS THAN ITS OWN WINDS STILL HAVE THE 50 DEGREE ISOTHERM NORTH OF I 88 AT 21Z. THIS SHOULD ALLOW SOUTHERN HALF OR 2/3 OF CWFA ONE MORE DAYS OF 50S. GRADIENT WOULD FAVOR A LAKE ENHANCED BREEZE DEVELOPING TO COOL OFF CHICAGO NEAR SHORE AREAS.

THERE SHOULD BE ENOUGH LOW LEVEL MOISTURE AROUND FOR SOME DRIZZLE TO DEVELOP BEHIND THE FRONT, FROM THE NORTH MONDAY AND MONDAY EVENING.

AFTER THAT THINGS REMAIN QUITE UNDECIDED BUT MAIN QUANTITATIVE PRECIPITATION THREAT APPEARS DELAYED BEYOND PREVIOUS INDICATIONS. FLOW ABOVE SHALLOW ARCTIC AIR MASS IS MUCH MORE WEST THAN SOUTH FIRST DAY OR SO AFTER FROPA AND MOISTURE APPEARS SCANT IN ALL PROGS. WITHOUT ANY WELL DEFINED IMPULSE IN THE FLOW, WOULD EXPECT LITTLE SIGNIFICANT PRECIPITATION AND WILL TRIM BACK TUESDAY.TUESDAY NIGHT POPS. STILL COULD BE A MIX OF -FZDZ/-SN ESPECIALLY NORTHERN SECTIONS, BUT ACCUMULATING SNOW UNLIKELY.

THE MEDIUM RANGE HAS ABOUT AS MANY SOLUTIONS AS MODELS. MORE IF ONE TRIES TO RECTIFY SOME APPARENT INTERNAL CONSISTENCIES. UKMET AND YESTERDAY'S ECMWF HAVE SIMILAR SOLUTIONS WITH MORE FULL LATITUDE TROUGH AND A SURFACE WAVE COMING UP ACROSS SOUTHERN IL WEDNESDAY INTO THURSDAY. AVN SHEARS OFF NORTHERN PORTION OF TROUGH AND LEAVES CLOSED LOW IN SOUTHWEST AND BRINGS OUT A MORE OPEN WAVE WEDNESDAY-THURSDAY FARTHER SOUTH AND WITH PRECIP MAINLY TO THE SOUTH.

BY WEEK'S END MODELS CONSENSUS IMPLIES A SURFACE HIGH OF HYBRID CONTINENTAL/PACIFIC ORIGIN OVER THE MID PORTION OF THE U.S. AS ZONAL FLOW ALOFT BEGINS TO TAKE OVER AGAIN. GIVEN THE HISTORY OF THE WINTER AND THE RUN TO RUN MODEL TRENDS THIS IS REASONABLE (BUT LIKE ANYTHING 6-7 DAYS OUT, FAR FROM CERTAIN). IN THAT CASE, UNLESS WE HAVE A SNOW COVER, ZONE TEMPS IN FRIDAY-SATURDAY TIME FRAME WOULD LIKELY BE CONSIDERABLY ON COLD SIDE. AT THIS TIME WILL NOT MAKE ANY ADJUSTMENTS THAT FAR OUT.

.CHI...NONE

KAPLAN