Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 06/21/07

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
845 PM PDT WED JUN 20 2007 .SHORT TERM...SATELLIE IMAGERY SHOWING MOSTLY CLEAR SKIES ACROSS THE REGION THIS EVENING...WITH THE EXCEPTION OF PATCHY LOW CLOUDS AND FOG RETURNING TO THE CENTRAL COAST. 00Z VANDENBERG SOUNDING SHOWED MARINE LAYER DEPTH AROUND 1900 FEET...BUT LATEST ACARS DATA SHOWING A DEPTH AROUND 800 FEET ACROSS THE LA BASIN AS OF 03Z. WITH UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDING ACROSS THE REGION THROUGH THURSDAY...LOOK FOR MARINE INVERSION TO REMAIN LOW AND STRENGTHEN WITH TIME. AS A RESULT...WOULD EXPECT LOW CLOUDS AND FOG TO GENERALLY BE CONFINED TO COASTAL AREAS THROUGH FRIDAY. WITH A MODERATE NORTHWEST FLOW PATTERN SETTING UP ACROSS SBA COUNTY THIS EVENING...IT MAY BE DIFFICULT FOR ANY STRATUS TO RETURN ACROSS THE SOUTH COAST OVERNIGHT. THE MAIN WEATHER CONCERNS DURING THE NEXT COUPLE OF DAYS WILL BE VERY WARM AND DRY CONDITIONS...ALONG WITH GUSTY WINDS ACROSS PORTIONS OF THE MOUNTAINS AND SOUTH COAST DURING THE LATE AFTERNOON THROUGH NIGHTTIME HOURS. WARMING TREND ALREADY UNDERWAY TODAY WITH SEVERAL INTERIOR LOCATIONS CLIMBING WELL INTO THE 90S. LOOK FOR THE WARMING TREND TO CONTINUE ON THURSDAY...WITH MOST INLAND LOCATIONS CLIMBING AN ADDITIONAL 3 TO 7 DEGREES. TRIPLE DIGIT HEAT COULD BE RECORDED ACROSS SOME OF THE WARMEST INTERIOR VALLEY AND MOUNTAIN LOCATIONS...WITH MORE WIDESPREAD 100 DEGREE READINGS EXPECTED ACROSS THE ANTELOPE VALLEY. VERY SIMILAR MAX TEMPERATURES ARE EXPECTED ON FRIDAY. WITH AIR MASS WARMING WITH TIME...LOOK FOR MINIMUM TEMPERATURES TO CLIMB NEXT COUPLE OF NIGHTS AS WELL. THE COMBINATION OF VERY WARM TEMPERATURES AND DRY CONDITIONS WILL CONTINUE CRITICAL FIRE WEATHER CONDITIONS IN THE MOUNTAINS...WHERE A RED FLAG WARNING REMAINS IN EFFECT. SEVERAL HOURS OF SINGLE DIGIT HUMIDITIES HAVE BEEN REPORTED ACROSS SOME MOUNTAIN LOCATIONS YESTERDAY AND TODAY...WITH ANOTHER ROUND EXPECTED ON THURSDAY. ANOTHER SIGNIFICANT FIRE WEATHER CONCERN WILL BE SUNDOWNER CONDITIONS ANTICIPATED ACROSS THE SANTA YNEZ RANGE AND ADJACENT PASSES AND CANYONS OF SOUTHERN SBA COUNTY ON THURSDAY NIGHT AND FRIDAY NIGHT. AT THIS POINT...IT APPEARS THAT THE SUNDOWNER CONDITION WILL BE MODERATE IN INTENSITY ON THURSDAY NIGHT...PERHAPS STRONGER ON FRIDAY NIGHT. THESE SUNDOWNER WINDS WILL LIKELY BRING WARMING CONDITIONS INTO THE SBA SOUTH COAST DURING THE LATE AFTERNOON AND EVENING HOURS ON BOTH THURSDAY AND FRIDAY. THE COMBINATION OF GUSTY WINDS AND CONTINUED DRY CONDITIONS HAS PROMPTED A FIRE WEATHER WATCH FOR SOUTHERN SBA COUNTY THURSDAY NIGHT INTO FRIDAY NIGHT. IN ADDITION...THERE WILL ALSO BE SOME GUSTY NORTHWEST WINDS ACROSS THE INTERSTATE 5 CORRIDOR EACH NIGHT AS WELL...WHICH MAY REQUIRE THE EXTENSION OF THE RED FLAG WARNING FOR THE LA COUNTY MOUNTAINS AS WELL. *** LONG TERM FROM PREVIOUS DISCUSSION *** .LONG TERM...MADE MINOR CHANGES THROUGH THE PERIOD. WESTERN EDGE OF THE THERMAL RIDGE IS EXPECT TO REBOUND AND PROPAGATE OFFSHORE THROUGH THE PERIOD. LOW CLOUDS WILL LIKELY PERSIST BENEATH A RELATIVELY STRONG CAPPING INVERSION. ABOVE NORMAL TEMPERATURES NEARLY TEN DEGREES ARE LIKELY OVER THE COASTAL VALLEYS AS WELL AS THE HIGHER ELEVATIONS TUE AND WED. && .AVIATION...21/0330Z LATER RETURN OF LOW CLOUDS AND FOG EXPECTED ACROSS COASTAL AREAS OVERNIGHT. WITH MARINE LAYER DEPTH EXPECTED TO REMAIN BETWEEN 800 AND 1000 FEET OVERNIGHT...LOOK FOR LOWERING CEILINGS AND VSBYS WITH IFR CONDITIONS LIKELY. AT THIS POINT...IT DOES NOT APPEAR THAT STRATUS WILL BE ABLE TO REACH KSBA OVERNIGHT. KLAX...BASED ON LATEST SATELLITE TRENDS WILL LIKELY BE BACKING OFF TIMING OF STRATUS ONSET IN NEXT TAF PACKAGE. BEST ESTIMATE OF CEILING AT KLAX WILL BE 08Z-10Z WITH A CEILING HEIGHT OF 600-800 FEET EXPECTED. STRATUS BURNOFF AROUND 17Z STILL LOOKS REASONABLE. KBUR...GOOD CONFIDENCE IN CLEAR SKIES THROUGH THURSDAY. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...RED FLAG WARNING (SEE LAXRFWLOX). FIRE WEATHER WATCH (SEE LAXRFWLOX). PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY (SEE LAXCWFLOX). && $$ PUBLIC...GOMBERG/FORWOOD AVIATION...GOMBERG WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
215 PM PDT TUE JUN 19 2007 .SYNOPSIS... A STRONG HIGH PRESSURE RIDGE WILL BUILD OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. TEMPERATURES WILL BE WELL ABOVE NORMAL AND NEAR RECORD TEMPERATURES ARE POSSIBLE THURSDAY AND FRIDAY OVER THE INLAND AREAS. A WEAK COASTAL EDDY AND ONSHORE FLOW WILL CONTINUE NIGHT AND MORNING CLOUDS AND FOG ALONG THE COASTS...OTHERWISE SKIES WILL BE CLEAR. MINOR COOLING AND A SLIGHT INCREASE IN CLOUDS IS EXPECTED FOR THE WEEKEND. THE SUMMER SOLSTICE WILL OCCUR ON THURSDAY JUNE 21 AT 1106 AM PDT. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM...TONIGHT THROUGH FRIDAY HOT AND DRY WEATHER PATTERN FOR SOUTHWEST CALIFORNIA. MODELS CONSISTENT IN BUILDING 500 MB RIDGE DIRECTLY OVERHEAD WITH HEIGHTS +5960 METERS BY THURSDAY AND THEN WEAKEN THE RIDGE EVER SO SLIGHTLY ON FRIDAY. THICKNESS VALUES AND 850 MB TEMPERATURES INCREASE THROUGH FRIDAY...INDICATING TEMPERATURES WILL BE ABOUT 2 TO 4 DEGREES WARMER WEDNESDAY...5 TO 10 DEGREES WARMER THURSDAY...AND ANOTHER 1 TO 2 DEGREES ON FRIDAY. CROSS SECTIONS...DEPENDING ON WHICH MODEL IS USED SHRINK MARINE LAYER TO 1000-1300 FEET TONIGHT/WEDNESDAY AND 500-800 FEET THURSDAY/FRIDAY. MOS GUIDANCE IS LIKELY TOO COOL AND PROBABLY TRENDING TOWARDS CLIMATOLOGY BEYOND DAY 2. EXPECT NEAR RECORD TEMPERATURES MOST LOCATIONS AND MINIMUM TEMPERATURES OVER LOWER DESERTS TO REMAIN NEAR OR ABOVE 80 DEGREES THURSDAY NIGHT THROUGH SATURDAY. && .LONG TERM...SATURDAY THROUGH TUESDAY 500 MB RIDGE STILL ACROSS FORECAST AREA SATURDAY AND SUNDAY WITH HEIGHTS +5880 METERS...SO DESERTS AND MOUNTAINS LIKELY TO STILL BE QUITE WARM AND VERY DRY. BY MONDAY WEAK TROUGH OFF BAJA COAST AND 500 MB HIGH CENTERED VERY CLOSE TO FOUR CORNERS AREA SET UP PATTERN SUPPORTIVE OF BRINGING MOISTURE UP FROM THE SOUTHEAST AND OVER SOUTHWEST CALIFORNIA. THE 06Z RUN OF THE GFS SHOWED PRECIPITATION AS EARLY AS SUNDAY NIGHT OVER SAN DIEGO COUNTY MOUNTAINS AND DESERTS...BUT SUSPECT THIS IS PREMATURE AND WILL LIKELY ONLY SEE SOME HIGH LEVEL CONVECTIVE DEBRIS. CURRENTLY HAVE SLIGHT POPS...GENERALLY LESS THAN 10 PERCENT...OVER MOUNTAINS FOR MONDAY AND TUESDAY. 12Z RUN OF GFS HAS FAVORABLE 850-700 MB FLOW AND MID LEVEL MOISTURE MOVING UP OVER SOUTHWEST CALIFORNIA BUT VERY DRY IN THE LOW LEVELS AND MODEL SOUNDINGS OVER DESERTS AND MOUNTAINS SHOW K VALUES IN THE MID 20S AND DRY MICROBURST POTENTIAL BETWEEN 30-40 KNOTS SO INCLUDED CHANCE DRY LIGHTNING AND GUSTY WINDS ON MONDAY AND TUESDAY FOR THESE AREAS. && .AVIATION... 191930Z...LATE MORNING MDCRS SOUNDINGS INDICATE THE MARINE LAYER DEPTH HAD LOWERED TO AROUND 1200 FEET NEAR KSAN AND TO LESS THAN 800 FEET NEAR KSNA SINCE EARLIER THIS MORNING. MARINE LAYER MAY SHOW SOME RECOVERY THIS EVENING AND TONIGHT BUT SHOULD REMAIN LESS THAN 1500 FEET. STRATUS WITH BASES AROUND 1000 FEET MSL WAS WELL OFF THE COAST BUT SHOULD BEGIN TO PUSH BACK ONTO THE SHORELINE LATER THIS AFTERNOON AFTER 23Z THEN PUSH BACK INTO THE LOWER INLAND VALLEY AREAS DURING THE MID TO LATE EVENING...AFTER 04Z. STRATUS SHOULD REMAIN OUT OF THE KONT AREA TONIGHT BUT SOME VISIBILITY RESTRICTION IS POSSIBLE BY SUNRISE. EARLIER CLEARING OF THE STRATUS IS EXPECTED ON WEDNESDAY WITH COASTAL AIRPORTS SCATTERING OUT BY 16Z. ABOVE THE MARINE LAYER...VFR CONDITIONS WILL CONTINUE THROUGH WEDNESDAY WITH CEILINGS AND VISIBILITIES UNRESTRICTED. && .FIRE WEATHER... STRONG DRYING OCCURRED OVERNIGHT AT ELEVATIONS ABOVE 2000 FEET. RELATIVE HUMIDITY AT MANY MOUNTAIN LOCATIONS FELL BELOW 10 PERCENT AROUND 3 AM. A SLIGHT INCREASE IN DEWPOINTS DUE TO MIXING TODAY WILL BRING HUMIDITY UP TO AROUND 15 PERCENT DURING THE LATE AFTERNOON. OVERNIGHT RECOVERY WILL BE POOR AGAIN TONIGHT ABOVE THE MARINE LAYER AND OVER THE MOUNTAINS AND DESERTS...WITH ONLY A FEW HOURS OF HUMIDITY ABOVE 25 PERCENT FORECAST. JUST AS DRY OR DRIER CONDITIONS ARE EXPECTED WEDNESDAY THROUGH FRIDAY DUE TO A LOWERING MARINE LAYER...AND WARMER TEMPERATURES...BOTH DAY AND NIGHT...WITH NO INCREASE IN MOISTURE. && .SGX WATCHES/WARNINGS/ADVISORIES... .SGX WATCHES/WARNINGS/ADVISORIES... CA...RED FLAG WARNING UNTIL 5 AM PDT THURSDAY FOR RIVERSIDE COUNTY MOUNTAINS-INCLUDING THE SAN JACINTO RANGER DISTRICT OF THE SAN BERNARDINO NATIONAL FOREST-SAN BERNARDINO COUNTY MOUNTAINS-INCLUDING THE MOUNTAIN TOP AND FRONT COUNTRY RANGER DISTRICTS OF THE SAN BERNARDINO NATIONAL FOREST-SAN DIEGO COUNTY MOUNTAINS-INCLUDING THE PALOMAR AND DESCANSO RANGER DISTRICTS OF THE CLEVELAND NATIONAL FOREST. PZ...NONE. && $$ PUBLIC/FIRE WEATHER...BALFOUR AVIATION/MARINE.......HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
935 AM PDT TUE JUN 19 2007 .SYNOPSIS... A STRONG HIGH PRESSURE RIDGE WILL BUILD OVER SOUTHERN CALIFORNIA THROUGH THURSDAY AND WARM TEMPERATURES TO WELL ABOVE NORMAL. NEAR RECORD TEMPERATURES ARE POSSIBLE THURSDAY AND FRIDAY OVER INLAND AREAS. A WEAK COASTAL EDDY AND ONSHORE FLOW WILL CONTINUE NIGHT AND MORNING CLOUDS AND FOG ALONG THE COASTS...OTHERWISE SKIES WILL BE CLEAR. MINOR COOLING AND A SLIGHT INCREASE IN CLOUDS IS EXPECTED FOR THE WEEKEND. THE SUMMER SOLSTICE WILL OCCUR ON THURSDAY JUNE 21 AT 1106 AM PDT. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM...TODAY THROUGH FRIDAY HOT AND DRY WEATHER PATTERN FOR SOUTHWEST CALIFORNIA. MODELS CONSISTENT IN BUILDING 500 MB RIDGE DIRECTLY OVERHEAD WITH HEIGHTS +5960 METERS BY THURSDAY AND THEN WEAKEN THE RIDGE EVER SO SLIGHTLY ON FRIDAY. THICKNESS VALUES AND 850 MB TEMPERATURES INCREASE THROUGH FRIDAY...INDICATING TEMPERATURES WILL BE ABOUT 2 TO 4 DEGREES WARMER WEDNESDAY...5 TO 10 DEGREES WARMER THURSDAY...AND ANOTHER 1 TO 2 DEGREES ON FRIDAY. CROSS SECTIONS...DEPENDING ON WHICH MODEL IS USED SHRINK MARINE LAYER TO 1000-13000 FEET TONIGHT/WEDNESDAY AND 500-800 FEET THURSDAY/FRIDAY. MOS GUIDANCE IS LIKELY TOO COOL AND EXPECT NEAR RECORD TEMPERATURES. && .LONG TERM...SATURDAY THROUGH TUESDAY...CORRECTED 500 MB RIDGE STILL ACROSS FORECAST AREA SATURDAY AND SUNDAY WITH HEIGHTS +5880 METERS. BY MONDAY WEAK TROUGH OFF BAJA COAST AND 500 MB HIGH CENTERED VERY CLOSE TO FOUR CORNERS AREA SET UP PATTERN SUPPORTIVE OF BRINGING MOISTURE UP FROM THE SOUTHEAST AND OVER SOUTHWEST CALIFORNIA. THE 06Z RUN OF THE GFS SHOWED PRECIPITATION AS EARLY AS SUNDAY NIGHT OVER SAN DIEGO COUNTY MOUNTAINS AND DESERTS...BUT SUSPECT THIS IS PREMATURE AND WILL LIKELY ONLY SEE SOME HIGH LEVEL CONVECTIVE DEBRIS. CURRENTLY HAVE SLIGHT POPS...GENERALLY LESS THAN 10 PERCENT...OVER MOUNTAINS FOR MONDAY AND TUESDAY. WILL LOOK AT 12Z RUN OF GFS AND SEE IF 850-700 MB FLOW IS SUPPORTIVE OF BRINGING MID LEVEL MOISTURE OVER SOUTHWEST CALIFORNIA...IF SO MAY INCLUDE MENTION SLIGHT CHANCE OF DRY THUNDERSTORMS ON TUESDAY. && .AVIATION... 191400Z...MARINE LAYER DEPTH WAS AROUND 2000 FEET THIS MORNING BASED ON MORNING TOP REPORTS AND MDCRS SOUNDINGS. THE MARINE LAYER DEPTH SHOULD LOWER TO AROUND 1500 FEET THIS AFTERNOON AND TONIGHT. STRATUS WITH BASES AROUND 1500 FEET MSL SHOULD CLEAR TO THE SHORELINE BETWEEN 15Z AND 17Z. SOME STRATUS WILL PUSH BACK ONTO THE COAST DURING THE AFTERNOON BETWEEN 22Z AND 00Z THEN PUSH BACK INLAND THIS EVENING AFTER SUNSET REACHING THE LOWER INLAND VALLEY AREAS AROUND MIDNIGHT. STRATUS IS NOT EXPECTED TO REACH THE INLAND EMPIRE NEAR KONT TONIGHT. A LITTLE EARLIER CLEARING IS EXPECTED ON WEDNESDAY. ABOVE THE MARINE LAYER...VFR CONDITIONS WILL CONTINUE THROUGH WEDNESDAY WITH CEILINGS AND VISIBILITIES UNRESTRICTED. && .FIRE WEATHER... STRONG DRYING OCCURRED OVERNIGHT AT ELEVATIONS ABOVE 2000 FEET. RELATIVE HUMIDITY AT MANY MOUNTAIN LOCATIONS FELL BELOW 10 PERCENT AROUND 3 AM. A SLIGHT INCREASE IN DEWPOINTS DUE TO MIXING TODAY WILL BRING HUMIDITY UP TO AROUND 15 PERCENT DURING THE LATE AFTERNOON. OVERNIGHT RECOVERY WILL BE POOR AGAIN TONIGHT ABOVE THE MARINE LAYER AND OVER THE MOUNTAINS AND DESERTS...WITH ONLY A FEW HOURS OF HUMIDITY ABOVE 25 PERCENT FORECAST. JUST AS DRY OR DRIER CONDITIONS ARE EXPECTED WEDNESDAY THROUGH FRIDAY DUE TO A LOWERING MARINE LAYER...AND WARMER TEMPERATURES...BOTH DAY AND NIGHT...WITH NO INCREASE IN MOISTURE. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC/FIRE WEATHER...BALFOUR AVIATION/MARINE.......HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
920 AM PDT TUE JUN 19 2007 .SYNOPSIS... A STRONG HIGH PRESSURE RIDGE WILL BUILD OVER SOUTHERN CALIFORNIA THROUGH THURSDAY AND WARM TEMPERATURES TO WELL ABOVE NORMAL. NEAR RECORD TEMPERATURES ARE POSSIBLE THURSDAY AND FRIDAY OVER INLAND AREAS. A WEAK COASTAL EDDY AND ONSHORE FLOW WILL CONTINUE NIGHT AND MORNING CLOUDS AND FOG ALONG THE COASTS...OTHERWISE SKIES WILL BE CLEAR. MINOR COOLING AND A SLIGHT INCREASE IN CLOUDS IS EXPECTED FOR THE WEEKEND. THE SUMMER SOLSTICE WILL OCCUR ON THURSDAY JUNE 21 AT 1106 AM PDT. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM...TODAY THROUGH FRIDAY HOT AND DRY WEATHER PATTERN FOR SOUTHWEST CALIFORNIA. MODELS CONSISTENT IN BUILDING 500 MB RIDGE DIRECTLY OVERHEAD WITH HEIGHTS +5960 METERS BY THURSDAY AND THEN WEAKEN THE RIDGE EVER SO SLIGHTLY ON FRIDAY. THICKNESS VALUES AND 850 MB TEMPERATURES INCREASE THROUGH FRIDAY...INDICATING TEMPERATURES WILL BE ABOUT 2 TO 4 DEGREES WARMER WEDNESDAY...5 TO 10 DEGREES WARMER THURSDAY...AND ANOTHER 1 TO 2 DEGREES ON FRIDAY. CROSS SECTIONS...DEPENDING ON WHICH MODEL IS USED SHRINK MARINE LAYER TO 1000-13000 FEET TONIGHT/WEDNESDAY AND 500-800 FEET THURSDAY/FRIDAY. MOS GUIDANCE IS LIKELY TOO COOL AND EXPECT NEAR RECORD TEMPERATURES. && .LONG TERM...SATURDAY THROUGH TUESDAY 500 MB RIDGE STILL ACROSS FORECAST AREA SATURDAY AND SUNDAY WITH HEIGHTS +5880 METERS. BY MONDAY WEAK TROUGH OFF BAJA COAST AND 500 MB HIGH CENTERED VERY CLOSE TO FOUR CORNERS AREA SET UP PATTERN SUPPORTIVE OF BRINGING MOISTURE UP FROM THE SOUTHEAST AND OVER SOUTHWEST CALIFORNIA. THE 06Z RUN OF THE GFS SHOWED PRECIPITATION AS EARLY AS SUNDAY NIGHT OVER SAN DIEGO COUNTY MOUNTAINS AND DESERTS...BUT SUSPECT THIS IS PREMATURE AND WILL LIKELY ONLY SEE SOME HIGH LEVEL CONVECTIVE DEBRIS. CURRENTLY HAVE SLIGHT POPS...LESS THAN 10 PERCENT OVER...MOUNTAINS FOR MONDAY. WILL LOOK AT 12Z RUN OF GFS AND SEE IF 850-700 MB FLOW IS SUPPORTIVE OF BRINGING MID LEVEL MOISTURE OVER SOUTHWEST CALIFORNIA ON TUESDAY. IF SO WILL INCLUDE POPS ON THIS DAY AND MAY MENTION SLIGHT CHANCE OF DRY THUNDERSTORMS. && .AVIATION... 191400Z...MARINE LAYER DEPTH WAS AROUND 2000 FEET THIS MORNING BASED ON MORNING TOP REPORTS AND MDCRS SOUNDINGS. THE MARINE LAYER DEPTH SHOULD LOWER TO AROUND 1500 FEET THIS AFTERNOON AND TONIGHT. STRATUS WITH BASES AROUND 1500 FEET MSL SHOULD CLEAR TO THE SHORELINE BETWEEN 15Z AND 17Z. SOME STRATUS WILL PUSH BACK ONTO THE COAST DURING THE AFTERNOON BETWEEN 22Z AND 00Z THEN PUSH BACK INLAND THIS EVENING AFTER SUNSET REACHING THE LOWER INLAND VALLEY AREAS AROUND MIDNIGHT. STRATUS IS NOT EXPECTED TO REACH THE INLAND EMPIRE NEAR KONT TONIGHT. A LITTLE EARLIER CLEARING IS EXPECTED ON WEDNESDAY. ABOVE THE MARINE LAYER...VFR CONDITIONS WILL CONTINUE THROUGH WEDNESDAY WITH CEILINGS AND VISIBILITIES UNRESTRICTED. && .FIRE WEATHER... STRONG DRYING OCCURRED OVERNIGHT AT ELEVATIONS ABOVE 2000 FEET. RELATIVE HUMIDITY AT MANY MOUNTAIN LOCATIONS FELL BELOW 10 PERCENT AROUND 3 AM. A SLIGHT INCREASE IN DEWPOINTS DUE TO MIXING TODAY WILL BRING HUMIDITY UP TO AROUND 15 PERCENT DURING THE LATE AFTERNOON. OVERNIGHT RECOVERY WILL BE POOR AGAIN TONIGHT ABOVE THE MARINE LAYER AND OVER THE MOUNTAINS AND DESERTS...WITH ONLY A FEW HOURS OF HUMIDITY ABOVE 25 PERCENT FORECAST. JUST AS DRY OR DRIER CONDITIONS ARE EXPECTED WEDNESDAY THROUGH FRIDAY DUE TO A LOWERING MARINE LAYER...AND WARMER TEMPERATURES...BOTH DAY AND NIGHT...WITH NO INCREASE IN MOISTURE. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC/FIRE WEATHER...BALFOUR AVIATION/MARINE.......HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS MIAMI FL
249 PM EDT TUE JUN 19 2007 .DISCUSSION...LATEST VISIBLE SATELLITE AND SURFACE OBS SHOW SEA BREEZE HAS MADE PROGRESS FAIRLY FAR INLAND ACROSS SOUTH FLORIDA AND LIES ACROSS THE EVERGLADES. ISOLATED SHOWERS AND THUNDERSTORMS WERE FORMING ALONG THE BOUNDARY ACROSS THE EVERGLADES...WITH OTHER STORMS DEVELOPING ALONG THE WEST COAST SEA BREEZE JUST INLAND FROM THE COAST. STORM MOTION IS SLOW ONCE AGAIN TODAY WITH A SLIGHT SOUTHWARD DRIFT. OVERALL ACTIVITY HAS BEEN SOMEWHAT LIMITED TODAY...POSSIBLY DUE TO SOME SLIGHT MID LEVEL WARMING SEEN ON ACARS SOUNDING DATA...AND A SLIGHT DROP IN PRECIPITABLE WATER THROUGH THE DAY. MODELS ARE STILL IN DECENT AGREEMENT ON THE EVOLUTION OF THE LARGE SCALE PATTERN OVER THE NEXT SEVERAL DAYS WITH NOT MUCH CHANGE. A DEEP LAYERED MID/UPPER RIDGE WILL CONTINUE TO STRENGTHEN OVER THE SOUTHERN ROCKIES...ALLOWING TROUGHING TO DEVELOP ALONG THE U.S. EAST COAST AS A POTENT SHORTWAVE CURRENTLY ACROSS ALABAMA MOVES EAST ALONG THE GULF COAST. GLOBAL MODELS HAVE BEEN WAVERING SOMEWHAT AS TO WHAT TO DO WITH THIS SYSTEM...AS SOME OF THE MODELS...00Z ECMWF/CANADIAN AND 12Z GFS MOVE THE SYSTEM INTO THE WESTERN ATLANTIC OFF THE GA/CAROLINA COAST WHILE THE 00Z/06Z GFS...LAST FEW NAM RUNS...AND 00Z UKMET DROP THE SYSTEM OVER OR NEAR THE NE GULF OF MEXICO/CENTRAL FLORIDA...AND DEVELOP A SFC LOW IN THIS VICINITY. THE NEW/12Z GFS AS PREVIOUSLY MENTIONED IS FASTER AND MORE NORTHERLY WITH THIS SYSTEM THAN ALL OF THE PREVIOUS GFS RUNS THE LAST FEW DAYS...MORE IN LINE WITH THE ECMWF AND CANADIAN. REGARDLESS OF WHERE THIS DEVELOPING SYSTEM TRACKS...IT`S REASONABLE THAT A SURFACE TROUGH LIKE FEATURE WILL PASS ACROSS CENTRAL/SOUTH FLORIDA VERY SLOWLY LATER THIS WEEK/THIS WEEKEND WITH GENERAL WEAK UPPER TROUGHINESS AND ABUNDANT MOISTURE REMAINING IN PLACE...AND THIS WILL LEAD TO CHANCES FOR THUNDERSTORMS EACH DAY. BEST CHANCE FOR STORMS ON WEDNESDAY APPEARS TO BE ACROSS NORTHERN INTERIOR/EAST COAST AREAS AS STORMS DEVELOP ALONG THE EAST COAST SEA BREEZE ACROSS THE EVERGLADES AND THEN DRIFT E/NE. SFC/UPPER LEVEL FLOW BECOMES PREDOMINANTLY SW ON THURSDAY AND FRIDAY WHICH WILL HEAVILY FAVOR CONVECTION ACROSS THE EASTERN HALF OF THE EVERGLADES AND EAST COAST METRO AREAS DURING THE AFTERNOON...THOUGH HAVE NOT BROUGHT POPS INTO LIKELY CATEGORY YET ON THURSDAY UNTIL EXACT TRACK OF THE SYSTEM IS RESOLVED. && .AVIATION...VFR CONDITIONS EAST COAST TERMINALS THIS AFTERNOON THROUGH WEDNESDAY. CONVECTION WILL START FIRING SOON INLAND, ALTHOUGH LATER THAN YESTERDAY. WHEN THIS ACTIVITY MEETS UP WITH THE WEST COAST SEA BREEZE, EXPECT SCATTERED TO NUMEROUS THUNDERSTORMS INTERIOR SOUTHWEST UNTIL EARLY EVENING POSSIBLY MISSING NAPLES AS THE FLOW IS TO THE SSW. && .MARINE...LIGHT WINDS WILL CONTINUE THROUGH THE PERIOD...WITH SPEEDS GENERALLY 10 KNOTS OR LESS OUTSIDE THUNDERSTORM INFLUENCES...WITH SEAS 3 FEET OR LESS OUTSIDE THUNDERSTORMS AS WELL. WINDS WILL GRADUALLY SHIFT TO S/SE ON WEDNESDAY AND THEN SW FOR THE END OF THE WEEK...AND WINDS/SEAS MAY INCREASE BRIEFLY TO 10-15 KNOTS/3 FEET ON THURSDAY AFTERNOON IF SURFACE TROUGH GETS CLOSE ENOUGH TO MAKE FOR A SLIGHTLY TIGHTER PRESSURE GRADIENT. && .FIRE WEATHER...NO CONCERNS AT THIS TIME AS ABUNDANT LOW LEVEL MOISTURE WILL KEEP RH`S ABOVE CRITICAL LEVELS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 74 88 74 88 / 20 40 30 50 FORT LAUDERDALE 75 87 75 87 / 20 40 30 50 MIAMI 74 89 74 89 / 20 40 30 50 NAPLES 73 88 73 87 / 30 30 20 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ AVIATION: GR REST: STRASSBERG
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1044 AM EDT TUE JUN 19 2007 .UPDATE...12Z MIAMI SOUNDING SHOWED PRECIPITABLE WATER AROUND 2 INCHES THIS MORNING...AND SFC OBS INDICATE DEWPOINTS CONTINUING IN THE LOW TO MID 70S. THIS WILL LEAD TO PLENTY OF INSTABILITY AGAIN TODAY...AND DEVELOPMENT OF NUMEROUS THUNDERSTORMS ACROSS INTERIOR AREAS. CHANCES ARE A LITTLE MORE UNCERTAIN ALONG THE EAST COAST SINCE A SEA BREEZE SHOULD PUSH SOME WAYS INLAND EARLY THIS AFTERNOON...BUT JUST HOW FAR IS UNCERTAIN. STEERING FLOW IS LIGHT OUT OF THE NNE TODAY SO ANY STORMS THAT FORM SHOULD DRIFT SSW. THIS MEANS THAT CHANCES FOR STORMS ACROSS THE EAST COAST METRO AREAS DEPENDS ON WHERE STORMS ACTUALLY BEGIN DEVELOPING. AT THIS POINT...FEEL THAT STORMS MAY DEVELOP ACROSS THE WESTERN METRO AREAS BEFORE MOVING TO THE SSW AWAY FROM THEM. THEREFORE, HAVE DECIDED TO LOWER THESE AREAS TO CHANCE POPS FROM LIKELY DUE TO THE STORM MOTIONS BEING MAINLY AWAY FROM THE METRO AREAS TODAY. OTHER STORMS ARE EXPECTED TO FORM ALONG THE WEST COAST SEA BREEZE AS IT PUSHES INLAND...WITH THE NNE STORM MOTION ALLOWING STORMS TO DRIFT SLOWLY BACK TOWARDS THE WEST COAST. .AVIATION...AVIATION CONCERNS ARE SOMEWHAT UNCERTAIN TODAY AS SEA BREEZE PUSHES INLAND...BUT HOW FAR INLAND REMAINS IN QUESTION. THIS WILL ULTIMATELY DETERMINE HOW MUCH THUNDERSTORMS MAY IMPACT EAST COAST TERMINALS THIS AFTERNOON. EXPECT THE MORE INLAND TERMINALS/KMIA/KOPF/KFXE WOULD HAVE THE GREATEST THREAT OF THUNDER AND ASSOCIATED TEMPORARY IFR CONDITIONS. STORMS OVER THE INTERIOR SHOULD DRIFT SSW IN THE GENERAL VICINITY OF KAPF BUT THIS MAY NOT HAPPEN UNTIL LATE AFTERNOON. STRASSBERG && .PREV DISCUSSION... /ISSUED 357 AM EDT TUE JUN 19 2007/ SYNOPSIS...WEAK HIGH PRESSURE REMAINS CENTERED OVER THE WESTERN NORTH ATLANTIC. DISCUSSION...THE OVERALL PATTERN HAS NOT CHANGED SINCE YESTERDAY... PRECIPITABLE WATER IS STILL RUNNING NEAR THE SAME, THE STEERING FLOW IS NEARLY THE SAME, THE SURFACE WINDS ARE NEARLY THE SAME, AND IT APPEARS THAT THE 500MB TEMPS MAY HAVE EVEN COOLED SOME COMPARED TO YESTERDAY (ACCORDING TO AIRCRAFT SOUNDINGS AND FORECAST SOUNDINGS FOR TODAY). FROM MY PERSPECTIVE THERE SHOULD NOT BE ANY REASON TO EXPECT MUCH LESS ACTIVITY TODAY THAN THERE WAS YESTERDAY ESPECIALLY WITH THE FORECAST SOUNDINGS LARGELY UNCAPPED BY AFTERNOON. SO WENT WELL OVER GUIDANCE AND KEPT POPS NEARLY THE SAME AS ON MONDAY. THE ONLY DIFFERENCE IS THAT THE EAST COAST SEA BREEZE MAY BE STRONG ENOUGH TO KEEP MOST OF THE ACTIVITY OFF THE IMMEDIATE COAST FOR MOST OF THE DAY, BUT WITH THE STEERING FLOW SO SLOW AND THE SURFACE WINDS SO WEAK ANY OUTFLOW BOUNDARY MAY STILL CREATE SOME STORMS ALONG THE COAST. VIRTUALLY THE SAME SCENARIO FOR THE WEST COAST AS WELL, BUT WITH THE WEAK SOUTHEAST FLOW AT THE SURFACE AND SLOW SOUTH SOUTHWEST STORM MOTION TODAY THE WEST COAST SEA BREEZE MAY BE MORE ACTIVE THAN ITS EAST COAST COUNTERPART. THIS STORMY PATTERN IS EXPECTED TO CONTINUE THROUGH THE REST OF THE WEEK AND INTO THE WEEKEND AS WELL. THE UPPER RIDGE CURRENTLY OVER THE GULF IS EXPECTED TO RETROGRADE WEST AND ALLOW AN UPPER TROUGH TO BECOME ESTABLISHED ACROSS FLORIDA BY WEDNESDAY. MULTIPLE UPPER DISTURBANCES ARE EXPECTED TO ROUND THE BASE OF THIS TROUGH AND WITH AMPLE MOISTURE AND DAYTIME HEATING CONVECTION WILL LIKELY OCCUR EACH DAY. THE BIGGEST QUESTION STEMS FROM THE PLACEMENT OF A SURFACE LOW AND ASSOCIATED TROUGH. GUIDANCE HAS MOVED THE LOW AND TROUGH AROUND WITH MOST RUNS, BUT IF THIS LOW PRESSURE SYSTEM MOVES FARTHER SOUTH INTO SOUTH FLORIDA, POP CHANCES MAY NEED TO BE INCREASED EVEN MORE. THUNDERSTORM CHANCES ARE NOT EXPECTED TO DECREASE OVER THE WEEKEND AS EVEN DEEPER TROPICAL MOISTURE STREAMS OUT OF THE CARIBBEAN AND INTERACTS WITH THE ALREADY IN PLACE UPPER TROUGH AND POSSIBLY IN PLACE SURFACE TROUGH. AVIATION...VFR ALL TERMINALS THROUGH 16Z THEN AFTERNOON CONVECTION DEVELOPS. WEAK STEERING WINDS ALLOW VCTS ALL TERMINALS WITH A CONCENTRATION OF TSRA AGAIN TOWARD THE SE COAST AS WHAT STEERING WINDS THERE ARE SENDS TSRA MAINLY TOWARD KFLL...KFXE...KOPF...KMIA AND KTMB PRIMARILY. MARINE...A LIGHT WIND REGIME IS EXPECTED TROUGH THE PERIOD, AND THIS WILL KEEP WINDS GENERALLY LESS THAN 15 KNOTS AND WAVES AT OR BELOW 4 FEET TROUGH THE PERIOD. HOWEVER, WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED OVER THE COASTAL WATERS EACH DAY MARINERS CAN EXPECT TH POSSIBILITY OF HIGHER WINDS AND WAVES IN AND NEAR ANY SHOWER OR THUNDERSTORM. FIRE WEATHER...NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 75 89 75 / 40 20 50 30 FORT LAUDERDALE 87 77 88 75 / 40 20 50 30 MIAMI 88 75 89 74 / 50 20 50 30 NAPLES 91 73 90 74 / 50 30 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ LONG TERM...04/AT SHORT TERM/AVIATION...15/JR
AREA FORECAST DISCUSSION
NWS MIAMI FL
357 AM EDT TUE JUN 19 2007 .SYNOPSIS...WEAK HIGH PRESSURE REMAINS CENTERED OVER THE WESTERN NORTH ATLANTIC. && .DISCUSSION...THE OVERALL PATTERN HAS NOT CHANGED SINCE YESTERDAY... PRECIPITABLE WATER IS STILL RUNNING NEAR THE SAME, THE STEERING FLOW IS NEARLY THE SAME, THE SURFACE WINDS ARE NEARLY THE SAME, AND IT APPEARS THAT THE 500MB TEMPS MAY HAVE EVEN COOLED SOME COMPARED TO YESTERDAY (ACCORDING TO AIRCRAFT SOUNDINGS AND FORECAST SOUNDINGS FOR TODAY). FROM MY PERSPECTIVE THERE SHOULD NOT BE ANY REASON TO EXPECT MUCH LESS ACTIVITY TODAY THAN THERE WAS YESTERDAY ESPECIALLY WITH THE FORECAST SOUNDINGS LARGELY UNCAPPED BY AFTERNOON. SO WENT WELL OVER GUIDANCE AND KEPT POPS NEARLY THE SAME AS ON MONDAY. THE ONLY DIFFERENCE IS THAT THE EAST COAST SEA BREEZE MAY BE STRONG ENOUGH TO KEEP MOST OF THE ACTIVITY OFF THE IMMEDIATE COAST FOR MOST OF THE DAY, BUT WITH THE STEERING FLOW SO SLOW AND THE SURFACE WINDS SO WEAK ANY OUTFLOW BOUNDARY MAY STILL CREATE SOME STORMS ALONG THE COAST. VIRTUALLY THE SAME SCENARIO FOR THE WEST COAST AS WELL, BUT WITH THE WEAK SOUTHEAST FLOW AT THE SURFACE AND SLOW SOUTH SOUTHWEST STORM MOTION TODAY THE WEST COAST SEA BREEZE MAY BE MORE ACTIVE THAN ITS EAST COAST COUNTERPART. THIS STORMY PATTERN IS EXPECTED TO CONTINUE THROUGH THE REST OF THE WEEK AND INTO THE WEEKEND AS WELL. THE UPPER RIDGE CURRENTLY OVER THE GULF IS EXPECTED TO RETROGRADE WEST AND ALLOW AN UPPER TROUGH TO BECOME ESTABLISHED ACROSS FLORIDA BY WEDNESDAY. MULTIPLE UPPER DISTURBANCES ARE EXPECTED TO ROUND THE BASE OF THIS TROUGH AND WITH AMPLE MOISTURE AND DAYTIME HEATING CONVECTION WILL LIKELY OCCUR EACH DAY. THE BIGGEST QUESTION STEMS FROM THE PLACEMENT OF A SURFACE LOW AND ASSOCIATED TROUGH. GUIDANCE HAS MOVED THE LOW AND TROUGH AROUND WITH MOST RUNS, BUT IF THIS LOW PRESSURE SYSTEM MOVES FARTHER SOUTH INTO SOUTH FLORIDA, POP CHANCES MAY NEED TO BE INCREASED EVEN MORE. THUNDERSTORM CHANCES ARE NOT EXPECTED TO DECREASE OVER THE WEEKEND AS EVEN DEEPER TROPICAL MOISTURE STREAMS OUT OF THE CARIBBEAN AND INTERACTS WITH THE ALREADY IN PLACE UPPER TROUGH AND POSSIBLY IN PLACE SURFACE TROUGH. && .AVIATION...VFR ALL TERMINALS THROUGH 16Z THEN AFTERNOON CONVECTION DEVELOPS. WEAK STEERING WINDS ALLOW VCTS ALL TERMINALS WITH A CONCENTRATION OF TSRA AGAIN TOWARD THE SE COAST AS WHAT STEERING WINDS THERE ARE SENDS TSRA MAINLY TOWARD KFLL...KFXE...KOPF...KMIA AND KTMB PRIMARILY. && .MARINE...A LIGHT WIND REGIME IS EXPECTED TROUGH THE PERIOD, AND THIS WILL KEEP WINDS GENERALLY LESS THAN 15 KNOTS AND WAVES AT OR BELOW 4 FEET TROUGH THE PERIOD. HOWEVER, WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED OVER THE COASTAL WATERS EACH DAY MARINERS CAN EXPECT TH POSSIBILITY OF HIGHER WINDS AND WAVES IN AND NEAR ANY SHOWER OR THUNDERSTORM. && .FIRE WEATHER...NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 75 89 75 / 60 20 50 30 FORT LAUDERDALE 87 77 88 75 / 50 20 50 30 MIAMI 88 75 89 74 / 60 20 50 30 NAPLES 91 73 90 74 / 50 30 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ LONG TERM...04/TINGLER SHORT TERM/AVIATION...15/JR
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
942 PM EDT WED JUN 20 2007 .SYNOPSIS... HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT. A COUPLE OF WEAK COLD FRONT WILL CROSS THE REGION THROUGH THE END OF THE WEEK. HIGH PRESSURE WILL BUILD THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WATER VAPOR LOOP SHOWS THE PASSAGE OF A SHARP TROUGH WITH VERY DRY AIR ALOFT MOVING INTO THE REGION. A SHORTWAVE IS MOVING SOUTHEAST ACROSS THE UPPER GREAT LAKES...WITH RIDGING ACROSS THE FOUR CORNERS REGION. ACARS 400-250MB WIND OBSERVATIONS INDICATES TROUGH ALOFT IS REBUILDING ACROSS TH EASTERN GREAT LAKES AHEAD OF A 90-120KT NORTHWESTERLY JET FROM SOUTH CENTRAL CANADA. 19Z SURFACE ANALYSIS PLACED A COLD FRONT OFF THE MID ATLANTIC COAST...WITH A 1020MB ANTICYCLONE ACROSS THE MIDWEST. THE NEXT COLD FRONT WAS DROPPING SOUTH THROUGH THE UPPER MIDWEST. 00Z KIAD RAOB AND GPS DERIVED PRECIPITABLE WATER VALUES ARE IN THE 0.55-0.65" RANGE THIS EVENING...ALLOWING CUMULUS TO DECAY AS WINDS DECOUPLE IN THE VALLEYS. WATCHING SOME UPSTREAM MID AND UPPER LEVEL BLOWOFF FROM CONVECTION WHICH MAY BRING A PERIOD OF PARTLY CLOUDY SKY OVERNIGHT. LOW TEMPERATURES ARE BASED ON THE 12Z ETA MOS WITH LOCAL TWEAKS FOR BIAS. WINDS ARE BASED ON THE 18Z LWX WRF-ARW. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... WNDS BACK A LTL TMRW IN ADVC OF WK CDFNT/SFC TROF APPCHG CWFA. FEATURE NOW ACRS WI/MN...AND THERE/S NOT MUCH CLDCVR PRESENT THERE ATTM. SO...WL BE MORE RESERVED THAN GOING FCST. HWVR...CANNOT RULE OUT SCT HIGH CLDS...W/ A FEW-SCT DIURNAL CU TOSSED IN AS WELL. NRN CNTYS SHUD BE CLDIEST DUE TO RELATIVE LOCATION OF SFC-H5 TROF AXIS. GNDC ALSO KICKING OUT SOME WND GUSTS. NAM MORE EMPHATIC. HWVR... TDA/S WNDS WERE OVERDONE A BIT...SO WL TONE DOWN. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... NORTHWEST FLOW WILL CONTINUE ON FRIDAY WITH THE NAM STREAMING IN A FEW WEAK BANDS OF MOISTURE...MAINLY DEBRIS FROM THUNDERSTORM COMPLEXES OVER THE SOUTHERN GREAT LAKES...NORTHERN OHIO RIVER VALLEY REGION. THE GFS...WHICH HAS CONSISTENTLY BROUGHT THIS FEATURE OVER THE MID ATLANTIC FOR THE PAST FEW DAYS...NOW PULLS THE SYSTEM FURTHER SOUTH. WENT A BLEND OF THE SOLUTIONS WITH SOME ADJUSTED NW TO SE POPS FRI INTO SAT. BOTH MODELS DEVELOP A POTENT LITTLE MESO LOW PRESSURE AREA NEAR THE QUAD CITIES AREA OF THE MIDWEST...WITH THE NAM PUSHING A THIN BAND OF MOISTURE ALL THE WAY TO THE ATLANTIC COAST. THE GFS STALLS THE SYSTEM OVER THE MID MISSISSIPPI REGION AND WASHES IT OUT AND HIGH PRESSURE BUILDS ACROSS THE EAST. MOST LONG RANGE MODELS HAVE SEVERAL SYSTEMS COMING TOGETHER DURING THE MIDDLE OF THE WEEK. UNCERTAINTY WILL REMAIN ABOUT THIS TIME PERIOD...THOUGH IT LOOKS LIKE ZONAL FLOW OVER THE UPPER MIDWEST BRINGS A PRECEDING SYSTEM INTO THE OHIO VALLEY TO MEET WITH RETURN FLOW FROM THE GULF OF MEXICO FOR AN ACTIVE MIDDLE OF NEXT WEEK. BEFORE THAT TIME AND THROUGH THE WEEKEND...TEMPS WILL RISE STEADILY INTO THE U80S AND L90S. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... HIGH PRESSURE BUILDING IN WILL ALLOW WINDS TO DECOUPLE OVERNIGHT. THE BIGGEST CONCERN AT THIS TIME IS THE AFTERNOON PUSH TOMORROW AS A DRY COLD FRONTAL PASSAGE FROM THE NORTHWEST WILL BRING VEERING AND GUSTY WINDS TO THE REGION. WEAK FRONTAL BANDS WITH LIMITED MOISTURE WILL STREAM ACROSS THE AREA FRI THRU SUN. NOT MUCH EXPECTED FROM THEM...EXCEPT SOME ISOL SHRA/TSTRM ACTIVITY. NO PROBLEMS EXPECTED THROUGH THE MIDDLE OF NEXT WEEK. && .MARINE... 12Z ETA/18Z GFS MOS GUIDANCE AT THOMAS POINT SUGGEST SUSTAINED WINDS OVERNIGHT FALL BELOW 10KTS (ALTHOUGH 18Z LWX WRF-ARW DOES INDICATE NORTHERLY CHANNELING 10-15KTS DEVELOPS OVERNIGHT). NEITHER THE 12Z NAM/GFS PROXIMITY FORECAST SOUNDINGS INDICATE ADDITONAL MOMENTUM TRANSFER OVERNIGHT. SMALL CRAFT WINDS EXPECTED TOMORROW AFTERNOON WITH THE PASSAGE OF ANOTHER COLD FRONT FROM THE NORTHWEST. BRIEF PERIODS OF GUSTINESS WILL BE POSSIBLE OVER THE WEEKEND WITH A FEW WEAK PRESSURE TROUGHS REACHING THE AREA...THOUGH NO PROBLEMS EXPECTED FROM THE WEEKEND THRU NEXT WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 1 PM TO 7 PM EDT THURSDAY FOR ANZ530>537. && $$ SYNOPSIS...GMS NEAR TERM...ROGOWSKI SHORT TERM...HTS LONG TERM...GMS AVIATION...ROGOWSKI/GMS MARINE...ROGOWSKI/GMS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1008 PM EDT WED JUN 20 2007 .UPDATE...WHAT REMAINS OF THE BAND OF SHOWERS AND THUNDERSTORMS THAT HAD BEEN DROPPING STEADILY SOUTHWARD ACROSS THE FORECAST AREA DURING THE LATE AFTERNOON/EVENING HOURS HAS PRETTY MUCH CLEARED THE FORECAST AREA. SCATTERED WEAK CONVECTION CONTINUES TO TRY AND DEVELOP SOUTH OF M-32 IN AREAS OF MOISTURE CONVERGENCE ASSOCIATED WITH LOW LEVEL CONFLUENCE AXIS COINCIDENT WITH 850MB THETA-E RIDGE POKING INTO NORTHERN LOWER. MAIN SHORT WAVE TROUGH WHICH HELPED INITIATE CONVECTION ACROSS WESTERN/CENTRAL UPPER DURING THE AFTERNOON HAS MOVED WELL EAST OF LAKE SUPERIOR. SO DESPITE 01Z MESOANALYSIS SHOWING COLD FRONT JUST PASSING THE KEWEENAW PENINSULA...PASSAGE OF SHORT WAVE TROUGH AND EARLIER CONVECTION HAS STABILIZED THINGS ACROSS EASTERN UPPER AND THE STRAITS AREA AS SUGGESTED BY RECENT AIRCRAFT SOUNDINGS. SO WILL FOCUS REMAINING PRECIPITATION CHANCES OVERNIGHT TO AREAS ALONG AFOREMENTIONED LOW LEVEL THETA-E/ELEVATED INSTABILITY AXIS...WHICH WILL LIE SOUTH OF M-72 FOR A WHILE TONIGHT THEN SINK INTO THE SOUTHERN HALF OF THE LOWER PENINSULA TOWARD DAYBREAK. PRECIPITATION COVERAGE SHOULD BE PRETTY SPOTTY THROUGH THE REST OF THE NIGHT...ADDITIONAL CONVECTION DEVELOPING UPSTREAM ACROSS MN/WI WILL PROPAGATE SOUTHEAST WITH TIME. COLD FRONT ACROSS WESTERN UPPER/NORTHWEST WI SHOULD CLEAR THE FORECAST AREA SHORTLY AFTER DAYBREAK...WITH A PUSH OF LOWER DEW POINTS BEHIND IT. JPB && .AVIATION... /ISSUED 731 PM EDT WED JUN 20 2007/ BAND OF SHOWERS AND THUNDERSTORMS THAT ORIGINATED OVER UPPER MI/ NORTHEAST WI DROPPING SOUTH OF THE STRAITS...STRONGEST ACTIVITY WILL IMPACT TVC THROUGH 01Z WITH SOME GUSTY WINDS. FARTHER EAST ANTICIPATING RAIN AT PLN TO END AT TAF ISSUANCE...AND APN WITHIN AN HOUR OR TWO. CONDITIONS SHOULD IMPROVE AFTER THAT...WITH COLD FRONTAL PASSAGE EXPECTED IN THE 05Z-09Z TIME FRAME. AS LOW LEVEL THETA-E RIDGE POKES INTO LOWER MI LATER THIS EVENING AHEAD OF COLD FRONT...CAN`T RULE OUT SOME ADDITIONAL DEVELOPMENT THAT COULD IMPACT TVC THROUGH MIDNIGHT OR SO THOUGH THINK THE BULK OF THE EVENING PRECIPITATION WILL BE SOUTH OF M-72. EXPECT MAINLY CLEAR SKIES THURSDAY WITH GUSTY NORTHWEST WINDS. JPB && .PREV DISCUSSION... /ISSUED 353 PM EDT WED JUN 20 2007/ LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW A SURFACE LOW LOCATED OVER SOUTHERN ONTARIO WITH A TRAILING COLD FRONT MOVING SE ACROSS LAKE SUPERIOR...WESTERN UPPER MICHIGAN AND NORTHERN WISCONSIN. CONVECTION HAS DEVELOPED RAPIDLY THIS AFTERNOON ACROSS WESTERN AND CENTRAL UPPER AHEAD OF THE FRONT WHERE THE JUICIER AIRMASS RESIDES. GREAT DYNAMICS AHEAD OF THE FRONT WITH 0-6KM BULK SHEAR VALUES 50-60KTS AND SB CAPES AROUND 1000 J/KG ARE SUPPORTING SEVERE THUNDERSTORMS NEAR MQT. LEADING EDGE OF THIS JUICY AIR REMAINS ACROSS LAKE MICHIGAN AND CENTRAL UPPER AND IS KNOCKING ON THE DOOR...USHERED IN BY A 30-40KTS 850MB LLJ. SOME SHOWERS AND ISOLATED THUNDERSTORM HAVE DEVELOPED ALONG THIS THETAE GRADIENT AND HAVE IMPACTED PORTIONS OF EASTERN UPPER AND ARE CROSSING NORTHERN LAKE MICHIGAN AT THE MOMENT. MAIN FORECAST CONCERNS FOR THE REST OF TODAY AND TONIGHT INCLUDE SHOWER AND THUNDERSTORM POTENTIAL. TONIGHT...SHORTWAVE MOVING ACROSS SOUTHERN ONTARIO THIS AFTERNOON...WILL CONTINUE ITS ESE JAUNT AND PASS ACROSS NORTHERN LAKE SUPERIOR THIS EVENING. BUT STRONG NW WINDS WITHIN A 105KT JET STREAK ALONG WITH THIS SHORTWAVE WILL PUSH A COLD FRONT ACROSS THE AREA. COOL...DRY AIRMASS EARLY THIS AFTERNOON WILL GAVE WAY TO A INCREASINGLY WARM/MOIST AIRMASS AS A 30KT WESTERLY LLJ ADVECTS HIGHER THETAE AIR IN FROM MINNESOTA AND WISCONSIN. EXPECT A BAND OF SHOWERS AND THUNDERSTORMS TO DEVELOP WITHIN THIS 850MB THETAE AXIS AHEAD OF THE FRONT AND REACH EASTERN UPPER BETWEEN 21-00Z AND THEN SWEEP ACROSS NORTHERN LOWER BETWEEN 00-06Z. SEVERE POSSIBILITIES CONTINUE TO LOOK MARGINAL. ON THE FAVORABLE SIDE...WIND FIELDS ARE IMPRESSIVE WITH A 30-40KT LLJ...40-50KT AT 700MB...AND 60-70KTS AT 500MB WHICH EQUATES TO 50-60KT 0-6KM BULK SHEAR...AND DECENT FORCING FROM THE COLD FRONT. ON THE OTHERHAND...BEST UPPER LEVEL SUPPORT IN THE FORM OF DPVA AND DIVERGENCE WITHIN THE LEFT EXIT REGION OF 105KT JET STREAK LOOKS TO REMAIN TO THE NORTH OVER ONTARIO. BUT THE BIGGEST LIMITING FACTOR CONTINUES TO BE THE AMOUNT OF INSTABILITY FOR WHICH THE FRONT CAN TAP INTO. SURFACE TEMPS/DEWPOINTS CONTINUE TO BE SLOW TO RISE THIS AFTERNOON WITH THE 850MB THETAE GRADIENT STILL RESIDING JUST WEST OF THE AREA. WITH THE JUICIER AIRMASS ARRIVING OVER THE NEXT SEVERAL HOURS...IF PORTIONS OF EASTERN UPPER COULD REACH T/TD OF 72/55...ABOUT 500 J/KG OF ML CAPE COULD BE REALIZED. ONCE THE SUN GOES DOWN...SKINNY ELEVATED INSTABILITY BETWEEN 400-700 J/KG WILL EXIST AHEAD OF THE FRONT SO CANNOT RULE OUT SOME CONVECTION SUSTAINING ITSELF THROUGH THE EARLY OVERNIGHT HOURS. IT WOULD NOT TAKE MUCH FOR THESE THUNDERSTORMS TO TAP INTO THE STRONGER WINDS ALOFT...AND WILL CONTINUE TO MENTION THE THREAT OF DAMAGING WINDS AND LARGE HAIL...WITH MORE EMPHASIS ON THE WIND THREAT. MPC REST OF THE FORECAST (THURSDAY THROUGH NEXT WEDNESDAY)...SEASONABLE TEMPERATURES AND LOW HUMIDITY LEVELS WILL CONTINUE OVER THE NEXT COUPLE OF DAYS. WARMER AIR WILL BEGIN TO WORK ITS WAY IN OVER THE WEEKEND BUT THE HUMIDITY WILL REMAIN RELATIVELY LOW. THE BEGINNING OF NEXT WEEK WILL TURN VERY WARM AND ELEVATED HUMIDITY LEVELS WILL TEND TO MAKE IT FEEL UNCOMFORTABLE. A COLD FRONT IS EXPECTED TO MOVE THROUGH LATER TUESDAY INTO EARLY WEDNESDAY WHICH WOULD BRING SOME RELIEF. THURSDAY INTO FRIDAY...TROUGHING ALONG THE WEST COAST WILL LEAD TO INCREASING DOWNSTREAM RIDGING ACROSS THE WESTERN GREAT LAKES. HIGH PRESSURE AT THE SURFACE WILL BUILD DOWN FROM THE NORTH. MEAN 1000-500 MB RH BETWEEN 40 AND 50 PERCENT THURSDAY DROPS TO 30 TO 40 PERCENT ON FRIDAY. THIS SHOULD LEAD TO PARTLY CLOUDY CONDITIONS. 850 MB TEMPERATURES BETWEEN PLUS 8 AND 10 C BOTH DAYS EXPECTED TO LEAD TO HIGHS IN THE 70S ACROSS THE ENTIRE FORECAST AREA (HIGHEST SOUTHERN ZONES). COMFORTABLY COOL AT NIGHT WITH LOWS RANGING FROM THE MIDDLE 40S TO LOWER 50S. SATURDAY AND SUNDAY...EXTENDED MODELS ARE IN GENERAL AGREEMENT THAT THE RIDGE CONTINUES TO SLOWLY AMPLIFY. THERE ARE DIFFERENCES ON THE HANDLING OF A CUTOFF LOW UNDER THE RIDGE SOMEWHERE IN THE VICINITY OF THE LOWER MISSISSIPPI VALLEY. THIS IS THE ONE FEATURE THAT HAS THE POTENTIAL TO MESS UP THE ONGOING FORECAST...OTHERWISE A PLEASANT WEEKEND IS ANTICIPATED WITH CONTINUED LOWER HUMIDITY LEVELS. 850 MB TEMPERATURES BLOSSOM TO BETWEEN PLUS 13 AND 15 C SATURDAY THEN TO BETWEEN PLUS 14 AND 16 C SUNDAY. THEREFORE HIGHS RANGING FROM THE MIDDLE 70S NORTH TO THE LOWER 80S SOUTH EXPECTED. MONDAY AND TUESDAY...RIDGE CONTINUES TO BUILD WITH A MORE MOIST SOUTH SOUTHWEST SURFACE FLOW LEADING TO HIGHER HUMIDITY LEVELS. AS 850 MB TEMPERATURES RISE TO BETWEEN PLUS 18 AND 20 C HIGHS WILL INCREASE TO NEAR 80 NORTH AND AROUND 90 SOUTH. A NORTHERN STREAM SHORT WAVE AND ASSOCIATED SURFACE COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY LEADING TO CHANCE POPS ACROSS NORTHERN ZONES ON TUESDAY. WEDNESDAY...SURFACE COLD FRONT IS SHOWN TO PUSH ACROSS THE REGION. TIMING THIS FAR OUT IS OBVIOUSLY IN QUESTION BUT WILL CONFINE CHANCE POPS TO EASTERN/SOUTHERN ZONES TO LINE UP WITH SURROUNDING OFFICES. ANY COOL AIR PUSH SHOULD BE MINIMIZED AS A ZONAL FLOW ALOFT IS SHOWN TO DEVELOP FOR THE MIDDLE OF NEXT WEEK. FORECAST HIGH TEMPERATURES WILL BE A FEW DEGREES LOWER THAN PREVIOUS DAYS BUT STILL RANGE FROM THE MIDDLE 70S NORTH TO THE MIDDLE 80S FAR SOUTH. SULLIVAN APX WATCHES/WARNINGS/ADVISORIES...NONE. && .APX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
709 PM EDT WED JUN 20 2007 .SYNOPSIS... 19Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED NW FLOW ALOFT FROM A RIDGE STRETCHING FROM NEW MEXICO NORTH TO SOUTHERN ALBERTA AND A TROUGH IN EASTERN ONTARIO/WESTERN QUEBEC. WITHIN THIS FLOW...SHRTWVS ARE HARD TO DEPICT...THOUGH THERE ARE TWO OF NOTE. ONE IS LOCATED AROUND THUNDER BAY ONTARIO AND ANOTHER IS IN CENTRAL SASKATCHEWAN. SHRTWV NEAR THUNDER BAY IS REFLECTED AT THE SFC BY A 1010MB LOW LOCATED IN NORTH CENTRAL ONTARIO...WITH A COLD FRONT EXTENDING SW TO IWD AND MSP. A PRE-FRONTAL TROUGH ALSO EXTENDS FROM THE LOW SOUTHWARD TO ESC. ALTHOUGH SOME ELEVATED CLOUDS AND SHOWERS PASSED ACROSS THE CWA (PARTICULARLY THE NORTH) EARLIER IN THE DAY DUE TO ISENTROPIC LIFTING...PARTLY SUNNY SKIES OVERALL AND 850MB TEMPS AROUND 13C BASED ON TAMDAR SOUNDINGS HAVE ALLOWED TEMPERATURES TO CLIMB INTO THE UPPER 70S. IN ADDITION...DEWPOINTS IN THE MID 50S HAVE ADVECTED INTO THE AREA...RESULTING IN 100MB MLCAPE VALUES OF 1000 J/KG AND LITTLE CIN PER LATEST RUC ANALYSIS. THE COMBINATION OF THIS INSTABILITY AND LAKE BREEZES DEVELOPING AND CONVERGING ON THE PRE-FRONTAL TROUGH HAS RESULTED IN SCATTERED SEVERE THUNDERSTORMS... THE MOST SGNFT OF WHICH DROPPED HAIL UP TO 3 INCHES IN DIAMETER NR THE CITY OF MQT. TO THE NW...HIGH PRESSURE AND DRIER AIR IS PUSHING INTO NW MN. 12Z SOUNDING FROM CWLO HAD A PRECIPITABLE WATER OF 0.48 IN. FARTHER TO THE NW...A BAND OF HIGH BASED STRATUS IS MOVING ACROSS CENTRAL SASKATCHEWAN...WITH A FEW -RA REPORTS ASSOCIATED WITH IT. THIS BAND IS ASSOCIATED WITH BOTH THE CENTRAL SASKATCHEWAN SHRTWV AND SOME 800-700MB FRONTOGENESIS. .SHORT TERM (TONIGHT AND THURSDAY)... NW FLOW ALOFT WILL CONTINUE THROUGH THU AS TROUGHING DEEPENS OVER NEW ENGLAND AND THE RIDGE OVER SOUTHERN ALBERTA SHIFTS EASTWARD INTO SASKATCHEWAN AND MANITOBA. ANY LINGERING SHOWERS AND THUNDERSTORMS SHOULD END QUICKLY THIS EVENING AS THEY GET SHOVED SE IN THE NW FLOW. THE HIGH PRESSURE RIDGE OVER NW MN WILL THEN BUILD INTO THE AREA...HELPING TO CLEAR SKIES OUT AND DIMINISH THE WIND (PARTICULARLY OVER THE WEST HALF). LOW TEMPERATURES BECOME THE NEXT ISSUE GIVEN THE LOW PRECIPITABLE WATER VALUES UPSTREAM ADVECTING IN. GIVEN THAT THEY ARE FAIRLY SIMILAR TO YESTERDAY...LOWS MIGHT BE SIMILAR TO THOSE LAST NIGHT. HOWEVER WE ARE STARTING OFF QUITE A BIT WARMER...AND THAT THERE ARE INDICATIONS OF SOME MID CLOUDS MOVING IN AFTER 06Z WHICH SHOULD PREVENT TEMPERATURES FROM FALLING AS MUCH. THUS HAVE LOWS ABOUT 5 TO 10 DEGREES WARMER THAN LAST NIGHT. THOSE MID CLOUDS MENTIONED ARE ASSOCIATED WITH THE 800-700MB FRONTOGENESIS OCCURRING UPSTREAM WITH THE CENTRAL SASKATCHEWAN SHRTWV. THE 06Z GFS DID PRODUCE SOME QPF AS THEY CROSSED ON THU...THOUGH THE 12Z GFS HAS BACKED OFF AND HAS THE PCPN ENDING BEFORE IT GETS TO IWD. THE 12Z NAM HAS NO QPF AT ALL...LIKELY DUE TO A VERY DRY SUBCLOUD LAYER. WAS TEMPTED TO MENTION SOME SPRINKLES GIVEN THE -RA REPORTS UPSTREAM...BUT GIVEN THE TREND IN THE MODELS TO DIMINISH THE QPF WITH TIME...AND THE DRY SUBCLOUD LAYER...HAVE OPTED TO KEEP THE GRIDS DRY FOR NOW. LATER SHIFTS WILL NEED TO LOOK AT THIS CLOSER. THE CLOUDS...ALONG WITH COOLER 850MB TEMPS PROGGED AROUND 8C NORTH TO 10C SOUTHWEST WILL RESULT IN A COOLER DAY THAN TODAY...ESPECIALLY ALONG THE GREAT LAKES WHERE ONSHORE FLOW DEVELOPS IN THE AFTERNOON. GOING FCST HIGH TEMPS LOOK REASONABLE. .LONG TERM DISCUSSION (THU NGT THRU WED)... HI PRES RDG FCST TO DOMINATE ON THU NGT/FRI IN CONFLUENT NW FLOW ALF BTWN BLDG RDG OVER CNTRL NAMERICA AND TROF IN SE CAN. AFT ANY DIURNAL CU DSPT THU EVNG...EXPECT SKIES TO BCM MOCLR. WL TEND TOWARD THE LO END OF MOS GUIDANCE FOR MIN TEMPS THU NGT...ESPECIALLY OVER THE INTERIOR W...WITH LGT WINDS UNDER RDG AXIS. FLAT PRES GRADIENT WL ALLOW LK BREEZES TO DVLP ON FRI...ESPECIALLY NR LK SUP AND S OF ESC WITH LGT ENE FLOW S OF HUDSON BAY HI CENTER. LOOK FOR JUST SOME HI CLDS AS WELL AS SOME DIURNAL CU TO DVLP INLAND FM THE LK BREEZE BNDRY. FCST H85 TEMPS IN THE 8C-12C (WARMEST W) RANGE AND MIXING TO H75 ON GFS FCST SDNGS SUPPORT HI TEMPS OVER THE INTERIOR W HALF ARND 80. GFS/UKMET HINT AT SOME MAINLY MID LVL MSTR RETURN ON FRI NGT AS SFC HI CENTER SINKS TOWARD THE LOWER GREAT LKS AND LLVL FLOW TURNS WSW BTWN DEPARTING HI AND SHRTWV/COLD FNT MOVING THRU ONTARIO. EXPECT THE MAJORITY OF THE ASSOCIATED MID CLD COVER OVER THE NRN TIER ZNS. OPTED TO RETAIN LO CHC POPS OVER THE NW ZNS LATE FRI NGT AS GFS FCST SDNG FOR CMX INDICATES 12Z SAT CAPE APRCHG 300 J/KG WITH KINX OF 35 AND MINIMAL CIN LIFTING FM H825. HOWEVER...WL GO MORE THAN A 20 POP WITH LACK OF REAL FOCUSING MECHANISM WITH SFC TROF SO FAR TO THE N YET. OTRW...THE OVERNGT WL BE QUITE A BIT WARMER THAN ON FRI NGT WITH STRONGER WSW FLOW/MSTR RETURN. LOWEST MIN TEMPS EXPECTED OVER THE INTERIOR SCNTRL AND E CLOSER TO DEPARTING SFC HI/DRIER AIR. BNDRY TO THE N FCST TO SINK SLOWLY SWD ON SAT/SAT NGT AS SHRTWV DROPPING INTO NW ONTARIO AMPLIFIES SE CNDN TROF AND UPR FLOW OVER ONTARIO TURNS MORE NW. HOWEVER...SHARPENING RDG AXIS UPSTREAM WL GRDLY RESULT IN A MORE DYNAMICALLY UNFVRBL...CAPPED ENVIRONMENT THRU THE PD AS BNDRY SHOULD UNDERGO EVENTUAL FRONTOLYSIS. RETAINED LO CHC POPS ON SAT ACRS THE NRN TIER ZNS CLOSER TO APRCHG BAND OF H7-8 FGEN/AXIS OF LWR SSI JUST BLO 0C. FCST SDNGS FARTHER S SHOW A PROHIBITIVELY DRY AIRMASS FOR ANY PCPN FARTHER FM THE BNDRY. THE WX IN THE EXTENDED PD (SUN THRU WED) WL BE DOMINATED BY UPR RDGING BTWN SLOW MOVING VORTEX IN SE CAN AND TROFFING THAT IS NOW CUTOFF IN THE GLFAK AND FCST TO MOVE INTO SW CAN/NRN ROCKIES BY EARLY NEXT WEEK. EXPLICIT MODEL GUIDANCE OFFERS A VARIETY OF SCENARIOS AS TO TIMING OF DISTURBANCES RIDING THRU THIS FLOW AND POSITION OF ACTIVE WARM FNT/HOW QUICKLY COLD FNT ASSOCIATED WITH SW CNDN TROF WL PUSH EWD AND IMPACT THE UPR GRT LKS. CONSIDERING CONSENSUS VIEW THAT WARM FNT WL BE IN THE VCNTY MON-TUE TO THE N OF BUBBLE OF VERY WARM AIR TO THE S WITH COLD FROPA TUE-WED...COULD BE AN ACTIVE PD OF WX ACRS THE UPR GRT LKS. NCEP MANUAL GUIDANCE SEEMS TO OFFER A RSNBL COMPROMISE BTWN VARIOUS OPERATIONAL MODELS/GFS AND CNDN ENSEMBLE GUIDANCE SHOWING HUDSON BAY HI PRES OVER THE UPR LKS ON SUN IN CONFLUENCE BTWN APRCHG RDG AND SLOWLY DEPARTING TROF IN SE CAN. THIS HI THEN GIVES WAY TO APRCHG WARM FNT ON MON AS CNDN TROF/ CONFLUENCE ZN LIFTS TO THE NE BEFORE COLD FROPA TUE NGT/WED MRNG. COORDINATED WITH GRB. && .AVIATION (FOR 00Z TAF ISSUANCE)... DO NOT HAVE TIME TO WRITE ANYTHING DUE TO SEVERE WEATHER AND A SPOT FORECAST. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FCST ISSUANCE)... HIGH PRESSURE BUILDING IN FROM NW MN WILL HELP DIMINISH THE WINDS THIS EVENING ACROSS LAKE SUPERIOR BELOW 20 KT. BEYOND THIS EVENING...THE REST OF THE FORECAST PERIOD LOOKS BELOW 20 KT. ONLY MAJOR CONCERN IS WIND FIELDS AS THEY ARE A LITTLE UNCERTAIN WITH A COLD FRONT POSSIBLY COMING DOWN AROUND SAT NIGHT. FOR NOW FOLLOWED THE GFS...BUT THIS TIME PERIOD IS SUBJECT TO CHANGE. && .MQT WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH MIZ012 TIL 9 PM EDT. && $$ SHORT TERM...AJ LONG TERM...KC AVIATION...GM MARINE...AJ
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1000 PM EDT WED JUN 20 2007 .SYNOPSIS... HIGH PRESSURE OVER THE MIDWEST WILL MOVE INTO THE TENNESSEE VALLEY TONIGHT...WHILE A WEAK LOW TRACKS EAST ACROSS SOUTHERN ONTARIO. THE LOW WILL PUSH A COLD FRONT ACROSS WESTERN AND CENTRAL NEW YORK THURSDAY AFTERNOON AND SET OFF A FEW SHOWERS AND THUNDERSTORMS. HIGH PRESSURE FOLLOWING THE FRONT WILL BUILD SOUTH ACROSS THE GREAT LAKES FRIDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... CONVECTION DROPPING SOUTHEAST ACROSS LOWER MICHIGAN AHEAD OF A COLD FRONT HANDLED FAIRLY WELL BY THE LATEST RUC AND NAM12. BOTH MODELS SUGGESTING SOME OF THIS CONVECTION COULD HOLD TOGETHER LONG ENOUGH TO REACH WESTERN NEW YORK BY 12Z. HOWEVER...THIS ACTIVITY HAS BEEN WEAKENING WITH LOSS OF DIURNAL HEATING AND EXPECT THIS WEAKENING TREND TO CONTINUE...MORE THAN SUGGESTED BY THE RUC AND NAM12... SINCE CONVECTION WILL BE ENCOUNTERING A DRY AND STABLE ENVIRONMENT IN PLACE ACROSS THE AREA. THEREFORE...WILL LIMIT PRECIPITATION THREAT OVERNIGHT TO NO MORE THAN A SLIGHT CHANCE. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/... THE AFOREMENTIONED COLD FRONT IS FORECAST TO PUSH SOUTH ACROSS OUR CWA THURSDAY AFTERNOON. WHILE LOW LEVEL MOISTURE WILL REMAIN LIMITED AHEAD OF THE FRONT...THE RELATIVELY COOL TEMPERATURES ALOFT WILL RESULT IN MODERATELY STEEP LAPSE FROM 900MB TO 700MB. THE LOW LEVEL INSTABILITY...COMBINED WITH THE ADDED LIFT AHEAD OF THE APPROACHING UPPER LEVEL JET STREAK...WILL MAKE THE ATMOSPHERE UNSTABLE ENOUGH TO GENERATE A FEW AFTERNOON THUNDERSTORMS...ESPECIALLY ACROSS THE NORTH COUNTRY WHERE AFTERNOON CAPES MAY EXCEED 1000 J/KG. THE PREDOMINANT NORTHWEST FLOW AND RELATIVELY LOW WET BULB ZERO HEIGHTS MAY ALSO RESULT IN SOME SMALL HAIL ACROSS THE NORTH COUNTY. THE CONVECTION WILL DIE OUT WITH THE LOSS OF DAYTIME HEATING FRIDAY EVENING. FRIDAY WILL START OUT SUNNY...BUT SC/CU WILL INCREASE DURING THE AFTERNOON WITH COOL TEMPERATURES PERSISTING AT 850 MB. A SHORT WAVE THAT IS FORECAST TO DIG SOUTH ACROSS EASTERN NEW YORK STATE AND NEW ENGLAND FRIDAY AFTERNOON WILL PROBABLY BRING A FEW SHOWERS TO THE ST LAWRENCE VALLEY...BUT PLAN TO KEEP ALL PCPN EAST OF THE NORTH COUNTRY FOR NOW. HIGH PRESSURE WILL BUILD SOUTH ACROSS THE LOWER GREAT LAKES SATURDAY WHILE LOW PRESSURE TRACKS ACROSS THE MIDWEST. THE RIDGE SHOULD KEEP OUR CWA DRY SATURDAY. EXPECT A GRADUAL INCREASE IN CLOUDS SATURDAY NIGHT AS A COLD FRONT PUSHES THROUGH SOUTHERN ONTARIO. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... THIS PERIOD WILL FEATURE WARMING TEMPERATURES AND GENERALLY DRY WEATHER AS A BROAD RIDGE OVER THE NATIONS MID SECTION WILL GRADUALLY BUILD TO THE EAST. THE RIDGE WILL MAKE ITS WAY ACROSS THE GREAT LAKES REGION ON TUESDAY...THEN IS EXPECTED TO FLATTEN AS A STRONG SHORTWAVE OVER MANITOBA WILL SHEAR OUT TO THE NORTHEAST. IN FACT...IT WILL BE THE REMNANTS OF THE ASSOCIATED SFC PACIFIC COLD FRONT THAT IS FORECAST TO CROSS OUR REGION ON WEDNESDAY. THIS COULD TOUCH OFF A SHOWER OR THUNDERSTORM...SO LOW CHC POPS WILL BE INSERTED. A CLOSER DAY TO DAY EXAMINATION OF THIS PERIOD SHOWS THAT HIGH PRESSURE TO OUR SOUTHEAST ON SUNDAY MORNING WILL GIVE WAY TO A DRY FRONTAL PASSAGE LATE IN THE DAY OR SUNDAY EVENING. THIS FRONT WILL BECOME STATIONARY IN THE VICINTY OF WRN NEW YORK MONDAY AND TUESDAY...BUT A DRY NORTHWEST FLOW IN PLACE WILL ONLY INCLUDE SLGT CHC POPS FOR ANY CONVECTION. FOR WEDNESDAY...THE STALLED FRONT WILL LIFT NORTH OF THE REGION WITH THE BEFORE MENTIONED PACIFIC FRONT TO FOLLOW LATE IN THE DAY. AS HEADLINED AT THE TOP OF THIS SECTION...IT WILL GET WARMER DURING THIS FORECAST PERIOD. H8 TEMPS THAT WILL START OUT IN THE MID TEENS ON SUNDAY WILL WARM TO NEAR 20 (FAR WEST) BY TUESDAY AFTERNOON. THE GFS ENSEMBLES REMAIN A COUPLE DEGREES BEHIND THE OPERATIONAL MODEL...BUT GIVEN THE DEPARTURE FROM NORMAL...THIS IS NOT SURPRISING. WILL THUS CONTINUE TO LEAN MORE TOWARDS THE OPERATIONAL MODEL AND AIM HIGH ON MAX TEMPS FOR TUESDAY...OVERSHOOTING BOTH MEX AND HPC GUIDANCE. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... NO WIDESPREAD AVIATION PROBLEMS ANTICIPATED THROUGH AT LEAST THURSDAY. HIGH PRESSURE EXTENDING FROM THE LOWER OHIO VALLEY ACROSS THE EASTERN GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH TONIGHT. THIS WILL RESULT IN VFR CONDITIONS FOR THE ENTIRE REGION...WITH ONLY SOME DIUNALLY INDUCED SCT-BKN CU EXPECTED DURING THE REMAINDER OF THIS AFTERNOON. WHILE VFR CONDITIONS WILL BE IN PLACE THIS AFTERNOON...9 TO 10 DEG C LAPES RATES FROM THE SFC TO ABOUT 5K FT WILL RESULT IN SOME RATHER `BUMPY` CONDITIONS FOR SMALLER AIRCRAFT. TONIGHT...ANY DIURNALLY INDUCED CU WILL COLLAPSE AND GIVE WAY TO A FEW HOURS OF CLEAR SKIES BEFORE A LAYER OF ALTO-CU WILL MOVE IN FROM THE NORTHWEST. THIS ALTO-CU CIG WILL BE IN THE PLACE FOR THE SECOND HALF OF TONIGHT. ON THURSDAY...A WEAK COLD FRONT WILL APPROACH AND PASS ACROSS THE FORECAST AREA. WHILE THE VAST MAJORITY OF THE DAY WILL FEATURE VFR STRATO-CU CIGS OF ABOUT 4K FT...THERE WILL BE A SLIGHT CHANCE FOR A THUNDERSTORM FOR THE MIDDAY AND AFTERNOON. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR FRIDAY AND SATURDAY WITH VFR CONDITIONS PREVIALING. WHILE A COLD FRONT WILL BE NEARING OUR REGION FROM THE NORTH ON SUNDAY...WIDESPREAD VFR CONDITIONS SHOULD REMAIN IN PLACE. && .MARINE... NO MARINE HEADLINES ARE EXPECTED TONIGHT THROUGH AT LEAST FRIDAY. HIGH PRESSURE EXTENDING FORM THE LOWER OHIO VALLEY TO THE EASTERN GREAT LAKES WILL KEEP GENERALLY LIGHT WINDS AND MINIMAL WAVES ACROSS BOTH LAKES ERIE AND ONTARIO THROUGH TONIGHT. A COLD FRONT APPROACHING FROM THE UPPER GREAT LAKES WILL SHARPEN THE PRESSURE GRADIENT ON THURSDAY...WITH WINDS AND WAVES PICKING UP...BUT LIKELY REMAINING BELOW SMALL CRAFT ADVISORY CRITERIA. HIGH PRESSURE NOSING TO THE SOUTH FROM JAMES BAY ON THURSDAY NIGHT AND FRIDAY WILL THEN ONCE AGAIN RELAX THE PRESSURE GRADIENT WITH ANOTHER ROUND OF GENERALLY LIGHT WINDS AND SMALL WAVES ANTICIPATED FOR BOTH LAKES ERIE AND ONTARIO. THE HIGH PRESSURE SYSTEM WILL THEN BODILY DRIFT SOUTH ACROSS THE GREAT LAKES DURING THE DAY SATURDAY WITH IDEAL BOATING CONDITIONS EXPECTED. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...TJP NEAR TERM...TMA SHORT TERM...TJP LONG TERM...RSH AVIATION...WCH MARINE...RSH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
338 PM EDT WED JUN 20 2007 .SYNOPSIS... HIGH PRESSURE OVER THE MIDWEST WILL MOVE INTO THE TENNESSEE VALLEY TONIGHT...WHILE A WEAK LOW TRACKS EAST ACROSS SOUTHERN ONTARIO. THE LOW WILL PUSH A COLD FRONT ACROSS WESTERN AND CENTRAL NEW YORK THURSDAY AFTERNOON AND SET OFF A FEW SHOWERS AND THUNDERSTORMS. HIGH PRESSURE FOLLOWING THE FRONT WILL BUILD SOUTH ACROSS THE GREAT LAKES FRIDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... THE DIURNAL CU WILL DISSIPATE EARLY THIS EVENING AND GIVE WAY TO CLEAR SKIES THROUGH THE FIRST HALF OF THE NIGHT. THE LOW THAT IS CENTERED JUST NORTH OF LAKE SUPERIOR WILL TRACK TO THE SOUTHEAST TONIGHT AND DRAG ITS ASSOCIATED COLD FRONT ACROSS THE CENTRAL GREAT LAKES. EXPECT SOME INCREASE IN MID LEVEL CLOUDS NORTH OF THE SOUTHERN TIER TONIGHT WITH THE APPROACH OF THE FRONT...BUT THERE IS VERY LITTLE PCPN ASSOCIATED WITH THIS SYSTEM. THEREFORE...WILL FOLLOW THE DRIER GFS SOLUTION AND LEAVE PCPN OUT OF OUR CWA TONIGHT. THE DRYNESS OF THE AIRMASS WILL ALLOW TEMPERATURES TO DIP INTO THE 50S OVERNIGHT...BUT THE ANTICIPATED INCREASE IN CLOUD COVER SHOULD KEEP READINGS ABOVE 50 AT MOST LOCATIONS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/... THE AFOREMENTIONED COLD FRONT IS FORECAST TO PUSH SOUTH ACROSS OUR CWA THURSDAY AFTERNOON. WHILE LOW LEVEL MOISTURE WILL REMAIN LIMITED AHEAD OF THE FRONT...THE RELATIVELY COOL TEMPERATURES ALOFT WILL RESULT IN MODERATELY STEEP LAPSE FROM 900MB TO 700MB. THE LOW LEVEL INSTABILITY...COMBINED WITH THE ADDED LIFT AHEAD OF THE APPROACHING UPPER LEVEL JET STREAK...WILL MAKE THE ATMOSPHERE UNSTABLE ENOUGH TO GENERATE A FEW AFTERNOON THUNDERSTORMS...ESPECIALLY ACROSS THE NORTH COUNTRY WHERE AFTERNOON CAPES MAY EXCEED 1000 J/KG. THE PREDOMINANT NORTHWEST FLOW AND RELATIVELY LOW WET BULB ZERO HEIGHTS MAY ALSO RESULT IN SOME SMALL HAIL ACROSS THE NORTH COUNTY. THE CONVECTION WILL DIE OUT WITH THE LOSS OF DAYTIME HEATING FRIDAY EVENING. FRIDAY WILL START OUT SUNNY...BUT SC/CU WILL INCREASE DURING THE AFTERNOON WITH COOL TEMPERATURES PERSISTING AT 850 MB. A SHORT WAVE THAT IS FORECAST TO DIG SOUTH ACROSS EASTERN NEW YORK STATE AND NEW ENGLAND FRIDAY AFTERNOON WILL PROBABLY BRING A FEW SHOWERS TO THE ST LAWRENCE VALLEY...BUT PLAN TO KEEP ALL PCPN EAST OF THE NORTH COUNTRY FOR NOW. HIGH PRESSURE WILL BUILD SOUTH ACROSS THE LOWER GREAT LAKES SATURDAY WHILE LOW PRESSURE TRACKS ACROSS THE MIDWEST. THE RIDGE SHOULD KEEP OUR CWA DRY SATURDAY. EXPECT A GRADUAL INCREASE IN CLOUDS SATURDAY NIGHT AS A COLD FRONT PUSHES THROUGH SOUTHERN ONTARIO. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... THIS PERIOD WILL FEATURE WARMING TEMPERATURES AND GENERALLY DRY WEATHER AS A BROAD RIDGE OVER THE NATIONS MID SECTION WILL GRADUALLY BUILD TO THE EAST. THE RIDGE WILL MAKE ITS WAY ACROSS THE GREAT LAKES REGION ON TUESDAY...THEN IS EXPECTED TO FLATTEN AS A STRONG SHORTWAVE OVER MANITOBA WILL SHEAR OUT TO THE NORTHEAST. IN FACT...IT WILL BE THE REMNANTS OF THE ASSOCIATED SFC PACIFIC COLD FRONT THAT IS FORECAST TO CROSS OUR REGION ON WEDNESDAY. THIS COULD TOUCH OFF A SHOWER OR THUNDERSTORM...SO LOW CHC POPS WILL BE INSERTED. A CLOSER DAY TO DAY EXAMINATION OF THIS PERIOD SHOWS THAT HIGH PRESSURE TO OUR SOUTHEAST ON SUNDAY MORNING WILL GIVE WAY TO A DRY FRONTAL PASSAGE LATE IN THE DAY OR SUNDAY EVENING. THIS FRONT WILL BECOME STATIONARY IN THE VICINTY OF WRN NEW YORK MONDAY AND TUESDAY...BUT A DRY NORTHWEST FLOW IN PLACE WILL ONLY INCLUDE SLGT CHC POPS FOR ANY CONVECTION. FOR WEDNESDAY...THE STALLED FRONT WILL LIFT NORTH OF THE REGION WITH THE BEFORE MENTIONED PACIFIC FRONT TO FOLLOW LATE IN THE DAY. AS HEADLINED AT THE TOP OF THIS SECTION...IT WILL GET WARMER DURING THIS FORECAST PERIOD. H8 TEMPS THAT WILL START OUT IN THE MID TEENS ON SUNDAY WILL WARM TO NEAR 20 (FAR WEST) BY TUESDAY AFTERNOON. THE GFS ENSEMBLES REMAIN A COUPLE DEGREES BEHIND THE OPERATIONAL MODEL...BUT GIVEN THE DEPARTURE FROM NORMAL...THIS IS NOT SURPRISING. WILL THUS CONTINUE TO LEAN MORE TOWARDS THE OPERATIONAL MODEL AND AIM HIGH ON MAX TEMPS FOR TUESDAY...OVERSHOOTING BOTH MEX AND HPC GUIDANCE. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... NO WIDESPREAD AVIATION PROBLEMS ANTICIPATED THROUGH AT LEAST THURSDAY. HIGH PRESSURE EXTENDING FROM THE LOWER OHIO VALLEY ACROSS THE EASTERN GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH TONIGHT. THIS WILL RESULT IN VFR CONDITIONS FOR THE ENTIRE REGION...WITH ONLY SOME DIUNALLY INDUCED SCT-BKN CU EXPECTED DURING THE REMAINDER OF THIS AFTERNOON. WHILE VFR CONDITIONS WILL BE IN PLACE THIS AFTERNOON...9 TO 10 DEG C LAPES RATES FROM THE SFC TO ABOUT 5K FT WILL RESULT IN SOME RATHER `BUMPY` CONDITIONS FOR SMALLER AIRCRAFT. TONIGHT...ANY DIURNALLY INDUCED CU WILL COLLAPSE AND GIVE WAY TO A FEW HOURS OF CLEAR SKIES BEFORE A LAYER OF ALTO-CU WILL MOVE IN FROM THE NORTHWEST. THIS ALTO-CU CIG WILL BE IN THE PLACE FOR THE SECOND HALF OF TONIGHT. ON THURSDAY...A WEAK COLD FRONT WILL APPROACH AND PASS ACROSS THE FORECAST AREA. WHILE THE VAST MAJORITY OF THE DAY WILL FEATURE VFR STRATO-CU CIGS OF ABOUT 4K FT...THERE WILL BE A SLIGHT CHANCE FOR A THUNDERSTORM FOR THE MIDDAY AND AFTERNOON. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR FRIDAY AND SATURDAY WITH VFR CONDITIONS PREVIALING. WHILE A COLD FRONT WILL BE NEARING OUR REGION FROM THE NORTH ON SUNDAY...WIDESPREAD VFR CONDITIONS SHOULD REMAIN IN PLACE. && .MARINE... NO MARINE HEADLINES ARE EXPECTED TONIGHT THROUGH AT LEAST FRIDAY. HIGH PRESSURE EXTENDING FORM THE LOWER OHIO VALLEY TO THE EASTERN GREAT LAKES WILL KEEP GENERALLY LIGHT WINDS AND MINIMAL WAVES ACROSS BOTH LAKES ERIE AND ONTARIO THROUGH TONIGHT. A COLD FRONT APPROACHING FROM THE UPPER GREAT LAKES WILL SHARPEN THE PRESSURE GRADIENT ON THURSDAY...WITH WINDS AND WAVES PICKING UP...BUT LIKELY REMAINING BELOW SMALL CRAFT ADVISORY CRITERIA. HIGH PRESSURE NOSING TO THE SOUTH FROM JAMES BAY ON THURSDAY NIGHT AND FRIDAY WILL THEN ONCE AGAIN RELAX THE PRESSURE GRADIENT WITH ANOTHER ROUND OF GENERALLY LIGHT WINDS AND SMALL WAVES ANTICIPATED FOR BOTH LAKES ERIE AND ONTARIO. THE HIGH PRESSURE SYSTEM WILL THEN BODILY DRIFT SOUTH ACROSS THE GREAT LAKES DURING THE DAY SATURDAY WITH IDEAL BOATING CONDITIONS EXPECTED. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...TJP NEAR TERM...TJP SHORT TERM...TJP LONG TERM...RSH AVIATION...RSH MARINE...RSH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
149 PM EDT WED JUN 20 2007 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVER THE AREA TODAY WITH COOLER AND DRIER AIR. A WEAK COLD FRONT WILL BRING A CHANCE OF SHOWERS THURSDAY. HIGH PRESSURE WILL THEN BRING PLEASANT SUNNY WEATHER ON FRIDAY. A WEAK WARM FRONT WILL BRING INCREASING CLOUDS SATURDAY WITH A CHANCE OF SHOWERS EAST OF LAKE ONTARIO. && .NEAR TERM /THROUGH TONIGHT/... THE COMBINATION OF DAYTIME HEATING AND COOLER TEMPERATURES ALOFT IS GENERATING A FAIR AMOUNT OF SC/CU ACROSS THE AREA EARLY THIS AFTENROON. THE MAIN EXCEPTION TO THIS GENERAL TREND IS SOUTHEAST OF LAKE ONTARIO AND EAST OF LAKE ERIE WHERE THE LAKE BREEZES ARE HELPING TO STABILIZE THE ATMOSPHERE. THEREFORE...WILL INDICATE MORE OF A MIX OF SUN AND CLOUDS IN THE SKY GRIDS AND CORRESPONDING ZFP. AREA TEMPERATURES SEEM TO BE IN LINE WITH THE FORECAST. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... A WEAK COLD FRONT WILL CROSS THE AREA THURSDAY WITH A CHANCE OF SHOWERS OR THUNDERSTORMS NORTH OF THE SOUTHERN TIER. HIGH PRESSURE FOLLOWING THIS FRONT WILL BRING MOSTLY SUNNY SKIES AND NEAR SEASONABLE TEMPERATURES FRIDAY. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... A BROAD RIDGE CENTERED OVER THE NATIONS MID SECTION AT THE START OF THIS PERIOD WILL EXPAND EASTWARD ACROSS THE GREAT LAKES REGION ON MONDAY AND TUESDAY. AS A RESULT...NEAR NORMAL TEMPERATURES WITH COMFORTABLE HUMIDITY LEVELS WILL GIVE WAY TO VERY WARM AND INCREASINGLY UNCOMFORTABLE CONDITIONS AS WE HEAD INTO THE NEW WORK WEEK. SOME DETAILS... A VERY WEAK BOUNDARY WILL SAG ACROSS WESTERN NEW YORK ON SATURDAY. WHILE MOST SITES WILL EXPERIENCE A DRY DAY...THERE WILL BE A LOW CHANCE FOR A PASSING SHOWER OR THUNDERSTORM. HIGH PRESSURE OVER ONTARIO WILL THEN NOSE SOUTH ACROSS THE EASTERN GREAT LAKES. THIS WILL PRODUCE A FINE DAY ACROSS OUR REGION ON SUNDAY WITH MAX TEMPERATURES LIKELY NOT CLIMBING OUT OF THE 70S. WHILE H8 TEMPS WILL BE IN THE VICINITY OF +8 TO +10C...THE FORECAST WILL BE A FEW DEGREES HIGHER THAN GUIDANCE DUE TO THE CONTINUED DRY ANTECEDENT CONDITIONS. HIGH PRESSURE WILL SLIDE TO THE EAST OF OUR FORECAST AREA FOR MONDAY...WITH WARM ADVECTION QUICKLY RAISING H8 TEMPS BACK INTO THE MID TEENS. HAVE AIMED HIGH ON TEMPERATURES AGAIN...BUT MAY STILL BE UNDERDONE AS HIGHS COULD EASILY EXCEED THE UPPER 70S/LOW 80S. THE CURRENT FORECAST IS BEING SUPPORTED MORE BY THE 12Z GFS ENSEMBLES... RATHER THAN THE VERY WARM 12Z OPERATIONAL RUN. THE ENSEMBLES ONLY SHOW H8 TEMPS OF ABOUT +10C. IN ANY CASE...THE WARMTH WILL BE BACK IN FORCE FOR MONDAY NIGHT AND TUESDAY AS THE H5 PLAINS RIDGE WILL NOSE ACROSS THE GREAT LAKES. H8 TEMPS WILL CLIMB INTO THE UPPER TEENS/LOW 20S C. THIS WILL SUPPORT SURFACE TEMPERATURES OF 90 OR HIGHER FOR TUESDAY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... NO WIDESPREAD AVIATION PROBLEMS ANTICIPATED THROUGH AT LEAST THURSDAY. HIGH PRESSURE EXTENDING FROM THE LOWER OHIO VALLEY ACROSS THE EASTERN GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH TONIGHT. THIS WILL RESULT IN VFR CONDITIONS FOR THE ENTIRE REGION...WITH ONLY SOME DIUNALLY INDUCED SCT-BKN CU EXPECTED DURING THE REMAINDER OF THIS AFTERNOON. WHILE VFR CONDITIONS WILL BE IN PLACE THIS AFTERNOON...9 TO 10 DEG C LAPES RATES FROM THE SFC TO ABOUT 5K FT WILL RESULT IN SOME RATHER `BUMPY` CONDITIONS FOR SMALLER AIRCRAFT. TONIGHT...ANY DIURNALLY INDUCED CU WILL COLLAPSE AND GIVE WAY TO A FEW HOURS OF CLEAR SKIES BEFORE A LAYER OF ALTO-CU WILL MOVE IN FROM THE NORTHWEST. THIS ALTO-CU CIG WILL BE IN THE PLACE FOR THE SECOND HALF OF TONIGHT. ON THURSDAY...A WEAK COLD FRONT WILL APPROACH AND PASS ACROSS THE FORECAST AREA. WHILE THE VAST MAJORITY OF THE DAY WILL FEATURE VFR STRATO-CU CIGS OF ABOUT 4K FT...THERE WILL BE A SLIGHT CHANCE FOR A THUNDERSTORM FOR THE MIDDAY AND AFTERNOON. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR FRIDAY AND SATURDAY WITH VFR CONDITIONS PREVIALING. WHILE A COLD FRONT WILL BE NEARING OUR REGION FROM THE NORTH ON SUNDAY...WIDESPREAD VFR CONDITIONS SHOULD REMAIN IN PLACE. && .MARINE... HIGH PRESSURE WILL BUILD ACROSS THE EASTERN GREAT LAKES TODAY AND TONIGHT. A COLD FRONT IS FORECAST TO CROSS THE REGION THURSDAY AFTERNOON AND EVENING. WHILE WINDS AND WAVES WILL REMAIN BELOW SCA CRITERIA DURING THAT PERIOD...THERE WILL BE THE THREAT FOR HIGHER WINDS AND WAVES WITH THUNDERSTORMS. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...APB NEAR TERM...TJP SHORT TERM...APB LONG TERM...RSH AVIATION...RSH MARINE...LEVAN
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
120 AM EDT THU JUN 21 2007 UPDATED AVIATION DISCUSSION FOR 06Z TAFS .SYNOPSIS... 19Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED NW FLOW ALOFT FROM A RIDGE STRETCHING FROM NEW MEXICO NORTH TO SOUTHERN ALBERTA AND A TROUGH IN EASTERN ONTARIO/WESTERN QUEBEC. WITHIN THIS FLOW...SHRTWVS ARE HARD TO DEPICT...THOUGH THERE ARE TWO OF NOTE. ONE IS LOCATED AROUND THUNDER BAY ONTARIO AND ANOTHER IS IN CENTRAL SASKATCHEWAN. SHRTWV NEAR THUNDER BAY IS REFLECTED AT THE SFC BY A 1010MB LOW LOCATED IN NORTH CENTRAL ONTARIO...WITH A COLD FRONT EXTENDING SW TO IWD AND MSP. A PRE-FRONTAL TROUGH ALSO EXTENDS FROM THE LOW SOUTHWARD TO ESC. ALTHOUGH SOME ELEVATED CLOUDS AND SHOWERS PASSED ACROSS THE CWA (PARTICULARLY THE NORTH) EARLIER IN THE DAY DUE TO ISENTROPIC LIFTING...PARTLY SUNNY SKIES OVERALL AND 850MB TEMPS AROUND 13C BASED ON TAMDAR SOUNDINGS HAVE ALLOWED TEMPERATURES TO CLIMB INTO THE UPPER 70S. IN ADDITION...DEWPOINTS IN THE MID 50S HAVE ADVECTED INTO THE AREA...RESULTING IN 100MB MLCAPE VALUES OF 1000 J/KG AND LITTLE CIN PER LATEST RUC ANALYSIS. THE COMBINATION OF THIS INSTABILITY AND LAKE BREEZES DEVELOPING AND CONVERGING ON THE PRE-FRONTAL TROUGH HAS RESULTED IN SCATTERED SEVERE THUNDERSTORMS... THE MOST SGNFT OF WHICH DROPPED HAIL UP TO 3 INCHES IN DIAMETER NR THE CITY OF MQT. TO THE NW...HIGH PRESSURE AND DRIER AIR IS PUSHING INTO NW MN. 12Z SOUNDING FROM CWLO HAD A PRECIPITABLE WATER OF 0.48 IN. FARTHER TO THE NW...A BAND OF HIGH BASED STRATUS IS MOVING ACROSS CENTRAL SASKATCHEWAN...WITH A FEW -RA REPORTS ASSOCIATED WITH IT. THIS BAND IS ASSOCIATED WITH BOTH THE CENTRAL SASKATCHEWAN SHRTWV AND SOME 800-700MB FRONTOGENESIS. .SHORT TERM (TONIGHT AND THURSDAY)... NW FLOW ALOFT WILL CONTINUE THROUGH THU AS TROUGHING DEEPENS OVER NEW ENGLAND AND THE RIDGE OVER SOUTHERN ALBERTA SHIFTS EASTWARD INTO SASKATCHEWAN AND MANITOBA. ANY LINGERING SHOWERS AND THUNDERSTORMS SHOULD END QUICKLY THIS EVENING AS THEY GET SHOVED SE IN THE NW FLOW. THE HIGH PRESSURE RIDGE OVER NW MN WILL THEN BUILD INTO THE AREA...HELPING TO CLEAR SKIES OUT AND DIMINISH THE WIND (PARTICULARLY OVER THE WEST HALF). LOW TEMPERATURES BECOME THE NEXT ISSUE GIVEN THE LOW PRECIPITABLE WATER VALUES UPSTREAM ADVECTING IN. GIVEN THAT THEY ARE FAIRLY SIMILAR TO YESTERDAY...LOWS MIGHT BE SIMILAR TO THOSE LAST NIGHT. HOWEVER WE ARE STARTING OFF QUITE A BIT WARMER...AND THAT THERE ARE INDICATIONS OF SOME MID CLOUDS MOVING IN AFTER 06Z WHICH SHOULD PREVENT TEMPERATURES FROM FALLING AS MUCH. THUS HAVE LOWS ABOUT 5 TO 10 DEGREES WARMER THAN LAST NIGHT. THOSE MID CLOUDS MENTIONED ARE ASSOCIATED WITH THE 800-700MB FRONTOGENESIS OCCURRING UPSTREAM WITH THE CENTRAL SASKATCHEWAN SHRTWV. THE 06Z GFS DID PRODUCE SOME QPF AS THEY CROSSED ON THU...THOUGH THE 12Z GFS HAS BACKED OFF AND HAS THE PCPN ENDING BEFORE IT GETS TO IWD. THE 12Z NAM HAS NO QPF AT ALL...LIKELY DUE TO A VERY DRY SUBCLOUD LAYER. WAS TEMPTED TO MENTION SOME SPRINKLES GIVEN THE -RA REPORTS UPSTREAM...BUT GIVEN THE TREND IN THE MODELS TO DIMINISH THE QPF WITH TIME...AND THE DRY SUBCLOUD LAYER...HAVE OPTED TO KEEP THE GRIDS DRY FOR NOW. LATER SHIFTS WILL NEED TO LOOK AT THIS CLOSER. THE CLOUDS...ALONG WITH COOLER 850MB TEMPS PROGGED AROUND 8C NORTH TO 10C SOUTHWEST WILL RESULT IN A COOLER DAY THAN TODAY...ESPECIALLY ALONG THE GREAT LAKES WHERE ONSHORE FLOW DEVELOPS IN THE AFTERNOON. GOING FCST HIGH TEMPS LOOK REASONABLE. .LONG TERM DISCUSSION (THU NGT THRU WED)... HI PRES RDG FCST TO DOMINATE ON THU NGT/FRI IN CONFLUENT NW FLOW ALF BTWN BLDG RDG OVER CNTRL NAMERICA AND TROF IN SE CAN. AFT ANY DIURNAL CU DSPT THU EVNG...EXPECT SKIES TO BCM MOCLR. WL TEND TOWARD THE LO END OF MOS GUIDANCE FOR MIN TEMPS THU NGT...ESPECIALLY OVER THE INTERIOR W...WITH LGT WINDS UNDER RDG AXIS. FLAT PRES GRADIENT WL ALLOW LK BREEZES TO DVLP ON FRI...ESPECIALLY NR LK SUP AND S OF ESC WITH LGT ENE FLOW S OF HUDSON BAY HI CENTER. LOOK FOR JUST SOME HI CLDS AS WELL AS SOME DIURNAL CU TO DVLP INLAND FM THE LK BREEZE BNDRY. FCST H85 TEMPS IN THE 8C-12C (WARMEST W) RANGE AND MIXING TO H75 ON GFS FCST SDNGS SUPPORT HI TEMPS OVER THE INTERIOR W HALF ARND 80. GFS/UKMET HINT AT SOME MAINLY MID LVL MSTR RETURN ON FRI NGT AS SFC HI CENTER SINKS TOWARD THE LOWER GREAT LKS AND LLVL FLOW TURNS WSW BTWN DEPARTING HI AND SHRTWV/COLD FNT MOVING THRU ONTARIO. EXPECT THE MAJORITY OF THE ASSOCIATED MID CLD COVER OVER THE NRN TIER ZNS. OPTED TO RETAIN LO CHC POPS OVER THE NW ZNS LATE FRI NGT AS GFS FCST SDNG FOR CMX INDICATES 12Z SAT CAPE APRCHG 300 J/KG WITH KINX OF 35 AND MINIMAL CIN LIFTING FM H825. HOWEVER...WL GO MORE THAN A 20 POP WITH LACK OF REAL FOCUSING MECHANISM WITH SFC TROF SO FAR TO THE N YET. OTRW...THE OVERNGT WL BE QUITE A BIT WARMER THAN ON FRI NGT WITH STRONGER WSW FLOW/MSTR RETURN. LOWEST MIN TEMPS EXPECTED OVER THE INTERIOR SCNTRL AND E CLOSER TO DEPARTING SFC HI/DRIER AIR. BNDRY TO THE N FCST TO SINK SLOWLY SWD ON SAT/SAT NGT AS SHRTWV DROPPING INTO NW ONTARIO AMPLIFIES SE CNDN TROF AND UPR FLOW OVER ONTARIO TURNS MORE NW. HOWEVER...SHARPENING RDG AXIS UPSTREAM WL GRDLY RESULT IN A MORE DYNAMICALLY UNFVRBL...CAPPED ENVIRONMENT THRU THE PD AS BNDRY SHOULD UNDERGO EVENTUAL FRONTOLYSIS. RETAINED LO CHC POPS ON SAT ACRS THE NRN TIER ZNS CLOSER TO APRCHG BAND OF H7-8 FGEN/AXIS OF LWR SSI JUST BLO 0C. FCST SDNGS FARTHER S SHOW A PROHIBITIVELY DRY AIRMASS FOR ANY PCPN FARTHER FM THE BNDRY. THE WX IN THE EXTENDED PD (SUN THRU WED) WL BE DOMINATED BY UPR RDGING BTWN SLOW MOVING VORTEX IN SE CAN AND TROFFING THAT IS NOW CUTOFF IN THE GLFAK AND FCST TO MOVE INTO SW CAN/NRN ROCKIES BY EARLY NEXT WEEK. EXPLICIT MODEL GUIDANCE OFFERS A VARIETY OF SCENARIOS AS TO TIMING OF DISTURBANCES RIDING THRU THIS FLOW AND POSITION OF ACTIVE WARM FNT/HOW QUICKLY COLD FNT ASSOCIATED WITH SW CNDN TROF WL PUSH EWD AND IMPACT THE UPR GRT LKS. CONSIDERING CONSENSUS VIEW THAT WARM FNT WL BE IN THE VCNTY MON-TUE TO THE N OF BUBBLE OF VERY WARM AIR TO THE S WITH COLD FROPA TUE-WED...COULD BE AN ACTIVE PD OF WX ACRS THE UPR GRT LKS. NCEP MANUAL GUIDANCE SEEMS TO OFFER A RSNBL COMPROMISE BTWN VARIOUS OPERATIONAL MODELS/GFS AND CNDN ENSEMBLE GUIDANCE SHOWING HUDSON BAY HI PRES OVER THE UPR LKS ON SUN IN CONFLUENCE BTWN APRCHG RDG AND SLOWLY DEPARTING TROF IN SE CAN. THIS HI THEN GIVES WAY TO APRCHG WARM FNT ON MON AS CNDN TROF/ CONFLUENCE ZN LIFTS TO THE NE BEFORE COLD FROPA TUE NGT/WED MRNG. COORDINATED WITH GRB. && .AVIATION (FOR 06Z TAF ISSUANCE)... LIGHT WINDS AND LINGERING LOWER LEVEL MOISTURE FM RAIN THAT FELL YDY COULD AID IN DEVELOPING FOG AT KSAW TOWARD SUNRISE. POTENTIAL FOR AT LEAST LOCALIZED IFR VISIBILITIES/CEILINGS IN THE FOG. ANY FOG WILL DISSIPATE QUICKLY AFTER SUNRISE AS IT WOULD BE SHALLOW. VFR CONDITIONS OTHERWISE AT BOTH SITES FOR REST OF PERIOD. AS WINDS REMAIN LIGHT...EXPECT LK BREEZE DEVELOPMENT THIS AFTN AT BOTH SITES. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FCST ISSUANCE)... HIGH PRESSURE BUILDING IN FROM NW MN WILL HELP DIMINISH THE WINDS THIS EVENING ACROSS LAKE SUPERIOR BELOW 20 KT. BEYOND THIS EVENING...THE REST OF THE FORECAST PERIOD LOOKS BELOW 20 KT. ONLY MAJOR CONCERN IS WIND FIELDS AS THEY ARE A LITTLE UNCERTAIN WITH A COLD FRONT POSSIBLY COMING DOWN AROUND SAT NIGHT. FOR NOW FOLLOWED THE GFS...BUT THIS TIME PERIOD IS SUBJECT TO CHANGE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...AJ LONG TERM...KC AVIATION...JLA MARINE...AJ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
112 AM EDT THU JUN 21 2007 .AVIATION...PRECIPITATION THREAT HAS ENDED AT TVC...WITH GENERALLY CLEAR/PARTLY CLOUDY CONDITIONS EXPECTED THROUGH THE NIGHT. COLD FRONT WILL PASS ACROSS NORTHERN LOWER MI DURING THE PRE-DAWN HOURS...BRINGING DRIER AIR IN BEHIND IT. GIVEN AFTERNOON RAINFALL CAN/T RULE OUT SOME PATCHY FOG TRYING TO DEVELOP AHEAD OF THE COLD FRONT BUT WINDS WILL PROBABLY STAY UP ENOUGH TO PREVENT ANY MAJOR ISSUES. VFR CONDITIONS EXPECTED THROUGH THE DAY THURSDAY. JPB/JZ && .UPDATE... /ISSUED 1008 PM EDT WED JUN 20 2007/ WHAT REMAINS OF THE BAND OF SHOWERS AND THUNDERSTORMS THAT HAD BEEN DROPPING STEADILY SOUTHWARD ACROSS THE FORECAST AREA DURING THE LATE AFTERNOON/EVENING HOURS HAS PRETTY MUCH CLEARED THE FORECAST AREA. SCATTERED WEAK CONVECTION CONTINUES TO TRY AND DEVELOP SOUTH OF M-32 IN AREAS OF MOISTURE CONVERGENCE ASSOCIATED WITH LOW LEVEL CONFLUENCE AXIS COINCIDENT WITH 850MB THETA-E RIDGE POKING INTO NORTHERN LOWER. MAIN SHORT WAVE TROUGH WHICH HELPED INITIATE CONVECTION ACROSS WESTERN/CENTRAL UPPER DURING THE AFTERNOON HAS MOVED WELL EAST OF LAKE SUPERIOR. SO DESPITE 01Z MESOANALYSIS SHOWING COLD FRONT JUST PASSING THE KEWEENAW PENINSULA...PASSAGE OF SHORT WAVE TROUGH AND EARLIER CONVECTION HAS STABILIZED THINGS ACROSS EASTERN UPPER AND THE STRAITS AREA AS SUGGESTED BY RECENT AIRCRAFT SOUNDINGS. SO WILL FOCUS REMAINING PRECIPITATION CHANCES OVERNIGHT TO AREAS ALONG AFOREMENTIONED LOW LEVEL THETA-E/ELEVATED INSTABILITY AXIS...WHICH WILL LIE SOUTH OF M-72 FOR A WHILE TONIGHT THEN SINK INTO THE SOUTHERN HALF OF THE LOWER PENINSULA TOWARD DAYBREAK. PRECIPITATION COVERAGE SHOULD BE PRETTY SPOTTY THROUGH THE REST OF THE NIGHT...ADDITIONAL CONVECTION DEVELOPING UPSTREAM ACROSS MN/WI WILL PROPAGATE SOUTHEAST WITH TIME. COLD FRONT ACROSS WESTERN UPPER/NORTHWEST WI SHOULD CLEAR THE FORECAST AREA SHORTLY AFTER DAYBREAK...WITH A PUSH OF LOWER DEW POINTS BEHIND IT. JPB && .PREV DISCUSSION... /ISSUED 353 PM EDT WED JUN 20 2007/ LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW A SURFACE LOW LOCATED OVER SOUTHERN ONTARIO WITH A TRAILING COLD FRONT MOVING SE ACROSS LAKE SUPERIOR...WESTERN UPPER MICHIGAN AND NORTHERN WISCONSIN. CONVECTION HAS DEVELOPED RAPIDLY THIS AFTERNOON ACROSS WESTERN AND CENTRAL UPPER AHEAD OF THE FRONT WHERE THE JUICIER AIRMASS RESIDES. GREAT DYNAMICS AHEAD OF THE FRONT WITH 0-6KM BULK SHEAR VALUES 50-60KTS AND SB CAPES AROUND 1000 J/KG ARE SUPPORTING SEVERE THUNDERSTORMS NEAR MQT. LEADING EDGE OF THIS JUICY AIR REMAINS ACROSS LAKE MICHIGAN AND CENTRAL UPPER AND IS KNOCKING ON THE DOOR...USHERED IN BY A 30-40KTS 850MB LLJ. SOME SHOWERS AND ISOLATED THUNDERSTORM HAVE DEVELOPED ALONG THIS THETAE GRADIENT AND HAVE IMPACTED PORTIONS OF EASTERN UPPER AND ARE CROSSING NORTHERN LAKE MICHIGAN AT THE MOMENT. MAIN FORECAST CONCERNS FOR THE REST OF TODAY AND TONIGHT INCLUDE SHOWER AND THUNDERSTORM POTENTIAL. TONIGHT...SHORTWAVE MOVING ACROSS SOUTHERN ONTARIO THIS AFTERNOON... WILL CONTINUE ITS ESE JAUNT AND PASS ACROSS NORTHERN LAKE SUPERIOR THIS EVENING. BUT STRONG NW WINDS WITHIN A 105KT JET STREAK ALONG WITH THIS SHORTWAVE WILL PUSH A COLD FRONT ACROSS THE AREA. COOL...DRY AIRMASS EARLY THIS AFTERNOON WILL GAVE WAY TO A INCREASINGLY WARM/MOIST AIRMASS AS A 30KT WESTERLY LLJ ADVECTS HIGHER THETAE AIR IN FROM MINNESOTA AND WISCONSIN. EXPECT A BAND OF SHOWERS AND THUNDERSTORMS TO DEVELOP WITHIN THIS 850MB THETAE AXIS AHEAD OF THE FRONT AND REACH EASTERN UPPER BETWEEN 21-00Z AND THEN SWEEP ACROSS NORTHERN LOWER BETWEEN 00-06Z. SEVERE POSSIBILITIES CONTINUE TO LOOK MARGINAL. ON THE FAVORABLE SIDE...WIND FIELDS ARE IMPRESSIVE WITH A 30-40KT LLJ...40-50KT AT 700MB...AND 60-70KTS AT 500MB WHICH EQUATES TO 50-60KT 0-6KM BULK SHEAR...AND DECENT FORCING FROM THE COLD FRONT. ON THE OTHERHAND...BEST UPPER LEVEL SUPPORT IN THE FORM OF DPVA AND DIVERGENCE WITHIN THE LEFT EXIT REGION OF 105KT JET STREAK LOOKS TO REMAIN TO THE NORTH OVER ONTARIO. BUT THE BIGGEST LIMITING FACTOR CONTINUES TO BE THE AMOUNT OF INSTABILITY FOR WHICH THE FRONT CAN TAP INTO. SURFACE TEMPS/DEWPOINTS CONTINUE TO BE SLOW TO RISE THIS AFTERNOON WITH THE 850MB THETAE GRADIENT STILL RESIDING JUST WEST OF THE AREA. WITH THE JUICIER AIRMASS ARRIVING OVER THE NEXT SEVERAL HOURS...IF PORTIONS OF EASTERN UPPER COULD REACH T/TD OF 72/55...ABOUT 500 J/KG OF ML CAPE COULD BE REALIZED. ONCE THE SUN GOES DOWN...SKINNY ELEVATED INSTABILITY BETWEEN 400-700 J/KG WILL EXIST AHEAD OF THE FRONT SO CANNOT RULE OUT SOME CONVECTION SUSTAINING ITSELF THROUGH THE EARLY OVERNIGHT HOURS. IT WOULD NOT TAKE MUCH FOR THESE THUNDERSTORMS TO TAP INTO THE STRONGER WINDS ALOFT...AND WILL CONTINUE TO MENTION THE THREAT OF DAMAGING WINDS AND LARGE HAIL...WITH MORE EMPHASIS ON THE WIND THREAT. MPC REST OF THE FORECAST (THURSDAY THROUGH NEXT WEDNESDAY)...SEASONABLE TEMPERATURES AND LOW HUMIDITY LEVELS WILL CONTINUE OVER THE NEXT COUPLE OF DAYS. WARMER AIR WILL BEGIN TO WORK ITS WAY IN OVER THE WEEKEND BUT THE HUMIDITY WILL REMAIN RELATIVELY LOW. THE BEGINNING OF NEXT WEEK WILL TURN VERY WARM AND ELEVATED HUMIDITY LEVELS WILL TEND TO MAKE IT FEEL UNCOMFORTABLE. A COLD FRONT IS EXPECTED TO MOVE THROUGH LATER TUESDAY INTO EARLY WEDNESDAY WHICH WOULD BRING SOME RELIEF. THURSDAY INTO FRIDAY...TROUGHING ALONG THE WEST COAST WILL LEAD TO INCREASING DOWNSTREAM RIDGING ACROSS THE WESTERN GREAT LAKES. HIGH PRESSURE AT THE SURFACE WILL BUILD DOWN FROM THE NORTH. MEAN 1000-500 MB RH BETWEEN 40 AND 50 PERCENT THURSDAY DROPS TO 30 TO 40 PERCENT ON FRIDAY. THIS SHOULD LEAD TO PARTLY CLOUDY CONDITIONS. 850 MB TEMPERATURES BETWEEN PLUS 8 AND 10 C BOTH DAYS EXPECTED TO LEAD TO HIGHS IN THE 70S ACROSS THE ENTIRE FORECAST AREA (HIGHEST SOUTHERN ZONES). COMFORTABLY COOL AT NIGHT WITH LOWS RANGING FROM THE MIDDLE 40S TO LOWER 50S. SATURDAY AND SUNDAY...EXTENDED MODELS ARE IN GENERAL AGREEMENT THAT THE RIDGE CONTINUES TO SLOWLY AMPLIFY. THERE ARE DIFFERENCES ON THE HANDLING OF A CUTOFF LOW UNDER THE RIDGE SOMEWHERE IN THE VICINITY OF THE LOWER MISSISSIPPI VALLEY. THIS IS THE ONE FEATURE THAT HAS THE POTENTIAL TO MESS UP THE ONGOING FORECAST...OTHERWISE A PLEASANT WEEKEND IS ANTICIPATED WITH CONTINUED LOWER HUMIDITY LEVELS. 850 MB TEMPERATURES BLOSSOM TO BETWEEN PLUS 13 AND 15 C SATURDAY THEN TO BETWEEN PLUS 14 AND 16 C SUNDAY. THEREFORE HIGHS RANGING FROM THE MIDDLE 70S NORTH TO THE LOWER 80S SOUTH EXPECTED. MONDAY AND TUESDAY...RIDGE CONTINUES TO BUILD WITH A MORE MOIST SOUTH SOUTHWEST SURFACE FLOW LEADING TO HIGHER HUMIDITY LEVELS. AS 850 MB TEMPERATURES RISE TO BETWEEN PLUS 18 AND 20 C HIGHS WILL INCREASE TO NEAR 80 NORTH AND AROUND 90 SOUTH. A NORTHERN STREAM SHORT WAVE AND ASSOCIATED SURFACE COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY LEADING TO CHANCE POPS ACROSS NORTHERN ZONES ON TUESDAY. WEDNESDAY...SURFACE COLD FRONT IS SHOWN TO PUSH ACROSS THE REGION. TIMING THIS FAR OUT IS OBVIOUSLY IN QUESTION BUT WILL CONFINE CHANCE POPS TO EASTERN/SOUTHERN ZONES TO LINE UP WITH SURROUNDING OFFICES. ANY COOL AIR PUSH SHOULD BE MINIMIZED AS A ZONAL FLOW ALOFT IS SHOWN TO DEVELOP FOR THE MIDDLE OF NEXT WEEK. FORECAST HIGH TEMPERATURES WILL BE A FEW DEGREES LOWER THAN PREVIOUS DAYS BUT STILL RANGE FROM THE MIDDLE 70S NORTH TO THE MIDDLE 80S FAR SOUTH. SULLIVAN && .APX WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
300 AM PDT THU JUN 21 2007 .SYNOPSIS...MARINE CLOUDS ENTRENCHED ACROSS THE AREA TODAY AS AN UPPER LOW OVER THE NORTHEAST PACIFIC MAINTAINS A SOUTHWEST FLOW. ON THE COAST FOR THE NEXT FEW DAYS A LITTLE LIGHT PRECIPITATION MAY OCCUR AT TIMES. EXPECT COOLER WEATHER INLAND FROM THE INCREASED CLOUDINESS AND MAYBE A FEW SPOTS OF LIGHT PRECIPITATION MAINLY NORTH. THE OFFSHORE UPPER LOW BEGINS TO MAKE A MOVE ONSHORE SATURDAY FOR A FEW MORE SHOWERS...THEN CURRENT MODELS CONTINUE TO SHOW IT SWINGING THROUGH THE PACIFIC NORTHWEST SATURDAY NIGHT AND SUNDAY FOR AN INCREASE IN SHOWERS...AND POSSIBLY SOME CONVECTION WITH THE COLD POOL ALOFT. DRYING IS LIKELY AGAIN EARLY NEXT WEEK. && .SHORT TERM...MARINE CLOUDS WELL ESTABLISHED ACROSS MOST OF THE CWA WITH THE EXCEPTION OF THE CENTRAL OREGON CASCADE ZONES. A NEARLY STATIONARY UPPER LOW OVER THE NORTHEAST PACIFIC WILL CONTINUE THE FAVORABLE PATTERN TO MAINTAIN THE FEED OF MARINE MOISTURE INTO THE AREA. SHORTWAVES ROTATING AROUND THE UPPER LOW WILL AFFECT MARINE LAYER. ONE WAVE IS FORECAST TO PUSH THE LEADING FRONTAL BOUNDARY ONTO THE COAST TODAY...WHICH THEN STALLS AND WEAKENS NEAR THE COAST RANGE. SO COULD EXPECT A CHANCE OF SOME LIGHT PRECIPITATION NEAR THE COAST TODAY...AND WITH PERHAPS A LITTLE SPOTTY DRIZZLE FARTHER INLAND EARLY THIS MORNING. SO FAR THIS MORNING TRACE AMOUNTS OF RAIN HAVE FALLEN AT ASTORIA AND HOQUIAM. MARINE LAYER PROBABLY DEEP ENOUGH AND ENOUGH LIFT IN TO KEEP A LITTLE DRIZZLE AT TIMES NEAR THE COAST INTO FRIDAY...WITH LESS OF A CHANCE INLAND. ANOTHER WAVE LOOKS TO LIFT NORTHEAST FRIDAY AFTERNOON INTO EARLY SATURDAY...ALONG WITH A 100 KT SOUTHWESTERLY JET TO ENHANCE LIFT ON MARINE LAYER. THOUGH THE MODELS LOOK DRY...THIS SHOULD ENHANCE THE LEFTOVER FRONTAL BOUNDARY AGAIN AND SHOULD SEE A LITTLE DRIZZLE OR LIGHT RAIN ESPECIALLY NEAR THE COAST FRIDAY NIGHT AND SATURDAY MORNING. TEMPS WILL BE QUITE A BIT COOLER INLAND FROM THE INCREASED CLOUDS AND ONSHORE FLOW. ON SATURDAY THE OFFSHORE LOW STARTS TO DIG A BIT AND SWING TOWARD THE COAST IN RESPONSE TO SHORT WAVE ENERGY SWINGING AROUND IS BASE...AND THIS COULD LEAD TO A FEW MORE SHOWERS IN THE AFTERNOON. BUT SATURDAY NIGHT AND SUNDAY LOOK TO BE THE MAIN FOCUS OF ANY SIGNIFICANT PRECIPITATION AS THE UPPER LOW AND ITS ASSOCIATED COLD POOL ALOFT MOVE THROUGH. .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... THE BEGINNING OF THE EXTENDED PERIOD BODES TO BE THE HIGHLIGHT OF THE EXTENDED FORECAST STARTING OFF WITH A SYSTEM CLOSING IN ON THE PAC NW SATURDAY EVENING AND MOVING ASHORE ON SUNDAY BRINGING WITH IT A SLIGHT CHANCE OF TSTMS. HAVE INCREASED POPS ACCORDINGLY ON SAT EVENING AND SUN. A WELL MODELED DEEP UPPER LEVEL TROUGH DIGS SOUTH INTO CALIFORNIA BRINGING COOL MID TO UPPER LEVEL TEMPS AND WARMER W TO SWLY FLOW LOW LEVEL FLOW. 1000-700 MU CAPE VALUES NEAR 700 J/KG AND -28 C 500 MB TEMPS FAVOR THE TSTM WORDING PARTICULARLY WITH THE FRONTOGENETIC FORCING ASSOCIATED WITH THE WEAK APPROACHING SYSTEM. NOT A WHOLE LOT TO TALK ABOUT AFTER THIS SYSTEM LEAVES...SOME LINGERING SHOWERS INTO MON MORNING BEFORE DRYING OUT AT LEAST UNTIL FRI. WOLFE && .AVIATION...DEEP MARINE LAYER LIES ACROSS THE ENTIRE FORECAST AREA THIS MORNING. RECENT AIRCRAFT SOUNDINGS SUGGEST CLOUD BEARING PORTIONS OF THIS MARINE AIRMASS SHOULD BE SOMEWHERE BETWEEN 3K TO 7K FT. OBSERVATIONS SUPPORT THIS CLAIM WITH 2800 TO 3500 FT CIGS BEING COMMONPLACE...AS DOES FOG PRODUCT SATELLITE IMAGERY WHICH SHOWS MARINE STRATUS EXTENSIVELY ALONG THE CREST OF THE CASCADES SUGGESTING TOPS NEAR 7K FT. WILL LIKELY AMEND SOONER THAN 12Z...HOWEVER 12Z TAF PACKAGE WILL CARRY VFR CONDITIONS AS DOMINANT CEILING TYPE INLAND WITH MARGINAL CIGS AT THE COAST. NAM MODEL SOUNDINGS PROBABLY A BIT TOO AGRESSIVE WITH CLEARING OUT CLOUDS TODAY BUT SHOULD HAVE THE GENERAL IDEA SO WILL FEATURE SCATTERED VFR DECKS...LIKELY AT ALL TAF SITES...BY EARLY AFTERNOON. DALTON && .MARINE...AT 09Z BUOY 46029 CAME IN WITH SMALL CRAFT WINDS...STATING GUSTS TO 21 KTS. DO NOT FEEL THIS WILL BE COMMON PLACE ACROSS THE WATERS THIS MORNING SO WILL HOLD OFF ON ISSUING ANY ADVISORIES. THAT BEING SAID PLAN ON WORDING THE MORNING COASTAL WATERS FORECAST AS 15 TO 20 KT WITH FEW GUSTS TO 25 KT. OTHERWISE MARINE CONDITIONS WILL BE LOW KEY AGAIN TODAY WITH SEAS RUNNING AROUND 5 FT AND NO ROUGH BAR CONDITIONS EXPECTED WITH EITHER OF THE EBB CURRENTS TODAY. DALTON && .PQR WATCHES/WARNINGS/ADVISORIES... OR/WA...NONE && .PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION) AST 42223 PDX 21112 SLE 21112 EUG 11112 $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
335 AM PDT THU JUN 21 2007 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BRING HOT WEATHER INLAND THROUGH FRIDAY. THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE COASTAL LOW CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS. A LITTLE COOLER THIS WEEKEND AND EARLY NEXT WEEK AS LOW PRESSURE MOVES PAST TO THE NORTH. SUMMER BEGINS TODAY AT 1106 AM PDT. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (TODAY THROUGH SATURDAY)... HIGH PRESSURE WILL PEAK TODAY...THEN BEGIN TO SLOWLY WEAKEN AS LOW PRESSURE MOVES INLAND TO THE NORTH. HIGH TEMPERATURES WILL PEAK IN INLAND AREAS TODAY...WELL ABOVE SEASONAL AVERAGES BUT MOSTLY NOT RECORD SETTING...THEN BEGIN TO SLOWLY COOL FRIDAY AND SATURDAY. RECENT ACARS SOUNDINGS SHOW A STRONG AND SHALLOW MARINE INVERSION WITH A MARINE LAYER DEPTH AROUND 1200 FEET. IN SAN DIEGO COUNTY... LOW CLOUDS WILL EXTEND INLAND TO THE MESAS OR LOWER COASTAL VALLEYS WITH LOCALLY DENSE FOG IN THESE AREAS. ONCE AGAIN...LOW CLOUDS HAVE BEEN SLOWER TO DEVELOP AND SPREAD INLAND INTO ORANGE COUNTY...BUT SHOULD GRADUALLY DEVELOP AND SPREAD INLAND ACROSS PORTIONS OF THE ORANGE COUNTY COASTAL PLAIN THROUGH SUNRISE...BUT NOT QUITE AS FAR INLAND AS YESTERDAY MORNING. FOR TONIGHT AND FRIDAY NIGHT...SLOW DEEPENING OF THE MARINE LAYER WITH LOW CLOUDS RETURNING TO THE LOWER COASTAL VALLEYS BY SATURDAY MORNING. LOW CLOUDS WILL CONTINUE TO CLEAR TO THE COAST BEFORE NOON EACH DAY AND THEN SPREAD ONLY SLOWLY INLAND OVERNIGHT...MOSTLY AFTER MIDNIGHT. && .LONG TERM (SUNDAY THROUGH WEDNESDAY)... 00Z/006Z GFS ARE MORE AGGRESSIVE WITH A TROUGH OF LOW PRESSURE OVER THE EASTERN PACIFIC. GFS TREND IS FOR DRIER SOUTHWEST FLOW ALOFT AND SLIGHTLY COOLER PATTERN CLOSER TO SEASONAL. ECWMF IS A LITTLE WEAKER WITH THIS TROUGH AND HENCE WOULD SUPPORT TEMPERATURES A LITTLE ABOVE SEASONAL AVERAGES. CURRENT FORECAST IS CLOSER TO THE ECMWF GIVEN THE CONTINUING LACK OF CONSISTENCY OF THE GFS IN THE LATTER PORTION OF THE EXTENDED. CURRENT FORECAST HAS A FEW CLOUDS OVER THE MOUNTAINS IN THE AFTERNOON. HOWEVER...GIVEN MODEL TRENDS INCLUDING THE ECMWF...THIS MAY BE GENEROUS. && .FIRE WEATHER... THERE HAS BEEN SLIGHT MOISTENING OF THE ATMOSPHERE ALOFT DURING THE PAST 24 HOURS WITH A LITTLE GREATER RECOVERY OF RELATIVE HUMIDITIES IN THE MOUNTAINS OVERNIGHT. HOWEVER...THE ATMOSPHERE IN THE MOUNTAINS AND DESERTS REMAINS QUITE DRY. WITH DAYTIME TEMPERATURES WELL ABOVE SEASONAL AVERAGES...RELATIVE HUMIDITIES WILL DROP BELOW 10 PERCENT FROM LATE MORNING THROUGH EARLY EVENING. WINDS IN THE AFTERNOON AND EVENING WILL GUST LOCALLY TO 30 MPH IN THE DESERTS AND ON DESERT SLOPES OF THE MOUNTAINS. && .AVIATION... 211015Z...STRATUS IS HAVING A TOUGH TIME MOVING INLAND DUE TO A VERY STRONG...LOW LYING INVERSION AT 1200 FT MSL. BASE OF STRATUS IS AROUND 800 FT MSL. THE STRATUS WILL NOT PENETRATE FAR INLAND AND SHOULD RAPIDLY MIX OUT BETWEEN 15Z AND 17Z. SOME AREAS OF 3-5SM VIS IN FOG WILL CONTINUE OVER THE INLAND VALLEYS UNTIL 15Z WITH SOME LOCALLY LOWER VIS IN SPOTS. ANY VISIBILITY RESTRICTIONS SHOULD LIFT BY 19Z. MARINE LAYER IS EXPECTED TO BE SLIGHTLY SHALLOWER TONIGHT...MOVING IN SLOWLY AFTER 04Z...AND CAUSING PATCHY DENSE FOG ON THE COASTAL MESAS AND WESTERN VALLEYS. ABOVE THE MARINE LAYER AND INLAND OVER THE MOUNTAINS AND DESERTS SKIES WILL REMAIN MOSTLY CLEAR WITH UNRESTRICTED VISIBILITY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR RIVERSIDE COUNTY MOUNTAINS-INCLUDING THE SAN JACINTO RANGER DISTRICT OF THE SAN BERNARDINO NATIONAL FOREST-SAN BERNARDINO COUNTY MOUNTAINS-INCLUDING THE MOUNTAIN TOP AND FRONT COUNTRY RANGER DISTRICTS OF THE SAN BERNARDINO NATIONAL FOREST-SAN DIEGO COUNTY MOUNTAINS-INCLUDING THE PALOMAR AND DESCANSO RANGER DISTRICTS OF THE CLEVELAND NATIONAL FOREST. PZ...NONE. && $$ PUBLIC...MARTIN AVIATION/MARINE...MACKECHNIE NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
643 AM CDT THU JUN 21 2007 .DISCUSSION... 312 AM CDT AFTER A COUPLE OF DAYS OF PERFECT WEATHER...THE PATTERN IS ABOUT TO BECOME MORE UNSETTLED AS A COLD FRONT DRIFTS SOUTHWARD FROM WISCONSIN INTO THE REGION. THIS FRONT HAS BEEN THE FOCUS POINT FOR THE DEVELOPMENT OF SEVERE STORMS WED AFTERNOON AND OVERNIGHT INTO THIS MORNING IN MINNESOTA AND WISCONSIN. IT APPEARS THAT THE FRONT WILL BE DRAPED ALONG THE IL/WI BORDER BY ABOUT 18Z...WHICH WILL GIVE MOST OF NORTHERN IL/IN AMPLE TIME TO WARM INTO THE MID TO UPPER 80S. BOTH THE GFS AND NAM WANT TO BRING DEW POINTS INTO THE UPPER 60S AND SOME LOW 70S BY THE END OF THE DAY TODAY. HOWEVER...WITH WEAK SFC FLOW AND THE MAIN AXIS OF THE LLJ STILL POINTED OUT TO THE WEST...HAVE A HARD TIME BELIEVING THAT THERE WILL BE A STRONG SOURCE OF MOISTURE ADVECTION INTO THE REGION...SO HAVE ONLY BROUGHT THEM INTO THE LOW TO MID 60S FOR THE NEAR TERM. BUFKIT AND OTHER FORECAST SOUNDINGS SHOW THE INVERSION ERODING AROUND 18Z...WHICH TIMES OUT WELL WITH THE FRONT GETTING INTO THE REGION. WITH A FAT CAPE PROFILE...THERE SHOULD BE SOME FAIRLY STRONG VERTICAL UPDRAFTS WHICH WOULD SUPPORT DECENT HAIL GROWTH. THE NAM IS A BIT OVERDONE WITH PRODUCING 3000 J/KG OF CAPE DUE TO THE HIGH DEW POINTS IT HAS TIED INTO IT. HOWEVER...ADJUSTING FOR THE SLIGHTLY LOWER DEW POINTS STILL LEADS TO ABOUT 2000 J/KG OF CAPE. 0-1KM AND 0-6KM BULK SHEAR IS NOT ALL THAT IMPRESSIVE...SO AM NOT OVERLY IMPRESSED WITH ANY TORNADO CHANCES TODAY. THE MAIN THREAT LOOKS TO BE WITH LARGE HAIL AND DAMAGING WIND FROM DOWNBURSTS. AS THE CONVECTION WEAKENS LATER IN THE EVENING...THE ATTENTION WILL SHIFT TO WHAT OCCURS OUT WEST OF US. A SHORTWAVE TROF CURRENTLY ROUNDING THE TOP OF THE RIDGE IN MONTANA WILL DIVE DOWN INTO THE UPPER MISSISSIPPI VALLY THIS EVENING AND AID IN THE DEVELOPMENT OF AN MCS OVER EASTERN IOWA. HOW FAR SOUTH THE COLD FRONT SAGS INTO NORTHERN ILLINOIS/INDIANA IS GOING TO PLAY A BIG ROLE IN WHERE THE MCS MEANDERS TO. ALL THE INGREDIENTS COME TOGETHER OVERNIGHT AS A 40KT LOW LEVEL JET DEVELOPS WITH THE NOSE OF IT POKING RIGHT UP TO THE SFC FRONTAL BOUNDARY. THE POOL OF HIGH THETA E AND THE LLJ WEAKEN RIGHT AS YOU GET TO THE ILLINOIS/INDIANA STATE LINE...SO HAVE USED THAT AS THE CUTOFF POINT FOR THE HIGHER POPS INTO FRIDAY MORNING. CURRENT THINKING IS THAT THE MCS WILL CUT THROUGH THE SOUTH-SOUTHWESTERN PORTION OF THE CWA...WHICH IS MAINLY FROM LEE COUNTY SOUTHEASTWARD DOWN THROUGH GRUNDY AND INTO IROQUOIS COUNTIES. STRAIGHT LINE DAMAGING WINDS WILL BE THE BIG CONCERN HERE. ANOTHER CONCERN...WHICH SEEMS UNLIKELY DUE TO HOW DRY THE REGION HAS BEEN OVER THE PAST 60 DAYS...IS THAT THERE IS THE POTENTIAL FOR FLOODING FROM EASTERN IOWA DOWN THROUGH NORTH CENTRAL ILLINOIS OVER THE NEXT 3 DAYS. WITH THE FRONTAL BOUNDARY STALLED OUT ACROSS THIS REGION...THERE WILL BE ROUND AFTER ROUND OF HEAVY RAINFALL...STARTING OFF WITH THE MCS. HPC 5-DAY ACCUMULATED QPF SHOWS A SWATH OF 3 TO 4 INCHES OF RAINFALL ACROSS THIS REGION...WHICH ALL WILL MAINLY HAPPEN IN THE NEXT THREE DAYS. THE GROUND SHOULD BE ABLE TO SOAK SOME OF THIS UP...BUT ENOUGH OF IT IN A SHORT TIME FRAME WILL LEAD TO PROBLEMS. NOT MANY CHANGES MADE TO TEMPERATURES OVER THE PERIOD. NUDGED MAX TEMPS UP A TAD OUT IN THE WESTERN PORTION OF THE CWA TOWARD ROCKFORD INTO THE UPPER 80S AS BETTER TEMPERATURE ADVECTION WILL BE OUT IN THAT REGION FOR TODAY. COOLER AIR BEHIND THE FRONT WILL SETTLE IN ACROSS THE REGION ON FRIDAY WITH TEMPERATURES STRUGGLING TO GET OUT OF THE 70S DUE TO CLOUD COVER AS WELL. THE WEATHER ASSOCIATED WITH THIS FRONT SHOULD CLEAR THE REGION BY SATURDAY NIGHT. AS THIS OCCURS...A STRONG RIDGE WILL DEVELOP OUT TO THE WEST WHICH WILL ASSIST IN ADVECTING WARMER AIR INTO THE REGION. TEMPS WILL CLIMB WELL ABOVE NORMAL FOR THE START OF NEXT WEEK. HALBACH && .AVIATION... FOR THE 0600 UTC TAFS...PRIMARY CHALLENGE CONTINUES TO BE TIMING/LOCATION OF THUNDERSTORMS THROUGH MUCH OF THE UPCOMIGN TAF CYCLE. COMPLEX OF SHRA/TSRA IS ORGANIZING OVER NE IA AND FAR SW WI EARLY THIS MORNING IN A REGION OF MODEST LOW LEVEL WARM AIR ADVECTION NEAR SURFACE FRONT THAT STRETCHED FROM JUST NORTH OF MKE TO JUST SOUTH OF LSE AT 11Z. WHILE UPPER FLOW WOULD TEND TO CARRY THIS CONVECTION SE TOWARD NORTHERN ILLINOIS...INSTABILITY AXIS OVER IOWA IS TENDING TO FAVOR THE WESTERN EDGE OF COMPLEX FOR RENEWED THUNDERSTORM DEVELOPMENT. AN 0830Z ACARS SOUNDING FROM RFD INDICATES A FORMIDIBLE AMOUNT OF CONVECTION INHIBITION REMAINS...EVEN FOR ELEVATED PARCELS...AND WITH NO QUICK DESTABILIZATION EXPECTED EARLY THIS MORNING WOULD EXPECT TO SEE TSRA ON THE EASTERN EDGE OF THIS COMPLEX CONTINUE TO STRUGGLE TO MAINTAIN ITSELF. STILL WILL PROBABLY SEE SOME SHRA AND POSSIBLY A BRIEF TSRA AT RFD AND POSSIBLY AS FAR EAST AS DPA THIS MORNING...HOWEVER TERMINALS EAST OF THERE WILL PROBABLY MISS MOST OF THE PRECIPITATION WITH THIS FIRST COMPLEX AS IT BEGINS TO DIMINISH LATER THIS MORNING WITH WEAKENING WARM AIR ADVECTION REGIME AS LOW LEVEL NOCTURNAL WIND MAXIMA SUBSIDES. STILL EXPECT SURFACE FRONT TO GET A BIT OF A KICK FROM THE CHILLIER LAKE TODAY AND HAVE BUMPED UP FROPA AN HOUR OR SO FROM PREVIOUS TAFS...NOW EXPECTING IT A BIT EARLIER IN THE AFTERNOON. THE EARLIER FRONTAL PASSAGE SHOULD KEEP MOST //IF NOT ALL// OF OUR TERMINALS WITH VERY SMALL IF ANY CHANCES OF THUNDERSTORM DEVELOPMENT THIS AFTERNOON. SEVERE THUNDERSTORMS WILL LIKELY ERUPT OVER SD/NW IA THIS AFTERNOON WITH THIS ACTIVITY LIKELY HEADING SOUTHEASTWARD TOWARD THE AREA LATER TONIGHT. LARGE DCAPES VALUES WOULD TEND TO SUGGEST THIS ACTIVITY SHOULD MORPH INTO AN MCS EARLY THIS EVENING...WITH CORFIDI VECTORS SUGGESTING ENOUGH OF A SOUTHWARD PROPAGATION TO POSSIBLY KEEP MOST OF THIS ACTIVITY AWAY FROM OUR TERMINALS...ESPECIALLY IF THE ACTIVITY WERE TO TRY AND BUILD INTO THE BETTER INSTABILITY WHICH WILL ALSO REMAIN JUST TO OUR SOUTHWEST. POTENTIAL FLY IN THE OINTMENT WILL BE THE FAIRLY IMPRESSIVE VORT OVER MT WHICH SHOULD CREST THE RIDGE AND HEAD ESE TOWARD THE AREA TONIGHT. THAT MAY CAUSE BOUNDARY TO TRY AND RETREAT NORTHWARD SOME TONIGHT AND DRAG THE ASSOCIATED TSRA CHANCES NORTHWARD WITH IT. GIVEN THIS IS IN THE FAR PERIODS OF THE TAF CYCLE CONFINED MENTION OF PRECIP TO OUR WESTERN MOST TERMINALS AND WILL LET LATER SHIFTS RE-EVALUATE THIS. VFR CONDITIONS WILL PREVAIL OUTSIDE OF THUNDERSTORMS WITH MVFR CIGS AND MVFR-IFR VSBYS IN THUNDERSTORMS THURSDAY AFTERNOON AND EVENING. IZZI && .MARINE...//ISSUED 226 AM CDT THU JUN 21 2007// COLD FRONT WILL DROP DOWN THE LAKE THIS MORNING WITH WINDS BECOMING NORTHERLY IN ITS WAKE. GRADIENT IS NOT PARTICULARLY TIGHT BEHIND THE BOUNDARY SO WINDS NOT EXPECTED TO BE ALL THAT STRONG. SURFACE FRONT EXPECTED TO STALL OUT SOUTH OF THE LAKE THROUGH SATURDAY AS A COUPLE MCS`S TRACK LARGELY SOUTH OF THE LAKE. WHILE THE FAR SOUTHERN PORTIONS OF THE LAKE COULD GET CLIPPED BY THE THUNDERSTORMS...WOULD EXPECT MOST OF THE ACTIVITY TO REMAIN SOUTH OF THE OPEN WATERS. WITH SURFACE RIDGE CONTROLLING THE WEATHER THROUGH SATURDAY EXPECT GENERALLY LIGHT WINDS AND NO SIGNIFICANT WAVES. IZZI && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
900 AM PDT THU JUN 21 2007 .SYNOPSIS...A LARGE QUASI STATIONARY UPPER LOW REMAINED IN THE NORTHEAST PACIFIC THIS MORNING...WITH A WEAK FRONTAL BOUNDARY ALONG THE NORTH COAST AND COAST RANGE TO NEAR KELSO THIS MORNING WITH A LITTLE LIGHT PRECIPITATION THAT SHOULD MOVE LITTLE TODAY. THE CLOUDS FROM THIS BOUNDARY WILL LIKELY SPREAD FARTHER INLAND ESPECIALLY TONIGHT WITH PERHAPS A FEW SPRINKLES IN THE MOUNTAINS BUT LITTLE ELSEWHERE EXCEPT FOR SOME DRIZZLE NEAR THE COAST. THE NEXT IMPULSE IS FORECAST TO SPREAD INLAND OUT OF THE OFFSHORE LOW FRIDAY NIGHT AND SATURDAY MORNING WITH JUST SOME SPOTTY LIGHT PRECIPITATION. THE OFFSHORE UPPER LOW BEGINS TO MAKE A MOVE ONSHORE SATURDAY FOR A FEW MORE SHOWERS...THEN THE CURRENT MODELS CONTINUE TO SHOW IT SWINGING THROUGH THE PACIFIC NORTHWEST SATURDAY NIGHT AND SUNDAY FOR AN INCREASE IN SHOWERS...AND POSSIBLY SOME CONVECTION WITH THE COLD POOL ALOFT. DRYING IS LIKELY AGAIN EARLY NEXT WEEK. && .SHORT TERM...A LARGE LOW REMAINS NEARLY STATIONARY IN THE NORTHEAST PACIFIC THIS MORNING...AND WILL NOT MOVE MUCH UNTIL THE WEEKEND. THIS IS PRODUCING SOUTHWEST FLOW ALOFT THAT HELPED PUSH LOW CLOUDS ONSHORE OVERNIGHT. A WEAK WAVE ROTATING OUT OF THE LOW ALSO PUSHED A WEAK FRONTAL BOUNDARY ONTO THE NORTH OREGON AND SOUTH WASHINGTON COAST. A GAP IN THE CLOUDS DEVELOPED FROM NEWPORT TO PORTLAND THIS MORNING SEPARATING THE LOW CLOUDS THAT PUSHED IN FROM THE SOUTHWEST OVERNIGHT AND THE CLOUDS ASSOCIATED WITH THE WEAK FRONTAL BOUNDARY NEAR THE COAST. IT LOOKS AS THOUGH THE LOW CLOUDS TO THE SOUTH OF PORTLAND WILL SLOWLY ERODE THROUGH THE DAY. THE CLOUDS TO THE NORTHWEST ARE PRODUCING A LITTLE LIGHT PRECIPITATION ESPECIALLY NEAR THE COAST... BUT SOME ECHOES HAVE BEEN SEEN ON NATIONAL WEATHER SERVICE DOPPLER RADAR UP THROUGH KELSO AND CASTLE ROCK WASHINGTON. HAVE REMOVED PRECIPITATION FOR TODAY SOUTHEAST OF ABOUT KELSO. STILL...THE MODELS SAY THESE CLOUDS WILL OOZE INLAND LATER TODAY AND TONIGHT...WITH POSSIBLY SOME SPRINKLES OVER THE HIGHER TERRAIN SUCH AS THE CASCADES AND FOOTHILLS. WILL KEEP THE VALLEY DRY FOR NOW. NOT A LOT OF ACTIVITY FRIDAY OTHER THAN MORNING CLOUDS UNDER THE PERSISTENT SOUTHWEST FLOW...BUT LITTLE IF ANY SHORT WAVE ACTIVITY. TIME SECTIONS SHOW THE CLOUDS LIFTING AND BREAKING UP IN THE AFTERNOON. ANOTHER SHORT WAVE LIFTS OUT FRIDAY NIGHT THAT COULD GIVE SOME DRIZZLE OR SPRINKLES AGAIN BUT MAINLY NEAR THE COAST. THE UPPER LOW BEGINS TO MOVE TOWARD THE COAST SATURDAY THAT COULD START TO INCREASE SOME SHOWERS LATER IN THE DAY...BUT THE MAIN PERIOD OF SHOWERS LOOKS TO BE SATURDAY NIGHT AND SUNDAY AS THE LOW MOVES ONSHORE. TOLLESON .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... THE BEGINNING OF THE EXTENDED PERIOD BODES TO BE THE HIGHLIGHT OF THE EXTENDED FORECAST STARTING OFF WITH A SYSTEM CLOSING IN ON THE PAC NW SATURDAY EVENING AND MOVING ASHORE ON SUNDAY BRINGING WITH IT A SLIGHT CHANCE OF TSTMS. HAVE INCREASED POPS ACCORDINGLY ON SAT EVENING AND SUN. A WELL MODELED DEEP UPPER LEVEL TROUGH DIGS SOUTH INTO CALIFORNIA BRINGING COOL MID TO UPPER LEVEL TEMPS AND WARMER W TO SWLY FLOW LOW LEVEL FLOW. 1000-700 MU CAPE VALUES NEAR 700 J/KG AND -28 C 500 MB TEMPS FAVOR THE TSTM WORDING PARTICULARLY WITH THE FRONTOGENETIC FORCING ASSOCIATED WITH THE WEAK APPROACHING SYSTEM. NOT A WHOLE LOT TO TALK ABOUT AFTER THIS SYSTEM LEAVES...SOME LINGERING SHOWERS INTO MON MORNING BEFORE DRYING OUT AT LEAST UNTIL FRI. WOLFE && .AVIATION...MVFR/LOW VFR MARINE CLOUDS ACROSS INLAND VALLEYS HAVE BEEN DISSIPATING FROM THE N AS THE INVERSION AROUND 850-900MB HAS BEEN ERODING WITH THE APPROACH OF COOLER AIR ALOFT ASSOCIATED WITH A WEAK FRONTAL BAND DRAPED ACROSS THE N OREGON COAST. OVERNIGHT AIRCRAFT SOUNDINGS AT KPDX HAVE SHOWN THIS TREND. WITHIN THE FRONTAL BAND MVFR/IFR CONDITIONS ALONG THE N COAST WILL SLOWLY DROP TO KONP THIS AFTERNOON AS THE BAND DRIFTS E...HOWEVER THE MAIN FORCING IS LIFTING N SO SHOULD NOT SEE INLAND CONDITIONS DROPPING TO MVFR CEILINGS UNTIL PERHAPS THIS EVENING OR OVERNIGHT WHEN RESIDUAL MOISTURE WORKS PAST THE COAST RANGE. RW && .MARINE...NO ADVISORIES TODAY WITH WINDS BELOW 20 KT AND DROPPING. SEAS RUNNING AROUND 5 FT AND NO ROUGH BAR CONDITIONS EXPECTED WITH EITHER OF THE EBB CURRENTS TODAY. RW && .PQR WATCHES/WARNINGS/ADVISORIES... OR/WA...NONE && .PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION) AST 42223 PDX 11112 SLE 11112 EUG 11112 $$ MORE WEATHER INFORMATION ONLINE AT... http://weather.gov/portland THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
200 PM PDT THU JUN 21 2007 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BRING HOT WEATHER INLAND THROUGH FRIDAY WITH NEAR RECORD HIGH TEMPERATURES. THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE COASTAL LOW CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS. A LITTLE COOLER THIS WEEKEND AND EARLY NEXT WEEK AS LOW PRESSURE MOVES PAST TO THE NORTH. SUMMER BEGINS TODAY AT 1106 AM PDT. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM...TONIGHT THROUGH MONDAY... TAIL END OF VERY WEAK UPPER LEVEL TROUGH SLIDING ACROSS FORECAST AREA AT THIS TIME...ONLY DISCERNIBLE IN WATER VAPOR IMAGERY AND 500 MB VORTICITY FIELD...BUT STRONG ENOUGH TO DELAY RIDGE BUILDING AND FORECAST WARMING AND DRYING TODAY. AS OF NOON...EXCEPT AT ELEVATIONS ABOVE 5000 FEET...MOST LOCATIONS WERE SLIGHTLY COOLER/MOISTER THAN YESTERDAY. NONETHELESS WILL STAY WITH WARMING AND DRYING TREND INTO FRIDAY AS RIDGE SHOULD REBOUND THIS EVENING AND BUILD INTO FRIDAY. FOR SATURDAY THROUGH MONDAY A SLOW COOLING AND MOISTENING TREND AS RIDGE IS SLOWLY ERODED AND SLIPS SOUTHEASTWARD IN RESPONSE TO GULF OF ALASKA MOVING INLAND/TRAILING TROUGH DRAGGING ACROSS CALIFORNIA. MARINE LAYER EXPECTED TO DEEPEN ABOUT 500 FEET PER NIGHT...REACHING AROUND 1700-2000 FEET BY SUNDAY NIGHT/MONDAY SO MOST INLAND VALLEYS WILL COOL BACK TO NORMAL. STRATUS AND FOG CLEARING INLAND AREAS AROUND 830 AND COAST BY 1030 STILL LOOKS GOOD FOR EACH DAY. MOUNTAINS AND DESERTS STAY DRY AND QUITE WARM DURING ENTIRE PERIOD AS 1000-500 MB THICKNESS VALUES ONLY FALL 60 METERS. MOUNTAINS SHOULD COOL ABOUT 4 DEGREES ON SATURDAY AND A FEW MORE DEGREES SUNDAY AND MONDAY. COOLING OVER DESERTS WILL BE ONLY A FEW DEGREES AS THICKNESS FALL WILL BE OFFSET BY DOWNSLOPE WARMING FROM INCREASE IN WINDS. && .LONG TERM...TUESDAY THROUGH THURSDAY... PREFER THE ECMWF MODEL BASED ON CONSISTENCY WITH PREVIOUS RUNS OF GFS MODEL AND ITSELF. THUS RIDGE REBUILDING THROUGH THE PERIOD FOR SHRINKING MARINE LAYER AND RENEWED WARMING AND DRYING TREND. && .AVIATION... 211930Z...LATE MORNING MDCRS SOUNDINGS INDICATE THE MARINE LAYER DEPTH HAD LOWERED TO 1000 FEET OR LESS OVER THE AREA. SOME RECOVERY OF THE MARINE LAYER IS EXPECTED OVERNIGHT WITH FURTHER DEEPENING EXPECTED FRIDAY NIGHT. A COASTAL EDDY IS EXPECTED TO DEVELOP TONIGHT WHICH WILL HELP WITH THE RECOVERY. STRATUS WITH BASES AROUND 800 FEET MSL SHOULD PUSH BACK ONTO THE COAST BY SUNSET THEN PUSH INLAND DURING THE EVENING...REACHING THE LOWER INLAND VALLEY AREAS BY MIDNIGHT. THE STRATUS COULD BRING CEILINGS CLOSE TO THE LOCALIZER RUNWAY 27 MINIMUMS...AGAIN... TONIGHT. STRATUS SHOULD CLEAR TO THE COAST BETWEEN 16 AND 17Z ON FRIDAY. ABOVE THE MARINE LAYER AND INLAND OVER THE MOUNTAINS AND DESERTS SKIES WILL REMAIN MOSTLY CLEAR WITH UNRESTRICTED VISIBILITY THROUGH FRIDAY. NOTE...COMMUNICATIONS PROBLEMS CONTINUE TO PREVENTING THE KCRQ ASOS METAR FROM GETTING OUT TO THE WORLD. THE ASOS IS OPERATIONAL... HOWEVER. TAF FOR KCRQ WILL ISSUED BUT WILL CARRY NIL AMD UNTIL ASOS COMMS ARE RESTORED. && .FIRE WEATHER... EXCEPT FOR ELEVATIONS BELOW 2700 FEET IN SANTA ANA MOUNTAINS AS ON NOON THE RELATIVE HUMIDITY AT MOST MOUNTAIN LOCATIONS WAS BELOW 10 PERCENT. DEWPOINTS ARE TRENDING UPWARD NOW BUT STILL HAVE ANOTHER 8 HOURS OF SUNSHINE SO HUMIDITY SHOULD REMAIN BELOW 10 PERCENT UNTIL 2100 PDT. PLAN TO CANCEL THE RED FLAG WARNING AT THAT TIME. HUMIDITY WILL STILL BE VERY LOW FRIDAY THROUGH MONDAY OVER THE MOUNTAINS BUT DURATIONS OF HUMIDITY BELOW 10 PERCENT SHOULD BE LESS THAN 10 HOURS PER DAY. CRITICAL FIRE WEATHER AREA WILL SHIFT TOWARDS DESERTS SATURDAY THROUGH MONDAY WHERE WIND GUSTS EXCEEDING 35 MPH WHILE HUMIDITY IS LESS THAN 15 PERCENT ARE POSSIBLE DURING THE LATE AFTERNOON AND EVENING HOURS. FOR NOW FORECAST DURATIONS ARE LESS THAN 3 CONSECUTIVE HOURS BUT WILL REEVALUATE FRIDAY MORNING AND COORDINATE WITH ADJACENT OFFICES TO SEE IF A FIRE WEATHER WATCH IS WARRANTED. FOR NOW WILL HIGHLITE WITH HEADLINES. IF RIDGE REBUILDS AS FORECAST FOR NEXT WEEK...CRITICAL FIRE WEATHER CONDITIONS LIKELY TO CONTINUE. && .MARINE... WEST NORTHWEST SWELL COMING OUT FROM GULF OF ALASKA LOW WILL AFFECT COASTAL WATERS THROUGH SUNDAY. MAIN IMPACT WILL BE HIGH RIP CURRENT RISK ALONG EXPOSED WEST AND NORTHWEST FACING BEACHES FRIDAY THROUGH SUNDAY. && .SGX WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR ALL MOUNTAINS. SEE RFWSGX. HIGH RIP CURRENT RISK ORANGE COUNTY AND SAN DIEGO COUNTY BEACHES. SEE HWOSGX AND SRFSGX. && $$ PUBLIC/FIRE WEATHER...BALFOUR AVIATION/MARINE.......HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
950 AM PDT THU JUN 21 2007 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BRING HOT WEATHER INLAND THROUGH FRIDAY WITH NEAR RECORD HIGH TEMPERATURES. THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE COASTAL LOW CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS. A LITTLE COOLER THIS WEEKEND AND EARLY NEXT WEEK AS LOW PRESSURE MOVES PAST TO THE NORTH. SUMMER BEGINS TODAY AT 1106 AM PDT. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM...TODAY THROUGH SATURDAY... HIGH PRESSURE RIDGE BUILDING THROUGH TONIGHT. THICKNESS VALUES TODAY AND FRIDAY SUPPORT TEMPERATURE INCREASE OF 3 TO 7 DEGREES TODAY AND SIMILAR OR SLIGHTLY WARMER TEMPERATURES OVER MOUNTAINS AND DESERTS ON FRIDAY...WHILE THE INLAND VALLEYS SHOULD COOL A FEW DEGREES DUE TO SLIGHTLY DEEPER MARINE LAYER. AREAS AFFECTED BY LOW CLOUDS AND FOG SHOULD BE CONFINED TO LESS THAN 1000 FEET TONIGHT...BELOW 1500 FEET FRIDAY NIGHT. HOT DAYS AND WARM NIGHTS WILL CONTINUE OVER LOWER DESERT THROUGH SATURDAY. MOUNTAINS SHOULD COOL ABOUT 4 DEGREES ON SATURDAY WHILE INLAND VALLEYS WILL BE 5 TO 15 DEGREES COOLER DEPENDING IF IN OR STILL OUT OF MARINE LAYER INFLUENCE. STRATUS AND FOG CLEARING INLAND AREAS AROUND 830 AND COAST BY 1030 STILL LOOKS GOOD FOR EACH DAY. && .LONG TERM...SUNDAY THROUGH WEDNESDAY...FROM PREVIOUS DISCUSSION... 00Z/006Z GFS ARE MORE AGGRESSIVE WITH A TROUGH OF LOW PRESSURE OVER THE EASTERN PACIFIC. GFS TREND IS FOR DRIER SOUTHWEST FLOW ALOFT AND SLIGHTLY COOLER PATTERN CLOSER TO SEASONAL. ECMWF IS A LITTLE WEAKER WITH THIS TROUGH AND HENCE WOULD SUPPORT TEMPERATURES A LITTLE ABOVE SEASONAL AVERAGES. CURRENT FORECAST IS CLOSER TO THE ECMWF GIVEN THE CONTINUING LACK OF CONSISTENCY OF THE GFS IN THE LATTER PORTION OF THE EXTENDED. CURRENT FORECAST HAS A FEW CLOUDS OVER THE MOUNTAINS IN THE AFTERNOON. HOWEVER...GIVEN MODEL TRENDS INCLUDING THE ECMWF...THIS MAY BE GENEROUS. && .AVIATION... 211400Z...12Z NKX SOUNDING AND EARLY MORNING MDCRS SOUNDINGS INDICATE THE MARINE LAYER DEPTH WAS AROUND 1300 FEET MSL. EXPECT SOME LOWERING TO LESS THAN 1000 FEET LATER THIS MORNING AND AFTERNOON WITH SOME RECOVERY TONIGHT. STRATUS WITH BASES AROUND 800 FEET MSL SHOULD PULL BACK TO THE COAST BETWEEN 15Z AND 16Z. STRATUS SHOULD BEGIN TO PUSH BACK ONTO THE COAST AROUND SUNSET AND THEN LOCALLY INLAND INTO THE LOWER COASTAL VALLEYS AROUND OR SHORTLY AFTER MIDNIGHT. THE STRATUS COULD BRING CEILINGS NEAR LOCALIZER RUNWAY 27 MINIMUMS...AGAIN...TONIGHT. EARLY CLEARING IS EXPECTED...AGAIN...FRIDAY MORNING. ABOVE THE MARINE LAYER AND INLAND OVER THE MOUNTAINS AND DESERTS SKIES WILL REMAIN MOSTLY CLEAR WITH UNRESTRICTED VISIBILITY. NOTE...COMMUNICATIONS PROBLEMS PREVENTING THE KCRQ ASOS METAR FROM GETTING OUT TO THE WORLD. ASOS IS OPERATIONAL...HOWEVER. TAF FOR KCRQ WILL CARRY NIL AMD UNTIL ASOS COMMS ARE RESTORED. && .FIRE WEATHER... DEWPOINTS TOOK ANOTHER NOSE DIVE AFTER 2200 PDT LAST NIGHT OVER THE MOUNTAINS...AND ALTHOUGH STARTING TO TREND UPWARD...TEMPERATURES WILL BE 3 TO 6 DEGREES WARMER THAN YESTERDAY...SO RELATIVE HUMIDITY SHOULD BE BELOW 10 PERCENT FOR MORE THAN 10 HOURS TODAY AT ELEVATIONS ABOVE 1500 FEET...INCLUDING THE SANTA ANA MOUNTAINS/TRABUCO DISTRICT OF THE CLEVELAND NATIONAL FOREST...HENCE EXPANDED RED FLAG WARNING TO PICK THIS ZONE TODAY. SLIGHTLY BETTER RECOVERY OF HUMIDITY TONIGHT...AND EVEN THOUGH JUST AS WARM TEMPERATURES EXPECTED ON FRIDAY...DURATIONS SHOULD BE LESS THAN 10 HOURS. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR RIVERSIDE COUNTY MOUNTAINS-INCLUDING THE SAN JACINTO RANGER DISTRICT OF THE SAN BERNARDINO NATIONAL FOREST-SAN BERNARDINO COUNTY MOUNTAINS-INCLUDING THE MOUNTAIN TOP AND FRONT COUNTRY RANGER DISTRICTS OF THE SAN BERNARDINO NATIONAL FOREST-SAN DIEGO COUNTY MOUNTAINS-INCLUDING THE PALOMAR AND DESCANSO RANGER DISTRICTS OF THE CLEVELAND NATIONAL FOREST. RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR SANTA ANA MOUNTAINS-INCLUDING THE TRABUCO RANGER DISTRICT OF THE CLEVELAND NATIONAL FOREST. PZ...NONE. && $$ PUBLIC/FIRE WEATHER...BALFOUR AVIATION/MARINE.......HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO