Forecast Discussions mentioning ACARS, received at FSL on 08/18/99

AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
AFDCAE 135 PM EDT TUE AUG 17 1999

UPDATE... DESPITE CAP EVIDENT ON ACARS AND GOES DERIVED SOUNDINGS...SCT SH/TSRA ALREADY DEVLPNG ACROSS THE REGION. SLIGHTLY HIGHER THAN EXPECTED SFC TEMPS/TDS AND LOW LVL MOIST CONVG COMBINING TO REQUIRE SCT POPS. WITH DRY AIR ALOFT...ONE OR TWO OF THE STRONGER CELLS COULD PRODUCE STG WIND GUSTS OR HAIL. LATEST GOES WINDEX IN THE 50 TO 60 KT RANGE. WILL ISSUE SPS.

PREV DISC... FCST QUESTION IS WHETHER POP WARRANTED FOR THIS AFT. MID LEVEL CAP EVIDENT ON 12Z GSO/MHX SOUNDINGS (FFC/CHS SOUNDINGS NOT AVBL)...CAE GOES DERIVED SOUNDINGS AND ON CAE ACARS SOUNDING. WEAK NVA AND UPPER CONVERGENT FLOW ALSO APPARENT ON VAPOR IMAGERY. HOWEVER...MODELS AND SOUNDING MANIPULATION WITH SHARP PROGRAM INDICATE THAT DIURNAL HEATING AND ANY SFC CONVERGENCE COULD BARELY BREAK CAP...WITH DECENT INSTABILITY VALUES AND DRY AIR ALOFT. LATEST LAPS INDICATES SOME SFC CONV...ALTHOUGH VERY WEAK FLOW. 12Z RUC INDICATES SOME SFC MOIST CONV AND SOME PCPN FOR THIS AFT. GIVEN SUMMER CLIMO AND GIVEN AT LEAST SOME POTENTIAL FOR AN ISOLATED STRONG TSRA...WOULDNT HURT TO THROW IN SMALL (20) POP. SOUNDING INDICATIONS...PLUS TEMP TRENDS THIS MORNING BEING IN LINE WITH LAMP GUIDANCE...SHOW MAX TEMP FCST IN THE MID 90S STILL LOOKS FINE. APPEARS TDS WILL ALLOW FOR MARGINAL HEAT INDEX VALUES... SO WILL CONTINUE HEAT ADVISORY.

.CAE...HEAT ADVISORY THIS AFTERNOON SCZ015-016-018-020>022-025>31-035>038-041 GAZ040-063>065-077.

MILLER

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
AFDRAP 800 PM MDT TUE AUG 17 1999

THE SFC TROUGH IS NOW INTO CENTRAL SD...EXTENDING SWWD THROUGH WRN NE. WEAK SHWR/TSTM ACTVTY CONTS OVER TRIPP COUNTY THIS EVENING...BUT IT IS EXPCTD TO DISSIPATE SHORTLY. HIGH PRESS OVER THE NRN PLAINS WILL PRODUCE DRY/MILD CONDITIONS FOR WED. AS MENTIONED IN THE PREV DISCN THE NEXT TROUGH IS FORECAST TO MOVE INTO THE NORTHERN HIGH PLAINS ON THU...LIKELY PRODUCING SOME TSTMS OVER NE WY. JUST RECEIVED NOTIFICATION OF AN AIRCRAFT ACCIDENT IN NEWCASTLE WY LATE THIS AFTERNOON. WILL ISSUE AN OAV.

.UNR...NONE.

CARPENTER

AREA FORECAST DISCUSSION
NWS COLUMBIA SC
AFDCAE 1031 AM EDT WED AUG 18 1999

LOOKING AT AREA NWS MORNING SOUNDINGS...GOES DERIVED...ACARS...AND RUC FCST SOUNDINGS...APPEARS MID LEVEL CAP NOT AS PRONOUNCED AS YESTERDAY. LOW LEVEL MOISTURE STILL PRESENT AT CHS/MHX WHILE GSO AND FFC HAVE DRIED OUT CONSIDERABLY AT LOW LEVELS...INDICATIVE OF DOWNSLOPE EFFECT. LATEST TEMPS/TDS ALSO REFLECT DOWNSLOPE EFFECT WITH GSP/CLT WARMER/DRIER. LOOKING AT BUFKIT...AND PLAYING AROUND WITH INTERACTIVE SKEW-T AND SHARP...APPEARS CONVECTIVE INDICES NOT QUITE AS HIGH AS YESTERDAY. LATEST SFC ANLYS PLACES SFC TROF/MOIST CONVG ACROSS THE CWA. ALSO...LATEST RUC INDICATES WEAK VORT SLOWLY MOVG S ACROSS THE CWA TOD. RUC HANDLED YESTERDAYS CONVECTION WELL...AND KEEPS TODAYS PCPN ACTIVITY ACROSS THE S HALF OF THE STATE WITH THESE FEATURES. THINK ISO POP FINE FOR THE NORTH BUT WILL RAISE SOUTH POP TO 30. FCST TEMPS LOOK FINE. DOWNSLOPE EFFECT AND MIXING OF SLIGHTLY DRIER AIR WILL ALLOW LOWER TDS TODAY...ESPECIALLY NORTH. BUT HIGH MAX TEMPS WILL STILL ALLOW HEAT INDICES TO APPROACH MARGINAL CRITERIA FOR THE NORTH. SO...WILL KEEP HEAT ADVISORY IN PLACE ALL CWA.

.CAE...HEAT ADVISORY THIS AFTERNOON SCZ015-016-018-020>022-025>031-035>037-041 GAZ040-063>065-077.

MILLER