Forecast Discussions mentioning ACARS, received at FSL on 02/03/00

HAVE ISSUED A QUICK UPDATE TO HIGHLIGHT THE POSSIBILITY OF SOME FREEZING RAIN AND SLEET TONIGHT. REPORTS/FORECASTS OUT OF WISCONSIN INDICATE A WINTRY MIX AND SOME GLAZING DESPITE 00Z 850 MB TEMP OF -6C AT GREEN BAY. CLOSER EXAMINATION OF THE 00Z GRB RAOB SHOWS A WARM POCKET JUST ABOVE 0C AROUND 810 MB. THIS IS ALSO EVIDENT IN THE EXPERIMENTAL FSL AIRCRAFT DATA (ACARS) ACROSS NORTHERN ILLINOIS. FLOW IS WSW AROUND 40 KNOTS AT THIS LEVEL SO SUSPECT THE WARM LAYER WILL HAVE NO PROBLEM GETTING INTO WRN MI. NOT SURE HOW LONG THIS WILL LAST THOUGH AS IT IS ALSO QUITE DRY BETWEEN 850 AND 700 MB. THIS MAY JUST ACT TO COOL THE ENTIRE SOUNDING BACK DOWN BELOW FREEZING AFTER 1-2 HOURS OF PCPN. COORD WITH MILWAUKEE NWS OFFICE INDICATES PCPN HAS A CONVECTIVE NATURE SO WE COULD SEE A BRIEF PERIOD OF MDT FREEZING RAIN WITH BAND CURRENTLY CROSSING THE LAKE.

.GRR...NONE. MEADE

IR/WV IMAGRY INDICATING LOW OFF CA CST ELONGATING AND TAPPING ADDITIONAL MOISTURE ALG SE QUADRANT. ACARS/AVN SIMILAR WITH INTENSITY OF JET LIFTING OUT OF LOW THAT STREAMS N THEN ARCHES W ACRS NRN OREGON/CENTRAL WA. VIS PIC SHOWING SOME ENHANCEMENT IN THE SLY FLOW YET DEVLOPING SFC ELY FLOW DRYING OUT LOWER LYRS. THUS XPCT TO SEE INCRG HIGH CLOUDS IN THIS WLY FLOW ALF THRU THU. IN SHORT TERM WILL ADD MORE WIND TO THU FORECAST WITH MM5 SHOWING GAP WINDS THRU THE PASSES EXTENDING CLEAR TO THE COAST THROUGH FRI NIGHT. IN ADDITION SEA LEVEL PRESSURES OVER THE OKANOGAN ARE RUNNING ABOUT 2-3MB HIGHER THAN ETA AT 18Z WHICH IS BY ABOUT 2-3MBS. AS WELL, CONSIDERABLE SUBSIDENCE AND COMPRESSIONAL HEATING TO FORCE TEMPS UP ABOVE 50 MANY AREAS THU. 85H TEMPS WITH LOWER 5H HEIGHTS FRI TO ALLOW FOR SLIGHT DCRS IN TEMPS FOR FRI. IN THE LONGER RANGE POSN OF REX BLOCK SHIFTING SLIGHTLY E - YET EFFECTIVELY KEEPING MOST ENERGY SOUTH IN THE SRN BRANCH OF THE SPLIT FLOW THRU FRI NIGHT. HOWEVER AS MENTIONED EARLIER A SECONDARY LOW WILL DEVELOP OFF CA COAST FRI THAT ROTATES NORTH AND WEAKENS IN RESPONSE TO THIS REX BLOCK. YET WITH THE MODEL SHOWING THAT RIDGE AXIS TO SLIP E SAT...DOOR COULD OPEN FOR SOME MOISTURE TO MOVE N INTO WRN WA SAT/SUN. NOGAPS/MRF IN BETTER AGREEMENT WITH THIS SOLUTION...AS DOES THE GLOBAL CANADIAN MDL. IN DISCUSSION WITH THE CANADIANS/PDX WILL ADD MENTION OF SHOWERS TO EXTENDED SAT/SUN. QUERCIAGROSSA

UIL 0011 SEA 0011 OLM 0011

.KATX...VCP21/CSR21...OPERATIONAL...

.SEW...SMALL CRAFT ADVISORY W ENTRANCE STRAIT... SMALL CRAFT ADVISORY COAST FOR HEAVY SWELL...

SATELLITE IMAGERY SHOWS UPPER LEVEL BLOCK ALONG WEST COAST WITH HIGH AMPLITUDE RIDGE ALONG PACIFIC NORTHWEST AND BRITISH COLUMBIA COASTLINE WITH A CUT OFF LOW SPINNING OFF CALIFORNIA COAST. 06Z SURFACE ANALYSIS HAS SURFACE HIGH PRES OVER EASTERN WASHINGTON AND SURFACE PRES HAVE RISEN RAPIDLY EAST OF THE CASCADES IN THE LAST FEW HOURS. OFFSHORE PRESSURE GRADIENTS INCREASING WITH SEA-EAT NOW -8.7 MB. TWO LATEST ACARS SOUNDINGS OVER KSEA BOTH HAVE FLOW REVERSAL AROUND 700 MB WHICH AGREES WITH THE MODEL SOUNDINGS. THIS BRINGS UP THE POSSIBILITY OF A MOUNTAIN WAVE SURFACING THIS MORNING ALONG THE WEST SLOPES OF THE CASCADES BUT MODELS SHOW FLOW REVERSAL DISSIPATING 12-18Z AND SURFACE PRESSURE GRADIENT NOT QUITE STRONG ENOUGH. WILL GO VERY WINDY ALONG WEST SLOPES AND CASCADE FOOTHILLS IN THE ZONES. WITH THE STRONG OFFSHORE FLOW DEVELOPING WARM DAY IN STORE FOR WESTERN WASHINGTON WITH MAX TEMPS 5 TO 10 DEGREES ABOVE NORMAL. HIGH LEVEL MOISTURE ASSOCIATED WITH CUT OFF LOW MOVING NORTHWARD OVER THE AREA TODAY BUT STILL PLENTY OF SUNSHINE. CUT OFF LOW GETS EJECTED NORTHWARD FRIDAY AS ANOTHER LOW MOVES IN FROM THE WEST OFF THE CALIFORNIA COAST TO TAKE ITS PLACE. STRONG OFFSHORE FLOW AT THE SURFACE WILL KEEP THE LOW LEVELS DRY AND WITH CUTOFF LOW MOVING INTO THE RIDGE DONT EXPECT MUCH OTHER THAN SOME HIGH CLOUDS OVER WESTERN WASHINGTON BY THE TIME THE LOW MAKES ITS WAY UP THE COAST FRIDAY. .EXTENDED...NEXT LOW FOLLOWING THE SAME PATH FOR SATURDAY A LITTLE STRONGER. WILL KEEP CHANCE OF SHOWERS IN THE FORECAST FOR SATURDAY FOR THE SOUTH PART. DIFFERENCES IN THE EXTENDED MODELS THIS MORNING HAVE TO DO WITH THE PLACEMENT OF THE UPPER LEVEL RIDGE. MRF AND EURO SHIFT THE RIDGE AXIS TO THE EAST OVER THE ROCKIES FOR THE WEEKEND WHILE THE CANADIAN MODEL LEAVES THE RIDGE AXIS ALONG THE COAST. GIVEN THE HIGH AMPLITUDE OF THE RIDGE AND THE STRONGER THAN FORECAST UPPER LEVEL TROUGH JUST WEST OF THE DATELINE WILL GO WITH THE CANADIAN MODEL AS FAR AS WHERE THE RIDGE AXIS WILL BE. THIS LEADS TO A SIMILAR SITUATION AS THE NEXT TWO DAYS WITH VARIABLE CLOUDINESS SUNDAY AS WHAT IS LEFT OF THE NEXT LOW MOVES OVER THE AREA. YET ANOTHER LOW MOVING INTO POSITION OFF THE CALIFORNIA COAST MONDAY. SURFACE HIGH PRES EAST OF THE CASCADES MONDAY GIVING OFFSHORE FLOW AT THE SURFACE. FELTON

UIL 001 SEA 001 OLM 001

.KATX...VCP21/CSR21...OPERATIONAL...

.SEW...GALE WARNING W ENTRANCE STRAIT... SMALL CRAFT ADVISORY COAST AND PUGET SOUND AND HOOD CANAL...