AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 140 PM CST TUE MAR 23 1999 MAIN WEATHER CONCERNS FOR TONIGHT WILL BE CLEARING IN SRN PARTS OF ILX FA AND APPROACHING COLD FRONT FROM THE NORTH. LOW CLOUDS ROUGHLY SOUTH OF A UIN-HUF LINE HAVE BEEN RATHER PERSISTANT IN CYCLONIC FLOW ACRS MO/SRN IL. A WEAK SFC WAVE NEAR THE MO BOOTHEEL IS EXPECTED TO CONTINUE WEAKENING AS IT MOVES THROUGH THE OH VALLEY. LOW LVL RIDGING WILL THEN MAKE ITS WAY INTO SRN IL RESULTING IN CLEARING. MOST OF THE MODELS HANG ON TO LOW LEVEL MOISTURE UNTL LATE EVENING/OVERNIGHT. HOWEVER...15Z RUC 850 MB RH PROFILE HAS THE BEST HANDLE ON THE SITUATION...AND CLEARS THINGS OUT EARLY THIS EVENING. OVERNIGHT...EXPECT PATCHY FOG TO DEVELOP IN SE IL AS A RESULT OF MOISTURE TRAPPED VERY NEAR THE SFC DUE TO CLOUDS MUCH OF TODAY...EVENTUAL CLEARING AND LIGHT WIND. REST OF ILX FA WILL BE CLEAR TONIGHT WITH TEMPS IN THE LOWER 30S. A COLD FRONT CURRENTLY FROM THE NRN PLAINS TO ERN LK SUP WILL RAPIDLY PUSH SOUTH INTO IL TONIGHT. THIS FRONT WILL ONLY SWITCH THE WINDS TO THE NORTH AND WILL GIVE US COOLER TEMPS WED NITE AND THURSDAY. PIA 31/51 00 SPI 32/53 00 DEC 32/52 00 CMI 31/52 00 LWV 34/56 00 MILLER NNNN il AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DES MOINES IA 345 PM CST MON MAR 22 1999 MAIN CONCERN IS SNOW - WHERE AND HOW MUCH. LTST RDR LOOPS SHOW AREA MOVG SEWRD. GLANCE AT PROFLR NETWRK VORTCY SHOWS SLGHT TURN SWRD WHICH STLT LOOPS SPT. WL CUT BACK ANY MNTN OF ACCUMULATIONS JUST WORD LTL IF ANY. LOOK AT LTST RUC FCSTS LESSENING OF LIFT INVOF MO/IA BRDR. TEMPS LOOKING GD ATTM. .DSM...NONE FORSTER NNNN ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 155 PM CST TUE MAR 23 1999 ENHANCED CLOUDS...DEEPER MSTR HAVE MOVED EAST OF FA PER IR/WVAPOR. KPAH 88D SHOWS DIMINISHING SHRA ACTIVITY WRN KY...XTRM SE MO. RUC INDICATES MID-LVL THERMAL TROF (EVIDENT ON H5 12Z ANALYSIS) MOVED EAST REDUCING THE THREAT OF THUNDER. MODELS IN DECENT AGREEMENT. WILL KEEP SCT SHRA MENTION FOR SRN 1/4 OF FA THIS EVE AS SECONDARY WK S/WV ROTATES THRU...AND SLIGHTLY DEEPER MSTR PERSISTS IN THIS AREA. OTHERWISE WIND PROFILERS FROM WINCHESTER IL AND BLOOMFIELD MO INDICATE H8 BOUNDARY ACROSS MO AND IL. WK FLOW ENE NORTH OF...SW SOUTH OF 850MB FRONT...THUS CLOUDS WILL BE SLOW TO CLEAR. CLEARING MAY REACH NORTH COUNTIES BY MORNING. EXPECT BREAK UP IN THE CLOUDS WEDNESDAY AS NORTHERLY LOW TROP FLOW DRIVES DRIER AIR SOUTH. GUIDANCE NUMBERS ON TRACK. LOOKS DRY FOR MUCH OF THE REST OF THE WEEK. .PAH...NONE. NOLES NNNN ky SYNOPTIC EXPLANATION/FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON 1010 AM EST TUE MAR 23,1999 MRNG DATA AT THE SFC INDICATE WEAK FRNTL WAVE NEAR THE MO BOOTHEEL WITH WMFNT XTNDG E ALONG THE KY-TN BORDER TO NEAR SW VA. MEANWHILE HI PRES OVR THE MID-ATLC REGION EASING OUT TO THE E. ASSOC PCP N OF THE WAVE AND WMFNT A LTL MORE WIDESPREAD THAN 12Z RUC SHOWS. HOWEVER IN ANY EVENT 12Z RUC FCSTS MEASUREABLE MOVING INTO THE FAR WRN ZNS BY LATE AFTN OR EVNG WHILE INCRSG CLDS WILL BE THE RULE ELSW THIS AFTN. OTW FEW CHGS TO PREV FCST IF ANY. THAT'S IT FOR NOW...LATER. .WBC...NONE. PAP EFFECTIVE 9 AM EST MONDAY MARCH 29 1999...THE SYNOPTIC EXPLANATION/ FORECAST DISCUSSION ISSUED UNDER WMO HEADER FXUS71 KLWX AND AFOS HEADER WBCSFDWBC WILL BE REPLACED BY AN AREA FORECAST DISCUSSION. THE AREA FORECAST DISCUSSION WILL BE FOUND UNDER WMO HEADER FXUS61 KLWX AND AFOS HEADER WBCAFDLWX. NNNN md MISSOURI STATE FORECAST DISCUSSION NATIONAL WEATHER SERVICE ST LOUIS MO 400 AM CST TUE MAR 23 1999 PCPN CONTS OVR MAINLY ERN MO AHD OF SHRTWV PUSHING SEWD THRU W CNTRL MO...AND IN AREA OF STG 850 MB WAA AND CNVG ON NOSE OF 30-40KT SLY LOW LVL JET PUSHING INTO SRN MO WHICH IS DEPICTED WELL BY 00Z ETA MDL. ALL THREE MDLS PUSH MOST OF THE PCPN E OF MO BY THIS AFTN AS SHRTWV WKNS AND AREA OF WAA MOVS E OF THE STATE AS 850 MB TROF/INVERTED SFC TROF MOVS INTO SERN MO BY THIS EVNG. WL MENTION MAINLY MRNG PCPN IN ZNS WITH ETA HINTING AT CLRG IN NRN MO ALREADY THIS AFTN AS NRN PLAINS HI BGNS TO BUILD SWD. WL FCST LGT SLEET AND SN OVR NERN ZN WITH RUC SOUNDING SHOWING TEMPS BELOW ZERO AT ALL LVLS ABV THE SFC THIS MRNG...ALTHOUGH IT APRS THAT MOST OF THE PCPN HAS REMAINED S OF THE NRN TIER COUNTIES WITH LOW LYRS REMAINING DRY OVR NERN MO W CNTRL IL. GUIDANCE TEMPS APR A LTL WRM TDA OVR E CNTRL SERN ZNS WITH CONT CLD CVR AND AT LEAST MRNG PCPN...BUT LOOK REASONABLE LTR PERIODS. .STL...NONE GKS NNNN mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 919 AM MST TUE MAR 23 1999 NO UPDATES THIS PACKAGE. LATEST RUC RUN FOR 23/12Z IS IN LINE WITH THE FORECAST FOR THE FIRST PERIOD. WILL DEAL WITH THE LATER PERIODS IN THE AFTERNOON PACKAGE. NO NEED TO FIX AN ALREADY GOOD PRODUCT. CHB BIL UU 063/035 065/037 070 52000 LVM .. 063/032 064/... ... 52000 HDN .. 067/033 069/... ... 52000 MLS .. 064/034 066/035 ... 52000 4BQ .. 064/032 065/... ... 52000 BHK .. 061/030 063/... ... 52000 SHR UU 064/031 066/033 070 52000 NNNN mt WEST TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 402 AM CST TUE MAR 23 1999 09Z SFC ANALYSIS INDICATED LOW PRES SE OF KSPS WITH A CD FNT EXTENDING NR A KMLC-KABI-KMAF-KCNM LN. THE DRY LN HAD BACKED UP INTO THE PECOS RVR VLY. FNT SHOULD CONT SWRD INTO MUCH OF WTX FCST AREA TDA AND LOOKS TO BANK UP AGAINST THE MTNS BY THIS AFTN. DECENT LOW LVL MSTR IN PLACE AHD OF THE FNT OVR SERN PTNS AND THE 00Z MM5 MODEL INDICATES AROUND 1000 J/KG OF CAPE PSBL ACRS THIS AREA BY THIS AFTN. FCST SOUNDINGS FM 06Z RUC AND 00Z ETA SUGGEST AMS MAY BE CAPPED BUT WITH THE BOUNDARY IN THE VCNTY...FEEL ISOLD POPS WARRANTED ATTM ACRS THE EDWARDS PLATEAU. WL ALSO INCLUDE ISOLD POPS OVR THE TRANS PECOS WHERE THE FNT WL BCM STNRY. E/SELY LOW LVL WINDS SHOULD HELP HOLD IN THE MSTR AND A HI-BASED TSRA OR TWO SEEMS QUITE PSBL. INTERESTING SCENARIO UNFOLDG FOR TNGT. FAIRLY STG SHORT WV TROF WL TRANSLATE FM SRN CA TDA AND INTO THE SRN PLAINS BY LATE TNGT PER ALL THE SHORT RANGE MODELS. ISENT LIFT/WAA PROGGED TO INCRS BY ALL THE MODELS AS WINDS ABV THE SFC VEER IN RESPONSE TO THE APPRCHG SHORT WV. THE AVN MODEL IS THE MOST MOIST OF THE MODELS AND SHOWS H85 DEWPOINTS APRCHG 10 DEGREES C OVR SRN PTNS OF WTX BY 12Z WED. AVN MODEL ALSO SHOWS COND PRES DEFICITS AROUND 20MB. ALL THE MODELS INDICATE A MDTLY UNSTABLE AMS OVR ERN PERMIAN AND CONCHO VLY WITH LIS ARND -5 AND CAPE AROUND 1500 J/KG. THE ONLY DIFFERENCE SEEMS TO BE THAT THE AVN IS THE ONLY MODEL THAT BREAKS OUT PCPN ACRS THE AREA. GIVEN THE EXPECTED AMOUNT OF LIFT AND THE QUALITY OF THE MSTR THAT WL BE INTACT ALG/S OF THE FNT...WOULD HAVE TO LEAN TOWARD THE AVN SOLN AND GO WITH SOME LOW POPS TNGT NRN PERMIAN BASIN...CONCHO VLY AND S PLAINS ASSUMG THIS MSTR WL BE DRAWN UP OVR THE QUASI-STNRY FNT AHD OF THE APPRCHG TROF. THE SHORT WV WL SLOWLY MOVE ACRS THETX PANHANDLE WED/WED NGT AND THE FNT WHICH WL LKLY MOVE BACK INTO THE S PLAINS BY LATE WED WL AGAIN BEGIN HEADG SWRD TOWARD THE MTNS AND EDWARDS PLATEAU. SHORT WV RDG WL BUILD OVR THE SRN PLAINS WED NGT BUT BY LATE THU DIFFLUENT SWLY FLOW ALOFT WL DVLP OVR WTX AHD OF STG W COAST SYS WHICH STILL LOOKS TO GIVE US A GD SHOT OF PCPN TO END THE WORK WK. COORD FTW...AMA...MAF AND SJT. LBB 67/42/68/40 -221 .LBB...NONE. EJC NNNN tx DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 240 AM CST TUE MAR 23 1999 UPPER RIDGE CONTINUES TO BUILD OVER THE NORTHERN ROCKIES AND SOUTHERN CANADA WHILE THERE IS A COOL FRONT WORKING ITS WAY SOUTH THROUGH NORTHERN SECTIONS OF TEXAS EARLY THIS MORNING. THROUGH THE FORECAST PERIOD...THE UPPER RIDGE WILL SLOWLY MOVE INTO THE NORTHERN PLAINS SENDING A COOL SFC RIDGE DOWN INTO THE SOUTHERN PLAINS AND PORTIONS OF TEXAS. THE WEAK FRONT IN THE STATE NOW WILL STALL TO OUR NORTH AND WAIT FOR A SECOND PUSH OF COOL AIR ON THURSDAY IN ORDER FOR THE FRONT TO PUSH DOWN NEAR OUR AREA. WHILE UPPER RIDGING OCCURS TO OUR NORTH...ZONAL FLOW WILL DOMINATE SOUTHERN AREAS OF THE NATION. THIS ZONAL FLOW WILL KEEP CONDITIONS BREEZY-WINDY AS LEE SIDE TROFING CONTINUES THROUGH WEDNESDAY. UPPER VORT MAX OVER CALIFORNIA THIS MORNING WILL WEAKEN AS IT CROSSES THE ROCKIES. THIS WAVE WILL HELP MAINTAIN THE LEE SIDE TROF AND KEEP OUR BREEZY SOUTHERLY FLOW ESPECIALLY OVER EASTERN ZONES AND THE COAST. NEWEST RUC AND MESOETA SHOW WINDS TO BE FAIRLY MODERATE OVER THE WEST TODAY AND WED SO WILL KEEP WITH THE CURRENT TREND IN THE ZONES AND HAVE HIGHER WIND SPEEDS FOR THE EAST. BECAUSE OF CURRENT WIND SPEEDS OUT IN STARR COUNTY HOWEVER, WILL GO WITH 15-25 ALL ZONES WITH WORDING OF DECREASING SPEEDS IN THE AFTERNOON OUT WEST. VAD PROFILE CURRENTLY HAS 40-45 KNOTS IN THE LOWEST 4K FT. THIS IS MUCH HIGHER THAN ANYTHING IN THE ETA FORECASTED SOUNDINGS. WILL WAIT UNTIL LAUNCH TIME TO SEE IF BIRDS ARE CAUSING THIS INCREASE ON THE VAD. SOUNDING AT 00Z SHOWED MOISTURE VERY DEEP...UP TO 800 MB. WILL GO WITH MOSTLY CLOUDY THIS MORNING...BECOMING PARTLY CLOUDY BY LATE AFTERNOON. WILL STICK FAIRLY CLOSE TO MOS NUMBERS. IN THE EXTENDED....A LARGE AND STRONG STORM SYSTEM WILL BE MOVING ONTO THE CALIFORNIA COAST LATE WEDNESDAY INTO THURSDAY. THE 00Z AVN HAS THE STORM SYSTEM MUCH FURTHER TO THE NORTH THAN THE MRF RUN FROM YESTERDAY. RAIN CHANCES WILL DEPEND ON THE EXACTNESS OF STORM TRACK. AT THIS POINT IT LOOKS LIKE THE FRONT MAY STILL BE HANGING AROUND THE AREA WHICH MAY ALLOW FOR RAIN CHANCES EARLY THIS WEEKEND. MRF STORM TRACK WILL LIKELY BE ADJUSTED TO THE NORTH THE NEXT COUPLE OF RUNS SO MAIN FOCUS WILL LIKELY BE ACROSS CENTRAL AND SOUTH CENTRAL TEXAS. WILL WAIT TO SEE THE NEW MRF BEFORE MAKING ANY CHANGES TO THE EXTENDED. OFFSHORE WINDS SHOULD KEEP IN THE 15-20 KT RANGE TODAY. WILL GO WITH SCEC STATEMENT. BRO EB 081/066 081/067 081 000 MFE EB 084/066 084/067 084 000 RGC EB 086/063 086/063 086 000 SPI BB 079/069 079/068 078 000 63 .BRO...NONE. NNNN tx SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 910 PM MST TUE MAR 23 1999 .SYNOPSIS... HIGH PRESSURE ALOFT BUILDING OVER THE REGION WILL KEEP SKIES MOSTLY CLEAR THROUGH WEDNESDAY. ANOTHER PACIFIC LOW PRESSURE SYSTEM WILL MOVE TOWARD OUR AREA THURSDAY. SOME WIND AND INCREASING CLOUDS ARE EXPECTED AS WELL AS A FEW SHOWERS OVER SE CA DURING THE AFTERNOON. THIS WEATHER SYSTEM WILL MOVE ACROSS THE AREA THURSDAY NIGHT AND FRIDAY...EXITING TO THE EAST BY FRIDAY NIGHT. HIGH PRESSURE ALOFT WILL DEVELOP OVER THE AREA OVER THE WEEKEND FOR SUNNY TO PARTLY CLOUDY SKIES...AND WARMER TEMPERATURES. .DISCUSSION... SURFACE WINDS HAVE DIMINISHED ACROSS ENTIRE CWFA AS WEAK S/WV MOVES THRU 4 CRNRS THIS EVENING. RUC PUTS US UNDER WEAK EASTERLY FLOW BY 12Z...AND CURRENT FCSTS HAVE EXCELLENT TRENDS. NO UPDATES. IN THE LONGER TERM...NEW ETA SHOWS LITTLE MORE AMPLITUDE ON RIDGE OVER ROCKIES BY 12Z THURSDAY...AND MAJOR PAC TROF SLIGHTLY SLOWER AND DEEPER THAN THE PREVIOUS RUN. WILL BE INTERESTING TO SEE HOW AVN HANDLES THIS SYSTEM. SIPPLE NNNN az STATE FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1000 PM EST TUE MAR 23 1999 MAIN CHANGE WILL BE TO LOWER POPS ACROSS MOST AREAS. 21Z RUC INDICATING CURRENT H500 VORT MAX ABOUT READY TO EXIT AREA...WITH PVA/MOISTURE INCREASE ONCE AGAIN BEGINNING BETWEEN 06Z-09Z. NOTING THIS...PLAN ON KEEPING LIKELY POPS ACROSS SW WV/SW VA ZONES AND REDUCING THE REST OF THE AREA TO CHANCE. THE EDGE OF THE LOW CLOUD DECK IS TANTALIZINGLY CLOSE TO THE BORDER OF THE FCST AREA IN SE OH...BUT PLENTY OF LOW LEVEL MOISTURE AND A TOUCH OF WARM AIR ADVECTION OVER THE MOIST GROUND WILL KEEP THE LOW CLOUDS AROUND. TEMPS MORE OR LESS IN THE BALLPARK...BUT WILL MAKE SOME ADJUSTMENTS. WRKZFP COMING RIGHT UP. .CRW... WV...NONE. VA...NONE. KY...NONE. OH...NONE. .END / CL NNNN ky FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 845 PM CST TUE MAR 23 1999 SFC FRONT/WINDSHIFT LINE ALONG AR/LA BORDER EXTENDING INTO CENT TX S OF KACT AT 00Z. SFC PRES RISE/FALL FIELDS ARE VERY WEAK WITH FRONTAL MOVEMENT BASED ON AIR MASS DENSITY ONLY. FRONT SHOULD HAVE SOME HELP FROM MID AND UPPER LEVEL SHORT WAVE MOVING INTO CENTRAL PLAINS THIS EVENING AS SOME COOLER/COLDER AIR SPILLS IN TO THE WEST OF ITS PATH. LIGHT RAIN SHOWERS INDICATED ON KSHV 88D IN NE TX AND S AR WITH -RA AT KPBF AT 02Z. MSAS GRAPHICS SHOW THETA E RIDGE AND SOME SFC CONVG RIGHT ALONG FRONT SO SHOWERS LOOK IN ORDER. PER COORD WITH KLCH...00Z SNDG AT LCH AND SIL CAPPED. WILL NEED SOME MODIFICATION OF AIRMASS BE IT FROM THE FRONT OR DAYTIME HEATING. WILL REMOVE POPS FROM SW BUT LEAVE 20 PERCENT AND PHRASE AS LATE FOR CENT LA ZNS AS RUC MODEL SUITE SHOWING FRONT WILL LIKELY SLOW NEAR KESF/KAEX AROUND DAYBREAK. PER COORD WITH KSHV WILL UP OVERNIGHT MINS TONIGHT TO UPPER 50S. TSTM WORDING LOOKS IN ORDER AS 00Z SHV SOUNDING SHOWED A TRANSITION TO A MORE FAVORABLE CONVECTIVE ENVIRONMENT AT 00Z FROM 12Z SOUNDING. LAPSE RATES HAVE INCREASED IN MID LEVELS AND WITH THE SHORT WAVE MOVING THROUGH TX PANHANDLE DYNAMICS WILL LIKELY STRENGTHEN. THANKS FOR COORD CALLS AND AFDS KLCH AND KSHV. .NEW...NONE. MS...NONE. LA...NONE. 13 NNNN la SYNOPTIC EXPLANATION/FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON 920 PM EST TUE MAR 23 1999 RAIN IS ATTEMPTING TO FALL...BUT NOT HAVING MUCH LUCK. RADAR SHOWING SOME AREAS THAT COULD BE SOME LIGHT SHOWERS...MOST NOTABLY TOWARDS NORTH CENTRAL MD ATTM. OBS SHOW LIGHT RAIN AT DCA AND BWI BUT THAT/S IT. S/W TRAIN WILL CONTINUE TO MOVE A COUPLE OF WEAK WAVES ACROSS THE REGION THRU WED AFTERN. LOOKS LIKE 850 CAA AND WEAK DOWNWARD MOTION SHOULD PUT A STOMP ON THESE OUTBURSTS OF VERY LIGHT RAIN BY ABOUT 21Z TOMORROW. 21Z RUC AND 18Z ETA DOWNPLAY PRECIP FOR TNT. WILL GO CHC OF LIGHT RAIN ALL AREAS. TEMPS HAD SOME MINOR ADJSTMNTS BUT LOOKED OK FOR THE MOST PART. WAS LOOKING AT THE LONG RANGE MRF HUMIDTY/PRES/HGHT/VORT FIELDS ON GARP AND WASN/T READY TO WRITE OFF PRECIP AT THIS POINT FOR LATE WEEK. CUTOFF 500 WAVE OVER THE REGION WITH S/W MOVING THRU ORF SAYS A CHC TO ME. WILL ADVISE MID SHIFT AND THEY CAN MAKE ANY CHANGES TO EXTND IF THEY SEE FIT WITH THE NEW MODL INFO. OTW WRKZFP HAD BEEN ISSUED. ZONES OUT SHORTLY. .WBC...NONE. STRONG EFFECTIVE 9 AM EST MONDAY MARCH 29 1999...THE SYNOPTIC EXPLANATION/ FORECAST DISCUSSION ISSUED UNDER WMO HEADER FXUS71 KLWX AND AFOS HEADER WBCSFDWBC WILL BE REPLACED BY AN AREA FORECAST DISCUSSION. THE AREA FORECAST DISCUSSION WILL BE FOUND UNDER WMO HEADER FXUS61 KLWX AND AFOS HEADER WBCAFDLWX. NNNN md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 830 PM EST TUE MAR 23 1999 WEATHER CONCERN TONIGHT IS EXTENT OF LAKE ENHANCED SNOWFALL. OMEGA BLOCK OVER NORTH AMERICA HAS AN UPPER TROF OVER EASTERN CANADA AND A RIDGE FROM THE ROCKIES. THIS LEAVES UPPER MICHIGAN IN A NORTHERLY FLOW REGIME... WITH TRANSIENT SHORTWAVES PROVIDING THE WEATHER ACTION. THE LATEST OF THESE SHORTWAVES IS JUST NOW EXITING UPPER MICHIGAN TO THE SOUTHEAST. IN ITS WAKE ALL MODELS SHOW Q-VECTOR CONVERGENCE BEING REPLACED BY Q-VECTOR DIVERGENCE OVER THE FORECAST AREA... AND UPWARD SYNOPTIC SCALE OMEGA IS EXITING THE REGION AS WELL. WITHOUT DYNAMIC HELP... THE BOUNDARY LAYER AIRMASS ISN'T COLD ENOUGH TO SUPPORT LAKE EFFECT CONVECTION ON ITS OWN. MODELS HAVE THEIR DIFFERENCES REGARDING 850MB TEMPERATURES... WITH THE ETA AGAIN THE COLDEST. EVENING SATELLITE IMAGERY SHOWS NEARLY NO CLOUD OVER THE WESTERN HALF OF LAKE SUPERIOR AT THIS TIME... WHICH AGREES WELL WITH THE ABSENCE OF SYNOPTIC LIFT THERE AND LAKE SURFACE TO 850MB DELTA T'S AROUND 11-12C. CLOUDS SHOULD DIMINISH OVER THE NEXT FEW HOURS IN THE EAST AS WELL AS SYNOPTIC LIFT CONTINUES ITS EXIT. KMQT 88D RETURNS CORRELATE WELL WITH THE SATELLITE IMAGERY AND SHOW BEST REFLECTIVITIES TO THE EAST...WHERE MAX RETURNS ARE IN THE MID 20S DBZ. THE NORTHWEST FLOW WILL CONTINUE AND LOW LEVEL COLD ADVECTION WILL PERSIST THROUGH THE NIGHT. BY 12Z DELTA T'S OVER THE LAKE SHOULD BE AROUND 15C ACCORDING TO THE AVN AND NGM. THE ETA TAKES THE COLDEST 850MB AIR FURTHER WEST... THROUGH MINNESOTA. GIVEN THE PROBLEMS THE ETA HAS HAD WITH 850MB TEMPERATURES THIS WINTER... WILL GO WITH THE AVN/NGM SOLUTION. RUC MODEL SHOWS 1000MB COVERGENCE OVER THE FORECAST AREA MAINTAINING ITSELF THROUGH THE NIGHT... WITH THE AXIS OF THE CONVERGENCE ALONG THE LAKE SUPERIOR SHORELINE. THIS LAND/LAKE FRICTIONAL CONVERGENCE SHOULD ACT TO MAINTAIN SOME CLOUDS OVER THE LAND LONGER THAN THE CLEARING OVER THE LAKE DEPICTED ON THE SATELLITE IMAGERY WOULD IMPLY. DESPITE THE COLD ADVECTION... LAKE EFFECT CLOUDS AND SNOW WILL LIKELY BE LIMITED BY THE DRYNESS OF THE UPSTREAM AIRMASS... THE MODELS SHOW NO INCREASE IN BOUNDARY LAYER HUMIDITY THROUGH THE NIGHT. GUSTY NORTHWEST WINDS WILL LAST THROUGH THE NIGHT (AS PER FWC) GIVEN THE COLD ADVECTION AND PERSISTENT PRESSURE GRADIENT. .MQT...NONE. ES NNNN mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 842 PM EST TUE MAR 23 1999 PER LATEST RUC MODEL RUN...UVVS FROM ASSOCIATED VORT MOVG THRU NC-SC HELPING TO AID THE DEVELOPMENT OF MID-UPPER LEVEL CLOUDINESS ACROSS ILM CWA. THIS CAN BE SEEN NICELY ON LATEST IR LOOPS. WILL TWEAK OVERNIGHT SKY CONDITIONS. TEMPS...WEAK COASTAL FRNT OR WARM FRONT STRADDLING ALONG THE NC-SC COAST. THIS DELINEATION DEPICTED NICLY BY LATEST MSAS DEWPOINT DISCONTINUITY. WILL TWEAK TEMPS...WITH SLITELY WARMER READINGS ALONG THE COAST. CWF...ONLY TWEAKING NEEDED IS THE WIND DIR. WILL INIT WITH A SE WND BECOMING S DUE TO CURRENT SYNOPTIC SFC RESSURE PATTERN. .ILM...NONE. DCH NNNN nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 830 PM CST TUE MAR 23 1999 SATELLITE IS INDICATING MAIN H5 SHORTWAVE ENERGY IS WELL TO THE EAST OF THE CWA WITH NEXT SIGNIFICANT ENERGY PACKAGE OVER THE 4 CORNERS. LATEST RUC INDICATES A WEAK VORT CENTER LOCATED IN SOUTHERN MISSOURI MOVING EASTWARD. WINDOW CHANNEL IR DOES NOT SHOW THIS FEATURE BUT THERE DOES APPEAR TO BE A CYCLONIC TWIST IN MID/HI LEVEL MOISTURE OV FEATURE DOES NOT APPEAR TO BE ENHANCING LIFT TO ANY SIGNIFICANT DEGREE THUS IT MAY NOT PLAY A ROLE IN TONIGHT'S WEATHER PICTURE. WK FNT CONTINUES ACROSS MIDDLE TENNESSEE WITH 45-50 NORTH OF THE FRONT AND 55-60 SOUTH OF THE FRONT. WINDS ARE PREDOMINANTLY EAST TO THE NORTH OF THE FRONT AND SOUTHEAST/SOUTH SOUTH OF THE FRONT. WILL TRY AND REWORK ZONES TO REFLECT CURRENT TRENDS IN TEMPS AND WINDS. JLM NNNN tn COASTAL BEND FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 900 PM CST TUE MAR 23 1999 ANALYSIS OF LATEST SATELLITE IMAGERY INDICATES JET STREAM CIRRUS CONTINUING ACROSS SOUTH TEXAS. CLOSER TO THE SURFACE...STRATUS CONTINUES WITH SOUTHEASTERLY FLOW DOMINATING. CAP CONTINUES TO INHIBIT CONVECTION. LATEST RUC TRIES TO DEVELOP A 500 MB VORT MAX OVER KDRT BY MIDNIGHT TONIGHT. HOWEVER...SATELLITE ANALYSIS INDICATES THIS FEATURE TO BE FURTHER NORTH AND EAST NEAR KACT ATTM. SOME LIFT POSSIBLE ACROSS NORTHERN ZONES. THUS...CURRENT PACKAGE LOOKS ON TRACK. AS FOR MARINE ZONES...WILL DECREASE WINDS AND SEA STATE FOR REMAINDER OF TONIGHT. TH (SYNOPTIC/MESO) 71 NNNN tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE 1005 AM EST WED MAR 24 1999 PROBLEM FOR TODAY IS CLOUDINESS OR SNOW SHOWERS IN EASTERN CWA SHORTWAVE IS NE OF CWA NEAR JAMES BAY PROGRESSIVELY INVADING DURING THE DAY. 88D RETURNS AT 14Z SHOW NOTHING ON THE HORIZON WITH CLR SKIES IN CNTRL AND WSTRN CWA. EARLY VIS SAT SHOWS CLDS IN ESTRN CWA. EARLY MESOETA AND RUC AT 15Z SHOWED SOME SLIGHT LFTING IN ESTRN AND CNTRL CWA...BUT VERY LITTLE MSTR. HOWEVER THIS WAS ENOUGH TO GIVE EARLY AM CLOUDS. BY EVE SAME MODELS SHOW MORE Q-VECTOR FORCING OVER THE USUAL SUSPECT AREAS...NAMELY KEWEENAW PENINSULA AND MARQUETTE AND BARAGA COUNTIES. ESTRN COUNTIES THOUGH SHOW LITTLE IN THE WAY OF ENHANCING DYNAMICS. ETA SNDNGS SHOW VERY LITTLE MSTR THROUGHOUT CWA AND APPROACHING SHRT WAVE. POSSIBLE ENHANCEMENT COMES FROM N TO NW WINDS BRING COLD AIR IN TODAY. MOS HAS TEMPS OF MID TWENTIES FOR TODAY WITH PARTLY CLDY SKIES. TEMPS SEEM A LITTLE LOW AS SKIES ARE CLEAR THIS MORNING AND INSOLATION IS STRONG AT THE END OF MARCH. SNOWPACK RAPIDLY MELTING AND CONSIDERABLE GND IS SHOWING..ALLOWING SFC HEATING AND BRINGING MSTR INTO BNDRY LYR. HOWEVER...MSTR WILL REMAIN IN SFC LYR. WILL RAISE TEMPS 5F OVER CNTRL AND ESTRN CWA. DELTA T UP TO 10C IS GOING TO BE MARGINAL AT BEST FOR ANY LES. SFC HIGH DSNDING FROM CAN INTO MN...AND OVER ENTIRE LK SUPERIOR RGN FOR THU IS GOING TO EAT AWAY MSTR IN PLACE. ONLY LEFT WITH SHALLOW LK SUPERIOR MSTR. WILL USE CLOUDY SKIES...WITH FLURRIES THIS PM FOR ESTRN COUNTIES. WILL CHANGE ZFP FOR WEST AND CNTRL DURING DAYTIME HRS FOR PARTLY CLDY TO MOSTLY SUNNY...WITH SOME FLURRIES THIS EVE. ULMER NNNN mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1045 AM CST WED MAR 24 1999 THE ZONES HAVE JUST BEEN UPDATED TO REMOVE MORNING WORDING AND TO MAKE MINOR CHANGES. WE HAVE ADJUSTED AFTERNOON HIGHS SLIGHTLY GIVEN THE CURRENT TEMPERATURES AND INCOMING 12Z DATA. HOWEVER...THE GOING NE-SW TEMPERATURE GRADIENT STILL LOOKS GOOD. 12Z DATA FROM THE RUC AND NGM SUGGEST THAT EVEN WITH SOME MIXING...WINDS WILL STAY IN THE 10 TO 15 MPH RANGE ACROSS MUCH OF EASTERN NEBRASKA. WINDS MAY BE A LITTLE STRONGER ACROSS THE WRN IA AND EXTREME ERN NEB COUNTIES WHERE THE WOOD LAKE AND SLATER PROFILERS ARE INDICATING 20 TO 25 KT 850MB FLOW. OTHERWISE...THE STRATUS DECK ACROSS CNTRL NEB IS ERODING WWD ATTM WITH SUNNY SKIES EXPECTED ACROSS THE CWFA TODAY. .OMA...NONE MEAD NNNN ne STATE FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 1044 AM EST WED MAR 24 1999 .DISC...GARP IR2 INDICATES VRY LTL IF ANY EVIDENCE OF A DISORGANZIED BAROCLINIC LEAF ALG MID ATLANTIC SEABOARD. DISORGANIZED LW PRESSURE IN WVA MOISTURE STARVED. WSR-88D KENX AND RGNL SHOWS -RA BRUSHING SRN SXNS ATTM AND SHWG NO REAL SIGNS OF WANTING LFT FURTHER N. A FEW LIGHTER RETURNS N AND W OF NY ST ASSCD WITH ARCTIC FNT. WK ISENTROPIC LFT OF THE 286K (FM 790 AT RAOB PIT TO 860MB AT KALY). RESULT HS BEEN A SC CLD DECK. SAT PIXS SHOW THIS DECK MVG SLOLY EXPANDING N AND W WITH TIME. STL PLENTY OF SUN FM LK GEORGE NWD. MM5 AND LTST RUC INDICATED -RA WL EXPAND 2 CVR MUCH ERN NEW ENGLAND BUT VRY LTL IF ANY PCPN ELSEWHERE. THIS IS THE RESULT OF REGENEFRICATION OF THE STM UPON TAPING INTO SOME ATLANTIC MOISTURE. SO...WL REMOVE POPS FM CD AND IN MANY PLACES. HOWEVER WL LV A SML POP IN MOHAWK VLY AND WRN ADRCKS AS -SHRA/-SHSN MAY SNEAK IN THERE BY DAY/S END. LKS LK A T-.01 EVNT MST OTR PLCS...XCPT SERN WHERE KPOU COULD GET A FEW HUNDRETHS. NO BIG DEAL SO DOWN THERE CALL OCC RA OR SPRINKLES AND STL KP A POP. TEMPS ND 2B BUMPED UPWRD A NOTCH BASED ON 15Z READINGS. NO REAL CHANGES 2 LTR PDS. PRELIMINARY WRKZFP AVBL. FULL PACKAGE AVBL BY 1040 AM. PLN 2 HV MIDDAY PACKAGE OUT THE DOOR AOB 11AM. BYE BYE! .ALB...NONE. HWJIV NNNN ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 1014 AM EST WED MAR 24 1999 CHECKING 88D'S AND SATELLITE IT APPEARS VORT WHICH HAS BEEN PRODUCING -SHRA ACROSS FA IS SHIFTING QUICKLY E WHILE WEAK SFC FNT REMAINS DRAPED NE TO SW FM NEAR LOZ TO CHA. 12Z RUC INDICATES LITTLE UPPER LEVEL SUPPORT FOR ADDITIONAL -SHRA AND WITH TRENDS IN CURRENT WX WOULD LIKE TO REPLACE GOOD CHC POPS WITH LOWER PROBABILITY FOR REMAINDER OF AFTERNOON AS FNT WILL ONLY SLOWLY SHIFT E THRU FA AND LOW LEVELS REMAIN MOIST. WILL TWEEK SKY CONDITION A BIT AS SOME RATHER LARGE BREAKS OCCURRING OVR W ZONES. WILL NOT TRY TO ALTER TEMP FCST WITH LIMITED RAYS AVAILABLE FOR WARMING AND CAA BUILDING IN ALOFT. TH NNNN tn