Forecast Discussions mentioning ACARS, received at FSL on 07/30/99

...SYNOPSIS... A WEAK UPPER LOW WILL REMAIN OFF THE CALIFORNIA COAST THROUGH THE WEEKEND WITH WEAK DRY SOUTHWESTERLY FLOW ALOFT OVER SOUTHERN CALIFORNIA AND WEAK ONSHORE LOW LEVEL FLOW. NIGHT AND MORNING LOW COASTAL LOW CLOUDS WILL INCREASE IN COVERAGE SOME DURING THE WEEKEND WITH LESS HUMID CONDITIONS IN THE MOUNTAINS AND DESERTS. TEMPERATURES WILL REMAIN SEASONALLY WARM TO HOT.

...DISCUSSION... THE ETA TURNED OUT TO BE CORRECT IN SHOWING THE SPEED AND AMOUNT OF DRYING THAT OCCURRED TODAY...WITH A CORRESPONDING SHIFT WELL TO THE EAST OF AFTERNOON THUNDERSTORMS. UNLIKE LAST SUMMER WHEN THE ETA HAD GREAT DIFFICULTY IN FORECASTING MONSOONAL MSTR SURGES DUE TO TEETHING PROBLEMS ASSOCD WITH A NEW DATA ASSIMILATION SYS...THE ETA THIS SUMMER HAS BEEN PERFORMING VERY WELL OVR SRN CA IN HANDLING THE ARRIVAL AND DEPARTURE OF MONSOONAL MSTR INTO SRN CA... DEPTH... AMOUNT...AND TIMING. OVERALL SLIGHT SOUTHWARD SHIFT OF THE PATTERN OVR NOAM SHOULD KP MONSOONAL MSTR JUST SOUTH AND EAST OF SRN CA THRU THE WEEKEND WITH DRY SWLY FLOW ALF AND WK-MDT ONSHR LOW LVL FLOW. CHANGES IN TEMPERATURES FOR MTNS AND DESERTS THRU THE WEEKEND WL BE MAINLY DUE TO EFFECTS OF DECRD MSTR (I.E. ...HIGHER MAXES...LWR MINS). HIGH TEMPERATURES W OF THE MTNS WL TREND A LTL LWR DUE TO SLIGHT INCR IN ONSHR FLOW AND RETURN OF CSTL STRATUS. OTHERWISE... ONLY MINOR DAY TO DAY CHANGES EXPECTED THROUGH THE WEEKEND.

MARINE LYR...COAMPS...RUC...AND 18Z ETA ALL FORECAST A WK EDDY OVR THE CSTL WATERS LATE TONIGHT. SYNOPTIC SUPPORT IS SUFFICIENT FOR A WK EDDY TO FORM TONIGHT...SO MDL FORECASTS APPEAR REASONABLE. SYNOPTIC SUPPORT FOR AN EDDY IS STRONGER FRI NIGHT...THEN A LTL LESS FOR SAT NIGHT. CURRENT PATCHY WORDING IN FORECAST FOR CSTL LOW CLOUDS FOR TONIGHT LOOKS OKAY AS LINGERING EFFECTS OF MONSOONAL MSTR MAY SLOW REDEVELOPMENT OF STRATUS. AREAS WORDING LOOKS GOOD FOR FRI NIGHT AS WELL AS STRATUS FIELD SHOULD BE MORE EXTENSIVE FRI NIGHT THAN TONIGHT. EVENING ACARS SOUNDINGS AND RAOBS SHOW THE BASE OF A STRONG MARINE INVERSION BETWEEN 1000 AND 1500 FT...SUFFICIENT FOR CSTL STRATUS TO REACH CSTL PLAIN AND CSTL VLYS...BUT NOT INLAND VLYS...AGAIN COVERED IN CURRENT ZONES. NO UPDATES PLANNED.

SAN 0000

.SAN...NONE.

MARTIN

LATEST SATELLITE IMAGE DEPICTS KY IS PRETTY MUCH CLOUD FREE EXCEPT FOR THE EXTREME EAST WHERE THEY ARE GETTING SOME DEBRIS CLOUD FROM A COMPLEX IN WV. WITH THE CLEAR SKIES THIS SHOULD LEAD US TO ANOTHER HOT AND STEAMY DAY ACROSS THE CWFA. HEAT INDICES YESTERDAY RANGED FROM 105 TO 110 OVER HEAT ADVISORY AREA WITH TEMPERATURES AROUND THE CENTURY MARK. WOULD NOT EXPECT MUCH CHANGE TODAY AS THE UPPER LEVEL RIDGE AXIS CENTERS ITSELF OVER CENTRAL KY. MEANWHILE...03Z ACARS SOUNDING FROM SDF SHOWS 700 MB RIGHT AROUND 12 DEG C AND 850 MB TEMPERATURES AROUND 26 DEG C. THIS SPELLS OUT TO BE VERY LITTLE CU DEVELOPMENT TODAY WITH POSSIBLY AS WARM OR WARMER TEMPERATURES THAN YESTERDAY DEPENDING ON MUCH THE 850 MB TEMPERATURES CHANGE DURING THE COURSE OF THE MORNING. WE BUMPED UP HIGHS A CATEGORY EVERYWHERE THIS AFTERNOON AND MENTIONED A HEAT ADVISORY IN ALL AREAS. THE ETA HANDLED THE CAPPING AND WARMER TEMPERATURES YESTERDAY...SO WE FOLLOWED IT CLOSELY TO REPRESENT TODAY'S SITUATION. SEVERAL PLACES SHOULD TIE OR POSSIBLY BREAK A RECORD TODAY...BUT THIS WILL BE DEPENDENT ON HOW LOW THE DEWPOINTS GO. FOR NOW WE WILL SHOOT FOR HEAT INDICES AROUND 110 IN THE LOUISVILLE AND BWG AREAS TO 105 TO 110 ELSEWHERE.

TONIGHT AND TOMORROW...THE ETA/NGM SHOW ANOTHER WEAK SHORTWAVE RIDING OVER THE RIDGE AND MOVING INTO CENTRAL INDIANA BY TOMORROW EVENING. A PIECE OF THIS WAVE TRIES TO ROTATE OUT AHEAD OF THIS MAINWAVE LATE TONIGHT AND TOMORROW MORNING...BUT WITH CONTINUED STRONG CAPPING OVER THE AREA THE CONVECTION WILL MOST LIKELY BE ISOLATED. THUS WE HAVE ELECTED TO KEEP THE MENTION OF POPS OUT EVEN THOUGH THE NGM TRIES TO INTRODUCE THEM. WITH SOME MOISTURE RETURN EXPECTED TOMORROW TEMPERATURES MIGHT BE A TAD LOWER BUT HEAT INDICES SHOULD STILL EXCEED CRITERIA.

.SDF...HEAT ADVISORY FOR ALL OF CENTRAL KY AND SOUTH CENTRAL INDIANA.

COX

LATEST SATELLITE IMAGE DEPICTS KY IS PRETTY MUCH CLOUD FREE EXCEPT FOR THE EXTREME EAST WHERE THEY ARE GETTING SOME DEBRIS CLOUD FROM A COMPLEX IN WV. WITH THE CLEAR SKIES THIS SHOULD LEAD US TO ANOTHER HOT AND STEAMY DAY ACROSS THE CWFA. HEAT INDICES YESTERDAY RANGED FROM 105 TO 110 OVER HEAT ADVISORY AREA WITH TEMPERATURES AROUND THE CENTURY MARK. WOULD NOT EXPECT MUCH CHANGE TODAY AS THE UPPER LEVEL RIDGE AXIS CENTERS ITSELF OVER CENTRAL KY. MEANWHILE...03Z ACARS SOUNDING FROM SDF SHOWS 700 MB RIGHT AROUND 12 DEG C AND 850 MB TEMPERATURES AROUND 26 DEG C. THIS SPELLS OUT TO BE VERY LITTLE CU DEVELOPMENT TODAY WITH POSSIBLY AS WARM OR WARMER TEMPERATURES THAN YESTERDAY DEPENDING ON MUCH THE 850 MB TEMPERATURES CHANGE DURING THE COURSE OF THE MORNING. WE BUMPED UP HIGHS A CATEGORY EVERYWHERE THIS AFTERNOON AND MENTIONED A HEAT ADVISORY IN ALL AREAS. THE ETA HANDLED THE CAPPING AND WARMER TEMPERATURES YESTERDAY...SO WE FOLLOWED IT CLOSELY TO REPRESENT TODAY'S SITUATION. SEVERAL PLACES SHOULD TIE OR POSSIBLY BREAK A RECORD TODAY...BUT THIS WILL BE DEPENDENT ON HOW LOW THE DEWPOINTS GO. FOR NOW WE WILL SHOOT FOR HEAT INDICES AROUND 110 IN THE LOUISVILLE AND BWG AREAS TO 105 TO 110 ELSEWHERE.

TONIGHT AND TOMORROW...THE ETA/NGM SHOW ANOTHER WEAK SHORTWAVE RIDING OVER THE RIDGE AND MOVING INTO CENTRAL INDIANA BY TOMORROW EVENING. A PIECE OF THIS WAVE TRIES TO ROTATE OUT AHEAD OF THIS MAINWAVE LATE TONIGHT AND TOMORROW MORNING...BUT WITH CONTINUED STRONG CAPPING OVER THE AREA THE CONVECTION WILL MOST LIKELY BE ISOLATED. THUS WE HAVE ELECTED TO KEEP THE MENTION OF POPS OUT EVEN THOUGH THE NGM TRIES TO INTRODUCE THEM. WITH SOME MOISTURE RETURN EXPECTED TOMORROW TEMPERATURES MIGHT BE A TAD LOWER BUT HEAT INDICES SHOULD STILL EXCEED CRITERIA.

.SDF...HEAT ADVISORY FOR ALL OF CENTRAL KY AND SOUTH CENTRAL INDIANA.

COX