AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 400 AM PDT WED JUN 27 2001 LOOK AT NCEP MODEL VERIFICATION WEB PAGE GRAPHICS SHOWS POOR PERFORMANCE OF TUESDAYS ETA FORECASTS. 850 MB TEMPS WERE FORECAST ABOUT 6 DEG C TOO COLD OVER NRN/CNTRL CA WITH 500 MB HEIGHTS ABOUT 40M TOO LOW. THIS HAS RESULTED IN PLENTIFUL PACIFIC MOISTURE BEING CONCENTRATED IN A PREFRONTAL BAND OF PRECIPITATION STRETCHING FROM ROUGHLY SONOMA COUNTY NNE THROUGH SHASTA COUNTY INSTEAD OF MOST OF THE NORTHERN PORTION OF THE CWA. 24 HOUR STORM TOTALS OVER THE SHASTA-TRINITY MOUNTAINS ARE IN THE 2.5-3.25 INCH RANGE...HUGE FOR THIS TIME OF YEAR. HOWEVER THESE TOTALS DROP OFF RAPIDLY TO THE SE...WITH GAGES NEAR CHICO AND OROVILLE ONLY RECEIVING A FEW HUNDREDTHS. FRONT MAKING SLOW EASTWARD PROGRESS. RUC 500 MB TEMP ANALYSES SHOW FRONT PUSHING INTO OR AND EXTREME NRN CA COAST. RADAR AND GOES IR DATA SHOW CORRESPONDING THINNING OF CLOUDS AND DECREASE IN PRECIPITATION RETURNS OVER THE SAME AREAS. THIS HAS PUSHED MAIN PRECIPITATION BAND INTO CENTRAL VALLEY NORTH OF MARYSVILLE WITH SOMEWHAT SLOWER MOVEMENT FURTHER SOUTH. THIS LIKELY DUE TO SHORTWAVE/VORT MAX AXIS SEEN IN SAT IMAGERY STILL OFFSHORE AND MOVING NE ALONG FRONT. LOOKS LIKE EFFECTS OF THIS ON PCPN INTENSITY WILL DIMINISH AS WAVE GETS SHEARED APART BUT COULD GIVE NORTHERN HALF OF CWA LAST GASP OF SIGNIFICANT PRECIPITATION OVER THE NEXT 4-6 HOURS. THUS WIND DOWN OF REMAINING ACTIVITY AND WINDS TODAY LOOKS GOOD. CAD ALOFT WILL LIKELY BE ONLY SIGNIFICANT NORTH OF ABOUT 40N TODAY SO WILL KEEP MENTION OF THUNDERSTORMS THERE. TEMPS WILL BE TRICKY TODAY...DEPENDING ENTIRELY ON HOW QUICKLY POST-FRONTAL SUBSIDENCE EVAPORATES CLOUDS. ONLY SURE THING LOOKS TO BE BIG WARMUP OF 8-12 DEG F ON THURSDAY. WARMING CONTINUES INTO NEXT WEEK AS SUBTROPICAL RIDGE MIGRATES NORTH. MEDIUM RANGE MODELS PUSH RIDGE AXIS WELL INTO PAC NW BY NEXT WED WHICH SHOULD BRING ALONG WITH IT AFTERNOON THUNDERSTORMS AS FAR NORTH AS THE SOUTHERN CASCADES. SJC .STO...NONE BLU CU 060/050 070/055 072 63700 RBL WU 078/060 090/064 094 63720 SAC EU 080/058 091/064 093 63400 ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 815 PM EDT WED JUN 27 2001 BROKEN LINE OF CONVECTION ASSOCIATED W/ THE E COAST SEA BREEZE CONTINUES TO PROPAGATE WWD ACROSS SRN TIER GA/WRN BIG BEND COUNTIES...BUT ACTIVITY HAS BEEN DECREASING IN INTENSITY & COVERAGE DURING PAST HOUR. EARLIER MERGER OF OUTFLOW BNDRY W/ PANHANDLE SEA BREEZE SPARKED ISOLD PULSE CELL OVER JACKSON COUNTY W/ WIND DAMAGE INVOF MAI. A FEW SHOWERS/TSTMS MOVING NWD INTO SE AL/XTRM SW GA AHEAD OF PANHANDLE SEA BREEZE...AS WELL AS OVER PORTIONS OF SCNTRL GA. UPSTREAM ENERGY ROTATING S & E FROM MID/UPPER LOW PARKED NEAR STL HAS TRIGGERED ACTIVE CONVECTION OVER AR/LA/MS. LATEST RUC40 PROGS KEEP THIS ENERGY NW OF OUR CWFA OVERNIGHT. FL & AL CONVECTION SHOULD DISSIPATE OVER THE FEW HOURS WHILE GA ACTIVITY LAST TO WIND DOWN. WILL MONITOR RADAR TRENDS THE NEXT FEW HOURS...BUT CURRENT THINKING IS TO REMOVE ALL POPS FOR LATE EVENING UPDATE. NO OTHER CHANGES TO ZONE PACKAGE EXPECTED. KTNF1 C-MAN REPORTED E21G25KT AS CONVECTIVE OUTFLOW BNDRY PASSED (KTLH REPORTED E23G28KT). LIGHT ELY FLOW TO PREVAIL OVERNIGHT W/ SEAS LESS THAN 2 FT & SMOOTH ON THE BAYS & INLETS. ONLY CHANGE FOR 1030 PM CWF WILL BE TO REMOVE EVENING WORDING FOR FIRST PERIOD. .TLH... AL...NONE. GA...NONE. FL...NONE. MAJ fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 915 PM CDT WED JUN 27 2001 SCATTERED THUNDERSTORMS MOVING MOSTLY SOUTH OF AREA. SOME WEAKER SHOWERS SKIRTING NORTHERN EDGE OF ARKANSAS PORTIONS. WITH UPPER LOW SITUATED OVER MISSOURI BOOTHEEL...ACTIVITY CLOSER TO LOW SUBJECT TO NOCTURNAL ENDURANCE. LOW WILL LIKELY DRIFT SLIGHTLY SOUTHWARD OVERNIGHT. THUS...WILL PUT 30 PERCENT POPS FOR PORTIONS OF SOUTH AR...WITH LOWER POPS ELSEWHERE. HOWEVER...WILL LEAVE IN 20 PERCENT FOR SOUTHERN TIER OF AREA TO ACCOUNT FOR CURRENT ACTIVITY...BUT WILL WORD MAINLY BEFORE MIDNIGHT. OVERNIGHT LOWS LAST NIGHT ONLY FELL TO AROUND 70...ALSO WHERE CURRENT DEWPOINTS ARE RANGING. RUC INDICATING SATURATED SURFACE LAYER AND CURRENTS SPREADS NARROWING... WILL ADD PATCHY FOG TO FORECAST...ESPECIALLY WHERE GROUND IS VERY WET FROM DAYTIME STORMS. VII .SHV...NONE. la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1015 PM EDT WED JUN 27 2001 FCST CONCERN OVERNIGHT IS WHETHER ANY SHRA/TSRA WILL DEVELOP. WV IMAGERY SHOWS UPPER LOW CENTERED NEAR KSTL WITH RIDGING ACROSS UPPER MIDWEST/UPPER LAKES REGION. CLOSEST APPARENT SHORTWAVE IS LIFTING NE INTO WRN SD. AT THE SFC...DIFFICULT TO PICK OUT FRONTAL BOUNDARY THAT DRIFTED INTO UPPER MI AS LK BREEZES/OUTFLOW BOUNDARIES TODAY HAVE SPREAD THROUGH THE AREA. A WARM FRONT IS TAKING SHAPE OUT TO THE WEST AS SHORTWAVE LIFTS NE FROM ROCKIES. FRONT EXTENDS FROM SW ND INTO SW ONTARIO. ALTHOUGH DIFFICULT TO FIND FRONTAL BOUNDARY IN CURRENT SFC DATA... 18Z ETA/00Z RUC SHOW TROF EXTENDING E/W ACROSS UPPER MI OVERNIGHT. ETA SHOWS IT LIFTING NE LATE TONIGHT AS SFC LOW MOVES NE THROUGH DAKOTAS. SO QUESTION IS WHETHER A FEW SHRA/TSRA WILL DEVELOP AS IT MOVES NE. BOTH RUC AND ETA INDICATE LOW-LEVEL JET FOCUSED WELL W OF FA OVERNIGHT...POSING NO THREAT FOR TSRA DEVELOPMENT HERE...AND NOTHING IN THE WAY OF UPPER JET SUPPORT NOTED. HOWEVER...AXIS OF 850MB THETA-E ADV ASSOCIATED WITH LIFTING WARM FRONT DOES EXTEND AS FAR E AS WRN LK SUPERIOR...AND 850-300MB THICKNESSES/CORFIDI VECTORS INDICATE TSRA DEVELOPING TO THE W WILL TAKE A TURN SE TWD NW UPPER MI. TSRA DO APPEAR TO BE ORGANIZING NOW IN FAR NW MN/SE MANITOBA/SW ONTARIO...AND THESE WILL BE THE ONES TO WATCH. BELIEVE THERE IS A THREAT (ALTHOUGH LOW) OF SOME OF THESE SHRA OR TSRA SURVIVING FAR ENOUGH E TO AFFECT PART OF FA. WILL MENTION ISOLD SHRA/TSRA OVER KEWEENAW LATE TONIGHT AND INCLUDE MENTION IN EARLY MORNING THU. REST OF FA SHOULD REMAIN DRY THRU MORNING. LOWS A PROBLEM ALONG LK SUPERIOR TONIGHT. TEMPS HAVE BEEN FLUCTUATING THIS EVENING AS MARINE LAYER OCCASIONALLY EDGES ONSHORE IN SOME SPOTS. PRESQUE ISLE DEFINITELY THE COOLEST...HOLDING BTWN 50-55 SO FAR THIS EVENING...ONTONAGON WENT FROM 59 TO 64 AND THEN BACK TO 57 WHILE KP59 HAS FALLEN FROM 70 TO 63. WILL STICK WITH GOING FCST OF 55 ALONG LKSHORE...BUT DON'T THINK ALL LKSHORE AREAS WILL SEE TEMPS THAT LOW. AROUND 65 SHOULD COVER INLAND AREAS AS CURRENT DWPTS MOSTLY IN MID 60S. .MQT...NONE. ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 317 PM CDT WED JUN 27 2001 SURFACE BOUNDARY HAS PREVAILED THIS AFTERNOON FROM KMQT TO KMSP. THUNDERSTORM COMPLEX HAS DEVELOPED OVER THE UPPER PENINSULA OF MICHIGAN WITH SCATTERED THUNDERSTORMS NORTH AND WEST OF EAU CLAIRE AND NOW JUST RECENTLY NEAR MANKATO. LATEST RUC SHOWING VERY HIGH SURFACE THETA-E AND CAPE VALUES NORTH OF EAU CLAIRE. MBE VELOCITY FROM BUFKIT INDICATES MOVEMENT TO THE SW AT 15 KTS WHICH AGREES WITH WHAT IS OCCURRING AND THIS GOES ALONG WELL WITH THE H8-H3 THICKNESS PATTERN. WILL HAVE WIDELY SCATTERED THUNDERSTORMS FOR EASTERN AND SOUTHERN AREAS THIS EVENING. ANOTHER WARM DAY FOR TOMORROW WITH LOW LEVEL TEMPERATURES MUCH LIKE THOSE OF TODAY. ETA TRYING TO INDICATE SOMEWHAT DRIER LOW LEVEL AIR WORKING IN FROM THE SOUTHEAST WITH TIME. THIS LOOKS PLAUSIBLE AS SURFACE DEW POINTS ARE NOW NEAR 60 IN EASTERN IA..NORTHERN IL AND SOUTHERN WI. WILL HAVE TO WATCH LOW TEMPERATURES CAREFULLY TONIGHT AND THURSDAY NIGHT. LOW LEVEL THETA-E AXIS THAT HAS BEEN PARKED OVER THE DAKOTAS WILL PROGRESS INTO THE WESTERN AND NORTHERN PORTIONS OF THE MN CWA THURSDAY NIGHT AND THEN SAG SLOWLY SOUTH ACROSS THE REST OF THE FORECAST AREA ON FRIDAY. WILL HAVE CHANCE POPS THURSDAY NIGHT NORTHERN AND WESTERN AREAS AND OVER ALL OF THE AREA ON FRIDAY. OZFMPX AROUND 330 PM. .MSP...NONE. HILTBRAND mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 245 PM MDT WED JUN 27 2001 WIDELY SEPARATED THUNDERSTORMS FIRED BENEATH THE MOISTURE PLUME OVER THE EASTERN AND SOUTHERN ZONES...WITH DIFFERENTIAL HEATING INITIATING THE CONVECTION. THE UPPER HIGH BUILDING OVER WESTERN NM SERVED TO INHIBIT CONVECTION TO THE NORTHWEST OF A LINE RUNNING THROUGH TAOS...ALBUQUERQUE...AND QUEMADO. EXPECT MOST OF THE STORMS TO DISSIPATE SHORTLY AFTER DARK PER LATEST RUC2 OUTPUT AS NO SOURCES OF MID LEVEL FORCING TO KEEP STORMS GOING. A LARGE UPPER LEVEL HIGH PRESSURE AREA IS FORECAST TO CONTROL EVENTS OVER THE FORECAST AREA FROM THURSDAY INTO THE MIDDLE OF NEXT WEEK. THE CENTER OF THE UPPER HIGH IS EXPECTED TO MEANDER OVER THE FOUR CORNERS REGION THURSDAY THROUGH SUNDAY...THEN DRIFT NORTH OVER WESTERN OR CENTRAL COLORADO FOR THE PERIOD FROM MONDAY THROUGH WEDNESDAY. MEANWHILE...A PERSISTENT UPPER LOW THAT HAS BEEN SPINNING OVER THE LOWER MS VALLEY IS EXPECTED TO MORPH INTO AN EASTERLY WAVE AND PASS SOUTH OF THE AREA DURING THE MONDAY THROUGH WEDNESDAY TIMEFRAME. THIS EASTERLY WAVE SHOULD PROVIDE SUBSIDENCE AS IT APPROACHES SUNDAY AND MONDAY AND PROVIDE ADDED LIFT FOR A DAY OR SO AFTER ITS PASSAGE (MOST LIKELY TUESDAY AND WEDNESDAY). THE CIRCULATION ALOFT AROUND THE UPPER HIGH (FROM THE NORTH OR NORTHEAST THROUGH SUNDAY AND NORTHEAST TO EAST THEREAFTER) SHOULD SERVE TO KEEP THE MEXICAN MONSOON AWAY FROM THE FORECAST AREA DURING THE NEXT SEVEN DAYS. HOWEVER...THERE WILL BE ENOUGH MOISTURE AND INSTABILITY FOR POPCORN CONVECTION ACROSS THE AREA...WITH LOW POPS EXPECTED ACROSS THE AREA FROM THURSDAY THROUGH NEXT WEDNESDAY. ABQ BB 062/092 064/092 065 38212 SAF BB 054/087 055/088 055 38212 TCC BB 065/093 064/092 064 38212 .ABQ...NONE. nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON, NC 935 AM EDT WED JUN 27 2001 IMPRESSIVE 1029MB SFC HI ALONG VA/NC BORDER...AS UPPER LOW HAS RETROGRADED INTO LWR OHIO VLY. INLAND SC ZONES FINALLY BREAKING OUT OF LOW CLOUDS AND FOG. TROPICAL AIRMASS WELL ENTRENCHED WITH DEEP MOISTURE AND SFC DEWPOINTS IN LOW-MID 70S. WITH PLENTY OF INSTABILITY IT WON'T TAKE MUCH TO FIRE CONVECTION SO WILL LEAVE CHC POPS ALONE. UPPER RIDGE NOT QUITE ESTABLISHED OVER ILM CWA JUST YET. GOING TEMPS LOOK TO BE ON TRACK...SO NOT PLANNING ANY ZFP UPDATES THIS MORNING. CWF: WINDS REFUSE TO CLOCK AROUND TO S AS MODELS AND PREV FCSTS WOULD INDICATE. NEW RUC HOLDS E/SE DIRECTION THRU AFTERNOON...AND WITH SFC HI STILL SOLID OVER LAND I LIKE THIS SOLN IN THE SHORT TERM. WILL TWEAK DIR ACCORDINGLY. FCSTID = 35 ILM 88 70 90 71 / 20 20 10 10 LBT 90 69 91 69 / 20 20 10 10 FLO 90 70 91 70 / 20 20 10 10 MYR 87 70 88 71 / 20 20 10 10 .ILM... NC...NONE. SC...NONE. RAS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1052 AM CDT WED JUN 27 2001 THIN BAND OF STRONG TO OCCASIONALLY SEVERE CONVECTION CONTINUES MAINLY EAST OF I-35 THIS MORNING. RUC SHOWS WAA WEAKENING THIS MORNING AS WINDS BACK WITH BEST AREA OF CONTINUED DEVELOPMENT ACROSS SOUTHEAST COUNTIES. CLOUDS AND RAIN WILL KEEP AFTERNOON HIGHS LOWER THAN GOING FORECAST AND WILL ALSO HELP IN MORE DEVELOPMENT THIS AFTERNOON. .OUN... OK...NONE. TX...NONE. 6 ok AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 1010 AM CDT WED JUN 27 2001 WARM FRONT CONTS TO PUSH NORTH INTO NORTH DAKOTA TODAY. BAND OF THIN CI OVERSPREADING NERN COUNTIES...BUT SHOULDN'T HAVE ANY NET EFFECT ON TEMPS OVERALL. LOOKING AT LATEST RUC AND NEW LAMP GUIDANCE...TEMPS MAY NEED A SLIGHT NUDGE UPWARDS ALL AREAS. BAND OF MID-LEVEL INSTAB ASSOC WITH LEFTOVER NOCTURNAL JET SHOULD FADE THIS MORNING AND AFTERNOON AS 8H JET SUBSIDES. STILL LOOKS LIKE BREEZY-WINDY CONDS WILL EXIST LATER THIS AFTERNOON ACROSS ALL CWA. REMOVED MENTION OF MORNING TSRA AND BUMPED TEMPS UP A BIT. ALSO PLAYED A BIT WITH THE WINDS. UPDATED ZONES ALREADY SENT. .ABR...NONE. HINTZ sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 300 AM CDT THU JUN 28 2001 FORECAST QUANDARIES...CONVECTION STRENGTH...AREAL COVERAGE...CLOUD COVER...AND TEMPS. CURRENT ASOS/AWOS OBSERVATIONS AND REGIONAL SATELLITE/MOSIAC RADAR IMAGERY SHOWING CONVECTION CONTINUING EARLY THIS MORNING ACROSS N AL...N GA...AND SE PORTIONS OF CUMBERLAND PLATEAU...WITH ASSOCIATED CLOUDINESS STRETCHING THROUGH THE N CUMBERLAND PLATEAU REGION. ADDITIONAL HIGH LEVEL CLOUDINESS OVER THE REGION ASSOCIATED WITH PERSISTENT UPPER LEVEL LOW. RUC ILLUSTRATING UPPER LEVEL LOW CENTER CIRCULATION OVER THE MISSOURI BOOTHEEL PRESENTLY...WITH SWD MOISTURE ADVECTION. RUC ALSO SHOWING THAT LOW HAS CAUSED MAIN UPPER LEVEL FLOW TO REMAIN ACROSS THE N U.S. MSAS/HAND SFC ANALYSES DEPICTING HIGH PRESSURE OVER SWRN NC...BUT OTHERWISE A CONTINUING DIFFUSE SURFACE WEATHER PATTERN. FOG STARTING TO DEVELOP THROUGHOUT THE AREA. TEMPS/DEWPOINTS IN THE 60S...WITH CALM WINDS. OF PARTICULAR NOTE...LI VALUES -2 ACROSS SE CUMBERLAND PLATEAU ALONG WITH TIGHT THETA E GRADIENT. 00Z THU REGIONAL MODEL EVOLUTIONS THROUGH 12Z SAT IN GOOD AGREEMENT ...ESPECIALLY IN THE UPPER LEVELS. SFC PATTERN TO REMAIN DIFFUSE... WITH UPPER LEVEL CLOSED LOW EXPECTED TO DRIFT W INTO W AR BY 12Z SAT. LATEST MODEL DIAGNOSTIC DISCUSSION POINTS OUT THAT MODELS NOT PICKING UP WELL AT ALL SHORT WAVE FEATURES ROTATING AROUND THE CLOSED LOW. POOR CONTINUITY FROM RUN TO RUN ON THEIR QPF VALUES ALSO. THUS THERE IS LOW CONFIDENCE IN ANY MODEL SOLUTION IN ADEQUATELY DEPICTING THESE SHORTWAVE FEATURES AS THEY ROTATE AROUND THE LOW THROUGH THE PERIOD. ALL MODELS GENERALLY INITIALIZE WITH THE UPPER LEVEL LOW WELL...WITH THE AVN THE BEST INITIALIZED HERE AND AT THE SFC. DESPITE LOW NATIONAL GUIDANCE CONFIDENCE IN ANY PARTICULAR MODEL SOLUTION... WILL LEAN TOWARD THE AVN SOLUTION FOR THE MID STATE THROUGH THE PERIOD. MAIN FORECAST QUANDARY CENTERS AROUND STRENGTH OF CONVECTION THAT COULD DEVELOP AS THE DAY PROGRESSES. AS MENTIONED BY LATEST DAY ONE CONVECTIVE OUTLOOK...SLIGHT RISK AREA HAS MOVED W INTO W TN...WHERE WEAKER LAPSE RATES AND VERTICAL WIND SHEAR ARE EXPECTED THAN ON THE W SIDE OF THE CLOSED UPPER LEVEL LOW. AVN CONTINUING TO SHOW MULTIPLE ATMOSPHERIC INDICES SUPPORTIVE OF CONVECTIVE DEVELOPMENT TODAY...BUT WITH WET BULB ZERO AND FREEZING LEVEL HEIGHTS AROUND 13KFT AND SWEATS AROUND 200 AT 00Z FRI. HOWEVER...CAPE VALUES NOT IMPRESSIVE...UNTIL THE AFTERNOON HOURS ON FRI WHEN THEY INCREASE TO OVER 2000 J/KG. WE ARE IN A SLIGHT RISK CRITERIA FOR SVR TS ON FRIDAY AS A RESULT. HOWEVER...WITH MODELS HAVING DIFFICULTY IN PICKING UP SHORTWAVE PASSAGES WHICH COULD ENHANCE DIURNAL HEATING INFLUENCES...BELIEVE THAT SOME TS ACTIVITY COULD BECOME STRONG WITH GUSTY WINDS...ESPECIALLY ACROSS W PORTIONS TODAY. BELIEVE THAT MAIN CHANCE OF TS WILL OCCUR THIS AFTERNOON. THUS...WILL BREAK OUT A MORNING GROUP IN THE ZONES TO DEAL WITH AREAS OF FOG AND LOW SCT PCPN CHANCES...EXCEPT E WHERE PRESENT CONVECTION ACROSS SE WARRANTS LIKELY POPS...AND PLATEAU HIGHER SCT POPS. CURRENT AND MODEL RH PROGS SUGGEST THAT VARIABLE SKY CONDITIONS WILL BE MORE APPROPRIATE FOR THE MORNING HOURS. WILL ADDRESS SKY CONDITIONS DURING THE AFTERNOON HOURS AS MOSTLY CLOUDY WITH POPS LIKELY ELSEWHERE. WILL ADDRESS EVENING SH/TS AS WIDELY SCATTERED TONIGHT AND FRIDAY NIGHT UNDER VARIABLE SKY CONDITIONS WITH AREAS OF FOG AGAIN DEVELOPING TONIGHT. WILL NOT AT THIS TIME MENTION STRENGTH OF CONVECTION ON FRI...AND LEAVE THIS DECISION UP TO LATER MODEL RUNS AND NEXT CREWS FORECASTER JUDGMENT. WILL HOWEVER CONTINUE WITH SCT POPS ON FRI. BELIEVE VARIABLE SKY CONDITIONS HERE ALSO MORE APPROPRIATE. TEMPS...WILL GO CLOSE TO AVN MOS NUMBERS FOR THE FORECAST PERIOD. NGM MOS HIGHS TOO WARM AS OF LATE. PRELIMINARY NUMBERS FOR COORDINATION PURPOSES ONLY... BNA 083/067/086/068 6232 CSV 081/063/083/065 6232 .BNA...NONE. 14 JBW tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 915 AM EDT THU JUN 28 2001 12Z SOUNDING HAS A LITTLE MORE MOISTURE TODAY...HOWEVER EXPECT RIDGING ALOFT TO SUPPRESS CONVECTION WITH NO FORCING. DO EXPECT SOME TYPICAL AFTN SHRA/TSRA...ESPCLY ALONG SEA BRZ HOWEVER CVRG SHLD BE LIMITED AND WL CONT MENTION OF ISOLD. CI CROSSING REGION IS QUITE THIN WITH SKIES MOSTLY SUNNY...DO EXPECT CU DVLPMENT THIS AFTN AND FCST OF PTLY SUNNY MAY WORK OK. THICKNESSES AND LIGHT DOWNSLOPE FLOW SHLD GIVE MUGGY HIGHS IN THE 90 TO 95 DGR RANGE INLAND WITH BEACHES A BIT COOLER. HEAT INDEX VALUES MAY TOP 100 AT FEW SPOTS BUT WL REMAIN BELOW ADVRY CRITERIA. CWF...HIGH PRES WILL CONTINUE TREND OF LITTLE PRES GRAD AND LOTS OF VARIABILITY IN THE WIND DIRECTION. WILL UPDATE DIR BASED ON RUC/06Z MESO-ETA WINDS WITH SPEEDS AROUND 10 KT. .MHX...NONE FREDERICK/ELARDO nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1100 AM CDT THU JUN 28 2001 WIDESPREAD CONVECTION CONTINUES ACROSS EASTERN OKLAHOMA IN REGION OF STRONGEST 850-750 MB LIFT/CONVERGENCE AND LEFT FRONT QUADRANT OF UPPER LEVEL JET. EASTERN HALF OF THE FORECAST AREA...INCLUDING AREAS ALONG AND EAST OF INTERSTATE 35 IS ON THE WESTERN FRINGE. EXPECT ACTIVITY TO DIMINISH BY EARLY AFTERNOON AS LOW LEVEL JET WEAKENS AND WIND DIRECTION BACKS. MAIN CONCERN FOR THIS AFTERNOON WILL BE STRENGTH AND POSITION OF OUTFLOW BOUNDARY CURRENTLY MOVING WEST FROM NEAR A LINE FROM ENID...TO GUTHRIE...TO SHAWNEE...TO ARDMORE. ACROSS SOUTHWEST OKLAHOMA...WESTERLY COMPONENT OF LOW LEVEL JET HAS MIXED TO THE SURFACE...ALLOWING A CONVERGENCE ZONE TO DEVELOP THERE AS WELL HOWEVER CONVERGENCE ALONG THIS BOUNDARY SHOULD WEAKEN BY EARLY AFTERNOON AS WINDS IN THE BOUNDARY LAYER BACK. ANOTHER BOUNDARY TO BE CONCERNED WITH WILL BE THE DRYLINE WHICH HAS ALREADY MIXED INTO FAR NORTHWEST OKLAHOMA. 12Z UPPER AIR ANALYSIS SHOWS 60 KT 300 MB JET ROTATING AROUND NORTHWEST SIDE OF UPPER LOW WHICH SHOULD ALLOW UPPER LOW TO MOVE CLOSER TO AREA AND MID/UPPER WIND SPEEDS TO INCREASE. LATEST RUC MODEL INDICATES MAJORITY OF AREA TO BE IN LEFT FRONT QUAD OF UPPER JET LATE IN THE DAY ALONG WITH 35-45 KT 0-6 KM SHEAR SUPPORTING ORGANIZED STORMS. CAP SHOULD WEAKEN QUICKLY WITH AFTERNOON HEATING AND GREATER INFLUENCE FROM UPPER LOW. EXPECT GREATER AREAL COVERAGE OF AFTERNOON CONVECTION COMPARED TO THIS TIME YESTERDAY AND SHOULD BE MOSTLY FOCUSED ALONG PREVIOUSLY MENTIONED OUTFLOW BOUNDARY AND DRYLINE. HAZARDOUS WEATHER OUTLOOK WILL BE UPDATED SHORTLY HIGHLIGHTING RISK OF SEVERE THUNDERSTORMS AND POTENTIAL FOR HEAVY RAIN. LATEST MODEL GUIDANCE ALSO SUGGESTS THE EASTERN HALF OF THE FORECAST AREA...PARTICULARLY SOUTH CENTRAL AND SOUTHEAST OKLAHOMA MAY EXPERIENCE WIDESPREAD CONVECTION LATE TONIGHT/EARLY FRIDAY IN REGIME OF STRONG THERMAL ADVECTION AND UPPER LEVEL DIVERGENCE. DEEP MOISTURE AND POTENTIAL FOR BACK-BUILDING THUNDERSTORMS PRESENT A RISK FOR HEAVY RAIN. A FLASH FLOOD WATCH MAY BE NEEDED. .OUN... OK...NONE. TX...NONE. JAMES ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 1036 AM EDT THU JUN 28 2001 50H SHORTWAVE ROTATING AROUND UPPER LOW WAS OVER NORTHERN AL THIS MORNING. 06Z MESO-ETA AND 12Z RUC DIFFER ON HOW CLOSE IT GETS TO THE CWA AS IT CONTINUES TO ROTATE NORTHWARD. THE 06Z MESO-ETA HAS IT OVER MIDDLE TN AND DOES NOT BRING MUCH QPF FOR THE CWA. THE RUC IS MORE AGGRESSIVE. WILL KEEP THE SAME POPS NO MATTER WHICH MODEL VERIFIES BEST...AS THERE SHOULD BE PLENTY OF CONVECTION DEVELOPING ACROSS THE CWA THIS AFTERNOON. MODIFIED MODEL SOUNDINGS INDICATED UP TO 2000 J/KG OF CAPE...AND THERE ARE PLENTY OF BOUNDARIES AROUND TO INITIATE THE STORMS (TERRAIN...DIFFERENTIAL HEATING FROM OVC OVER THE PLATEAU AND SE TN...AND THE PARTIAL SUN OVER THE REST OF THE CWA). TEMPS IN GENERALLY LOOK GOOD BUT MAY DROP THEM A BIT WHERE THE CLOUDS ARE OVER THE PLATEAU...AND SE TN. .MRX... NC...NONE. TN...NONE. VA...NONE. RBP tn