Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/02/15


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
845 PM MST SAT AUG 1 2015 && .SYNOPSIS... LINGERING STORM CHANCES THE REST OF TODAY WILL MAINLY AFFECT AREAS ACROSS HIGHER TERRAIN AREAS OF CENTRAL AND EASTERN ARIZONA WITH A SLIGHT CHANCE OF A FEW STORMS OVER THE LOWER DESERTS. CONSIDERABLE DRYING OCCURS STARTING SUNDAY AND INTO THE MIDDLE OF NEXT WEEK WITH STORM CHANCES CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX. TEMPERATURES WILL HOVER NEAR NORMAL OR SLIGHTLY ABOVE THROUGH NEXT WEEK. && .DISCUSSION... A MUCH QUIETER AFTERNOON/EVENING TODAY THAN WHAT WE SAW YESTERDAY...ESPECIALLY ACROSS THE LOWER ELEVATIONS OF SOUTH- CENTRAL AZ. DRY AIR THAT IS BEING PULLED NORTHWARD AHEAD OF AN UPPER TROF THAT IS APPROACHING THE WEST COAST HAS NOW MOVED INTO SE CA AND THE WESTERN 1/2 OF ARIZONA. THIS DRY AIR HAS PRETTY MUCH SHUT CONVECTIVE ACTIVITY DOWN AND PUSHED SFC DEWPOINTS DOWN INTO THE 50S ACROSS THE WESTERN 3/4 OF OUR CWA THIS AFTERNOON. AHEAD OF THIS DRY SURGE...THUNDERSTORMS HAVE ONCE AGAIN DEVELOPED THIS AFTERNOON ACROSS SOUTHER GILA COUNTY...WHERE DEWPOINTS ARE STILL WELL UP IN THE 60S UNDER THE MAIN MONSOON MOISTURE PLUME AND CONTINUED DIFFLUENCE ALOFT. THIS TS ACTIVITY IS NOW BEGINNING TO SLOWLY DIMINISH AND SHIFT OFF TO THE NORTH THIS EVENING AS THE MOISTURE PLUME CONTINUES TO SHIFT OFF SLOWLY TO THE EAST...WITH THE LATEST HRRR HIGH-RES MODEL RUN INDICATING THAT ANY REMAINING CONVECTIVE ACTIVITY TO END BY MIDNIGHT TONIGHT. TOMORROW STILL LOOKS LIKE IT WILL BE THE 1ST IN A SERIES OF VERY QUIET DAYS AS DRY AIR MAKES ITS WAY ACROSS ALL OF AZ. AS FAR AS THE SHORT-TERM GRIDDED AND ZONE FORECASTS ARE CONCERNED...HAVE LOWERED POPS FOR THE REST OF THIS EVENING AND TONIGHT INTO THE SINGLE-DIGIT RANGE ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ AND HAVE MADE SOME MINOR EDITS TO THE SHORT-TERM TEMPERATURE/DEWPOINT GRIDS TO BETTER REFLECT CURRENT TRENDS. && .DISCUSSION... SO FAR THIS AFTERNOON WE HAVE LITTLE SHOWER OR THUNDERSTORM ACTIVITY AS THE ATMOSPHERE JUST HAS NOT RECOVERED. SKIES HAVE REMAINED MOSTLY CLEAR SO SUNSHINE HAS NOT BEEN AN ISSUE...BUT SURFACE TEMPERATURES ARE STILL SOMEWHAT COOL FOR THIS TIME OF DAY AND GENERALLY 5-8 DEGREES COOLER THAN YESTERDAY. MESOSCALE ANALYSIS DOES SHOW AMPLE MIXED LAYER CAPE ACROSS SOUTH-CENTRAL AND SOUTHEAST ARIZONA ALONG WITH BROAD DIFFLUENCE OVER MUCH OF ARIZONA. STILL EXPECTING MORE THUNDERSTORM DEVELOPMENT THROUGH THE REST OF THIS AFTERNOON...BUT COVERAGE WILL LIKELY BE LIMITED TO MOSTLY HIGHER TERRAIN AREAS. HAVE LOWERED POPS OVER THE LOWER DESERTS INTO THE SLIGHT CHANCE CATEGORY DUE TO THE POOR CONVECTIVE START TO THE AFTERNOON...BUT WE SHOULD STILL GET A FEW STORMS IN THE DESERTS BY THE END OF THE DAY. THERE IS SOME POTENTIAL FOR SOME STRONG DOWNDRAFT WINDS WITH ANY STRONGER STORMS...BUT WITH MORE MOIST AIR IN THE BOUNDARY LAYER...OUTFLOW INTERACTIONS SHOULD BE LESS ACTIVE THAN YESTERDAY. WATER VAPOR IMAGERY SHOWS DRY AIR QUICKLY MOVING NORTHWARD THROUGH THE BAJA AREA INTO NORTHERN MEXICO AND MODELS SHOW THIS DRY AIR WORKING ACROSS ARIZONA STARTING TONIGHT AND OVERTAKING ALL OF THE STATE BY SUNDAY NIGHT. LINGERING LOWER LEVEL MOISTURE WILL ALLOW FOR SOME HIGHER TERRAIN SHOWERS AND THUNDERSTORMS...BUT LITTLE TO NO CHANCE OF ANY ACTIVITY OVER THE LOWER DESERTS. THIS DRY AIR WILL BASICALLY END OUR STORM CHANCES FOR A FEW DAYS EARLY THIS WEEK...WHILE TEMPERATURES START TO WARM UP. HIGHS ACROSS OUR SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS WILL LIKELY BREAK 110 DEGREES SUNDAY THROUGH WEDNESDAY. SOUTH-CENTRAL ARIZONA DESERT TEMPERATURES WILL PEAK ON MONDAY OR TUESDAY...BUT FALL SHORT OF HITTING 110 DEGREES. THE SUBTROPICAL HIGH POSITIONED OVER THE DESERT SOUTHWEST FOR MONDAY AND TUESDAY IS FORECAST TO SHIFT EASTWARD INTO NEW MEXICO SOMETIME WEDNESDAY AND THURSDAY AND REDIRECTING OUR FLOW OUT OF THE SOUTHEAST. THIS WILL BRING A RETURN TO AT LEAST SOME LIMITED MONSOONAL MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS OVER MAINLY THE EASTERN HALF OF ARIZONA. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... THROUGH 18Z SUN...SCT CLDS AOA 10 THSD FT AGL. LIGHT MOSTLY SOUTHWEST WIND UNDER 8 KTS. HWVR...TSTMS OVR MTNS 50 MILES EAST OF PHX THROUGH 06Z SUN. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... THROUGH 18Z SUN...SCT CLDS AOA 12 THSD AGL. LIGHT WIND UNDER 8 KNOTS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY...DRIER AND STABLE WESTERLY FLOW ALOFT WILL PRODUCE PARTLY CLOUDY SKIES TUESDAY AND WEDNESDAY...WITH LOWER MINIMUM RELATIVE HUMIDITY GENERALLY IN THE 10 TO 15 PERCENT RANGE. MOISTURE WILL GRADUALLY INCREASE OVER SOUTHWEST AND SOUTH CENTRAL ARIZONA THURSDAY THROUGH SATURDAY...INTO THE 15 TO 25 PERCENT RANGE...WITH A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS IN SOUTHERN GILA COUNTY. AFTERNOON SOUTHWEST WINDS 10 TO 15 MPH. FAIR RECOVERY AT NIGHT. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/KUHLMAN AVIATION...VASQUEZ FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
225 PM MST FRI JUL 31 2015 .SYNOPSIS...A MORE ACTIVE THUNDERSTORM DAY ACROSS SOUTHEAST ARIZONA TODAY. ALTHOUGH SOME DRIER AIR WILL MOVE ACROSS THE AREA THIS WEEKEND INTO NEXT WEEK...THERE WILL BE ENOUGH MOISTURE AROUND FOR A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY ALONG THE INTERNATIONAL BORDER AS WELL AS THE MOUNTAIN TOPS. && .DISCUSSION...WATER VAPOR IMAGERY AND 31/12Z UPPER-AIR PLOTS SHOW THE CENTER OF HIGH PRESSURE IN THE GENERAL VICINITY OF THE TEXAS PANHANDLE...WITH A PACIFIC LOW PRESSURE SYSTEM WELL OFF THE SOUTHERN CALIFORNIA AND NORTHERN BAJA COASTS. WHAT A DIFFERENCE 12 HOURS CAN MAKE. YESTERDAYS 31/00Z KTWC SOUNDING REVEALED A PW OF 1.10 INCHES AND THE 31/12Z KTWC SOUNDING CAME IN WITH A PW OF 1.68 INCHES. THIS MORNINGS SOUNDING PARAMETERS SHOWED A MU CAPE OF AROUND 2200 J/KG AND A LIFTED INDEX OF MINUS 6. THE MOST RECENT RADAR MOSAIC SHOWS SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUING TO PROGRESS WESTWARD WEST OF AJO AND ORGAN PIPE. ELSEWHERE ACROSS SOUTHEAST ARIZONA...ISOLATED TO SCATTERED THUNDERSTORMS HAVE BEEN DEVELOPING DURING THE PAST HOUR OR TWO... WITH CELLS EXTENDING FROM EAST OF ELOY TO PICTURE ROCKS AND TOWARD ARIVACA. WEAK SHOWERS HAVE ALSO DEVELOPED OVER PARTS OF THE TUCSON METRO AS WELL. ADDITIONAL CELLS ARE OCCURRING OVER THE HIGHER TERRAIN OF GRAHAM...GREENLEE AND SANTA CRUZ COUNTIES...WITH ACTIVITY MOVING WEST OR WEST NORTHWEST AT 5 TO 10 MPH. U OF A 12Z WRF/NAM & GFS...AS WELL AS HRRR ALL SUGGEST THAT STORMS WILL CONTINUE TO BLOSSOM OVER CENTRAL AND WESTERN PORTIONS OF THE FORECAST AREA THIS AFTERNOON AND PUSH TO THE WEST OR WEST NORTHWEST EARLY THIS EVENING. ACTIVITY NOT AS WIDESPREAD BETWEEN TUCSON AND THE NEW MEXICO BORDER...WITH THE EXCEPTION OF THE MOUNTAIN TOPS. KEPT A MENTION OF BLOWING DUST OVER PARTS OF PIMA AND PINAL COUNTIES LATE THIS AFTERNOON AND EARLY THIS EVENING AS STORMS EXPECTED TO FIRE OFF AND MOVE IN THAT GENERAL DIRECTION. THIS ALSO MESHES WELL WITH THE FORECAST FROM THE PHOENIX OFFICE. MODELS INDICATE THAT A WEAK DISTURBANCE COMING UP FROM THE SOUTH WILL MOVE ACROSS SOUTH CENTRAL ARIZONA THIS EVENING AND THEN OVER SOUTHWEST ARIZONA EARLY SATURDAY AND WESTERN ARIZONA MIDDAY SATURDAY. AS THIS OCCURS...THIS SYSTEM WILL HELP TO ENHANCE ACTIVITY THIS AFTERNOON AND EVENING...BUT BY SATURDAY WE SHOULD SEE LESS THUNDERSTORM ACTIVITY AS THIS SYSTEM WILL BE OVER SRN NEVADA LATE IN THE AFTERNOON AND MOISTURE IS EXPECTED TO DECREASE A BIT LATE IN THE AFTERNOON OR INTO THE EVENING. BY SUNDAY AND CONTINUING THROUGH AROUND WEDNESDAY THE HIGH IS EXPECTED TO RECONSOLIDATE IN A WEST TO EAST ORIENTATION ACROSS NORTHERN MEXICO AND THEN MOVE NORTH OVER THE DESERT SOUTHWEST BY TUESDAY. AS A RESULT...DRIER SOUTHWEST TO WEST FLOW WILL REDUCE RAIN CHANCES A BIT AND KEEP THE BEST THREAT FOR SHOWERS AND THUNDERSTORMS...MAINLY BETWEEN NOGALES AND DOUGLAS AS WELL AS THE WHITE MOUNTAINS. THIS WILL ALSO RESULT IN WARMER DAYTIME TEMPS MONDAY THROUGH WEDNESDAY. FOR LATE WEEK THE HIGH WILL SHIFT TOWARD THE EAST AND RESULT IN A RETURN FLOW FROM THE SOUTH TO SOUTHEAST AND PULL IN MORE MOISTURE AND INCREASING THUNDERSTORM CHANCES...BUT STILL JUST ISOLATED TO SCATTERED IN NATURE. FOR TUCSON...HIGHS WILL BE NEAR NORMAL SATURDAY...THEN 4 TO 7 DEGS ABOVE NORMAL EACH DAY THROUGH FRIDAY. HOWEVER...THE WARMEST DAY WILL LIKELY OCCUR TUESDAY. LOWS WILL RANGE FROM 2 TO 4 DEGS ABOVE NORMAL EACH MORNING. HOWEVER...THE COOLEST MORNINGS WILL LIKELY OCCUR MONDAY AND TUESDAY. && .AVIATION...VALID THRU 02/00Z. SCT TO BKN CLOUDS 7-10K FT AGL WITH SCT-NMRS SHRA/TSRA GENERALLY BEFORE 01/04Z...AND MAINLY WEST OF A LINE FROM KOLS TO KSAD AND IN THE WHITE MOUNTAINS. BRIEF MVFR CONDITIONS WITH ERRATIC WIND GUSTS TO 45 KTS POSSIBLE IN AND AROUND THE STRONGER TSRA. AREAS OF BLDU PSBL W AND NW OF KTUS AFT 31/22Z. OUTSIDE OF STORM INFLUENCES SFC WINDS WILL GENERALLY BE LESS THAN 12 KTS WITH A FEW HIGHER GUSTS IN THE AFTERNOON/EARLY EVENING HOURS. SHRA/TSRA WILL OCCUR AGAIN SATURDAY AFTERNOON...ALTHOUGH WITH LESS COVERAGE THAN TODAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TODAY WITH STRONG OUTFLOW WINDS LIKELY...ESPECIALLY FROM TUCSON WEST. SATURDAY WILL SEE SLIGHTLY LESS CONVECTION. INCREASING SW WINDS ALOFT ON SUNDAY WILL BRING DRIER AIR INTO THE REGION FOR ISOLATED TO SCATTERED THUNDERSTORM COVERAGE TO BEGIN NEXT WEEK...WITH A FOCUS MAINLY SOUTH AND EAST OF TUCSON. OUTSIDE OF THUNDERSTORM WIND GUSTS...20-FT WINDS WILL GENERALLY BE TERRAIN DRIVEN AND LESS THAN 15 MPH. HOWEVER SOME AFTERNOON AND EARLY EVENING BREEZINESS IS LIKELY DUE TO DAYTIME HEATING...ESPECIALLY THROUGH THE GILA VALLEY NEAR SAFFORD. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MOLLERE AVIATION/FIRE WEATHER...FRENCH VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1234 PM MST FRI JUL 31 2015 .UPDATE...UPDATED AVIATION DISCUSSION... && .SYNOPSIS... ISOLATED TO SCATTERED STORM ACTIVITY IS ANTICIPATED OVER ARIZONA AND SOUTHEAST CALIFORNIA AGAIN TODAY. A NOTABLE DOWNTREND IN MOISTURE FROM WEST TO EAST IS EXPECTED OVER THE WEEKEND. THIS WILL KEEP STORM CHANCES LIMITED TO SOUTH- CENTRAL ARIZONA WELL INTO NEXT WEEK. TEMPERATURES WILL NOT CHANGE MUCH DAY TO DAY REMAINING AT OR ABOVE SEASONABLE AVERAGE. && .DISCUSSION... ISOLATED STORM ACTIVITY ALREADY GOING THIS MORNING ALONG OUR BOUNDARY WITH TWC CWA AND ADDITIONAL SHOWERS FURTHER SOUTH. THESE APPEAR TO BE INFLUENCED BY REMNANTS OF A COUPLE OF OVERNIGHT MCS/S. THERE ALSO LOOKS TO BE A BACKDOOR FRONT THAT HAS PUSHED THROUGH MUCH OF NEW MEXICO. SO THERE COULD BE A COUPLE OF MCV/S AFFECTING THE AREA TODAY...AND SOME OF THE HIGH RES MODELS DEPICT THAT. UNFORTUNATELY NONE OF THE HIGH RES MODELS HAVE CAPTURED THIS MORNING/S ACTIVITY VERY WELL...EVEN THE ONES THAT DID HANDLE THE EARLIER MCS/S FAIRLY WELL. THE HRRR RUNS THIS MORNING HAVE BEEN INDICATING DEVELOPMENT OVER SOUTH-CENTRAL ARIZONA...INCLUDING THE LOWER DESERTS...EARLIER IN THE DAY THAN IS TYPICAL. OVERALL...NOT A LOT OF GOOD AGREEMENT AMONGST THE MODELS ON THE SPATIAL COVERAGE OF STORMS. ONE SIMILARITY IS THAT THERE SHOULD BE MORE STORMS OVER SOUTH-CENTRAL ARIZONA TODAY THAN YESTERDAY. WILL MAKE SOME ADDITIONAL UPWARD ADJUSTMENTS TO POPS. MORE LATER. && .PREVIOUS DISCUSSION 334 AM MST/PDT... LOOKING AT 00Z SOUNDINGS FROM BOTH TUCSON AND PHOENIX...SOMEWHAT DRIER COMPARED TO 12Z ON THURSDAY...HOWEVER STILL FAIRLY AVERAGE FOR THIS TIME OF YEAR FOR PWAT VALUES. AFTER AN ACTIVE EVENING ACROSS SOUTHEAST ARIZONA AND SOUTHEAST CALIFORNIA...PER LATEST IR SATELLITE IMAGERY A NICE MCS HAS MADE AN APPEARANCE OVER SONORA AND IS TRACKING WESTWARD BUT STILL DELIVERING A VAST AMOUNT OF CLOUD COVER AND ISOLATED LIGHTNING THIS SIDE OF THE BORDER. THE STRUGGLE TODAY WILL BE CLOUD COVER AND IF IT WILL HINDER CONVECTION OPPORTUNITIES INTO THE CENTRAL DESERTS. STILL UNDER THE INFLUENCE OF SOUTH-SOUTHEASTERLY FLOW ON THE BACKSIDE OF THE HIGH...THE SHORTWAVE FEATURE THAT IS PROVIDING THE LIFT AND DYNAMICS CONTINUES TO MOVE NORTHWARD INTO THE FOUR CORNERS REGION. PRECIPITABLE WATER READINGS ARE FORECAST TO REACH 1.65-1.7 INCH THROUGH SATURDAY EVENING...WHICH AGAIN IS ABOUT PAR FOR THE COURSE THIS TIME OF YEAR. TWO OUT OF THREE KEY INGREDIENTS FOR STORM INITIATION ARE PRESENT AND THE THIRD REALLY HINGES ON DAYTIME HEATING. AS WE SAW A FEW DAYS AGO THE CLOUDS PLAY A LARGE PART IN WHETHER STORMS WILL INITIATE OR NOT. BOUNDARY LAYER AND OUTFLOW INTERACTION ALWAYS AIDE WITH DEVELOPMENT. LOCAL MESOSCALE CONVECTIVE MODELS ALLUDE TO CLOUDS CLEARING BY MID MORNING FOR CENTRAL ARIZONA AS WELL AS ELEVATED INSTABILITY BY MID-DAY /CLOSE TO 800 J/KG OF CAPE/ WHICH WOULD LATER BE REALIZED WITH DAYTIME HEATING. ALL THIS SAID...TODAY COULD PLAY OUT EITHER WITH STABLE CONDITIONS PERSISTING DUE TO NO CLEARING OR MID TO LATE AFTERNOON CONVECTION WILL INITIATE SOUTHEAST OF PHOENIX AND PROPAGATE NORTHWARD. I AM TENDING TO LEAN ON THE CLEARING OUT OPTION. FORECAST SOUNDINGS INDICATE A DRY BOUNDARY LAYER /7-8 G/KG MIXING RATIO/ WITH SUFFICIENT HEATING CREATING AN INVERTED-V TYPE SOUNDING WITH WARMER MAX TEMPS THIS AFTERNOON. INSTABILITY IN PLACE AND CONVECTION DEVELOPING SOUTHEAST OF PHOENIX WITH A SOUTHEASTERLY FLOW...SIGNS POINT TO BLOWING DUST. ALL HIGH-RES MODELS TEND TO AGREE ON A RATHER ACTIVE EVENING ACROSS THE LOWER DESERTS. WHILE NOT A SLAM-DUNK FLOOD SCENARIO...CAN`T RULE OUT LOCALIZED FLOODING...AS WELL AS GUSTY WINDS WITH THE STRONGER STORMS. AFTER TODAY DRIER AIR BEGINS TO FILTER IN WITH A SOUTHWESTERLY FLOW STARTING TO TAKE SHAPE. SATURDAY HAS LESS THAN IDEAL CONDITIONS FOR MONSOONAL ACTIVITY ACROSS THE LOWER AND CENTRAL DESERTS WITH MORE OF A CONFLUENT FLOW. MOUNTAIN LOCATIONS OF EASTERN ARIZONA WILL STILL SEE A SLIGHT OR BETTER CHANCE FOR AFTERNOON AND EVENING CONVECTION FOR THE NEXT SEVERAL DAYS...GRADUALLY TRENDING DOWNWARD. SLIGHT WARMING WILL ALSO TAKE PLACE WITH TEMPERATURES RANGING 102 TO 108 EACH DAY. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... AN ACTIVE START TO THE AFTERNOON WITH QUITE A BIT OF STORM ACTIVITY ALREADY FIRING OVER THE MOUNTAINS TO THE NORTH AND EAST OF PHOENIX. EVENTUALLY EXPECTING SOME STORM OUTFLOWS TO ALLOW FOR MORE STORM DEVELOPMENT OVER THE LOWER DESERTS BY LATE AFTERNOON. CONFIDENCE IN TIMING FOR STORMS IN THE LOWER DESERTS IS STILL SOMEWHAT LOW...BUT WE MAY SEE SOME OUTFLOWS INTO THE PHOENIX TERMINALS AS SOON AS 22- 00Z AND THEN A SHOT AT SOME THUNDERSTORMS DURING THE EVENING HOURS. WIND FORECASTS THROUGH MIDNIGHT ARE RATHER TRICKY DUE TO THE STRONG LIKELIHOOD OF STORM OUTFLOWS AFFECTING THE AREA. THERE IS POTENTIAL FOR SOME STRONG WIND GUSTS WITH THESE OUTFLOWS AND VISIBILITY RESTRICTIONS IN DUST OR RAIN. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... WEST WINDS TO HOLD MOSTLY FOR KIPL THROUGHOUT THE DAY WHILE SOUTHERLY HEADINGS ARE IN STORE FOR KBLH. SLIGHT CHANCE FOR ISOLATED THUNDERSTORM DEVELOPMENT INTO THE AFTN ALONG THE CO RIVER VALLEY...SO AT LEAST VCSH MENTION IS BACK IN THE KBLH TAF FOR THE AFTN/EVENING HOURS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... MONSOONAL MOISTURE WILL SLOWLY BEGIN TO THIN ACROSS THE AREA...FIRST ACROSS THE WESTERN FIRE DISTRICTS AND EVENTUALLY INTO THE ENTIRE LOWER DESERT ELEVATIONS AND REGION BY EARLY NEXT WEEK. THIS WILL RELEGATE STORM CHANCES BACK TOWARDS THE HIGHER TERRAIN AND FURTHER TO THE EAST ACROSS AZ. MINIMUM RH VALUES WILL BEGIN TO SETTLE INTO THE TEENS WHILE MAKING MOSTLY MODEST TO FAIR OVERNIGHT RECOVERIES. THE SLIGHTLY DRIER AIRMASS AND BUILDING UPPER RIDGE HEIGHTS WILL LEND THEMSELVES TOWARD WARMER SFC CONDITIONS...AT OR ABOVE SEASONAL NORMALS. WINDS WILL FOLLOW FAMILIAR WARM SEASON PATTERNS. BY MIDWEEK A SUBTLE RETURN OF GULF MOISTURE MAY BOOST AREA HUMIDITIES...BUT NOT LINGER MUCH THROUGH THE END OF THE WEEK. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ PREVIOUS DISCUSSION...DEWEY AVIATION...KUHLMAN FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
941 AM MST FRI JUL 31 2015 .SYNOPSIS... ISOLATED TO SCATTERED STORM ACTIVITY IS ANTICIPATED OVER ARIZONA AND SOUTHEAST CALIFORNIA AGAIN TODAY. A NOTABLE DOWNTREND IN MOISTURE FROM WEST TO EAST IS EXPECTED OVER THE WEEKEND. THIS WILL KEEP STORM CHANCES LIMITED TO SOUTH- CENTRAL ARIZONA WELL INTO NEXT WEEK. TEMPERATURES WILL NOT CHANGE MUCH DAY TO DAY REMAINING AT OR ABOVE SEASONABLE AVERAGE. && .DISCUSSION... ISOLATED STORM ACTIVITY ALREADY GOING THIS MORNING ALONG OUR BOUNDARY WITH TWC CWA AND ADDITIONAL SHOWERS FURTHER SOUTH. THESE APPEAR TO BE INFLUENCED BY REMNANTS OF A COUPLE OF OVERNIGHT MCS/S. THERE ALSO LOOKS TO BE A BACKDOOR FRONT THAT HAS PUSHED THROUGH MUCH OF NEW MEXICO. SO THERE COULD BE A COUPLE OF MCV/S AFFECTING THE AREA TODAY...AND SOME OF THE HIGH RES MODELS DEPICT THAT. UNFORTUNATELY NONE OF THE HIGH RES MODELS HAVE CAPTURED THIS MORNING/S ACTIVITY VERY WELL...EVEN THE ONES THAT DID HANDLE THE EARLIER MCS/S FAIRLY WELL. THE HRRR RUNS THIS MORNING HAVE BEEN INDICATING DEVELOPMENT OVER SOUTH-CENTRAL ARIZONA...INCLUDING THE LOWER DESERTS...EARLIER IN THE DAY THAN IS TYPICAL. OVERALL...NOT A LOT OF GOOD AGREEMENT AMONGST THE MODELS ON THE SPATIAL COVERAGE OF STORMS. ONE SIMILARITY IS THAT THERE SHOULD BE MORE STORMS OVER SOUTH-CENTRAL ARIZONA TODAY THAN YESTERDAY. WILL MAKE SOME ADDITIONAL UPWARD ADJUSTMENTS TO POPS. MORE LATER. && .PREVIOUS DISCUSSION 334 AM MST/PDT... LOOKING AT 00Z SOUNDINGS FROM BOTH TUCSON AND PHOENIX...SOMEWHAT DRIER COMPARED TO 12Z ON THURSDAY...HOWEVER STILL FAIRLY AVERAGE FOR THIS TIME OF YEAR FOR PWAT VALUES. AFTER AN ACTIVE EVENING ACROSS SOUTHEAST ARIZONA AND SOUTHEAST CALIFORNIA...PER LATEST IR SATELLITE IMAGERY A NICE MCS HAS MADE AN APPEARANCE OVER SONORA AND IS TRACKING WESTWARD BUT STILL DELIVERING A VAST AMOUNT OF CLOUD COVER AND ISOLATED LIGHTNING THIS SIDE OF THE BORDER. THE STRUGGLE TODAY WILL BE CLOUD COVER AND IF IT WILL HINDER CONVECTION OPPORTUNITIES INTO THE CENTRAL DESERTS. STILL UNDER THE INFLUENCE OF SOUTH-SOUTHEASTERLY FLOW ON THE BACKSIDE OF THE HIGH...THE SHORTWAVE FEATURE THAT IS PROVIDING THE LIFT AND DYNAMICS CONTINUES TO MOVE NORTHWARD INTO THE FOUR CORNERS REGION. PRECIPITABLE WATER READINGS ARE FORECAST TO REACH 1.65-1.7 INCH THROUGH SATURDAY EVENING...WHICH AGAIN IS ABOUT PAR FOR THE COURSE THIS TIME OF YEAR. TWO OUT OF THREE KEY INGREDIENTS FOR STORM INITIATION ARE PRESENT AND THE THIRD REALLY HINGES ON DAYTIME HEATING. AS WE SAW A FEW DAYS AGO THE CLOUDS PLAY A LARGE PART IN WHETHER STORMS WILL INITIATE OR NOT. BOUNDARY LAYER AND OUTFLOW INTERACTION ALWAYS AIDE WITH DEVELOPMENT. LOCAL MESOSCALE CONVECTIVE MODELS ALLUDE TO CLOUDS CLEARING BY MID MORNING FOR CENTRAL ARIZONA AS WELL AS ELEVATED INSTABILITY BY MID-DAY /CLOSE TO 800 J/KG OF CAPE/ WHICH WOULD LATER BE REALIZED WITH DAYTIME HEATING. ALL THIS SAID...TODAY COULD PLAY OUT EITHER WITH STABLE CONDITIONS PERSISTING DUE TO NO CLEARING OR MID TO LATE AFTERNOON CONVECTION WILL INITIATE SOUTHEAST OF PHOENIX AND PROPAGATE NORTHWARD. I AM TENDING TO LEAN ON THE CLEARING OUT OPTION. FORECAST SOUNDINGS INDICATE A DRY BOUNDARY LAYER /7-8 G/KG MIXING RATIO/ WITH SUFFICIENT HEATING CREATING AN INVERTED-V TYPE SOUNDING WITH WARMER MAX TEMPS THIS AFTERNOON. INSTABILITY IN PLACE AND CONVECTION DEVELOPING SOUTHEAST OF PHOENIX WITH A SOUTHEASTERLY FLOW...SIGNS POINT TO BLOWING DUST. ALL HIGH-RES MODELS TEND TO AGREE ON A RATHER ACTIVE EVENING ACROSS THE LOWER DESERTS. WHILE NOT A SLAM-DUNK FLOOD SCENARIO...CAN`T RULE OUT LOCALIZED FLOODING...AS WELL AS GUSTY WINDS WITH THE STRONGER STORMS. AFTER TODAY DRIER AIR BEGINS TO FILTER IN WITH A SOUTHWESTERLY FLOW STARTING TO TAKE SHAPE. SATURDAY HAS LESS THAN IDEAL CONDITIONS FOR MONSOONAL ACTIVITY ACROSS THE LOWER AND CENTRAL DESERTS WITH MORE OF A CONFLUENT FLOW. MOUNTAIN LOCATIONS OF EASTERN ARIZONA WILL STILL SEE A SLIGHT OR BETTER CHANCE FOR AFTERNOON AND EVENING CONVECTION FOR THE NEXT SEVERAL DAYS...GRADUALLY TRENDING DOWNWARD. SLIGHT WARMING WILL ALSO TAKE PLACE WITH TEMPERATURES RANGING 102 TO 108 EACH DAY. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... BKN-OVC MID AND HIGH LEVEL CIGS WILL CONTINUE TO DRIFT ACROSS THE AREA THIS AM FROM DECAYING STORM COMPLEXES SOUTH OF THE BORDER AND ACROSS SE AZ. HOW FAST AND TO WHAT EXTENT THESE CLEAR TODAY WILL EITHER HELP OR HURT THE PHX METRO IN TERMS OF STORM CHANCES IMPACTING THE TERMINALS LATER INTO THE EVENING. GNLY LIGHT AM SFC WINDS NOTED AT SITES AROUND THE METRO WITH SUBTLE WEST FLOW VIA TPHX AND KIWA VELOCITIES...SO ELECTED TO GO WITH VRB IN FOR PHX. SPEEDS SHOULD BE LIGHT AND MANAGEABLE UNTIL MORE PROMINENT WESTERLY FLOW SETTLES INTO THE AREA AFTER MIDDAY. IF SKIES CLEAR AND WE ARE ABLE TO DECENTLY WARM THE DESERTS...STORMS ARE FCST TO BEGIN FIRING OVER THE HIGHER TERRAIN AND FOOTHILLS EAST AND SOUTH OF PHOENIX. STORM INITIATION AND/OR SURVIVAL INTO THE PHX METRO WILL LIKELY DEPEND ON STORM OUTFLOWS AND THEIR INTERACTION. FOLLOWING HOW CONDITIONS HAVE MATERIALIZED SO FAR THIS SUMMER...THESE OUTFLOW PASSAGES TEND BE POST 00Z...SO DID INCLUDE VCTS MENTION 01/02Z FOR KSDL AND KIWA AND 01/04Z FOR KPHX. CONFIDENCE IS MODERATE ON STORM DEVELOPMENT THIS EVENING...HOPING THAT DAYTIME CLOUD COVER CLEARS ENOUGH TO NOT DAMPEN/SHUT DOWN STORM CHANCES LATER INTO THE EVENING. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... SCT-BKN MID LEVEL CLOUDS WILL CONTINUE TO STREAM OVER THE TERMINALS FROM THE SOUTH THROUGH THE AM...OTHERWISE SKIES WILL MAINTAIN FEW- SCT CLOUD COVERAGE. WEST WINDS TO HOLD MOSTLY FOR KIPL THROUGHOUT THE DAY WHILE SOUTHERLY HEADINGS ARE IN STORE FOR KBLH. SLIGHT CHANCE FOR ISOLATED THUNDERSTORM DEVELOPMENT INTO THE AFTN ALONG THE CO RIVER VALLEY...SO AT LEAST VCSH MENTION IS BACK IN THE KBLH TAF FOR THE AFTN/EVENING HOURS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... MONSOONAL MOISTURE WILL SLOWLY BEGIN TO THIN ACROSS THE AREA...FIRST ACROSS THE WESTERN FIRE DISTRICTS AND EVENTUALLY INTO THE ENTIRE LOWER DESERT ELEVATIONS AND REGION BY EARLY NEXT WEEK. THIS WILL RELEGATE STORM CHANCES BACK TOWARDS THE HIGHER TERRAIN AND FURTHER TO THE EAST ACROSS AZ. MINIMUM RH VALUES WILL BEGIN TO SETTLE INTO THE TEENS WHILE MAKING MOSTLY MODEST TO FAIR OVERNIGHT RECOVERIES. THE SLIGHTLY DRIER AIRMASS AND BUILDING UPPER RIDGE HEIGHTS WILL LEND THEMSELVES TOWARD WARMER SFC CONDITIONS...AT OR ABOVE SEASONAL NORMALS. WINDS WILL FOLLOW FAMILIAR WARM SEASON PATTERNS. BY MIDWEEK A SUBTLE RETURN OF GULF MOISTURE MAY BOOST AREA HUMIDITIES...BUT NOT LINGER MUCH THROUGH THE END OF THE WEEK. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ PREVIOUS DISCUSSION...DEWEY AVIATION...NOLTE FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS RENO NV
1007 AM PDT FRI JUL 31 2015 .UPDATE... MADE A QUICK UPDATE THIS MORNING TO DECREASE COVERAGE OF EXPECTED THUNDERSTORMS TODAY IN MONO COUNTY TO ISOLATED, INSTEAD OF SCATTERED. ABUNDANT CLOUD COVER WILL KEEP INSTABILITY MARGINALIZED THROUGH THE DAY, RESULTING IN LESS THUNDERSTORM POTENTIAL. STILL, ANY STORMS THAT DO HAPPEN TO FORM WILL HAVE TO OVERCOME A VERY DRY BOUNDARY LAYER, SO LITTLE RAINFALL IS EXPECTED OVERALL WITH VIRGA SHOWERS COMMON TODAY. HOON && .PREVIOUS DISCUSSION... /ISSUED 304 AM PDT FRI JUL 31 2015/ SYNOPSIS... MOISTURE WILL SPREAD NORTH ACROSS THE REGION TODAY AND BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY NEAR THE SIERRA AND IN WESTERN NEVADA SOUTH OF HIGHWAY 50, WITH GUSTY OUTFLOW WINDS AND LIGHTNING INDUCED FIRE STARTS POSSIBLE. THE BEST OVERALL SHOWER AND THUNDERSTORM POTENTIAL IS EXPECTED FOR THIS WEEKEND, WITH LOCALLY HEAVY RAINFALL AND FLOODING BECOMING THE MAIN THREATS. SHORT TERM... MID AND HIGH LEVEL MOISTURE CONTINUES TO SPREAD NORTH ACROSS CALIFORNIA AND NEVADA THROUGH THE EARLY MORNING. ANOTHER WEAK IMPULSE FARTHER SOUTH ACROSS INYO AND NYE COUNTIES IS BEING PICKED UP BY THE LATEST NAM AND HRRR GUIDANCE, WHICH SPREAD SOME SHOWERS ACROSS MONO, ALPINE AND SOUTHERN MINERAL COUNTIES DURING THE EARLY AND MID MORNING. FOR THE REMAINDER OF TODAY, FAVORED AREAS FOR AFTERNOON CONVECTION APPEAR TO BE LIMITED TO AREAS NEAR THE SIERRA FROM MONO COUNTY NORTHWARD TO WESTERN LASSEN COUNTY, AND IN WESTERN NV SOUTH OF HIGHWAY 50. ELSEWHERE, THICKER CLOUD COVER SPREADING ACROSS WESTERN NV AND NORTHEAST CA DURING THE DAY COMBINED WITH DRY EAST FLOW NEAR THE SURFACE MAY PRODUCE CONDITIONS TOO STABLE FOR FORMING OR SUSTAINING CONVECTION THAT MOVES NORTH OF HIGHWAY 50. HOWEVER, OUTFLOWS FROM CELLS THAT DEVELOP NEAR THE SIERRA COULD PUSH ACROSS WESTERN NV AND BRING A SHORT PERIOD OF STRONGER WIND GUSTS BY LATE AFTERNOON OR EARLY EVENING. MOST ACTIVITY WILL DIMINISH TONIGHT, ALTHOUGH A FEW BRIEF CELLS CAN`T BE RULED OUT MAINLY SOUTH OF HIGHWAY 50 AS MOISTURE CONTINUES TO INCREASE OVERNIGHT. THE MAIN CONVECTIVE POTENTIAL IS EXPECTED THIS WEEKEND AS MOISTURE CONTINUES TO SURGE NORTHWARD. WHILE CLOUD COVER COULD STILL DISRUPT CONVECTIVE DEVELOPMENT, THERE APPEARS TO BE A LARGER WINDOW OF HEATING ON SATURDAY, ALONG WITH RISING DEW POINTS CONTRIBUTING TO MORE INSTABILITY. A STRONGER UPPER LEVEL DISTURBANCE IS ALSO PROJECTED TO MOVE NORTH ACROSS THE SIERRA WITH ANOTHER DISTURBANCE TRACKING NORTHWARD ACROSS CENTRAL NV. THESE FEATURES WOULD PROVIDE ADDITIONAL FORCING AND INCREASE SHOWER AND THUNDERSTORM COVERAGE WHICH MAY HOLD TOGETHER THROUGH SATURDAY NIGHT. THE CURRENT SHORTWAVE TRACKS ARE FAVORING SOME OVERNIGHT PRECIP ACROSS THE TAHOE BASIN AND THE RENO-CARSON CITY VICINITY, ALTHOUGH THIS COULD VARY SINCE THE TRACK OF THESE DISTURBANCES ARE LIKELY TO CHANGE WITH UPCOMING MODEL RUNS. FOR SUNDAY, ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS PROBABLE WITH VERY MOIST AND UNSTABLE CONDITIONS REMAINING. IF FULL INSTABILITY IS REALIZED, THEN SOME STRONG STORMS WITH HEAVY RAIN WOULD DEVELOP. HOWEVER, THERE COULD BE TOO MUCH LEFTOVER CLOUD COVER FROM SATURDAY NIGHT`S ACTIVITY WHICH LIMITS HEATING AND CELL STRENGTH ON SUNDAY. THIS LIMITING FACTOR IS MORE PRONOUNCED ON THE GFS WHICH IS HOLDING MAX TEMPS DOWN TO THE MID-UPPER 80S ACROSS WESTERN NV. WE DIDN`T MAKE MUCH CHANGE TO THE CURRENT SUNDAY FORECAST WITH CHANCE POPS KEPT OVER MOST AREAS, SINCE THERE IS A LOT OF UNCERTAINTY WITH THE DETAILS OF WHERE CONVECTION EVENTUALLY OCCURS. MJD LONG TERM...MONDAY THROUGH THURSDAY... THE OVERALL IDEA FOR NEXT WEEK`S FORECAST HAS NOT CHANGED, BUT DID MAKE SOME CHANGES TO THE DETAILS. DRIER SOUTHWEST FLOW IS EXPECTED TO BEGIN MONDAY AND CONTINUE THROUGH THE WEEK. SOME MOISTURE WILL BE LEFT OVER MONDAY FOR SOME SHOWERS AND THUNDERSTORMS. HOWEVER, PUSHED THE BEST CHANCES TO MONO/MINERAL WHERE THE SOUTHWEST FLOW WILL BE WEAKEST. WHILE IT WON`T DRY OUT QUICKLY, THE ZEPHYR ACTS TO LIMIT THUNDERSTORM DEVELOPMENT BEHIND ITS LEADING EDGE. I WOULD NOT BE SURPRISED IF THE TAHOE BASIN IS COMPLETELY DRY AS EARLY AS MONDAY AND POSSIBLY THE SIERRA FRONT OUTSIDE THE PINE NUTS. TUESDAY THROUGH THURSDAY, DRY SOUTHWEST FLOW WILL CONTINUE. ONE THING TO NOTE IS THAT THERE IS ANOTHER WAVE EMBEDDED IN THE FLOW FOR TUESDAY THAT COULD BACK THE FLOW TO THE SOUTH OVER MONO/MINERAL AND KEEP THUNDERSTORMS POSSIBLE THERE. THE EC IS SHOWING THIS IDEA, WHILE THE GFS IS DRY. WILL KEEP TUESDAY DRY FOR NOW UNTIL THERE IS MORE CONSISTENCY. AS FOR THE WINDS, THEY LOOK TO BE FAIRLY TYPICAL FOR MIDSUMMER WITH AN AFTERNOON/EVENING ZEPHYR EACH DAY AND GUSTS 25-30 MPH. TEMPERATURES WILL ALSO COOL BACK CLOSER TO AVERAGE IF NOT A LITTLE BELOW. WALLMANN AVIATION... VFR CONDITIONS AS MONSOONAL MOISTURE STREAMS NORTH TODAY WITH BROKEN MID AND HIGH CLOUDS. A FEW LIGHT SHOWERS POSSIBLE THIS MORNING WITH ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON ALONG AND JUST EAST OF THE SIERRA. COVERAGE MAY BE MORE OVER MONO COUNTY INCLUDING KMMH, BUT THIS WILL BE DEPENDENT ON CLOUD COVER THIS MORNING. MAIN THREAT WILL BE GUSTY OUTFLOW WINDS 40+ KTS AND ASSOCIATED WIND SHEAR. MORE CLOUDS TONIGHT BEFORE A POTENTIAL REPEAT ON SATURDAY. MOISTURE INCREASES, BUT THE STORM COVERAGE WILL BE DEPENDENT ON CLOUD COVER. WALLMANN FIRE WEATHER... MAIN CONCERN WILL BE LIGHTNING TODAY WITH STORMS AS MOISTURE CONTINUES TO INCREASE. CLOUD COVER IS FAIRLY EXTENSIVE THIS MORNING SO COVERAGE IS LIKELY TO REMAIN ISOLATED. STORMS WILL START DRY AND BECOME WET/DRY HYBRIDS AS THE DAY PROGRESSES. AS WE MOVE INTO SATURDAY, MOISTURE WILL CONTINUE TO INCREASE AND EXPECT HYBRID STORMS THAT DAY. GIVEN THE DRYNESS AND HEAT PRECEDING, IT COULD BE A POTENTIALLY ACTIVE DAY. HOWEVER, CLOUD COVER LOOKS LIKE IT MIGHT BE EXTENSIVE THAT WOULD REDUCE THE INSTABILITY AND COVERAGE OF STORMS. GIVEN THE UNCERTAINTY, WILL NOT ISSUE A FIRE WEATHER WATCH FOR DRY LIGHTNING. AS WE MOVE INTO SUNDAY, MORE MOISTURE WILL BE PRESENT AND STORMS WILL BE SLOW MOVING. AT THAT POINT, HEAVY RAIN WILL BE THE BIGGER CONCERN ALTHOUGH A FEW STARTS OUTSIDE THE CORES WILL REMAIN POSSIBLE. HUMIDITY WILL ALSO BE HIGHER TOO WITH MINIMUMS LIKELY TO REMAIN ABOVE 20% IN WESTERN NV AND 30% IN THE SIERRA. DRY SOUTHWEST FLOW IS EXPECTED NEXT WEEK WITH A FEW STORMS POSSIBLE MONDAY. WINDS NEXT WEEK LOOK TO BE TYPICAL ZEPHYRS WITH GUSTS 25-30 MPH. WALLMANN && .REV WATCHES/WARNINGS/ADVISORIES... NV...NONE. CA...NONE. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS RENO NV
304 AM PDT FRI JUL 31 2015 .SYNOPSIS... MOISTURE WILL SPREAD NORTH ACROSS THE REGION TODAY AND BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY NEAR THE SIERRA AND IN WESTERN NEVADA SOUTH OF HIGHWAY 50, WITH GUSTY OUTFLOW WINDS AND LIGHTNING INDUCED FIRE STARTS POSSIBLE. THE BEST OVERALL SHOWER AND THUNDERSTORM POTENTIAL IS EXPECTED FOR THIS WEEKEND, WITH LOCALLY HEAVY RAINFALL AND FLOODING BECOMING THE MAIN THREATS. && .SHORT TERM... MID AND HIGH LEVEL MOISTURE CONTINUES TO SPREAD NORTH ACROSS CALIFORNIA AND NEVADA THROUGH THE EARLY MORNING. ANOTHER WEAK IMPULSE FARTHER SOUTH ACROSS INYO AND NYE COUNTIES IS BEING PICKED UP BY THE LATEST NAM AND HRRR GUIDANCE, WHICH SPREAD SOME SHOWERS ACROSS MONO, ALPINE AND SOUTHERN MINERAL COUNTIES DURING THE EARLY AND MID MORNING. FOR THE REMAINDER OF TODAY, FAVORED AREAS FOR AFTERNOON CONVECTION APPEAR TO BE LIMITED TO AREAS NEAR THE SIERRA FROM MONO COUNTY NORTHWARD TO WESTERN LASSEN COUNTY, AND IN WESTERN NV SOUTH OF HIGHWAY 50. ELSEWHERE, THICKER CLOUD COVER SPREADING ACROSS WESTERN NV AND NORTHEAST CA DURING THE DAY COMBINED WITH DRY EAST FLOW NEAR THE SURFACE MAY PRODUCE CONDITIONS TOO STABLE FOR FORMING OR SUSTAINING CONVECTION THAT MOVES NORTH OF HIGHWAY 50. HOWEVER, OUTFLOWS FROM CELLS THAT DEVELOP NEAR THE SIERRA COULD PUSH ACROSS WESTERN NV AND BRING A SHORT PERIOD OF STRONGER WIND GUSTS BY LATE AFTERNOON OR EARLY EVENING. MOST ACTIVITY WILL DIMINISH TONIGHT, ALTHOUGH A FEW BRIEF CELLS CAN`T BE RULED OUT MAINLY SOUTH OF HIGHWAY 50 AS MOISTURE CONTINUES TO INCREASE OVERNIGHT. THE MAIN CONVECTIVE POTENTIAL IS EXPECTED THIS WEEKEND AS MOISTURE CONTINUES TO SURGE NORTHWARD. WHILE CLOUD COVER COULD STILL DISRUPT CONVECTIVE DEVELOPMENT, THERE APPEARS TO BE A LARGER WINDOW OF HEATING ON SATURDAY, ALONG WITH RISING DEW POINTS CONTRIBUTING TO MORE INSTABILITY. A STRONGER UPPER LEVEL DISTURBANCE IS ALSO PROJECTED TO MOVE NORTH ACROSS THE SIERRA WITH ANOTHER DISTURBANCE TRACKING NORTHWARD ACROSS CENTRAL NV. THESE FEATURES WOULD PROVIDE ADDITIONAL FORCING AND INCREASE SHOWER AND THUNDERSTORM COVERAGE WHICH MAY HOLD TOGETHER THROUGH SATURDAY NIGHT. THE CURRENT SHORTWAVE TRACKS ARE FAVORING SOME OVERNIGHT PRECIP ACROSS THE TAHOE BASIN AND THE RENO-CARSON CITY VICINITY, ALTHOUGH THIS COULD VARY SINCE THE TRACK OF THESE DISTURBANCES ARE LIKELY TO CHANGE WITH UPCOMING MODEL RUNS. FOR SUNDAY, ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS PROBABLE WITH VERY MOIST AND UNSTABLE CONDITIONS REMAINING. IF FULL INSTABILITY IS REALIZED, THEN SOME STRONG STORMS WITH HEAVY RAIN WOULD DEVELOP. HOWEVER, THERE COULD BE TOO MUCH LEFTOVER CLOUD COVER FROM SATURDAY NIGHT`S ACTIVITY WHICH LIMITS HEATING AND CELL STRENGTH ON SUNDAY. THIS LIMITING FACTOR IS MORE PRONOUNCED ON THE GFS WHICH IS HOLDING MAX TEMPS DOWN TO THE MID-UPPER 80S ACROSS WESTERN NV. WE DIDN`T MAKE MUCH CHANGE TO THE CURRENT SUNDAY FORECAST WITH CHANCE POPS KEPT OVER MOST AREAS, SINCE THERE IS A LOT OF UNCERTAINTY WITH THE DETAILS OF WHERE CONVECTION EVENTUALLY OCCURS. MJD .LONG TERM...MONDAY THROUGH THURSDAY... THE OVERALL IDEA FOR NEXT WEEK`S FORECAST HAS NOT CHANGED, BUT DID MAKE SOME CHANGES TO THE DETAILS. DRIER SOUTHWEST FLOW IS EXPECTED TO BEGIN MONDAY AND CONTINUE THROUGH THE WEEK. SOME MOISTURE WILL BE LEFT OVER MONDAY FOR SOME SHOWERS AND THUNDERSTORMS. HOWEVER, PUSHED THE BEST CHANCES TO MONO/MINERAL WHERE THE SOUTHWEST FLOW WILL BE WEAKEST. WHILE IT WON`T DRY OUT QUICKLY, THE ZEPHYR ACTS TO LIMIT THUNDERSTORM DEVELOPMENT BEHIND ITS LEADING EDGE. I WOULD NOT BE SURPRISED IF THE TAHOE BASIN IS COMPLETELY DRY AS EARLY AS MONDAY AND POSSIBLY THE SIERRA FRONT OUTSIDE THE PINE NUTS. TUESDAY THROUGH THURSDAY, DRY SOUTHWEST FLOW WILL CONTINUE. ONE THING TO NOTE IS THAT THERE IS ANOTHER WAVE EMBEDDED IN THE FLOW FOR TUESDAY THAT COULD BACK THE FLOW TO THE SOUTH OVER MONO/MINERAL AND KEEP THUNDERSTORMS POSSIBLE THERE. THE EC IS SHOWING THIS IDEA, WHILE THE GFS IS DRY. WILL KEEP TUESDAY DRY FOR NOW UNTIL THERE IS MORE CONSISTENCY. AS FOR THE WINDS, THEY LOOK TO BE FAIRLY TYPICAL FOR MIDSUMMER WITH AN AFTERNOON/EVENING ZEPHYR EACH DAY AND GUSTS 25-30 MPH. TEMPERATURES WILL ALSO COOL BACK CLOSER TO AVERAGE IF NOT A LITTLE BELOW. WALLMANN && .AVIATION... VFR CONDITIONS AS MONSOONAL MOISTURE STREAMS NORTH TODAY WITH BROKEN MID AND HIGH CLOUDS. A FEW LIGHT SHOWERS POSSIBLE THIS MORNING WITH ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON ALONG AND JUST EAST OF THE SIERRA. COVERAGE MAY BE MORE OVER MONO COUNTY INCLUDING KMMH, BUT THIS WILL BE DEPENDENT ON CLOUD COVER THIS MORNING. MAIN THREAT WILL BE GUSTY OUTFLOW WINDS 40+ KTS AND ASSOCIATED WIND SHEAR. MORE CLOUDS TONIGHT BEFORE A POTENTIAL REPEAT ON SATURDAY. MOISTURE INCREASES, BUT THE STORM COVERAGE WILL BE DEPENDENT ON CLOUD COVER. WALLMANN && .FIRE WEATHER... MAIN CONCERN WILL BE LIGHTNING TODAY WITH STORMS AS MOISTURE CONTINUES TO INCREASE. CLOUD COVER IS FAIRLY EXTENSIVE THIS MORNING SO COVERAGE IS LIKELY TO REMAIN ISOLATED. STORMS WILL START DRY AND BECOME WET/DRY HYBRIDS AS THE DAY PROGRESSES. AS WE MOVE INTO SATURDAY, MOISTURE WILL CONTINUE TO INCREASE AND EXPECT HYBRID STORMS THAT DAY. GIVEN THE DRYNESS AND HEAT PRECEDING, IT COULD BE A POTENTIALLY ACTIVE DAY. HOWEVER, CLOUD COVER LOOKS LIKE IT MIGHT BE EXTENSIVE THAT WOULD REDUCE THE INSTABILITY AND COVERAGE OF STORMS. GIVEN THE UNCERTAINTY, WILL NOT ISSUE A FIRE WEATHER WATCH FOR DRY LIGHTNING. AS WE MOVE INTO SUNDAY, MORE MOISTURE WILL BE PRESENT AND STORMS WILL BE SLOW MOVING. AT THAT POINT, HEAVY RAIN WILL BE THE BIGGER CONCERN ALTHOUGH A FEW STARTS OUTSIDE THE CORES WILL REMAIN POSSIBLE. HUMIDITY WILL ALSO BE HIGHER TOO WITH MINIMUMS LIKELY TO REMAIN ABOVE 20% IN WESTERN NV AND 30% IN THE SIERRA. DRY SOUTHWEST FLOW IS EXPECTED NEXT WEEK WITH A FEW STORMS POSSIBLE MONDAY. WINDS NEXT WEEK LOOK TO BE TYPICAL ZEPHYRS WITH GUSTS 25-30 MPH. WALLMANN && .REV WATCHES/WARNINGS/ADVISORIES... NV...NONE. CA...NONE. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1019 AM MDT FRI JUL 31 2015 .UPDATE... ISSUED AT 1013 AM MDT FRI JUL 31 2015 SATELLITE IMAGERY SHOWING SOME CU START TO DEVELOP OVER THE HIGHER TERRAIN. HRRR AND RAP CONTINUING TO SHOW STORM DEVELOPMENT OVER THE DIVIDE THROUGH THE AFTERNOON. SOME OF THE STORMS MAY MOVE OFF THE MOUNTAINS OVER THE FOOTHILLS OF PARK...JEFFERSON AND DOUGLAS COUNTIES BY THE EARLY EVENING. BIGGEST THREATS WILL BE BRIEF MODERATE TO HEAVY RAIN WITH THE POSSIBILITY OF SOME SMALL HAIL AND WIND GUSTS UP TO 45 MPH WITH THE STRONGER STORMS. TEMPERATURES ARE STILL ON TRACK TO REACH THE UPPER 80S TO LOWER 90S FOR THE PLAINS. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 245 AM MDT FRI JUL 31 2015 THE BROAD UPPER HIGH WILL CONTINUE TO SHIFT FURTHER WEST AND NORTH ACROSS THE GREAT BASIN TODAY. THIS WILL ALLOW SOME ADDITIONAL MOISTURE TO ALSO SEEP INTO COLORADO WHERE INTEGRATED PW VALUES HAVE ALREADY INCREASED AROUND A THIRD OF AN INCH IN THE PAST 12 HOURS OVER THE FRONT RANGE. STILL THOUGH MID LEVEL INVERSION AROUND 500MB WILL LIMIT CONVECTION THROUGH THIS AFTERNOON. NAM SEEMS THE MOST BULLISH ON MOISTURE AND STORM POTENTIAL WHILE THE THE RAP IS THE DRIEST. EXPECT MAJORITY OF STORMS WILL BE OVER EAST SLOPES AND HIGHER TERRAIN. SOME OF THIS MAY SPILL OUT OVER THE ADJACENT PLAINS BY LATER THIS AFTERNOON. NOT MUCH HELP UPSTAIRS AS QG FIELDS SHOWING SOME SUBSIDENCE IN THE 700MB LAYERS AND NEUTRAL FORCING ALOFT. ISOLATED POPS ON THE PLAINS WITH HIGHER SCATTERED CHANCES IN THE MOUNTAINS SHOULD SUFFICE. EXPECT TEMPERATURES WILL BE SIMILAR TO THURSDAY READINGS. CONVECTION WILL DIMINISH DURING THE EVENING HOURS WITH LACK OF ANY UPPER AIR SUPPORT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 207 AM MDT FRI JUL 31 2015 BY SATURDAY MORNING...A NEGATIVELY TILTED UPPER RIDGE IS STILL OVER THE WRN CONUS WITH THE 500MB HIGH OVER SERN NEW MEX. AT THE SFC... BROAD CLOCKWISE CIRCULATION AROUND A STG HIGH IN NWRN ARKANSAS CONTINUES TO ADVECT INCREASING AMOUNTS OF LOW-LEVEL MOISTURE NORTHWARD ALONG THE COLORADO/KANSAS BORDER. MEANWHILE THE MID-LEVEL NWLY FLOW CONTINUES TO DRY ON THE SOUTH SIDE OF AN 80-90KT JET SEGMENT. BY LATE AFTERNOON...MODELS SHOW A NEARLY NEUTRAL TILT UPPER RIDGE MIGRATING EASTWARD OVER ERN UTAH/COLORADO CAUSING THE MID- LEVEL FLOW OVER THE FCST AREA TO BECOME N-NWLY. AT THE SAME TIME SELY BNDRY LAYER FLOW EAST OF THE MTNS CONTINUES TO TRANSPORT LOW LEVEL MOISTURE UP INTO THE FCST AREA. MODELS SHOW MEAN LAYER PW VALUES PUSHING AN INCH ACRS SERN SECTIONS OF THE CWA BY EVENING. HOWEVER...MOISTURE APPEARS RELATIVELY SHALLOW...CAPPED BY A MUCH DRIER N-NWLY FLOW ABOVE 650 MBS. OVERNIGHT SELY SFC WINDS ON THE PLAINS TURN SWLY WHICH FLUSHES OUT SOME OF THE MOISTURE UP ALONG THE FRONT RANGE. DRY OUT IS SHORT-LIVED AS THE GFS...SREF AND NAM SHOW A RETURN TO A MOIST SELY FLOW DURING THE DAY SUNDAY. MODELS SHOW MEAN LAYER PW VALUES APPROACH 1.25 INCH OVER NRN PORTIONS OF THE I-25 URBAN CORRIDOR BY LATE AFTERNOON. THIS TIME THE MOISTURE LAYER APPEARS DEEPER AND WITH LIGHT/VARIABLE TRANSPORT WINDS SLOW STORM MOTIONS WOULD CONCEIVABLY RESULT IN LOCALLY HEAVY RAINFALL. ALTHOUGH QPF FIELDS DO NOT INDICATE ANYTHING LIKE THAT HAPPENING APPARENTLY DUE TO A LACK OF CAPE AND SOME KIND OF FORCING MECHANISM SUCH AS A FRONTAL BNDRY OR DEEP UPSLOPE FLOW. HOWEVER MODELS INDICATE CAPES IN THE 1000-1500 J/KG RANGE...AND ON THE NAM AS HIGH AS 2000 J/KG...AND DECENT LOW-LEVEL CONVERGENCE/SHEAR ALONG THE PALMER DIVIDE. ITS MORE LIKELY HERE THAT A FEW SUPERCELLS CAPABLE OF HEAVY RAINFALL...HAIL AND STG GUSTY WINDS WILL FORM AND TRACK EAST-SOUTHEAST ALONG THE DIVIDE DURING THE LATE AFTERNOON AND EVENING HRS ON SUN. THE SRN FRONT RANGE FOOTHILLS AND SOUTH PARK IS ANOTHER AREA WHERE THERE`S AN ELEVATED POTENTIAL FOR T-STORMS AT THIS TIME DUE TO THIS MOIST AND UNSTABLE SELY FLOW. ACTUALLY THERE`S A GREATER POTENTIAL FOR STORMS PRODUCING HEAVY RAINFALL IN PARK COUNTY WITH THIS SET UP. BY SUNDAY NIGHT...THE NAM...GFS AND ECMWF ALL NOW SHOW A MID-LEVEL SHORTWAVE TROUGH LIFTING NEWRD ACRS THE STATE WITH THE UPPER RIDGE COLLAPSING AS IT CONTINUES TO SHIFT EAST. WAVE IS FCST TO REACH THE FRONT RANGE URBAN CORRIDOR BY EARLY MONDAY MORNING. ITS PASSAGE COULD ENHANCE OR EXTEND SHOWER/T-STORM DEVELOPMENT IN THE HIGH COUNTRY THROUGH THE LATE EVENING HRS. NOT SURE THIS DISTURBANCE WILL HAVE MUCH OF AN IMPACT ON AREAS EAST OF THE MTNS OVERNIGHT. ON MONDAY...MOISTURE...INSTABILITY AND MODEST QG LIFT ASSOCIATED WITH THE PASSING SHORTWAVE EXPECTED TO PRODUCE MORE CLOUD COVER AND A SLIGHTLY GREATER CHANCE OF SHOWERS/T-STORMS FOR THE ENTIRE FCST AREA. MOST MODELS SHOW THIS FEATURE EXITING THE STATE BY EVENING WITH DRYING AND STABILIZATION IN ITS WAKE AS THE UPPER RIDGE AXIS MOVES OVERHEAD OVERNIGHT. TUESDAY SHOULD BE A DRIER AND SLIGHTLY WARMER DAY WITH ANY STORM DEVELOPMENT RELEGATED TO THE HIGH COUNTRY. ON WEDNESDAY... TEMPS CONTINUE TO WARM BOTH SFC AND ALOFT...AND HUMIDITIES LOWER WITH THE UPPER RIDGE AMPLIFYING OVER THE CENTRAL ROCKIES. HOWEVER STILL CANNOT RULE OUT A FEW LATE DAY GUSTY T-STORMS IN THE HIGH COUNTRY. BY THURSDAY...MEDIUM RANGE MODELS SHOW THE UPPER RIDGE MOVING OVER THE GREAT PLAINS PLACING COLORADO UNDER SWLY FLOW ALOFT. COULD SEE SUBTROPICAL MOISTURE CARRIED NORTH BY THIS FLOW IN TANDEM WITH A SHORTWAVE TROUGH THAT MODELS SHOW SWINGING OUT OF THE 4-CORNERS REGION LATE IN THE DAY. AS A RESULT COULD SEE A MODEST INCREASE IN T- STORM CHANCES MAINLY FOR THE HIGH COUNTRY. OTHERWISE THURSDAY TEMPS LITTLE CHANGED FROM THE DAY BEFORE. && .AVIATION...(FOR THE TAFS THROUGH 18Z SATURDAY MORNING) ISSUED AT 1013 AM MDT FRI JUL 31 2015 VFR EXPECTED FOR THE NEXT 24 HOURS FOR ALL AIRPORTS. A MID LEVEL BKN DECK WILL FORM WITH INCREASED MOISTURE IN THE AFTERNOON WITH SOME SHOWERS IN THE VICINITY. WINDS WILL SLOWLY MAKE THEIR WAY TO THE SE THEN TRANSITION TO DRAINAGE BY THE EVENING. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BOWEN SHORT TERM...ENTREKIN LONG TERM...BAKER AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
246 AM MDT FRI JUL 31 2015 .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 245 AM MDT FRI JUL 31 2015 THE BROAD UPPER HIGH WILL CONTINUE TO SHIFT FURTHER WEST AND NORTH ACROSS THE GREAT BASIN TODAY. THIS WILL ALLOW SOME ADDITIONAL MOISTURE TO ALSO SEEP INTO COLORADO WHERE INTEGRATED PW VALUES HAVE ALREADY INCREASED AROUND A THIRD OF AN INCH IN THE PAST 12 HOURS OVER THE FRONT RANGE. STILL THOUGH MID LEVEL INVERSION AROUND 500MB WILL LIMIT CONVECTION THROUGH THIS AFTERNOON. NAM SEEMS THE MOST BULLISH ON MOISTURE AND STORM POTENTIAL WHILE THE THE RAP IS THE DRIEST. EXPECT MAJORITY OF STORMS WILL BE OVER EAST SLOPES AND HIGHER TERRAIN. SOME OF THIS MAY SPILL OUT OVER THE ADJACENT PLAINS BY LATER THIS AFTERNOON. NOT MUCH HELP UPSTAIRS AS QG FIELDS SHOWING SOME SUBSIDENCE IN THE 700MB LAYERS AND NEUTRAL FORCING ALOFT. ISOLATED POPS ON THE PLAINS WITH HIGHER SCATTERED CHANCES IN THE MOUNTAINS SHOULD SUFFICE. EXPECT TEMPERATURES WILL BE SIMILAR TO THURSDAY READINGS. CONVECTION WILL DIMINISH DURING THE EVENING HOURS WITH LACK OF ANY UPPER AIR SUPPORT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 207 AM MDT FRI JUL 31 2015 BY SATURDAY MORNING...A NEGATIVELY TILTED UPPER RIDGE IS STILL OVER THE WRN CONUS WITH THE 500MB HIGH OVER SERN NEW MEX. AT THE SFC... BROAD CLOCKWISE CIRCULATION AROUND A STG HIGH IN NWRN ARKANSAS CONTINUES TO ADVECT INCREASING AMOUNTS OF LOW-LEVEL MOISTURE NORTHWARD ALONG THE COLORADO/KANSAS BORDER. MEANWHILE THE MID-LEVEL NWLY FLOW CONTINUES TO DRY ON THE SOUTH SIDE OF AN 80-90KT JET SEGMENT. BY LATE AFTERNOON...MODELS SHOW A NEARLY NEUTRAL TILT UPPER RIDGE MIGRATING EASTWARD OVER ERN UTAH/COLORADO CAUSING THE MID- LEVEL FLOW OVER THE FCST AREA TO BECOME N-NWLY. AT THE SAME TIME SELY BNDRY LAYER FLOW EAST OF THE MTNS CONTINUES TO TRANSPORT LOW LEVEL MOISTURE UP INTO THE FCST AREA. MODELS SHOW MEAN LAYER PW VALUES PUSHING AN INCH ACRS SERN SECTIONS OF THE CWA BY EVENING. HOWEVER...MOISTURE APPEARS RELATIVELY SHALLOW...CAPPED BY A MUCH DRIER N-NWLY FLOW ABOVE 650 MBS. OVERNIGHT SELY SFC WINDS ON THE PLAINS TURN SWLY WHICH FLUSHES OUT SOME OF THE MOISTURE UP ALONG THE FRONT RANGE. DRY OUT IS SHORT-LIVED AS THE GFS...SREF AND NAM SHOW A RETURN TO A MOIST SELY FLOW DURING THE DAY SUNDAY. MODELS SHOW MEAN LAYER PW VALUES APPROACH 1.25 INCH OVER NRN PORTIONS OF THE I-25 URBAN CORRIDOR BY LATE AFTERNOON. THIS TIME THE MOISTURE LAYER APPEARS DEEPER AND WITH LIGHT/VARIABLE TRANSPORT WINDS SLOW STORM MOTIONS WOULD CONCEIVABLY RESULT IN LOCALLY HEAVY RAINFALL. ALTHOUGH QPF FIELDS DO NOT INDICATE ANYTHING LIKE THAT HAPPENING APPARENTLY DUE TO A LACK OF CAPE AND SOME KIND OF FORCING MECHANISM SUCH AS A FRONTAL BNDRY OR DEEP UPSLOPE FLOW. HOWEVER MODELS INDICATE CAPES IN THE 1000-1500 J/KG RANGE...AND ON THE NAM AS HIGH AS 2000 J/KG...AND DECENT LOW-LEVEL CONVERGENCE/SHEAR ALONG THE PALMER DIVIDE. ITS MORE LIKELY HERE THAT A FEW SUPERCELLS CAPABLE OF HEAVY RAINFALL...HAIL AND STG GUSTY WINDS WILL FORM AND TRACK EAST-SOUTHEAST ALONG THE DIVIDE DURING THE LATE AFTERNOON AND EVENING HRS ON SUN. THE SRN FRONT RANGE FOOTHILLS AND SOUTH PARK IS ANOTHER AREA WHERE THERE`S AN ELEVATED POTENTIAL FOR T-STORMS AT THIS TIME DUE TO THIS MOIST AND UNSTABLE SELY FLOW. ACTUALLY THERE`S A GREATER POTENTIAL FOR STORMS PRODUCING HEAVY RAINFALL IN PARK COUNTY WITH THIS SET UP. BY SUNDAY NIGHT...THE NAM...GFS AND ECMWF ALL NOW SHOW A MID-LEVEL SHORTWAVE TROUGH LIFTING NEWRD ACRS THE STATE WITH THE UPPER RIDGE COLLAPSING AS IT CONTINUES TO SHIFT EAST. WAVE IS FCST TO REACH THE FRONT RANGE URBAN CORRIDOR BY EARLY MONDAY MORNING. ITS PASSAGE COULD ENHANCE OR EXTEND SHOWER/T-STORM DEVELOPMENT IN THE HIGH COUNTRY THROUGH THE LATE EVENING HRS. NOT SURE THIS DISTURBANCE WILL HAVE MUCH OF AN IMPACT ON AREAS EAST OF THE MTNS OVERNIGHT. ON MONDAY...MOISTURE...INSTABILITY AND MODEST QG LIFT ASSOCIATED WITH THE PASSING SHORTWAVE EXPECTED TO PRODUCE MORE CLOUD COVER AND A SLIGHTLY GREATER CHANCE OF SHOWERS/T-STORMS FOR THE ENTIRE FCST AREA. MOST MODELS SHOW THIS FEATURE EXITING THE STATE BY EVENING WITH DRYING AND STABILIZATION IN ITS WAKE AS THE UPPER RIDGE AXIS MOVES OVERHEAD OVERNIGHT. TUESDAY SHOULD BE A DRIER AND SLIGHTLY WARMER DAY WITH ANY STORM DEVELOPMENT RELEGATED TO THE HIGH COUNTRY. ON WEDNESDAY... TEMPS CONTINUE TO WARM BOTH SFC AND ALOFT...AND HUMIDITIES LOWER WITH THE UPPER RIDGE AMPLIFYING OVER THE CENTRAL ROCKIES. HOWEVER STILL CANNOT RULE OUT A FEW LATE DAY GUSTY T-STORMS IN THE HIGH COUNTRY. BY THURSDAY...MEDIUM RANGE MODELS SHOW THE UPPER RIDGE MOVING OVER THE GREAT PLAINS PLACING COLORADO UNDER SWLY FLOW ALOFT. COULD SEE SUBTROPICAL MOISTURE CARRIED NORTH BY THIS FLOW IN TANDEM WITH A SHORTWAVE TROUGH THAT MODELS SHOW SWINGING OUT OF THE 4-CORNERS REGION LATE IN THE DAY. AS A RESULT COULD SEE A MODEST INCREASE IN T- STORM CHANCES MAINLY FOR THE HIGH COUNTRY. OTHERWISE THURSDAY TEMPS LITTLE CHANGED FROM THE DAY BEFORE. && .AVIATION...(FOR THE TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 207 AM MDT FRI JUL 31 2015 SURFACE TROF OVER DENVER WITH HEALTHY S-SW WINDS OVER DEN/APA AND NW WINDS AT BJC. WINDS EXPECTED TO TURN SOUTHEAST OVER ENTIRE AREA THIS AFTERNOON. MOISTURE LEVELS A BIT HIGHER TODAY AND EXPECT ISOLATED COVERAGE OF STORMS BY LATER THIS AFTERNOON. HOWEVER AREAL COVERAGE TOO LOW TO MENTION IN TERMINAL FORECASTS FOR NOW. EXPECT BRIEF RAIN AND GUSTY WINDS WITH ANY POTENTIAL SHOWERS IN THE AREA. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ENTREKIN LONG TERM...BAKER AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS MIAMI FL
801 PM EDT SAT AUG 1 2015 .UPDATE... LATEST IR SATELLITE SHOWS A GOOD AMOUNT OF DEBRIS CLOUDS FROM EARLIER CONVECTION AS WELL AS DECAYING CONVECTION NORTH OF THE AREA. THEREFORE WILL KEEP MOSTLY CLOUDY SKIES ACROSS THE AREA THROUGH THE NIGHT. LATEST HRRR KEEPS SHOWERS AND THUNDERSTORMS ACROSS THE ATLANTIC WATERS THROUGH MUCH OF THE NIGHT SO KEPT ONGOING POPS ACROSS THE WATERS WITH DECREASING CHANCES THROUGH THE NIGHT. UPDATE SENT. && .PREV DISCUSSION... /ISSUED 734 PM EDT SAT AUG 1 2015/ AVIATION... AFTERNOON SHOWERS/TSTMS HAVE MOVED OFFSHORE AND SHOULD REMAIN OVER THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA THROUGH THE NIGHT AS SURFACE HIGH PRESSURE DRIFTS NORTH ACROSS THE AREA. ERRATIC WINDS THROUGH ABOUT 01Z ALONG THE EAST COAST AS OUTFLOW BOUNDARIES FROM EARLIER STORMS WILL PRODUCE LIGHT NW WINDS. OTHERWISE, EXPECT LIGHT S-SE WINDS OVERNIGHT WITH BKN/OVC MID AND HIGH CLOUDS PERSISTING. FOR SUNDAY, RIDGE OVER SOUTH FLORIDA WILL LIKELY LEAD TO A SLIGHTLY EARLIER ONSET OF EAST COAST SEABREEZE. MOVEMENT OF TSTMS ON SUNDAY WILL BE SLOWER THAN TODAY, AGAIN FOCUSING OVER THE INTERIOR, FAVORING EAST SIDE OF THE PENINSULA VS WEST. FOR NOW WILL KEEP VCTS FOR MOST OF SUNDAY AT EAST COAST SITES AND ONLY VCSH FOR NAPLES. BKN/OVC MID AND HIGH LEVEL CLOUDS WILL LINGER OVER THE REGION BUT VFR CONDITIONS SHOULD PREVAIL. /MOLLEDA PREV DISCUSSION... /ISSUED 415 PM EDT SAT AUG 1 2015/ DISCUSSION... CONVECTION CONTINUES ACROSS THE AREA THIS AFTERNOON WITH SIMILAR MESOSCALE CONDITIONS AS WAS SEEN YESTERDAY. MORNING SOUNDING PARAMETERS WERE RELATIVELY SIMILAR. A COUPLE OF EXCEPTIONS ARE THE MID LEVEL LAPSE RATES AND CAPE VALUES WHICH ARE A BIT LESS IMPRESSIVE TODAY WHEN COMPARED TO YESTERDAY. NEVERTHELESS...STILL EXPECT SCATTERED STRONG STORMS ACROSS MUCH OF THE AREA THROUGH THE LATE AFTERNOON HOURS WITH MOST OF THE CONVECTION EXPECTED TO BE FOCUSED ACROSS THE INTERIOR AND ATLANTIC COAST WITH GENERAL SOUTHWEST STEERING FLOW. STORMS WILL BE CAPABLE OF PRODUCING FREQUENT LIGHTNING...GUSTY WINDS...AND SMALL HAIL. CONVECTION SHOULD WANE LATER THIS EVENING WITH HEATING LOSS. HOWEVER...COULD STILL SEE A FEW LINGERING THUNDERSTORMS ACROSS THE WATERS DURING THE OVERNIGHT HOURS WITH BROAD TROUGHING ACROSS THE FLORIDA PENINSULA. TROUGHING ALONG WITH A DEEP MOISTURE AXIS POSITIONED ACROSS NORTH-CENTRAL FLORIDA WILL BE THE RULE THROUGH THE REMAINDER OF THE WEEKEND AND INTO THE FIRST PART OF NEXT WEEK. WEAKNESSES EMBEDDED WITHIN THE TROUGH WILL ENHANCE SHOWER AND THUNDERSTORM POTENTIAL EACH DAY. BY MONDAY...STEERING FLOW WILL TRANSITION TO A MORE SOUTHERLY TO SOUTHEASTERLY DIRECTION AS AN H5 LOW ACROSS CUBA SLIDES TO THE WEST. THIS WILL ALLOW CONVECTION TO BE FOCUSED MORE ACROSS THE INTERIOR AND GULF COASTAL AREAS THROUGH WEDNESDAY. MODELS THEN AGREE ON BUILDING DEEP LAYER RIDGING ACROSS THE WESTERN ATLANTIC FOR THE LATTER HALF OF THE WEEK...POSSIBLY BRINGING IN SOME SLIGHTLY DRIER AIR BY THE END OF THE WEEK. THIS HOWEVER SHOULD NOT RENDER ANY MAJOR PATTERN CHANGE FOR THIS TIME FRAME ASIDE FROM POSSIBLY A SLIGHT DECREASE IN OVERALL AFTERNOON SHOWER AND THUNDERSTORM COVERAGE. MARINE... CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PERSIST ACROSS THE AREA WATERS EACH DAY THROUGH THE PERIOD. SOUTHEASTERLY SURFACE WINDS AVERAGING AROUND 10 KNOTS SHOULD PREVAIL ACROSS THE ATLANTIC WATERS THROUGH THE WEEKEND AND INTO NEXT WEEK WITH SEAS AROUND 2 FEET OR LESS. WINDS ARE EXPECTED TO DECREASE ACROSS THE GULF WATERS AND BECOME MOSTLY LIGHT AND VARIABLE. EXPECT INCREASED WINDS AND SEAS IN AND NEAR ANY THUNDERSTORMS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 77 90 77 92 / 30 30 20 50 FORT LAUDERDALE 79 90 79 90 / 30 30 20 40 MIAMI 80 91 78 91 / 20 30 20 50 NAPLES 77 90 78 91 / 10 20 10 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ UPDATE...10/CD AVIATION...59/RM
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
227 PM EDT FRI JUL 31 2015 .NEAR TERM.../TODAY THROUGH SATURDAY/... SLOW MOVING COLD FRONT OVER CENTRAL GA HAS SE GA/NE FL IN A MOIST LOW-MID LEVEL SW FLOW. SCATTERED SHOWERS HAVE FORMED OVER NE FL EARLY THIS AFTERNOON WITH ACTIVITY EXPECTED TO INCREASE OVER SE GA BY LATE AFTERNOON/EARLY EVENING AS HRRR MODEL INDICATES. SW WINDS WILL KEEP EAST COAST SEABREEZE NEAR THE COAST TODAY WITH STORMS EXPECTED TO STRENGTHEN UPON BOUNDARY COLLISIONS. EXPECT A SIMILAR SCENARIO ON SATURDAY WITH SCATTERED CONVECTION BECOMING NUMEROUS LATE AFTERNOON/EVENING NEAR THE EAST COAST. TEMPERATURES WILL BE NEAR AVERAGE LEVELS THIS WEEKEND. && .SHORT TERM.../SATURDAY NIGHT THROUGH TUESDAY/... TROUGHING WILL PERSIST ACROSS THE REGION THROUGH MONDAY...PROVIDING AN ACTIVE WEATHER PATTERN WITH DAILY ROUNDS OF AFTERNOON AND EVENING SHOWERS AND STORMS. THESE STORMS WILL BE INITIATED BY THE COMBINATION OF CONVERGENCE ALONG THE TROUGH AND DIURNAL INSTABILITY. WITH THE INCREASED CLOUD AND RAIN COVERAGE TEMPERATURES WILL BE A LITTLE BELOW NORMAL THROUGH MONDAY. THE TROUGH WEAKENS...WITH SLIGHT RIDGING FOR TUESDAY. PRECIPITATION CHANCES WILL BE A LITTLE LESS AS A RESULT...WITH MAIN INITIATION SOURCES FOR CONVECTION BEING DIURNAL HEATING AND SEA BREEZE CONVERGENCE. TEMPERATURES WILL RETURN TO NEAR NORMAL READINGS FOR TUESDAY. && .LONG TERM.../TUESDAY NIGHT THROUGH FRIDAY/... WEAK RIDGING WILL PERSIST INTO WEDNESDAY. A TROUGH WILL SETTLE INTO THE SOUTHEASTERN US ONCE AGAIN THURSDAY...WITH PRECIPITATION CHANCES INCREASING TOWARD WEEKS END. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL FOR THIS PERIOD. && .AVIATION... VFR CONDITIONS WILL PREVAIL TODAY WITH TEMPO IFR CONDITIONS IN SHRA/TSRA UNTIL AROUND 00Z. IFR CONDITIONS AGAIN POSSIBLE LATE TONIGHT AND EARLY SATURDAY MORNING AS LOW CLOUDS FORM MAINLY BETWEEN 08Z-13Z. && .MARINE... SW WINDS WILL DOMINATE INTO EARLY NEXT WEEK AS COLD FRONT STALLS JUST NORTH OF THE AREA. EXCEPTION WILL BE AFTERNOON SEABREEZES NEAR THE COAST EACH DAY. NOCTURAL WINDS SURGES WILL LIKELY PRODUCE SCEC CONDITIONS. RIP CURRENTS: LOW RISK THROUGH THE WEEKEND WITH OFFSHORE WINDS. && .PRELIMINARY POINT TEMPS/POPS... AMG 73 92 73 91 / 40 70 50 40 SSI 75 86 76 89 / 30 60 50 50 JAX 74 88 74 88 / 30 60 50 60 SGJ 73 86 74 86 / 40 60 50 60 GNV 72 87 73 86 / 40 50 50 60 OCF 72 87 73 87 / 40 50 60 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ STRUBLE/ZIBURA
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
938 PM EDT SAT AUG 1 2015 .SYNOPSIS... A STATIONARY FRONT WILL DISSIPATE OVER OR NEAR THE AREA THROUGH SUNDAY AS HIGH PRESSURE BUILDS IN EARLY NEXT WEEK. AN INLAND LOW PRESSURE TROUGH WILL THEN DEVELOP BY LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... CONDITIONS WILL FAVOR THE FORMATION AND THEN A SLOW EXPANSION OF LOW STRATUS AND FOG EARLY SUNDAY. THE RISK FOR FOG WILL BE HIGHEST ACROSS FAR INTERIOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA CLOSEST TO THE WEAK STATIONARY FRONT...WHILE STRATUS IS MORE LIKELY CLOSER TO THE COAST WHERE INFLUENCES FROM THE NOCTURNAL LOW-LEVEL JET CURRENTLY ORGANIZING OFF THE GEORGIA BEACHES WILL BE GREATER. IT IS STILL SOMEWHAT UNCLEAR EXACTLY HOW WIDESPREAD EITHER ELEMENT WILL BECOME THIS FAR OUT...BUT THE 02/18Z NAM 1000 MB CONDENSATION PRESSURE DEFICIT PROGS WITH SUPPORT FROM THE LATEST RAP AND 21Z RUN OF THE NCEP TIME-LAGGED NORTH AMERICAN RAPID REFRESH ENSEMBLE SYSTEM /NARRE-TL/ ARE CERTAINLY TRENDING TOWARDS A FOGGIER SOLUTION ACROSS THE SOUTHERN SOUTH CAROLINA MIDLANDS...EAST-CENTRAL GEORGIA AND OUR FAR INLAND ZONES. WILL INCREASE THE FOG COVERAGE QUALIFIER FROM PATCHY TO AREAS OF ACROSS THE FAR INLAND TIER OF ZONES WITH PATCHY FOG ELSEWHERE...EXCEPT SOUTH AND EAST OF A SAVANNAH-LUDOWICI LINE WHERE NO MENTION OF FOG WILL BE INCLUDED. THERE CONTINUE TO BE SIGNALS IN THE VARIOUS HIGH RESOLUTION GUIDANCE THAT ISOLATED TO PERHAPS SCATTERED SHOWERS/TSTMS COULD REDEVELOP ALONG THE GEORGIA COAST AFTER 3-4 AM AS LOW-LEVEL JETTING INTENSIFIES AND INTERACTS WILL A MODEST AMOUNT OF INSTABILITY THAT LINGERS JUST OFFSHORE. THE RAP IS STILL MUCH MORE EMPHATIC ON THE REDEVELOPMENT OF DEEP CONVECTION PRIOR TO SUNRISE...WHILE THE H3R IS LESS SO. WILL MAINTAIN 20-40 PERCENT POPS ROUGHLY ALONG AND SOUTH OF HILTON HEAD-LUDOWICI LINE...HIGHEST ACROSS COASTAL MCINTOSH COUNTY...WITH DRY CONDITIONS ELSEWHERE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... SUNDAY THROUGH TUESDAY...OVERALL THE PATTERN WILL NOT CHANGE APPRECIABLY THROUGH EARLY NEXT WEEK. ALOFT...THE FORECAST AREA WILL BE POSITIONED ON THE SOUTHERN EXTENT OF TROUGHING ACROSS THE GREAT LAKES AND NORTHEAST. THIS WILL RESULT IN A RATHER WEAK AND NEBULOUS NEARLY ZONAL FLOW THROUGH THE PERIOD. AT THE SURFACE...THE NEARLY STATIONARY FRONT WILL DISSIPATE AND ITS REMNANTS WILL LINGER ALONG THE COASTLINE SUNDAY AND MONDAY. THIS WILL RESULT IN A RATHER TIGHT PWAT GRADIENT ACROSS THE FORECAST AREA...RANGING FROM AROUND 1.5 INCHES OR LESS AROUND ALLENDALE TO WELL OVER 2 INCHES OVER THE ATLANTIC COASTAL WATERS. BY TUESDAY THE DEEP MOISTURE WILL PUSH EVEN FURTHER OFFSHORE AND MUCH DRIER AIR WILL COVER ALL OF THE REGION. POPS FOR SUNDAY AND MONDAY ARE FOCUSED ALONG THE COAST AND OVER THE COASTAL WATERS...WITH FURTHER DECREASING COVERAGE BY TUESDAY. POPS MAY BE A BIT OVERDONE FURTHER INLAND AT TIMES...BUT IT WOULDN/T REQUIRE A SIGNIFICANT SHIFT IN THE DEEP MOISTURE AXIS TO WARRANT RAISING POPS. TEMPERATURES ARE PRETTY SIMILAR TO WHAT THEY HAVE BEEN FOR THE LAST FEW DAYS. LOW TO MID 90S SUNDAY AND MONDAY WITH A SLIGHT WARMING TREND BY TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... UPPER SHORTWAVE ENERGY WILL BEGIN MOVING INTO THE SOUTHEAST UNITED STATES MID TO LATE WEEK WITH A PRONOUNCED SURFACE TROUGH DEVELOPING INLAND. PWATS WILL RETURN TO A MORE TYPICAL 2" FOR EARLY AUGUST BY THURSDAY. A COLD FRONT MAY AFFECT THE AREA FRIDAY INTO SATURDAY. WE HAVE INCREASING POPS DURING THIS PERIOD AND SLIGHTLY MODERATED TEMPERATURES DUE TO THICKER CLOUD COVER. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... TSTM IMPACTS AT BOTH TERMINALS HAS ENDED. PRIMARY CONCERN OVERNIGHT IS THE POTENTIAL FOR FOG/STRATUS IMPACTING KCHS/KSAV. THE RISK FOR LOW STRATUS LOOKS HIGHEST AT KSAV AS LOW-LEVEL JETTING TAKES HOLD AN INTERACTS WITH RICH LOW-LEVEL MOISTURE WHILE FOG IS MORE LIKELY AT KCHS. THE DEGREE OF JETTING WILL ULTIMATELY DETERMINE HOW IMPACTFUL EITHER ELEMENT WILL BECOME AT THE TERMINALS. WILL CONTINUE TO TAKE A TRENDED YET CONSERVATIVE APPROACH WITH THE 00Z TAF CYCLE. WILL CALL FOR LOW-END MVFR CIGS 09-14Z WITH VERY LIGHT FOG AT KSAV...WHILE A TEMPO GROUP FOR MVFR VSBYS FROM 09-12Z WILL BE SHOWN AT KCHS. ADJUSTMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME MORE APPARENT LATER TONIGHT. ONCE FOG/STRATUS DISSIPATES...EXPECT VFR CONDITIONS. EXTENDED AVIATION OUTLOOK...LOW CHANCES FOR DIRECT IMPACTS FROM AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS. ALSO LOW CHANCES FOR PERIODS OF STRATUS/FOG AROUND SUNRISE. && .MARINE... TONIGHT...WINDS WILL INCREASE ACROSS THE WATERS TONIGHT AS LOW- LEVEL JETTING TAKES HOLD. BOTH WINDS AND SEAS COULD GET VERY CLOSE TO SMALL CRAFT ADVISORY THRESHOLDS OVER THE THE FAR EASTERN PORTIONS OF THE GEORGIA OFFSHORE ZONE...BUT THE DURATION OF SUCH CONDITIONS LOOK TO BE ABOUT 3-4 HOURS AT BEST. GIVEN THE RELATIVELY SMALL AREA IMPACTED...WILL CAP BOTH WINDS AND SEAS AT 20 KT AND SEAS 5 FT...OR JUST BELOW SMALL CRAFT ADVISORY THRESHOLDS...AND NOT HOIST AN ADVISORY WITH THIS FORECAST CYCLE. SUNDAY THROUGH THURSDAY...THE LINGERING WEAK FRONT WILL DISSIPATE ALONG THE COAST ON SUNDAY AND SOUTHWEST FLOW WILL GENERALLY PREVAIL ACROSS THE LOCAL WATERS THROUGH THE MIDDLE OF NEXT WEEK. AS AN INLAND TROUGH OF LOW PRESSURE DEVELOPS...THE PRESSURE GRADIENT WILL TIGHTEN AT TIMES AND LEAD TO PERIODS OF SURGING IN THE SOUTHWEST FLOW. WIND SPEEDS WILL GENERALLY TOP OUT IN THE 15-20 KT RANGE...BUT COULD MARGINALLY APPROACH SMALL CRAFT ADVISORY CRITERIA AT TIMES. SEAS WILL INCREASE IN THE IMPROVING SOUTHWEST FETCH AS WELL...INCREASING TO 2-4 FT WITHIN 20 NM AND MAINLY 4-5 FT BEYOND. 6 FT SEAS COULD BEGIN ACROSS THE OUTER GEORGIA WATERS STARTING MONDAY AND A SMALL CRAFT ADVISORY COULD BE NEEDED. && .TIDES/COASTAL FLOODING... TIDES WILL REMAIN ELEVATED THROUGH SUNDAY...BUT THEREAFTER WILL BEGIN TO DECREASE AS WE MOVE FURTHER AWAY FROM THE FULL MOON AND PERIGEE. SHALLOW COASTAL FLOODING APPEARS UNLIKELY AFTER SUNDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
742 PM EDT SAT AUG 1 2015 .SYNOPSIS... A STATIONARY FRONT WILL DISSIPATE OVER THE AREA THROUGH SUNDAY AS HIGH PRESSURE BUILDS IN EARLY NEXT WEEK. AN INLAND LOW PRESSURE TROUGH WILL THEN DEVELOP BY LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... MOST OF THE MEASURABLE RAINFALL HAS ENDED FOR THIS EVENING. A FEW LINGERING SHOWERS WILL IMPACT PARTS OF LONG AND TATTNALL COUNTIES THROUGH 8 PM. EXPECT DRY CONDITIONS TO PREVAIL FOR THE REST OF THE NIGHT FOR MOST AREAS. THERE ARE SIGNALS IN THE VARIOUS HIGH RESOLUTION GUIDANCE THAT ISOLATED TO PERHAPS SCATTERED SHOWERS/TSTMS COULD REDEVELOP ALONG THE GEORGIA COAST AFTER 3-4 AM AS LOW-LEVEL JETTING INTENSIFIES AND INTERACTS WILL A MODEST AMOUNT OF INSTABILITY THAT LINGERS JUST OFFSHORE. THE RAP IS MUCH MORE EMPHATIC ON THE REDEVELOPMENT OF DEEP CONVECTION PRIOR TO SUNRISE...WHILE THE H3R IS LESS SO. WILL SHOW POPS INCREASING TO 20-40 PERCENT DURING THIS TIME ROUGHLY ALONG AND SOUTH OF HILTON HEAD-LUDOWICI LINE...HIGHEST ACROSS COASTAL MCINTOSH COUNTY...WITH DRY CONDITIONS ELSEWHERE TO TREND. IF THE H3R BEGINS TO COME MORE IN LINE WITH THE LATEST RAP...THEN AN INCREASE IN POPS MAY BE IN ORDER LATER THIS EVENING. CONDITIONS WILL FAVOR THE FORMATION AND SLOW EXPANSION OF LOW STRATUS AND FOG EARLY SUNDAY AS LOW-LEVEL JETTING TAKES HOLD. THE RISK FOR FOG WILL BE HIGHEST ACROSS INTERIOR SOUTHEAST SOUTH CAROLINA CLOSEST TO THE WEAK STATIONARY FRONT...WHILE STRATUS IS MORE LIKELY FAR SOUTH AND CLOSER TO THE COAST. IT IS UNCLEAR EXACTLY HOW WIDESPREAD EITHER ELEMENT WILL BECOME THIS FAR OUT SO ADJUSTMENTS WILL LIKELY BE NEEDED THROUGHOUT THE NIGHT AS TRENDS BECOME MORE APPARENT. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... SUNDAY THROUGH TUESDAY...OVERALL THE PATTERN WILL NOT CHANGE APPRECIABLY THROUGH EARLY NEXT WEEK. ALOFT...THE FORECAST AREA WILL BE POSITIONED ON THE SOUTHERN EXTENT OF TROUGHING ACROSS THE GREAT LAKES AND NORTHEAST. THIS WILL RESULT IN A RATHER WEAK AND NEBULOUS NEARLY ZONAL FLOW THROUGH THE PERIOD. AT THE SURFACE...THE NEARLY STATIONARY FRONT WILL DISSIPATE AND ITS REMNANTS WILL LINGER ALONG THE COASTLINE SUNDAY AND MONDAY. THIS WILL RESULT IN A RATHER TIGHT PWAT GRADIENT ACROSS THE FORECAST AREA...RANGING FROM AROUND 1.5 INCHES OR LESS AROUND ALLENDALE TO WELL OVER 2 INCHES OVER THE ATLANTIC COASTAL WATERS. BY TUESDAY THE DEEP MOISTURE WILL PUSH EVEN FURTHER OFFSHORE AND MUCH DRIER AIR WILL COVER ALL OF THE REGION. POPS FOR SUNDAY AND MONDAY ARE FOCUSED ALONG THE COAST AND OVER THE COASTAL WATERS...WITH FURTHER DECREASING COVERAGE BY TUESDAY. POPS MAY BE A BIT OVERDONE FURTHER INLAND AT TIMES...BUT IT WOULDN/T REQUIRE A SIGNIFICANT SHIFT IN THE DEEP MOISTURE AXIS TO WARRANT RAISING POPS. TEMPERATURES ARE PRETTY SIMILAR TO WHAT THEY HAVE BEEN FOR THE LAST FEW DAYS. LOW TO MID 90S SUNDAY AND MONDAY WITH A SLIGHT WARMING TREND BY TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... UPPER SHORTWAVE ENERGY WILL BEGIN MOVING INTO THE SOUTHEAST UNITED STATES MID TO LATE WEEK WITH A PRONOUNCED SURFACE TROUGH DEVELOPING INLAND. PWATS WILL RETURN TO A MORE TYPICAL 2" FOR EARLY AUGUST BY THURSDAY. A COLD FRONT MAY AFFECT THE AREA FRIDAY INTO SATURDAY. WE HAVE INCREASING POPS DURING THIS PERIOD AND SLIGHTLY MODERATED TEMPERATURES DUE TO THICKER CLOUD COVER. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... TSTM IMPACTS AT BOTH TERMINALS HAS ENDED. PRIMARY CONCERN OVERNIGHT IS THE POTENTIAL FOR FOG/STRATUS IMPACTING KCHS/KSAV. THE RISK FOR LOW STRATUS LOOKS HIGHEST AT KSAV AS LOW-LEVEL JETTING TAKES HOLD AN INTERACTS WITH RICH LOW-LEVEL MOISTURE WHILE FOG IS MORE LIKELY AT KCHS. THE DEGREE OF JETTING WILL ULTIMATELY DETERMINE HOW IMPACTFUL EITHER ELEMENT WILL BECOME AT THE TERMINALS. WILL CONTINUE TO TAKE A TRENDED YET CONSERVATIVE APPROACH WITH THE 00Z TAF CYCLE. WILL CALL FOR LOW-END MVFR CIGS 09-14Z WITH VERY LIGHT FOG AT KSAV...WHILE A TEMPO GROUP FOR MVFR VSBYS FROM 09-12Z WILL BE SHOWN AT KCHS. ADJUSTMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME MORE APPARENT LATER TONIGHT. ONCE FOG/STRATUS DISSIPATES...EXPECT VFR CONDITIONS. EXTENDED AVIATION OUTLOOK...LOW CHANCES FOR DIRECT IMPACTS FROM AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS. ALSO LOW CHANCES FOR PERIODS OF STRATUS/FOG AROUND SUNRISE. && .MARINE... TONIGHT...VARIABLE WINDS THIS AFTERNOON TO BECOME SOUTHWEST AND STRENGTHEN THIS EVENING AS THE LOW-LEVEL JET INTENSIFIES AHEAD OF LOW PRESSURE OVER THE WESTERN FLORIDA PANHANDLE. THERE IS A CHANCE THAT SMALL CRAFT ADVISORY CONDITIONS DEVELOP OVER EASTERN PORTION OF THE OUTER GEORGIA WATERS CLOSER TO THE GULF STREAM BUT FOR NOW WE KEPT CONDITIONS JUST BELOW SUCH LEVELS /20 KT AND 5 FT/. SUNDAY THROUGH THURSDAY...THE LINGERING WEAK FRONT WILL DISSIPATE ALONG THE COAST ON SUNDAY AND SOUTHWEST FLOW WILL GENERALLY PREVAIL ACROSS THE LOCAL WATERS THROUGH THE MIDDLE OF NEXT WEEK. AS AN INLAND TROUGH OF LOW PRESSURE DEVELOPS...THE PRESSURE GRADIENT WILL TIGHTEN AT TIMES AND LEAD TO PERIODS OF SURGING IN THE SOUTHWEST FLOW. WIND SPEEDS WILL GENERALLY TOP OUT IN THE 15-20 KT RANGE...BUT COULD MARGINALLY APPROACH SMALL CRAFT ADVISORY CRITERIA AT TIMES. SEAS WILL INCREASE IN THE IMPROVING SOUTHWEST FETCH AS WELL...INCREASING TO 2-4 FT WITHIN 20 NM AND MAINLY 4-5 FT BEYOND. 6 FT SEAS COULD BEGIN ACROSS THE OUTER GEORGIA WATERS STARTING MONDAY AND A SMALL CRAFT ADVISORY COULD BE NEEDED. && .TIDES/COASTAL FLOODING... CURRENT TIDE TRENDS SUGGEST LEVELS COULD GET IN THE 6.9-7.0 FT MLLW RANGE AT THE CHARLESTON HARBOR WITH HIGH TIDE THIS EVENING. NOT YET CONFIDENT ENOUGH THAT 7.0 FT ADVISORY CRITERIA WILL BE BREACHED...SO HAVE ISSUED A COASTAL FLOOD STATEMENT TO ADDRESS VERY MINOR FLOODING ISSUES THAT ARE KNOWN TO OCCUR IN DOWNTOWN CHARLESTON WITH TIDES FALLING JUST SHORT OF 7.0 FT MLLW. THE NEED FOR A COASTAL FLOOD ADVISORY CONTINUES TO BE EVALUATED. TIDES WILL REMAIN ELEVATED THROUGH SUNDAY...BUT THEREAFTER WILL BEGIN TO DECREASE AS WE MOVE FURTHER AWAY FROM THE FULL MOON AND PERIGEE. SHALLOW COASTAL FLOODING APPEARS UNLIKELY AFTER SUNDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST
AREA FORECAST DISCUSSION
NWS LINCOLN IL
317 PM CDT FRI JUL 31 2015 .SHORT TERM...(TONIGHT) ISSUED AT 315 PM CDT FRI JUL 31 2015 19Z/2PM SURFACE ANALYSIS SHOWS WEAK COLD FRONT SETTLING INTO CENTRAL ILLINOIS...EXTENDING FROM NEAR RANTOUL TO JUST SOUTH OF QUINCY. MINIMAL CONVERGENCE ALONG THE FRONT AND AN OVERALL LACK OF DEEP LAYER MOISTURE HAS LARGELY PREVENTED CONVECTION. THE EXCEPTION HAS BEEN FURTHER NORTHEAST ACROSS NORTHERN INDIANA WHERE A FEW CLUSTERS OF THUNDERSTORMS HAVE DEVELOPED. HRRR CONTINUES TO OVER-EMPHASIZE DEWPOINT POOLING ALONG THE FRONT AND PRODUCES NUMEROUS THUNDERSTORMS WITH ITS 1 AND 2-HOUR FORECAST. MEANWHILE...THE RAPID REFRESH HAS CONSISTENTLY PRESENTED A MORE REALISTIC SCENARIO...SUGGESTING ONLY ISOLATED STORMS MAINLY ACROSS THE E/NE KILX CWA OVER THE NEXT 2-4 HOURS. GIVEN THIS IS THE LOCATION WHERE CU-FIELD IS CURRENTLY MOST PRONOUNCED...WILL CONTINUE TO FOLLOW THIS SOLUTION CLOSELY. AS A RESULT...WILL CARRY SLIGHT CHANCE POPS ALONG/NORTHEAST OF A CHAMPAIGN TO MARSHALL LINE THROUGH THE AFTERNOON. ANY ISOLATED CONVECTION THAT DEVELOPS WILL QUICKLY DISSIPATE TOWARD SUNSET...FOLLOWED BY MOSTLY CLEAR AND DRY CONDITIONS TONIGHT. SLIGHTLY DRIER AIRMASS WILL TRICKLE IN FROM THE NORTHWEST ONCE THE FRONT PASSES...WITH OVERNIGHT LOW TEMPERATURES DROPPING INTO THE LOWER TO MIDDLE 60S. && .LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 315 PM CDT FRI JUL 31 2015 OVERALL A FAIRLY PERSISTENT WNW FLOW PATTERN WILL REMAIN ACROSS IL AND MUCH OF THE MIDWEST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. QUITE A BIT OF MODEL UNCERTAINTY REGARDING A BREAKDOWN OF THE WESTERN RIDGE AND DEEPENING OF THE EASTERN TROUGH FOR THE MIDDLE OF NEXT WEEK. IN THE NEAR TERM...VERY WARM AND INCREASINGLY HUMID CONDITIONS WILL BE ON TAP FOR CENTRAL AND EASTERN IL SATURDAY. AN ADVANCING WARM FRONT AND A CLUSTER OF CONVECTION FROM IOWA/NEBRASKA IS EXPECTED TO APPROACH AREAS WEST OF THE IL RIVER VALLEY LATE SATURDAY NIGHT AND INTO SUNDAY MORNING. THE REMNANTS OF THE EARLY MORNING T-STORMS ARE THEN EXPECTED TO SPREAD ACROSS MOST OF CENTRAL AND EASTERN IL SUNDAY MORNING AND EARLY AFTERNOON. RESIDUAL BOUNDARIES FROM THIS CONVECTION SHOULD RESULT IN REDEVELOPMENT OF T-STORMS SUNDAY AFTERNOON AND INTO THE EVENING...ESPECIALLY ALONG AND NORTH OF I-74. SOME OF THE STORMS LATER IN THE DAY SUNDAY COULD BE STRONG...MAINLY DUE TO MODERATE LEVELS OF WIND SHEAR AND INSTABILITY. MOST OF THE FORECAST AREA WILL BE IN THE WARM SECTOR OF AN ADVANCING FRONTAL BOUNDARY...YIELDING VERY WARM AND SOMEWHAT HUMID CONDITIONS MONDAY. THE AFOREMENTIONED FRONT IS EXPECTED TO SLOWLY MOVE INTO CENTRAL ILLINOIS MONDAY NIGHT AND THEN REMAIN NEARLY STATIONARY FOR MUCH OF THE WEEK. THIS SHOULD RESULT IN A RATHER UNSETTLED WEATHER PATTERN WITH THE POTENTIAL FOR SEVERAL PERIODS OF RAIN FROM LATE MONDAY...ON AND OFF...THROUGH THE END OF THE WEEK. THE UNCERTAINTY IN THE MODELS REVOLVES AROUND THE DETAILS OF POSSIBLE SHORTWAVE ENERGY BREAKING THROUGH THE WESTERN U.S. RIDGE AND INTERACTING WITH THE FRONT. THE GFS IS A BIT MORE AGGRESSIVE WITH THIS THAN THE EUROPEAN MODEL. HOWEVER...THE EUROPEAN NOT ONLY UNDERPLAYS THE AFFECTS OF THIS BUT KEEPS THE SURFACE FRONT FARTHER NORTH. UNTIL THE DETAILS ARE WORKED OUT IT IS HARD TO PIN DOWN WHERE A THREAT OF PERSISTENT...POSSIBLY HEAVY RAIN MAY SET UP THE MIDDLE OF NEXT WEEK. THUS...WILL NOT MAKE TOO MANY MAJOR CHANGES TO THE FORECAST AND KEEP CHANCE POPS FOR THUNDERSTORMS ACROSS A LARGE PART OF THE FORECAST AREA. THE ONE THING THE MODELS DO AGREE ON IS THAT WITH THE PERIODS OF CONVECTION AND RESIDUAL CLOUD COVER...TEMPERATURES SHOULD BE BELOW SEASONAL NORMALS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1255 PM CDT FRI JUL 31 2015 WEAK COLD FRONT CONTINUES TO SAG SOUTHWARD INTO NORTH-CENTRAL ILLINOIS EARLY THIS AFTERNOON. CU-FIELD REMAINS LARGELY ABSENT ALONG THE BOUNDARY THUS FAR...EXCEPT ACROSS NORTHERN INDIANA INTO NORTHEAST ILLINOIS. THIS CLOUD TREND FITS VERY WELL WITH THE RAPID REFRESH...WHICH SHOWS WIDELY SCATTERED CONVECTION DEVELOPING ACROSS THIS AREA OVER THE NEXT COUPLE OF HOURS...WHILE KEEPING THE REMAINDER OF THE FRONTAL BOUNDARY TOTALLY DRY. AS A RESULT...WILL ONLY MENTION VCTS AT KCMI BETWEEN 18Z AND 22Z. FEW-SCT DIURNAL CLOUDS ALONG/AHEAD OF THE FRONT WILL QUICKLY DISSIPATE TOWARD SUNSET...WITH CLEAR SKIES EXPECTED TONIGHT THROUGH SATURDAY MORNING. WINDS WILL INITIALLY BE FROM THE NORTHWEST GUSTING TO BETWEEN 15 AND 18KT THIS AFTERNOON...THEN WILL BECOME WESTERLY AT LESS THAN 5KT TONIGHT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...MILLER AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1129 PM CDT THU JUL 30 2015 .UPDATE... ISSUED AT 1126 PM CDT THU JUL 30 2015 HAVE ADDED ISOLATED STORM WORDING FAR SW SECTIONS EARLY FRI MORNING FOR A FEW HOURS. CONVECTION CONTINUES TO CYCLE ACROSS ERN NE AND JUST WILL NOT GO AWAY. LATEST SPC MESOANALYSIS SHOWS 1-2K J/KG MUCAPES WITH LESS THAN 50 J/KG CINHS IN ZONE OF INCREASING H85/H7 THETA-E ADVECTION. SEEMS TO BE SOME KINEMATIC CONTRIBUTION AS WELL DUE TO LIFT WELL AHEAD OF FAR NRN ND/MN SHORT WAVE NOTED IN WATER VAPOR IMAGERY. STORMS COULD JUST TOUCH STRONG LIMITS AT TIMES WITH 30KTS OF EFFECTIVE SHEAR AND DECENT DCAPES. && .SHORT TERM /TONIGHT/... ISSUED AT 357 PM CDT THU JUL 30 2015 SURFACE HIGH WILL REMAIN IN PLACE OVER FAR SOUTHERN IOWA TONIGHT WHILE ALOFT WE WILL REMAIN IN NORTHWEST FLOW. THE NAM IS SUGGESTING A SUBTLE SHORTWAVE CROSSING SOUTHWEST IOWA OVERNIGHT AS A WEAK COLD FRONT SINKS INTO THE NORTHWEST QUARTER OR SO OF THE STATE. THERE IS SOME POSSIBILITY THAT A SPRINKLE OR TWO COULD BE ASSOCIATED WITH EITHER OF THESE FEATURES BUT INSTABILITY IS RATHER MINIMAL AND FORCING IS TIED MORE TO THE FRONTAL BOUNDARY THAN THE SUBTLE WAVE ACROSS THE SOUTH...WHERE THE BETTER INSTABILITY LIES. CONFIDENCE AS TO WHERE ANY PRECIP MAY OCCUR IS VERY LOW AND AS SUCH I DO NOT HAVE A MENTION OF POPS IN THE FORECAST. HI-RES CONVECTION ALLOWING MODELS ARE IN POOR AGREEMENT AS WELL AS THE HRRR CURRENTLY IS FORECASTING SHOWERS ACROSS THE NORTHERN HALF OF IOWA WHERE THERE ARE BARELY A FEW CLOUDS. THE NAM 12 HAS SPITS OF PRECIP OVER BOTH THE SOUTH AND NORTHWEST WHILE THE OTHER MODELS DO THIS OVER THE SOUTH. COVERAGE WOULD BE SPARSE AND POPS MAY NEED TO BE ADJUSTED IN LATER SHIFTS IF SOMETHING IS ABLE TO DEVELOP. AS FOR TEMPS...NORTHWEST IOWA SHOULD BE THE COOLEST AS THE FRONT WILL BE THROUGH THEM BUT IT IS DOUBTFUL THAT IT WILL MAKE IT TOO FAR INTO OUR FORECAST AREA BY 12Z. AS A RESULT I HAVE KEPT LOWER 60S NORTH TO MID 60S SOUTH FOR TONIGHT`S LOWS. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 357 PM CDT THU JUL 30 2015 GENERAL PREMISE OF LONG TERM LOOKING SIMILAR TO YESTERDAY/S OUTPUT. DIFFERENCE IS THAT TODAY/S RUNS ARE A LITTLE MORE AMPLIFIED AND CONFIDENCE INCREASED IN MULTIPLE ROUND OF PRECIP OF THE NEXT SEVEN DAYS. FROM 12Z UNTIL 18Z FRIDAY...A WEAK BOUNDARY WILL BE PASSING THROUGH OUR CWA FROM NW TO SE. PWATS WITH THIS BOUNDARY BARELY GO ABOVE 1 INCH AND MOISTURE CONV AT THE SFC IS MINIMAL. TIME OF DAY ALSO TYPICALLY NOT FAVORABLE FOR CONVECTION. THEREFORE...AM KEEPING CWA DRY WITH THIS BOUNDARY PASSAGE. EXPECT ANOTHER MAINLY CLOUD- FREE DAY WITH 850MB TEMPS IN THE 17C TO 20C RANGE TO MIX DOWN AND YIELD MID TO UPPER 80S. FRIDAY EVENING INTO SATURDAY MORNING...THE AFOREMENTIONED BOUNDARY LOOKS TO LINGER IN NORTHERN MISSOURI TO NORTHEASTERN NEBRASKA AND WILL SERVE AS THE FOCUSING MECHANISM FOR EVENING CONVECTION...ESPECIALLY IN NORTHEASTERN NEBRASKA. CORFIDI VECTORS SUGGEST STORM MOVEMENT WILL BE TO THE SE...WITH ANY RIGHT-MOVERS MOVING MORE SOUTHERLY. WITH ENOUGH INSTABILITY PRESENT IN SOUTHERN IOWA AHEAD OF THESE STORMS...IT SEEMS PLAUSIBLE ANY OUTFLOW BOUNDARIES WILL PROPAGATE IN A NE/E DIRECTION INTO SOUTHERN IOWA...POSSIBLY CLIPPING OUR SW COUNTIES. THEREFORE HAVE SOME SLIGHT POPS GOING IN OUR SOUTH WHICH CAN OBVIOUSLY BE TWEAKED IN NEXT UPDATES. SATURDAY LOOKS TO BE DRY...BUT THE NEXT PRECIP CHANCES FOR ARRIVE LATE EVENING INTO THE OVERNIGHT PERIOD FOR SUNDAY MORNING. MODELS NOW VERY CONSISTENT IN PRODUCING A SIZABLE MCS OVER SE SOUTH DAKOTA AND PROPAGATING THIS MCS SOUTHEASTWARD THROUGH THE CENTRAL TO WESTERN PORTIONS OF OUR CWA. GFS SEEMING TO BE A FAST OUTLIER...SO LEANED AWAY FROM IT FOR TIMING PURPOSES. AM STARTING TO SEE HEAVY RAINFALL SIGNATURE AS SHORT TERM MODELS PLACING A SLUG OF 2 TO 2.25 INCH PWATS WITH THIS MCS...MIXING RATIOS OVER 8 J/KG...AND 0 TO 6 MU CAPE OVER 1500 J/KG. IN FACT THE 18Z NAM HAD PWATS OVER 2.5 INCHES...SO RECENT MODEL TRENDS CERTAINLY POINTING UPWARDS. BEYOND SUNDAY...YESTERDAY/S LONG TERM MODELS HINTED AT A BAROCLINIC ZONE TRYING TO ESTABLISH ITSELF OVER OUR SOUTHERN CWA THROUGH MID WEEK. REGION TO REMAIN IN WESTERLY TO NORTHWESTERLY FLOW ALOFT...SUGGESTING AN OVERALL PATTERN OF SHORTWAVE PROPAGATION THROUGH IOWA. TODAY/S MODEL RUNS YIELD A SIMILAR SETUP TO YESTERDAY/S...WITH THE MAIN DIFFERENCE BEING HIGHER PWATS IN THE 1.5 INCH RANGE OR SO OVER MUCH OF OUR CWA. THUS...HAVE INCREASED POPS FURTHER NORTH FROM YESTERDAY AND UPPED CONFIDENCE SLIGHTLY. INTERESTING THAT THE GFS...WHICH OFTEN HAS A DRY BIAS...IS PRODUCING SO MUCH MOISTURE IN IOWA. IF UPWARD TREND CONTINUES...NEXT WEEK COULD BE WET. WITH EXPECTED CLOUD COVER...BEGUN TO TRIM DIURNAL RANGE...SLIGHTLY LOWERING MAX TEMPS AND INCREASING MIN TEMPS. && .AVIATION...31/06Z ISSUED AT 1126 PM CDT THU JUL 30 2015 UNLESS CONDITIONS CHANGE SOON...EXPECT VFR CONDITIONS ACROSS TAFS AND NO THUNDER WITH ERN NE CONVECTION STAYING SW OF SITES. CONVECTION SEEMS TO HAVE CYCLED DOWN AND THEN BACK OUT OF NOWHERE RECENTLY HOWEVER...SO CONFIDENCE IN THAT HAS DECREASED SOMEWHAT. OTHERWISE EXPECT NOTHING MORE THAN SCT MID CLOUDS AND GENERALLY LIGHT WINDS EVENTUALLY VEERING TO NWLY DURING FRI PEAK HEATING MIXING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...SMALL SHORT TERM...FAB LONG TERM...KOTENBERG AVIATION...SMALL
...UPDATE TO AVIATION FORECAST DISCUSSION AND NEAR TERM CONVECTIVE
FORECAST...
.UPDATE... ISSUED AT 715 PM CDT SAT AUG 1 2015 ISOLATED THUNDERSTORMS HAVE BEEN ABLE TO DEVELOP NEAR CNK AND ALSO EMP IN AREAS OF WEAK CONVERGENCE. A FEW MORE STORMS MAY DEVELOP MAINLY IN THE AREA NEAR/SOUTH OF I-35 AND WILL BE CLOSELY WATCHING WELL FORMED OUTFLOW BOUNDARIES MOVING WEST INTO EASTERN KANSAS. HOWEVER...WHILE LOW LEVEL LAPSE RATES ARE STEEP, THE MID LEVELS HAVE VERY WEAK LAPSE RATES ALONG WITH DRY AIR. VISUAL APPEARANCE OF CB NEAR EMP/UKL ARE INDICATIVE OF THIS WEAKNESS IN THE MID LEVEL BUOYANCY AND EXPECT ANY FURTHER TS DEVELOPMENT TO BE POSSIBLE...BUT TO STRUGGLE TO ORGANIZE IN ANY WAY. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 326 PM CDT SAT AUG 1 2015 19Z WATER VAPOR IMAGERY SHOWS NORTHWEST FLOW ACROSS THE NORTHERN AND CENTRAL PLAINS WHILE THE CENTER OF A MID LEVEL RIDGE SITS OVER WEST TX. THE RIDGE AXIS EXTENDED NORTHWEST INTO OR. THE RAP ANALYSIS SUGGESTS THERE ARE ONLY A COUPLE WEAK VORT MAXIMUM UPSTREAM. ONE OVER EASTERN NEB AND ANOTHER MOVING INTO SD. AT THE SURFACE, A MESO HIGH REMAIN OVER CENTRAL NEB WHILE OUTFLOW BOUNDARIES FROM MORNING CONVECTION HAVE BECOME MORE DIFFUSE ACROSS CENTRAL AND EASTERN KS. FOR THIS AFTERNOON AND THIS EVENING, THERE REMAINS AN OUTSIDE CHANCE FOR A STORM TO DEVELOP AS OBJECTIVE ANALYSIS SHOWS MORE THAN ENOUGH INSTABILITY. HOWEVER SURFACE FLOW HAS BEEN RATHER WEAK SO CONVERGENCE AND LIFT ALONG ANY OF THE BOUNDARIES HAS ALSO BEEN RATHER WEAK. SATELLITE SHOWS LITTLE DEVELOPMENT TO THE CU FIELD ACROSS THE AREA INDICATING THERE HASN`T BEEN MUCH FORCING AS WELL. AND ANY WEAK VORTICITY ADVECTION FROM THE LEFT OVER CONVECTION IN EASTERN NEB IS LIKELY PROPAGATING INTO MO. BECAUSE OF THIS THINK THE CHANCES FOR ANY SPOT TO RECEIVE RAIN IS ONLY ABOUT 10 PERCENT AND NOT HIGH ENOUGH TO MENTION IN THE FORECAST. ONCE THE BOUNDARY LAYER STARTS TO COOL, THE THREAT FOR THUNDERSTORMS SHOULD DIMINISH. OVERNIGHT, MODELS SHOW THE LOW LEVEL JET SETTING UP ACROSS NEB AND IA WITH NO REAL ORGANIZED ISENTROPIC LIFT ACROSS THE FORECAST AREA. BECAUSE OF THIS HAVE A DRY FORECAST GOING THROUGH THE NIGHT. THERE SHOULD BE MOSTLY CLEAR SKIES, SO THINK WITH SOME RADIATIONAL COOLING LOWS WILL FALL INTO THE UPPER 60S TO AROUND 70. FOR SUNDAY, THE SETUP LOOKS VERY SIMILAR TO TODAY WITH DECENT SURFACE BASED INSTABILITY DEVELOPING AND NOT MUCH INHIBITION TO CONVECTION. WITH A LACK OF LARGE SCALE FORCING, PRECIP CHANCES LOOK UNLIKELY UNTIL A TROUGH AXIS APPROACHES NORTH CENTRAL KS LATE IN THE DAY. MOST MODEL SOLUTIONS SHOW THIS BOUNDARY MOVING INTO THE FORECAST AREA LATE IN THE AFTERNOON BUT THE GFS IS REALLY THE ONLY ONE THAT DEVELOPS CONVECTION. THE GFS ALSO IS THE WARMEST SOLUTION AND MAY BE A LITTLE EAGER TO BREAK WHAT CAP THERE IS. WHILE PRECIP CHANCES DON`T LOOK GREAT, IT`S DIFFICULT TO RULE OUT A CHANCE SO HAVE SLIGHT CHANCE POPS IN THE FORECAST FOR THE LATE AFTERNOON. WITH 850 TEMPS SLIGHTLY WARMER THAN TODAY, HAVE HIGHS A DEGREE OR SO WARMER WITH GENERALLY MID 90S EXPECTED. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 326 PM CDT SAT AUG 1 2015 SUNDAY EVENING WILL CONTINUE TO KEEP LOW PRECIPITATION CHANCES ALONG THE WEAK FRONTAL BOUNDARY AS WELL AS THE INSTABILITY AXIS ACROSS THE NORTHERN CWA. WILL LITTLE TO NO UPPER SUPPORT AND WEAK SURFACE CONVERGENCE EXPECT ANY CONVECTION TO BE ON THE WANE AFTER SUNSET. LOWS SUNDAY NIGHT WILL COOL INTO THE UPPER 60S TO LOWER 70S. MONDAY FOR MUCH OF THE DAY LOOKS DRY WITH INCREASING CHANCES FROM LATE AFTERNOON THROUGH EARLY MORNING HOURS ON TUESDAY ESPECIALLY NEAR THE NEBRASKA BORDER NEAR THE VICINITY OF THE SURFACE FRONTAL BOUNDARY IN SOUTHERN NEBRASKA. LOW LEVEL JET WILL INCREASE FROM THE SOUTH AND SOUTHWEST MONDAY NIGHT BEFORE WEAKENING TUESDAY MORNING. MODELS CONTINUE TO SHOW MID LEVEL SHORTWAVE MOVING THROUGH THE PLAINS TUESDAY AND TUESDAY NIGHT. WEDNESDAY THROUGH SATURDAY WILL BE MARKED BY COOLER TEMPERATURES WITH PRECIPITATION CHANCES OFF AND ON AS WAVES MOVE THROUGH THE NEARLY ZONAL FLOW ACROSS THE CENTRAL PLAINS. HIGH PRESSURE NOSES INTO EASTERN KANSAS ON THURSDAY WITH A FRONTAL BOUNDARY SOUTH OF THE FORECAST AREA. APPROACHING SHORTWAVE TROUGH AND INCREASING ISENTROPIC LIFT OVER THE FRONT WILL KEEP A CHANCE FOR ELEVATED THUNDERSTORMS THURSDAY NIGHT THEN CONTINUE ON FRIDAY WITH PASSAGE OF THE UPPER TROUGH. COOLER HIGH PRESSURE BUILDS IN SATURDAY. COOLER HIGH TEMPERATURES ARE EXPECTED FROM WEDNESDAY THROUGH SATURDAY IN THE 80S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 715 PM CDT SAT AUG 1 2015 VFR CONDITIONS ARE LIKELY THROUGH THE TAF WITH SOUTHWEST WINDS INCREASING TO 10-15 KTS BY LATE MORNING ON SUNDAY. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARJENBRUCH SHORT TERM...WOLTERS LONG TERM...53 AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
558 PM CDT FRI JUL 31 2015 ...UPDATE TO NEAR TERM CONVECTIVE FORECAST... .UPDATE... ISSUED AT 551 PM CDT FRI JUL 31 2015 MADE VERY LITTLE CHANGE TO THE ONGOING FORECAST. WHILE THUNDERSTORMS ARE ONGOING IN NEBRASKA WITH A STRONG SOUTHERLY COMPONENT TO THE MOTION, INSTABILITY DECREASES SHARPLY WITH APPROACH TOWARD THE KANSAS BORDER. THE MAIN INSTABILITY AXIS SEEMS TO RUN FROM SOUTHEAST NEBRASKA INTO NORTHWEST MISSOURI SO COULD SEE SOME THUNDERSTORM ACTIVITY CLIP NORTHERN AND PARTICULARLY NORTHEAST PARTS OF THE FORECAST AREA THIS EVENING. THE HRRR IS VERY AGGRESSIVE WITH THUNDERSTORM COVERAGE (AS IT CAN BE AT TIMES OF WEAK FORCING) AND BELIEVE IT IS LIKELY OVERDONE WITH THE OVERALL COVERAGE AND PERSISTENCE OF THE STORM ACTIVITY INTO KANSAS. AT THE SAME TIME...A STRONG COLD POOL HAS DEVELOPED FROM NORTHERN STORMS AND WILL LIKELY WEAKEN AS IT MOVES INTO NORTHERN KS...POSSIBLY STRONG ENOUGH TO KICK OFF ANOTHER STORM OR TWO. BOTTOM LINE...STORM CHANCES THIS EVENING REMAIN LOW AND FOCUSED OVER NORTHERN AND PERHAPS NORTHEAST KANSAS. IF ANYTHING DEVELOPS INTO THE AREA THERE IS A VERY SMALL CHANCE FOR IT TO PRODUCE MARGINALLY SEVERE HAIL OR LOCALLY DAMAGING WINDS. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 335 PM CDT FRI JUL 31 2015 THUNDERSTORMS WERE DEVELOPING IN THE MOISTURE AND INSTABILITY AXIS ALONG AN OLD OUTFLOW BOUNDARY IN NORTHERN AND EASTERN NEBRASKA THIS AFTERNOON AT 20Z. FORECAST SHEAR THIS EVENING ACROSS NORTHEAST KANSAS IS MARGINAL IN THE 25 TO 30 KT RANGE WITH MLCAPE FORECAST IN THE 1000-2000 J/KG RANGE. CONVECTION IN NEBRASKA IF IT HOLDS TOGETHER WOULD TRACK SOUTHEAST INTO NORTHEAST KANSAS THIS EVENING. WITH LACK OF UPPER FORCING AND THE FOCUS FOR INSTABILITY AND MOISTURE NORTH IN NEBRASKA WILL KEEP SMALL CHANCES OF PRECIPITATION ACROSS THE NORTHERN COUNTIES FOR THE EVENING HOURS. LOWS SHOULD FALL INTO THE UPPER 60S TO LOW 70S. SATURDAY...MODELS DEVELOP SCATTERED SHOWERS AND THUNDERSTORMS DURING THE LATE AFTERNOON ACROSS NEBRASKA AND THEN SOUTHEAST INTO SOUTHWEST IOWA, NORTHWEST MISSOURI AND FAR NORTHEAST KANSAS AHEAD OF A WEAK SHORTWAVE TROUGH. WILL KEEP A SMALL CHANCE OF THUNDERSTORMS NEAR THE NEBRASKA BORDER IN THE LATE AFTERNOON HOURS. HIGHS A LITTLE WARMER IN THE LOW TO MID 90S. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 335 PM CDT FRI JUL 31 2015 SATURDAY NIGHT T0 MONDAY... ANOTHER WAVE IS FCST TO SLIDE SE ACROSS THE REGION SAT NIGHT WHICH SHOULD BRING ANOTHER ROUND OF STORMS TO PARTS OF NE/IA/MO AND PERHAPS CLIPPING FAR NORTHEAST KS WITHIN THE LOW LEVEL WAA REGIME. STRONGEST FORCING SHOULD REMAIN NE OF THE AREA SO WILL ONLY KEEP LOWER CHC POPS FOR SAT NIGHT. BY SUNDAY SFC LOW PRESSURE WILL SLIDE INTO WI WITH A COLD FRONT FCST TO SAG INTO THE STATE BY PEAK HEATING. WILL LEAVE SLIGHT CHCS IN THE FCST FOR THE NORTHERN HALF NEAR THE FRONT ON SUNDAY FOR RISK OF ISOLATED THUNDER IN THE EVENING. BETTER CHANCES FOR STORMS WOULD APPEAR TO ARRIVE BY MONDAY NIGHT AND BEYOND AS MID/UPPER WAVES MOVE ACROSS THE ROCKIES INTO THE PLAINS AND INTERACT WITH A FRONTAL BOUNDARY IN THE VICINITY. MONDAY NIGHT TO FRIDAY... UPPER LEVEL NORTHWEST FLOW CONTINUES AS A SHORTWAVE MOVES OVER NORTHERN KANSAS MONDAY NIGHT TO TUESDAY MORNING. THIS SHORTWAVE IS PROGGED TO EXIT THE AREA BY TUESDAY AFTERNOON, BEFORE ANOTHER CHANCE FOR PRECIPITATION IS SEEN TUESDAY TO WEDNESDAY MORNING ASSOCIATED WITH ANOTHER PASSING SHORTWAVE. WITH NORTHWEST FLOW CONTINUING THROUGH THE END OF THE PERIOD, SLIGHT CHANCES FOR STORMS REMAIN UNTIL FRIDAY. HIGHS REMAIN IN THE LOW TO MID 90S THROUGH THURSDAY, WITH A SLIGHT COOL DOWN FRIDAY DUE TO A SURFACE FRONTAL PASSAGE. LOWS STAY MILD IN THE UPPER 60S/LOW 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1240 PM CDT FRI JUL 31 2015 VFR TO CONTINUE THROUGH THE PERIOD. SHOULD BE MIXED ENOUGH TO PREVENT VISIBILITY RESTRICTIONS LATE TONIGHT. CONVECTION IS EXPECTED TO REMAIN TO THE NORTH AND EAST OF THE TERMINALS. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARJENBRUCH SHORT TERM...53 LONG TERM...HELLER/OMITT AVIATION...53
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
339 PM CDT FRI JUL 31 2015 ...UPDATED LONG TERM SECTION... .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 1226 PM CDT FRI JUL 31 2015 THE SUMMER SUBTROPICAL RIDGE WAS CENTERED OVER ITS CLIMATOLOGICAL POSITION FROM THE SOUTHERN ROCKIES INTO TEXAS TODAY. IN THE UPPER TROPOSPHERE, WEST NORTHWEST FLOW EXTENDED FROM THE NORTHERN ROCKIES THROUGH THE UPPER MISSISSIPPI VALLEY. WESTERN KANSAS WAS ON THE SOUTH EDGE OF THE WESTERLIES AT 250MB. THE MESOSCALE CONVECTIVE SYSTEM (MCS) THAT AFFECTED EXTREME SOUTHWEST KANSAS OVERNIGHT AND THIS MORNING WAS DECREASING IN AREAL EXTENT AND MOVING VERY SLOWLY TO THE EAST-SOUTHEAST...FOLLOWING ROUGHLY THE 3-8KM AGL MEAN FLOW VECTOR (JUST NORTH OF THE CENTER OF THE MEAN ANTICYCLONE IN THIS LAYER OVER WEST TEXAS). A COUPLE OF MESOSCALE CONVECTIVE VORTICITY MAXIMAS COULD BE IDENTIFIED THROUGH VISIBLE SATELLITE AND EVEN THE HOURLY RAP ANALYSIS FROM NEAR TUCUMCARI NEW MEXICO TO NEAR SPRINGFIELD COLORADO. IT WOULD APPEAR AS OF THESE MESOSCALE FEATURES WERE ACTUALLY HELPING TO MAINTAIN THE SMALL MCS THROUGH THE EARLY AFTERNOON HOURS AS THE LEADING EDGE OF IT WAS MOVING INTO THE FAR EASTERN OK-TX PANHANDLES. THE VERY NORTHERN EXTENT OF THIS MCS EXTENDED INTO MORTON AND SEWARD COUNTIES, WHICH WAS HAVING AN IMPACT ON SURFACE TEMPERATURES (COOLER THAN FORECAST IN THIS AREA). WE HAVE ADJUSTED THE DAYTIME TEMPERATURES DOWNWARD ACROSS FAR SOUTHWEST KANSAS AS A RESULT. ELSEWHERE...ESPECIALLY ACROSS WEST CENTRAL AND CENTRAL KANSAS NORTH OF HIGHWAY 96, TEMPERATURES SHOULD TOP OUT IN THE LOWER TO MID 90S. AS WE GO IN TO TONIGHT...ANOTHER SMALL MCS SHOULD EVOLVE THROUGH THE LATE NIGHT HOURS FROM CONVECTION ACROSS THE HIGHER TERRAIN OF THE RATON MESA REGION. THIS CONVECTION SHOULD FOLLOW THE SAME GENERAL TRACK AS THIS MORNINGS MCS, SO WE WILL KEEP THE BEST POPS ACROSS FAR SOUTHWEST KANSAS AGAIN IN THE 40-50 PERCENT RANGE. THE BULK OF LATE TONIGHT/TOMORROWS MCS SHOULD REMAIN ACROSS THE PANHANDLES REGION. IT SHOULD BE CLOSE TO A RINSE AND REPEAT TYPE OF DEAL TOMORROW WITH A SLOWLY DECAYING MCS SOMEWHERE JUST SOUTH OF OUR FORECAST AREA (OR PERHAPS CLIPPING MORTON-SEWARD-MEADE) WITH WARMEST TEMPERATURES UP NORTH ALONG I-70 (MID 90S) AND COOLEST TEMPERATURES ALONG THE OK BORDER (LOWER-MID 80S, IF EVEN THAT WARM). .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 338 PM CDT FRI JUL 31 2015 THE BEST CHANCE FOR THE NEXT ORGANIZED PRECIPITATION EVENT WILL BE MONDAY NIGHT INTO TUESDAY. THE GLOBAL SPECTRAL MODELS CONTINUE TO SHOW AN INTERACTION BETWEEN MONSOON PERTURBATIONS MOVING NORTHWARD THROUGH THE DESERT SOUTHWEST...AND AN INCOMING SUBTROPICAL PACIFIC JET MOVING INTO THE INTERMOUNTAIN WEST REGION. THIS WILL ACT TO SHIFT THE MONSOON CIRCULATION NORTHEASTWARD SOME...ENHANCING THE PRECIPITATION POTENTIAL FOR SOUTHWEST KANSAS. IT VERY WELL COULD BE JUST ONE BIG MCS WE SEE OUT OF THIS EVENT, IN WHICH CASE IF THE ECMWF HAS A HANDLE ON THINGS, WOULD BE MONDAY NIGHT. THIS IS WHEN THE HIGHEST POPS ARE IN THE GRIDS FOR THE ENTIRE REGION. ONCE THAT WAVE EXITS THE CENTRAL PLAINS...THE SUMMER SUBTROPICAL RIDGE WILL BUILD BACK IN, HOWEVER DEEP TROPOSPHERIC MONSOON MOISTURE WILL BE FAIRLY SCANT AND IT WILL NEED TO BE RECHARGED AGAIN BY WAY OF LATE DAY HIGH TERRAIN THUNDERSTORMS. THE LATEST ECMWF FAVORS RIDGE- BUILDING INTO THE NORTHERN PLAINS WHICH WOULD RESULT IN A WARMING OF THE LOWER TROPOSPHERE AND SURFACE TEMPERATURES REACHING OR EXCEEDING THE UPPER 90S BY MID TO LATE NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1226 PM CDT FRI JUL 31 2015 FAIRLY QUIET AVIATION WEATHER IS EXPECTED THROUGH TONIGHT AND EARLY SATURDAY WITH A WEAK PRESSURE GRADIENT RESULTING IN THE CONTINUATION OF WINDS BELOW 12 KNOTS FOR THE MOST PART. CONVECTIVE ACTIVITY IS EXPECTED TO REMAIN SOUTH OF THE GCK AND DDC TERMINALS, SO WE WILL NOT BE FORECASTING ANY THUNDERSTORMS AT THIS TIME. VFR CONDITIONS ARE EXPECTED TO PREVAIL, HOWEVER THERE COULD BE A BRIEF PERIOD OF MVFR CEILINGS IN THE EARLY MORNING HOURS AT GCK AND DDC AS THUNDERSTORM ACTIVITY TO THE SOUTH COULD HAVE SOME IMPACT SIMILAR TO WHAT WE SAW EARLIER THIS MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 68 87 67 93 / 10 10 10 10 GCK 67 87 67 92 / 10 10 10 10 EHA 66 85 67 92 / 20 40 20 10 LBL 68 83 68 92 / 20 30 20 10 HYS 67 93 67 95 / 10 10 10 10 P28 71 90 70 94 / 10 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM...UMSCHEID AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS GOODLAND KS
200 PM MDT FRI JUL 31 2015 .SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY) ISSUED AT 141 PM MDT FRI JUL 31 2015 PERSISTENT UPPER LEVEL RIDGE CONTINUES TO DOMINATE PATTERN ACROSS WESTERN US THROUGH THE SOUTHERN PLAINS...WITH NW FLOW ACROSS THE NORTHERN PLAINS. WV IMAGERY SHOWS MONSOONAL MOISTURE PLUME EXTENDING FROM THE BAJA PENINSULA ACROSS THE FOUR CORNER AND INTO THE HIGH PLAINS WITH SEVERAL WEAK SHORTWAVE TROUGHS ROTATING AROUND RIDGE INTO THE SOUTHERN PLAINS AND THROUGH THE NW FLOW ALONG THE MISSOURI RIVER VALLEY. AT THE SURFACE...MEAN SURFACE TROUGH EXTENDS ACROSS NORTHERN COLORADO INTO CENTRAL NEBRASKA...WITH WEAK FLOW AND A SECONDARY WEAK TROUGH AXIS/SURFACE CONVERGENT ZONE ALONG THE KS CO BORDER EXTENDING SOUTH INTO SOUTH CENTRAL KS. MODELS CONTINUE TO UNDERESTIMATE TDS WITH 60-70F TD VALUES REPORTED MOST OF THE DAY...FINALLY BEGINNING TO FALL IN OUR NW. RESULT IS MUCH HIGHER CAPE VALUES THAN PREVIOUSLY ADVERTISED WITH RAP ANALYSIS SHOWS A SHARP GRADIENT OF SB CAPE FROM 250 J/KG IN NORTHEAST COLORADO TO 3000 J/KG OVER OUR SOUTHERN CWA. CONSIDERING THE MOIST BL LAYER AND FAVORABLE CAPE PROFILES OVER MOST OF THE AREA IT WON`T TAKE MUCH FOR THUNDERSTORMS TO DEVELOP. WITH ONLY WEAK HEIGHT FALLS THIS AFTERNOON/TONIGHT AND MODELS SHOWING ALMOST NO ACTIVITY INITIATING OVER OUR CA (DESPITE LOW CINH)...I AM FAVORING ISOLATED THUNDERSTORM MENTION FOR NOW. AS WITH LAST NIGHT...VERY LITTLE STORM MOTION (0-6KM 0-5KT ACROSS MUCH OF THE AREA) WILL RESULT IN POTENTIAL FOR FLASH FLOODING. IF CELL MERGERS OCCUR AND ARE ABLE TO DEVELOP A COLD POOL OR OUTFLOW WE COULD SEE BETTER COVERAGE. LOW CONFIDENCE AT THIS POINT. SATURDAY...PATTERN WILL BE VERY SIMILAR AS TODAY WITH SEASONAL HIGHS (UPPER 80S-MID 90S). GUIDANCE ACTUALLY INDICATING SUBSIDENCE WILL BE IN PLACE...SO WHILE HIGH CAPE VALUES/DECENT MOISTURE PROFILES WILL LIKELY SET UP OVER THE CWA ONCE AGAIN CONFIDENCE IN ANY INITIATION IS EVEN LOWER THAN TODAY. I DECIDED TO KEEP THUNDERSTORM MENTION OUT FOR NOW. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 200 PM MDT FRI JUL 31 2015 FOR THE EXTENDED PERIOD...THE LATTER PORTION OF THE WEEKEND RIGHT THROUGH MUCH OF NEXT WEEK...THE ENTIRE TRI STATE REGION WILL SEE ABOVE NORMAL TEMPERATURES BROUGHT ABOUT BY A STRONG AMPLIFIED 500/700 MB RIDGE OVER THE WESTERN PORTION OF THE COUNTRY...THAT SHIFTS EASTWARD INTO THE PLAINS REGION BY NEXT WEDNESDAY. LATEST MODEL RUNS STILL SHOW 850 MB TEMPS RANGING FROM +29C TO ALMOST +35C...UNDER WNW UPPER FLOW. THIS IS GOING TO GIVE THE AREA DAYTIME HIGHS WELL INTO THE 90S...WARMEST ON WEDNESDAY WHEN UPPER RIDGE AXIS SETTLES OVER THE REGION AND COULD GIVE MID TO UPPER 90S TO THE AREA. COOLER AIR COULD ARRIVE DURING THE DAY FRIDAY WITH SURFACE RIDGE BUILDING SOUTH THRU THE PLAINS AFTER FRONTAL PASSAGE LATE THURSDAY NIGHT. DESPITE STRONG RIDGING OVER THE REGION OVER THE NEXT WEEK...SEVERAL SHORTWAVES ARE EXPECTED TO TRAVERSE OVER THE NORTHERN HALF OF THE RIDGE...BRINGING THE CHANCE FOR SHOWERS/THUNDERSTORMS. THIS ACTIVITY THOUGH WILL SPARE THE FORECAST AREA FOR THIS UPCOMING WEEKEND...ONLY TO BEGIN WITH A STRONG TROUGH LATE MONDAY INTO TUESDAY AND THEN SUBSEQUENT SYSTEMS. BEST CHANCES FOR PRECIP THOUGH AS WEEK PROGRESSES WILL BEGIN TO SHIFT MORE EASTWARD OVER THE CWA...DUE TO MOVEMENT OF UPPER RIDGE WHICH WILL AFFECT PLACEMENT OF EACH LATTER SHORTWAVE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1119 AM MDT FRI JUL 31 2015 VFR CONDITIONS CURRENTLY FORECAST THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK. LOW CONFIDENCE OVERALL IN AVIATION FORECAST AS A RESULT OF POOR MODEL PERFORMANCE REGARDING LOW LEVEL MOISTURE OVER BOTH TERMINALS. I COULD SEE PATCHY FOG DEVELOPING AGAIN BY SUNRISE SATURDAY IF HIGHER DEWPOINTS CONTINUE TO LINGER...HOWEVER AT THIS POINT THERE IS NO MODEL SUPPORT SO I LEFT MENTION OUT. OTHER AVIATION CONCERN WILL BE POTENTIAL FOR THUNDERSTORMS. CURRENTLY ACTIVITY IS EXPECTED TO BE ISOLATED WITH BETTER CHANCES IN EASTERN COLORADO...SO WILL LEAVE OUT OF TAFS DURING THIS UPDATE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JN AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
141 PM MDT FRI JUL 31 2015 .SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY) ISSUED AT 141 PM MDT FRI JUL 31 2015 PERSISTENT UPPER LEVEL RIDGE CONTINUES TO DOMINATE PATTERN ACROSS WESTERN US THROUGH THE SOUTHERN PLAINS...WITH NW FLOW ACROSS THE NORTHERN PLAINS. WV IMAGERY SHOWS MONSOONAL MOISTURE PLUME EXTENDING FROM THE BAJA PENINSULA ACROSS THE FOUR CORNER AND INTO THE HIGH PLAINS WITH SEVERAL WEAK SHORTWAVE TROUGHS ROTATING AROUND RIDGE INTO THE SOUTHERN PLAINS AND THROUGH THE NW FLOW ALONG THE MISSOURI RIVER VALLEY. AT THE SURFACE...MEAN SURFACE TROUGH EXTENDS ACROSS NORTHERN COLORADO INTO CENTRAL NEBRASKA...WITH WEAK FLOW AND A SECONDARY WEAK TROUGH AXIS/SURFACE CONVERGENT ZONE ALONG THE KS CO BORDER EXTENDING SOUTH INTO SOUTH CENTRAL KS. MODELS CONTINUE TO UNDERESTIMATE TDS WITH 60-70F TD VALUES REPORTED MOST OF THE DAY...FINALLY BEGINNING TO FALL IN OUR NW. RESULT IS MUCH HIGHER CAPE VALUES THAN PREVIOUSLY ADVERTISED WITH RAP ANALYSIS SHOWS A SHARP GRADIENT OF SB CAPE FROM 250 J/KG IN NORTHEAST COLORADO TO 3000 J/KG OVER OUR SOUTHERN CWA. CONSIDERING THE MOIST BL LAYER AND FAVORABLE CAPE PROFILES OVER MOST OF THE AREA IT WON`T TAKE MUCH FOR THUNDERSTORMS TO DEVELOP. WITH ONLY WEAK HEIGHT FALLS THIS AFTERNOON/TONIGHT AND MODELS SHOWING ALMOST NO ACTIVITY INITIATING OVER OUR CA (DESPITE LOW CINH)...I AM FAVORING ISOLATED THUNDERSTORM MENTION FOR NOW. AS WITH LAST NIGHT...VERY LITTLE STORM MOTION (0-6KM 0-5KT ACROSS MUCH OF THE AREA) WILL RESULT IN POTENTIAL FOR FLASH FLOODING. IF CELL MERGERS OCCUR AND ARE ABLE TO DEVELOP A COLD POOL OR OUTFLOW WE COULD SEE BETTER COVERAGE. LOW CONFIDENCE AT THIS POINT. SATURDAY...PATTERN WILL BE VERY SIMILAR AS TODAY WITH SEASONAL HIGHS (UPPER 80S-MID 90S). GUIDANCE ACTUALLY INDICATING SUBSIDENCE WILL BE IN PLACE...SO WHILE HIGH CAPE VALUES/DECENT MOISTURE PROFILES WILL LIKELY SET UP OVER THE CWA ONCE AGAIN CONFIDENCE IN ANY INITIATION IS EVEN LOWER THAN TODAY. I DECIDED TO KEEP THUNDERSTORM MENTION OUT FOR NOW. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 209 AM MDT FRI JUL 31 2015 THE UPPER LEVEL SETUP FOR THE EXTENDED PERIOD CONTINUES TO BE RIDGING OVER THE WESTERN CONUS ALONG WITH A TROUGH TO THE EAST. THE RIDGE IS EXPECTED TO SHIFT EASTWARD WITH ITS AXIS LIKELY OVER THE AREA BY THURSDAY. SHOWERS AND THUNDERSTORMS ARE POSSIBLE AT THE START OF THE PERIOD AS A SHORTWAVE TROUGH PASSES THROUGH THE UPPER LEVEL FLOW AND OVER THE AREA MONDAY INTO TUESDAY. THE UPPER LEVEL RIDGE OVER THE WESTERN CONUS REGAINS ITS SHAPE LATE TUESDAY AND PROGRESSES EASTWARD ON WEDNESDAY AND THURSDAY TOWARDS THE PLAINS AS A CLOSED LOW APPROACHES THE PACIFIC NORTHWEST. WEAKER DISTURBANCES LOOK TO MOVE ALONG THE RIDGE WEDNESDAY AND THURSDAY...GENERATING PRECIP CHANCES ONCE AGAIN. WARM TEMPERATURES WILL CONTINUE FOR THE TRI STATE REGION WITH HIGHS IN THE UPPER 80S TO MID 90S FOR THE DURATION OF THE LONG TERM PERIOD. LOWS LOOK TO BE IN THE 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1119 AM MDT FRI JUL 31 2015 VFR CONDITIONS CURRENTLY FORECAST THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK. LOW CONFIDENCE OVERALL IN AVIATION FORECAST AS A RESULT OF POOR MODEL PERFORMANCE REGARDING LOW LEVEL MOISTURE OVER BOTH TERMINALS. I COULD SEE PATCHY FOG DEVELOPING AGAIN BY SUNRISE SATURDAY IF HIGHER DEWPOINTS CONTINUE TO LINGER...HOWEVER AT THIS POINT THERE IS NO MODEL SUPPORT SO I LEFT MENTION OUT. OTHER AVIATION CONCERN WILL BE POTENTIAL FOR THUNDERSTORMS. CURRENTLY ACTIVITY IS EXPECTED TO BE ISOLATED WITH BETTER CHANCES IN EASTERN COLORADO...SO WILL LEAVE OUT OF TAFS DURING THIS UPDATE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JBH AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1228 PM CDT FRI JUL 31 2015 ...UPDATED SHORT TERM AND AVIATION SECTIONS... .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 1226 PM CDT FRI JUL 31 2015 THE SUMMER SUBTROPICAL RIDGE WAS CENTERED OVER ITS CLIMATOLOGICAL POSITION FROM THE SOUTHERN ROCKIES INTO TEXAS TODAY. IN THE UPPER TROPOSPHERE, WEST NORTHWEST FLOW EXTENDED FROM THE NORTHERN ROCKIES THROUGH THE UPPER MISSISSIPPI VALLEY. WESTERN KANSAS WAS ON THE SOUTH EDGE OF THE WESTERLIES AT 250MB. THE MESOSCALE CONVECTIVE SYSTEM (MCS) THAT AFFECTED EXTREME SOUTHWEST KANSAS OVERNIGHT AND THIS MORNING WAS DECREASING IN AREAL EXTENT AND MOVING VERY SLOWLY TO THE EAST-SOUTHEAST...FOLLOWING ROUGHLY THE 3-8KM AGL MEAN FLOW VECTOR (JUST NORTH OF THE CENTER OF THE MEAN ANTICYCLONE IN THIS LAYER OVER WEST TEXAS). A COUPLE OF MESOSCALE CONVECTIVE VORTICITY MAXIMAS COULD BE IDENTIFIED THROUGH VISIBLE SATELLITE AND EVEN THE HOURLY RAP ANALYSIS FROM NEAR TUCUMCARI NEW MEXICO TO NEAR SPRINGFIELD COLORADO. IT WOULD APPEAR AS OF THESE MESOSCALE FEATURES WERE ACTUALLY HELPING TO MAINTAIN THE SMALL MCS THROUGH THE EARLY AFTERNOON HOURS AS THE LEADING EDGE OF IT WAS MOVING INTO THE FAR EASTERN OK-TX PANHANDLES. THE VERY NORTHERN EXTENT OF THIS MCS EXTENDED INTO MORTON AND SEWARD COUNTIES, WHICH WAS HAVING AN IMPACT ON SURFACE TEMPERATURES (COOLER THAN FORECAST IN THIS AREA). WE HAVE ADJUSTED THE DAYTIME TEMPERATURES DOWNWARD ACROSS FAR SOUTHWEST KANSAS AS A RESULT. ELSEWHERE...ESPECIALLY ACROSS WEST CENTRAL AND CENTRAL KANSAS NORTH OF HIGHWAY 96, TEMPERATURES SHOULD TOP OUT IN THE LOWER TO MID 90S. AS WE GO IN TO TONIGHT...ANOTHER SMALL MCS SHOULD EVOLVE THROUGH THE LATE NIGHT HOURS FROM CONVECTION ACROSS THE HIGHER TERRAIN OF THE RATON MESA REGION. THIS CONVECTION SHOULD FOLLOW THE SAME GENERAL TRACK AS THIS MORNINGS MCS, SO WE WILL KEEP THE BEST POPS ACROSS FAR SOUTHWEST KANSAS AGAIN IN THE 40-50 PERCENT RANGE. THE BULK OF LATE TONIGHT/TOMORROWS MCS SHOULD REMAIN ACROSS THE PANHANDLES REGION. IT SHOULD BE CLOSE TO A RINSE AND REPEAT TYPE OF DEAL TOMORROW WITH A SLOWLY DECAYING MCS SOMEWHERE JUST SOUTH OF OUR FORECAST AREA (OR PERHAPS CLIPPING MORTON-SEWARD-MEADE) WITH WARMEST TEMPERATURES UP NORTH ALONG I-70 (MID 90S) AND COOLEST TEMPERATURES ALONG THE OK BORDER (LOWER-MID 80S, IF EVEN THAT WARM). .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 200 AM CDT FRI JUL 31 2015 SATURDAY WILL BE SOMEWHAT INTERESTING. SYNOPTICALLY THERE ISN`T MUCH FOCUS FOR THUNDERSTORM DEVELOPMENT. ARW AND NMM ARE PRECIPITATION FREE. THE ECMWF, INTERESTINGLY ENOUGH, IS WETTER AS IT HAS STRONGER LOW LEVEL LIFT. AT THIS POINT, WILL KEEP THE FORECAST DRY AND LET FUTURE SHIFTS ADJUST AS NEEDED. IF THERE IS CONVECTION, THEN HIGH TEMPERATURES COULD BE TRICKY AS SOME COOLER AREAS WILL RESULT. SUNDAY SHOULD BE FAIRLY DRY AS SHORTWAVE RIDGING STARTS TO NOSE IN FROM THE WEST. HIGHS WILL MODERATE A FEW DEGREES AND WILL BE AROUND 90F. FOR THE REST, STUCK WITH SUPERBLEND POPS AND TEMPS AS THE GRIDS LOOK REASONABLE. THERE WILL BE A CHANCE FOR STORMS AGAIN AS A FEW SYNOPTIC WAVES MOVE ACROSS THE GREAT PLAINS NEXT WEEK. HIGHS WILL STILL BE ON THE WARM SIDE WITH MILD LOWS... SUMMER CONTINUES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1226 PM CDT FRI JUL 31 2015 FAIRLY QUIET AVIATION WEATHER IS EXPECTED THROUGH TONIGHT AND EARLY SATURDAY WITH A WEAK PRESSURE GRADIENT RESULTING IN THE CONTINUATION OF WINDS BELOW 12 KNOTS FOR THE MOST PART. CONVECTIVE ACTIVITY IS EXPECTED TO REMAIN SOUTH OF THE GCK AND DDC TERMINALS, SO WE WILL NOT BE FORECASTING ANY THUNDERSTORMS AT THIS TIME. VFR CONDITIONS ARE EXPECTED TO PREVAIL, HOWEVER THERE COULD BE A BRIEF PERIOD OF MVFR CEILINGS IN THE EARLY MORNING HOURS AT GCK AND DDC AS THUNDERSTORM ACTIVITY TO THE SOUTH COULD HAVE SOME IMPACT SIMILAR TO WHAT WE SAW EARLIER THIS MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 88 68 85 66 / 10 10 10 10 GCK 86 67 86 65 / 10 10 10 10 EHA 78 66 86 64 / 80 40 10 10 LBL 81 68 85 65 / 20 20 10 10 HYS 94 67 89 67 / 10 10 10 10 P28 85 71 84 68 / 10 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM...SUGDEN AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1119 AM MDT FRI JUL 31 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 209 AM MDT FRI JUL 31 2015 UPPER RIDGE OVER THE GREAT BASIN WILL GRADUALLY BUILD OVER THE CENTRAL ROCKIES AND BE THE DOMINANT FEATURE OF THE SHORT TERM PERIOD. AS A RESULT...PRECIPITATION CHANCES WILL BE RATHER LOW AND TEMPERATURES WILL BE WARMING. THAT BEING SAID...MAY SEE AN ISOLATED STORM OR TWO THIS AFTERNOON IN NORTHEAST COLORADO AS HINTED AT BY THE HRRR NEAR A WEAK SURFACE CONVERGENCE LINE. ENVIRONMENT WILL BE SIMILAR TO YESTERDAY SO CANT TOTALLY RULE OUT A SEVERE STORM CAPABLE OF PRODUCING STRONG WINDS...BUT THINK COVERAGE WILL BE VERY LIMITED DUE TO LACK OF UPPER SUPPORT. SOME OF THE HIRES NAM MEMBERS PAINT A SIMILAR SCENARIO SATURDAY AFTERNOON IN NORTHEAST COLORADO SO CARRIED SOME LOW POPS. ONCE AGAIN SEVERE PARAMETERS ARE FAIRLY DECENT SHOULD SOMETHING DEVELOP. PERHAPS THE NEXT BEST CHANCE FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND EVENING WITH SOMEWHAT BETTER LOOKING TROUGH COMING OUT OF COLORADO AND TOPPING THE RIDGE AXIS IN THE CENTRAL PLAINS. HOWEVER NOT ENOUGH CONFIDENCE AT THIS POINT WITH THE STRONG RIDGE IN PLACE THAT IT WILL ACTUALLY PLAY OUT THAT WAY SO WILL ONLY CARRY SILENT 10 POPS OR LESS. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 209 AM MDT FRI JUL 31 2015 THE UPPER LEVEL SETUP FOR THE EXTENDED PERIOD CONTINUES TO BE RIDGING OVER THE WESTERN CONUS ALONG WITH A TROUGH TO THE EAST. THE RIDGE IS EXPECTED TO SHIFT EASTWARD WITH ITS AXIS LIKELY OVER THE AREA BY THURSDAY. SHOWERS AND THUNDERSTORMS ARE POSSIBLE AT THE START OF THE PERIOD AS A SHORTWAVE TROUGH PASSES THROUGH THE UPPER LEVEL FLOW AND OVER THE AREA MONDAY INTO TUESDAY. THE UPPER LEVEL RIDGE OVER THE WESTERN CONUS REGAINS ITS SHAPE LATE TUESDAY AND PROGRESSES EASTWARD ON WEDNESDAY AND THURSDAY TOWARDS THE PLAINS AS A CLOSED LOW APPROACHES THE PACIFIC NORTHWEST. WEAKER DISTURBANCES LOOK TO MOVE ALONG THE RIDGE WEDNESDAY AND THURSDAY...GENERATING PRECIP CHANCES ONCE AGAIN. WARM TEMPERATURES WILL CONTINUE FOR THE TRI STATE REGION WITH HIGHS IN THE UPPER 80S TO MID 90S FOR THE DURATION OF THE LONG TERM PERIOD. LOWS LOOK TO BE IN THE 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1119 AM MDT FRI JUL 31 2015 VFR CONDITIONS CURRENTLY FORECAST THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK. LOW CONFIDENCE OVERALL IN AVIATION FORECAST AS A RESULT OF POOR MODEL PERFORMANCE REGARDING LOW LEVEL MOISTURE OVER BOTH TERMINALS. I COULD SEE PATCHY FOG DEVELOPING AGAIN BY SUNRISE SATURDAY IF HIGHER DEWPOINTS CONTINUE TO LINGER...HOWEVER AT THIS POINT THERE IS NO MODEL SUPPORT SO I LEFT MENTION OUT. OTHER AVIATION CONCERN WILL BE POTENTIAL FOR THUNDERSTORMS. CURRENTLY ACTIVITY IS EXPECTED TO BE ISOLATED WITH BETTER CHANCES IN EASTERN COLORADO...SO WILL LEAVE OUT OF TAFS DURING THIS UPDATE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...024 LONG TERM...JBH AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
518 AM MDT FRI JUL 31 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 209 AM MDT FRI JUL 31 2015 UPPER RIDGE OVER THE GREAT BASIN WILL GRADUALLY BUILD OVER THE CENTRAL ROCKIES AND BE THE DOMINANT FEATURE OF THE SHORT TERM PERIOD. AS A RESULT...PRECIPITATION CHANCES WILL BE RATHER LOW AND TEMPERATURES WILL BE WARMING. THAT BEING SAID...MAY SEE AN ISOLATED STORM OR TWO THIS AFTERNOON IN NORTHEAST COLORADO AS HINTED AT BY THE HRRR NEAR A WEAK SURFACE CONVERGENCE LINE. ENVIRONMENT WILL BE SIMILAR TO YESTERDAY SO CANT TOTALLY RULE OUT A SEVERE STORM CAPABLE OF PRODUCING STRONG WINDS...BUT THINK COVERAGE WILL BE VERY LIMITED DUE TO LACK OF UPPER SUPPORT. SOME OF THE HIRES NAM MEMBERS PAINT A SIMILAR SCENARIO SATURDAY AFTERNOON IN NORTHEAST COLORADO SO CARRIED SOME LOW POPS. ONCE AGAIN SEVERE PARAMETERS ARE FAIRLY DECENT SHOULD SOMETHING DEVELOP. PERHAPS THE NEXT BEST CHANCE FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND EVENING WITH SOMEWHAT BETTER LOOKING TROUGH COMING OUT OF COLORADO AND TOPPING THE RIDGE AXIS IN THE CENTRAL PLAINS. HOWEVER NOT ENOUGH CONFIDENCE AT THIS POINT WITH THE STRONG RIDGE IN PLACE THAT IT WILL ACTUALLY PLAY OUT THAT WAY SO WILL ONLY CARRY SILENT 10 POPS OR LESS. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 209 AM MDT FRI JUL 31 2015 THE UPPER LEVEL SETUP FOR THE EXTENDED PERIOD CONTINUES TO BE RIDGING OVER THE WESTERN CONUS ALONG WITH A TROUGH TO THE EAST. THE RIDGE IS EXPECTED TO SHIFT EASTWARD WITH ITS AXIS LIKELY OVER THE AREA BY THURSDAY. SHOWERS AND THUNDERSTORMS ARE POSSIBLE AT THE START OF THE PERIOD AS A SHORTWAVE TROUGH PASSES THROUGH THE UPPER LEVEL FLOW AND OVER THE AREA MONDAY INTO TUESDAY. THE UPPER LEVEL RIDGE OVER THE WESTERN CONUS REGAINS ITS SHAPE LATE TUESDAY AND PROGRESSES EASTWARD ON WEDNESDAY AND THURSDAY TOWARDS THE PLAINS AS A CLOSED LOW APPROACHES THE PACIFIC NORTHWEST. WEAKER DISTURBANCES LOOK TO MOVE ALONG THE RIDGE WEDNESDAY AND THURSDAY...GENERATING PRECIP CHANCES ONCE AGAIN. WARM TEMPERATURES WILL CONTINUE FOR THE TRI STATE REGION WITH HIGHS IN THE UPPER 80S TO MID 90S FOR THE DURATION OF THE LONG TERM PERIOD. LOWS LOOK TO BE IN THE 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 516 AM MDT FRI JUL 31 2015 PATCHY DENSE FOG WILL IMPACT KGLD THROUGH ABOUT 14Z BEFORE CLEARING. VISIBILITIES HAVE BEEN HIGHLY VARIABLE BUT AS LOW AS 1/4SM AT TIMES. OTHERWISE...VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE REMAINDER OF THE TAF PERIOD WITH RIDGING ALOFT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...024 LONG TERM...JBH AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
235 AM MDT FRI JUL 31 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 209 AM MDT FRI JUL 31 2015 UPPER RIDGE OVER THE GREAT BASIN WILL GRADUALLY BUILD OVER THE CENTRAL ROCKIES AND BE THE DOMINANT FEATURE OF THE SHORT TERM PERIOD. AS A RESULT...PRECIPITATION CHANCES WILL BE RATHER LOW AND TEMPERATURES WILL BE WARMING. THAT BEING SAID...MAY SEE AN ISOLATED STORM OR TWO THIS AFTERNOON IN NORTHEAST COLORADO AS HINTED AT BY THE HRRR NEAR A WEAK SURFACE CONVERGENCE LINE. ENVIRONMENT WILL BE SIMILAR TO YESTERDAY SO CANT TOTALLY RULE OUT A SEVERE STORM CAPABLE OF PRODUCING STRONG WINDS...BUT THINK COVERAGE WILL BE VERY LIMITED DUE TO LACK OF UPPER SUPPORT. SOME OF THE HIRES NAM MEMBERS PAINT A SIMILAR SCENARIO SATURDAY AFTERNOON IN NORTHEAST COLORADO SO CARRIED SOME LOW POPS. ONCE AGAIN SEVERE PARAMETERS ARE FAIRLY DECENT SHOULD SOMETHING DEVELOP. PERHAPS THE NEXT BEST CHANCE FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND EVENING WITH SOMEWHAT BETTER LOOKING TROUGH COMING OUT OF COLORADO AND TOPPING THE RIDGE AXIS IN THE CENTRAL PLAINS. HOWEVER NOT ENOUGH CONFIDENCE AT THIS POINT WITH THE STRONG RIDGE IN PLACE THAT IT WILL ACTUALLY PLAY OUT THAT WAY SO WILL ONLY CARRY SILENT 10 POPS OR LESS. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 209 AM MDT FRI JUL 31 2015 THE UPPER LEVEL SETUP FOR THE EXTENDED PERIOD CONTINUES TO BE RIDGING OVER THE WESTERN CONUS ALONG WITH A TROUGH TO THE EAST. THE RIDGE IS EXPECTED TO SHIFT EASTWARD WITH ITS AXIS LIKELY OVER THE AREA BY THURSDAY. SHOWERS AND THUNDERSTORMS ARE POSSIBLE AT THE START OF THE PERIOD AS A SHORTWAVE TROUGH PASSES THROUGH THE UPPER LEVEL FLOW AND OVER THE AREA MONDAY INTO TUESDAY. THE UPPER LEVEL RIDGE OVER THE WESTERN CONUS REGAINS ITS SHAPE LATE TUESDAY AND PROGRESSES EASTWARD ON WEDNESDAY AND THURSDAY TOWARDS THE PLAINS AS A CLOSED LOW APPROACHES THE PACIFIC NORTHWEST. WEAKER DISTURBANCES LOOK TO MOVE ALONG THE RIDGE WEDNESDAY AND THURSDAY...GENERATING PRECIP CHANCES ONCE AGAIN. WARM TEMPERATURES WILL CONTINUE FOR THE TRI STATE REGION WITH HIGHS IN THE UPPER 80S TO MID 90S FOR THE DURATION OF THE LONG TERM PERIOD. LOWS LOOK TO BE IN THE 60S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1122 PM MDT THU JUL 30 2015 VFR CONDITIONS ARE EXPECTED FOR BOTH TERMINALS THROUGH THE DURATION OF THE TAF PERIOD. AN UPPER LEVEL HIGH PRESSURE SYSTEM WILL BRING DRY CONDITIONS WITH LIMITED CLOUD COVER...AS WELL AS LIGHT SOUTHERLY WINDS TO BOTH KGLD AND KMCK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...024 LONG TERM...JBH AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1125 PM MDT THU JUL 30 2015 .UPDATE... ISSUED AT 743 PM MDT THU JUL 30 2015 THUNDERSTORMS IN EASTERN COLORADO ARE FOLLOWING A SOUTHWARD TRAJECTORY WITH THE CLOUD COVER MOVING MORE TO THE EAST/SOUTHEAST. MODELS INDICATE STORMS SHOULD HAVE ENDED...BUT STORMS CONTINUE TO MOVE ALONG 500 MB SHORTWAVE TROUGH JUST EAST OF THE 12 C 700 MB ISOTHERM. AT THE CURRENT SPEED...STRONGER STORMS SHOULD MOVE OUT OF THE FORECAST AREA BY MIDNIGHT MDT. SLIGHT CHANCES FOR SOME PRECIPITATION WILL LINGER A LITTLE AFTER MIDNIGHT MDT AS THE SMALL SHORTWAVE MOVES THROUGH THE HIGH PLAINS. UPDATE ISSUED AT 430 PM MDT THU JUL 30 2015 ISSUED A QUICK UPDATE TO ADJUST COVERAGE AND THUNDERSTORM TIMING MOVING INTO THE EASTERN COLORADO COUNTIES. THE WRF MODELS SEEM TO BE HAVING THE BEST HANDLE ON THE CURRENT CONVECTIVE MODE...HOWEVER PRECIPITATION IN THE MODELS ARE 3-6 HOURS LATE IN DEVELOPMENT. STORMS MAY DISSIPATE EARLIER THAN ANTICIPATED DUE TO THE EARLIER DEVELOPMENT...BUT WILL LEAVE IN PRECIPITATION CHANCES AFTER MIDNIGHT MDT FOR NOW. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 200 PM MDT THU JUL 30 2015 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS BROAD RIDGE ACROSS THE SOUTHERN PLAINS EXTENDING ACROSS THE CENTRAL ROCKIES AND ACROSS THE GREAT BASIN. NW FLOW IS IN PLACE ACROSS THE NORTHERN PLAINS AND GREAT LAKES REGIONS. A WEAK RIPPLE IN THE HEIGHT FIELD IS DEPICTED OVER NW KANSAS WITH A STRONGER PV HEIGHT ANOMALY OVER NEW MEXICO AND STRONGER SIGNAL IN WV IMAGERY. AT THE SURFACE LOW PRESSURE HAS DEVELOPED ACROSS EASTERN COLORADO WITH A STATIONARY FRONT EXTENDING FROM THE SW TO NE TOWARDS THE NEBRASKA PANHANDLE. HIGH PRESSURE IS IN PLACE ACROSS THE CENTRAL PLAINS AND CENTRAL MISSISSIPPI RIVER VALLEY. THIS AFTERNOON-TONIGHT...CAPE VALUES IN THE 1500-2500 J/KG RANGE ARE CURRENTLY IN PLACE WITH HIGHER TD VALUES (UPPER 50S TO MID 60S). RAP/HRRR INDICATE CAP ALREADY WEAKENED...AND THUNDERSTORM ACTIVITY MAY BEGIN TO DEVELOP ALONG WEAK CONVERGENCE ZONE NEAR SURFACE TROUGH/STATIONARY FRONT IN EASTERN COLORADO. GUIDANCE GENERALLY SHOWS BETTER PRECIP SIGNAL IN THIS AREA. VERY WEAK LIFT IS IN PLACE AND AT THIS POINT COVERAGE LOOKS TO BE ISOLATED TO WIDELY SCATTERED THROUGH TONIGHT. THERE WILL BE SOME WAA THROUGH THE NIGHT WHICH COULD SUPPORT CONTINUED DEVELOPMENT...HOWEVER WITH BEST FORCING OUTSIDE OUR CWA...NOT A LOT OF CONFIDENCE. I LIMITED POPS TO 15-24 RANGE (SLIGHT CHANCE). WITH WEAK SHEER PROFILES IN PLACE...LIMITED FORCING...AND MID LEVEL LAPSE RATES MAINLY LESS THAN 7 C/KM THUNDERSTORM ACTIVITY IS NOT EXPECTED TO BECOME ORGANIZED. FRIDAY...SURFACE TROUGH SHIFTS EAST TO BE CENTERED ROUGHLY OVER OUR CWA AND MAY ACT AS A FOCUS/INITIATION POINT FOR AFTERNOON THUNDERSTORM ACTIVITY. BEST UPPER LEVEL SUPPORT IS IN THE MORNING OUTSIDE OUR CWA...WITH POSSIBLY LESS UPPER LEVEL SUPPORT FRIDAY AFTERNOON THAN TODAY. THERE SHOULD STILL BE ENOUGH INSTABILITY/MOISTURE IN PLACE TO SUPPORT SOME THUNDERSTORM ACTIVITY ALONG TROUGH AXIS...HOWEVER COVERAGE STILL APPEARS TO BE ISOLATED IN NATURE. EFFECTIVE SHEER PROFILES AROUND 30KT AND CAPE VALUES 1500- 3000 J/KG COULD SUPPORT A FEW STRONGER STORMS HOWEVER LIKE TODAY SEVERE THREAT APPEARS TO BE LOW. HIGH TEMPERATURES WILL BE SLIGHTLY WARMER AND STILL SEASONAL WITH VALUES RANGING FROM THE UPPER 80S TO LOWER 90S. A FEW MID 90 TEMPERATURES WILL BE POSSIBLE AT KMCK/KHLC. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 150 PM MDT THU JUL 30 2015 ABOVE NORMAL TEMPERATURES ARE ON TAP FOR THE ENTIRE TRI STATE REGION...AS MAIN WEATHER FOCUS FOR THE EXTENDED PERIOD WILL CONCERN AMPLIFIED H5/H7 RIDGE OVER THE WESTERN PORTION OF THE COUNTRY... SHIFTING EASTWARD INTO THE PLAINS REGION BY NEXT WEDNESDAY/THURSDAY. EXPECTING BROAD WNW DOWNSLOPE FLOW AT 700/500 MB WITH RIDGE TO OUR WEST...WITH RIDGE AXIS OVER THE PLAINS BY MIDWEEK NEXT WEEK. 850 MB TEMPS DO RANGE FROM +28C UP TO +33C DURING THIS TIME...WITH WARMEST SET TO OCCUR WED/THURS...COINCIDING WITH RIDGE AXIS SETTING UP OVER THE AREA. WITH THESE CONDITIONS...DAYTIME HIGH TEMPERATURES WILL RANGE IN THE LOWER TO MID 90S...AND OVERNIGHT LOWS IN THE LOW TO MID 60S. THE AREA WILL ALSO SEE THE CHANCES FOR SHOWERS AND THUNDERSTORMS DESPITE THE INCREASE TEMPS. SEVERAL SHORTWAVES MOVING DOWN ALONG THE EAST SIDE OF THE MID-LEVEL RIDGE FRIDAY/FRIDAY NIGHT...NEXT MONDAY INTO TUESDAY...AND AGAIN LATE WEDNESDAY INTO THURSDAY WHEN SURFACE FRONT IS FOLLOWED BY TRAILING SHORTWAVE. CURRENT GFS A BIT MORE IN- LINE WITH LATEST ECMWF...MAKING CONFIDENCE A BIT STRONGER IN KEEPING CHANCE POPS FOR LATTER PORTION OF THE FORECAST. THE PUSH OF THE UPPER RIDGE EASTWARD INTO THE PLAINS DOES PUT A BIT MORE EMPHASIS FOR HIGHER POP CHANCES OVER EASTERN ZONES ON WEDNESDAY INTO THURSDAY. AS WITH EXPECTED RAINFALL POTENTIAL...THE CLOUD COVER WITH THESE EVENTS COULD IMPACT DAYTIME HIGHS/OVERNIGHT LOWS...ESPECIALLY IN EASTERN ZONES AS WEEK PROGRESSES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1122 PM MDT THU JUL 30 2015 VFR CONDITIONS ARE EXPECTED FOR BOTH TERMINALS THROUGH THE DURATION OF THE TAF PERIOD. AN UPPER LEVEL HIGH PRESSURE SYSTEM WILL BRING DRY CONDITIONS WITH LIMITED CLOUD COVER...AS WELL AS LIGHT SOUTHERLY WINDS TO BOTH KGLD AND KMCK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...MK SHORT TERM...DR LONG TERM...JN AVIATION...MK
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1216 PM CDT FRI JUL 31 2015 .UPDATE... UPDATED FORECAST AND GRIDS TO LOWER RAIN CHANCES ACROSS SOUTHERN HALF OF AREA TO 20 PERCENT...AND HRRR WOULD INDICATE THAT MAY BE A LITTLE HIGH. ADJUSTED HOURLY TEMPERATURES AND DEW POINTS TO FIT CURRENT TRENDS. && .PREV DISCUSSION... /ISSUED 415 AM CDT FRI JUL 31 2015/ SHORT TERM... THE HEAT WILL BE ON FOR A SHORT TIME TODAY. BUT A COLD FRONT JUST TO THE NORTH OF THE AREA WILL SLOWLY MOVE THROUGH TODAY. DEW PTS WILL BEGIN TO LOWER IN MCB BY SUNRISE AND SHOULD REACH ABOUT 63 DEGREES BY AFTERNOON. DP TEMPS WILL LOWER IN SLIDELL AROUND NOON AND TO THE SOUTH SHORE SHORTLY AFTER. THIS CONTRAST TO THE DP TEMPS THAT WE HAVE BEEN UNDER LATELY WILL BE FELT. THIS WILL ALSO DO TWO THINGS. ONE WILL BE TO KEEP TEMPS NEAR WHAT THEY HAVE BEEN OR EVEN SLIGHTLY HIGHER. THE SECOND THING WILL BE TO KEEP THE HEAT INDEX VALUES DOWN. TIMING OF SH/TS HAVE BEEN OFF THE LAST FEW DAYS AND THAT ALWAYS HAS A MAJOR IMPACT ON TEMPS AND THEREFORE HEAT INDEX VALUES. BUT TODAY SHOULD NOT BE A TIMING ISSUE AS DRY AIR WILL BE THE CAUSE OF LOWER HEAT INDICES. THE FRONT WILL MOVE BACK TO THE NORTH BY SAT NIGHT BRINGING BACK THE MOISTURE AND HIGHER HEAT INDEX VALUES. THE FRONT SHOULD ALSO KEEP ALL SH/TS ACTIVITY ALONG AND SOUTH OF IT SO POP GRADIENTS HAVE BEEN SET ACCORDINGLY. LONG TERM... SH/TS WILL ONCE AGAIN BE BACK TO THE AREA ONCE THE COLD FRONT LIFTS NORTH OVER THE WEEKEND. AFTER THE WEEKEND...MOST SH/TS WILL BE ACTIVATED BY C-BRZ AND OUTFLOW BOUNDARIES. AVIATION... VFR CONDITIONS ARE EXPECTED WITH THE MAIN EXCEPTION AT KHUM WHERE SOME TEMPO MVFR WILL CONTINUE THIS MORNING DUE TO LIGHT FOG. MAINTAIN VCTS THIS AFTERNOON FOR THE AIRPORTS CLOSER TO THE COAST WHERE THERE IS A BETTER CHANCE OF CONVECTION. 18 MARINE... A COLD FRONT IS EXPECTED TO PUSH SOUTH ACROSS THE TIDAL AND EXTREME NEAR SHORE WATERS TODAY AND STALL. A SLIGHT DECREASE IN THICKNESS 1000-700MB SHOW A 10 TO 15 METER DROP TODAY. NORTH WINDS WILL KICK UP TO 10 TO 15 KNOTS ACROSS NEAR SHORE WATERS THIS MORNING AND AGAIN SATURDAY MORNING. THE STALLED COLD FRONT OVER THE COASTAL WATERS WILL BEGIN TO LOSE ITS IDENTITY OVER THE WEEKEND. HIGH PRESSURE WILL BUILD OVER THE EAST GULF AND YIELD A WESTERLY FLOW OVER THE NORTH CENTRAL GULF EARLY NEXT WEEK. 18 DECISION SUPPORT... DSS CODE....BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...RIVER FLOOD WARNINGS ON MISSISSIPPI RIVER FROM RED RIVER LANDING TO DONALDSONVILLE. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 95 68 94 69 / 10 0 0 0 BTR 96 70 95 70 / 10 10 0 0 ASD 92 72 94 70 / 10 10 10 10 MSY 93 78 93 79 / 20 10 10 20 GPT 93 74 92 71 / 10 20 20 20 PQL 94 75 91 70 / 20 20 20 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
748 PM EDT SAT AUG 1 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 323 PM EDT SAT AUG 1 2015 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALOFT OVER THE GREAT LKS BTWN CLOSED UPR LO OVER HUDSON BAY AND RDG ACROSS THE WRN CONUS. THE 12Z INL/GRB RAOBS SHOW A RELATIVELY DRY...CAPPED ENVIRONMENT...SO THE DIURNAL CU THAT POPPED UP HAVE BEEN FAIRLY SHALLOW WITH LARGE SCALE DEEP LYR QVECTOR DVGC/SUBSIDENCE DOMINATING. THE ONLY EXCEPTION IS OVER THE SE CWA E OF ESCANABA... WHERE RADAR INDICATES A FEW SHOWERS HAVE POPPED UP IN AN AREA CLOSER TO SOME DEEPER MSTR/LESS CAPPED ENVIRONMENT SHOWN ON THE 12Z APX RAOB AND WHERE LLVL CNVGC HAS BEEN ENHANCED BY LK BREEZE CNVGC. LOOKING UPSTREAM...A SHRTWV IS DROPPING SEWD THRU MANITOBA. THERE IS A BAND OF CLDS AND A FEW SHOWERS ASSOCIATED WITH AXIS OF HIER H7 RH IN AREA OF DPVA/H7-5 QVECTOR CNVGC MOVING INTO NW ONTARIO AHEAD OF THIS FEATURE. FARTHER AWAY...ANOTHER SHRTWV TOPPING WRN RDG IS MOVING ESEWD THRU SASKATCHEWAN. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON SHOWER/TS CHANCES ASSOCIATED MAINLY WITH THE TWO SHRTWVS NOTED ABOVE. TNGT...FIRST SHRTWV OVER MANITOBA IS FCST TO SLIDE SEWD THRU NW ONTARIO...WITH SHARPER DPVA/DEEP LYR QVECTOR CNVGC REMAINING TO THE N. ALTHOUGH THE LLVL FLOW IS FCST TO BACK TOWARD THE WSW TO THE S OF THE TRACK OF THIS DISTURBANCE...GUIDANCE INDICATES THE MOST IMPRESSIVE MSTR CNVGC WL REMAIN TO THE S IN WI...JUST BRUSHING THE BORDER. WITH THE DISCONNECT BTWN THIS MOISTENING TO THE S AND THE MORE IMPRESSIVE DYNAMIC SUPPORT REMAINING TO THE N...SUSPECT PCPN OVER MUCH OF UPR MI WL BE RATHER LIMITED BTWN AXES OF HIER POPS TO THE N AND ALONG THE SRN CWA/WI. INCRSG PWAT AND WSW FLOW WL TEND TO LIMIT THE DIURNAL TEMP DROP. SUN...DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV NOW MOVING THRU SASKATCHEWAN IS FCST TO ARRIVE OVER SLOW MOVING...WEAKENING COLD FNT THAT WL BE DROPPING SLOWLY SE ACRS THE CWA ATTENDANT TO FIRST DISTURBANCE EXITING INTO QUEBEC. SOME OF THE MODELS... ESPECIALLY THE 12Z GFS...ALSO HINT AT THE POTENTIAL FOR SOME ENHANCED UPR DVGC IN RRQ OF EXITING H3 JET MAX SUPPORTING THE FIRST DISTURBANCE AND EXIT REGION OF INCOMING JET STREAK ASSOCIATED WITH 2ND SHRTWV. SINCE THIS FORCING WL BE ARRIVING DURING PERIOD OF DAYTIME HEATING...SUSPECT SHOWERS/TS WL BECOME MORE NUMEROUS. SO TENDED TO BUMP POPS UP INTO THE LIKELY RANGE OVER MUCH OF THE CWA. WITH INCRSG H85-5 RH...THERE ARE CONCERNS ABOUT HOW MORE CLDS WL IMPACT SFC DESTABILIZATION. THE 12Z NAM SHOWS MUCAPE AS HI AS 2500- 3000 J/KG OVER THE SCENTRAL UNDER AREA OF STEEP H7-5 LAPSE RATES APRCHG 8C/KM PER THE THE 12Z GFS. ALTHOUGH MOST OF THE GUIDANCE SUGGESTS THE BULK OF THE PCPN WL FALL ON THE COOL SIDE OF THE FNT AND THERE WL BE A GOOD DEAL OF CLD COVER THAT SUG THE NAM FCST MUCAPE IS TOO HI...TS THAT FORM ALONG AND AHEAD OF THE FNT ESPECIALLY OVER THE SCENTRAL COULD TURN STRONG TO SEVERE WITH DEEP LYR SHEAR NEAR 40 KTS. IN FACT...THE NEW SPC OUTLOOK FOR SUN AS SHIFTED THE NRN EDGE OF MARGINAL RISK FOR SVR STORMS AS FAR N AS SRN MNM COUNTY. POPS WL DIMINISH FM THE NW BY MID/LATE AFTN FOLLOWING ARRIVAL OF SUBSIDENCE/MID LVL DRYING FOLLOWING THE SHRTWV. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 317 PM EDT SAT AUG 1 2015 IMPACTS...COOLER TEMPERATURES AND GREATER MOISTURE WILL HAVE A POSITIVE IMPACT ON FIRE WEATHER...AT LEAST SOMEWHAT LOWERING CONCERNS. A TROUGH/COLD FRONT AND ASSOCIATED PRECIPITATION WILL BE MOSTLY OUT OF THE AREA BY 00Z MON AS THE UPPER LOW THAT HAS BEEN SITTING OVER HUDSON BAY MOVES S INTO ONTARIO. AS THE LOW MOVES FROM EXTREME NRN ONTARIO AT 00Z MON TO THE ONTARIO/QUEBEC BORDER E OF LAKE SUPERIOR BY 00Z WED...THE CORE OF COLDEST AIR (850MB TEMPS OF 3-4C) WILL SLIDE INTO THE CWA. THE COLDER MID LEVELS WILL ALLOW FOR CONVECTIVE SHOWERS MON THROUGH TUE AS LOW LEVEL MOISTURE WILL BE INCREASED AND SUBTLE SHORTWAVES WILL BE MOVING THROUGH. SFC TEMPS WILL BE 7-10 DEGREES BELOW NORMAL WITH HIGHS IN THE MID 60S TO MID 70S. LOWS WILL BE FROM THE MID 40S INLAND TO THE MID 50S NEAR THE GREAT LAKES. TUE NIGHT THROUGH WED NIGHT WILL SEE A SFC RIDGE MOVE OVERHEAD...WITH NO PRECIP EXPECTED. TEMPS MAY BE A DEGREE OR TWO WARMER THAN TUE WITH HIGHS IN THE UPPER 60S TO LOW 70S. THERE WILL STILL BE ENOUGH MOISTURE TUE NIGHT TO KEEP TEMPS FROM FALLING INTO THE 30S AND WED NIGHT MAY SEE INCREASING CLOUD COVER AND RETURN FLOW TO KEEP TEMPS FROM FALLING TO CONCERNING LEVELS. THE REST OF THE PERIOD THU THROUGH SAT IS QUITE A BIT MORE UNCERTAIN IN EXACT DETAILS AS CONDITIONS LOOK TO BE DRIVEN LARGELY BY SHORTWAVES. SLIGHT CHANCES OF PRECIP EACH DAY AS GIVEN BY CONSENSUS GUIDANCE IS REASONABLE...SO WILL LEAVE THAT IN THE FORECAST. ALSO...TEMPERATURES LOOK TO REMAIN BELOW NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 747 PM EDT SAT AUG 1 2015 WITH THE LOSS OF DIURNAL HEATING...WINDS WILL DIMINISH EARLY THIS EVENING. ALTHOUGH A PASSING DISTURBANCE MAY BRING SOME -SHRA TO UPPER MI LATE TONIGHT...LOW-LEVEL DRY AIR INDICATES VFR CONDITIONS WILL PREDOMINATE EVEN IF ANY OF THE SHOWERS PASS OVER KIWD/KCMX/KSAW. THERE WILL ALSO BE SOME MARGINAL LLWS OVERNIGHT WITH A STRENGTHENING WSW FLOW ABOVE NEAR SFC STABLE LAYER. APPROACH OF A STRONGER DISTURBANCE ON SUN WILL BRING A BETTER CHC OF SHRA AND PROBABLY SOME TS...BUT CONFIDENCE IN TS OCCURRING AT ANY OF THE TERMINALS IS LOW ENOUGH AT THIS POINT TO PRECLUDE A MENTION. VFR CONDITIONS SHOULD CONTINUE ON SUN...BUT IF THERE IS BRIEF MDT/HVY RAINFALL...MVFR AND PERHAPS EVEN IFR CONDITIONS COULD OCCUR FOR A SHORT TIME. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 323 PM EDT SAT AUG 1 2015 A LOW SPINNING OVER SOUTHERN HUDSON BAY WILL SWEEP A PAIR OF TROFS ACROSS LAKE SUPERIOR TONIGHT AND SUN. WINDS WILL GENERALLY BE IN THE 10-20KT RANGE. HI PRES FROM THE CANADIAN PRAIRIES WILL MOVE OVER THE REGION THROUGH MOST OF NEXT WEEK...KEEPING WINDS UNDER 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
952 PM MDT SAT AUG 1 2015 .UPDATE... HEAVY RAIN THREAT IS ENDING ACROSS N/C NEW MEXICO. MAINLY STRATIFORM TYPE OF EVENT WITH EMBEDDED CONVECTION DURING THE REST OF THE OVERNIGHT. LOOKS LIKE THE MAIN BAND ACROSS WESTERN/CENTRAL NM SHOULD SHIFT NORTHWARD DURING THE OVERNIGHT ALTHOUGH MAY JUST DIE OUT OVER CENTRAL AREAS. UPDATED POPS AND ENDED THE FLASH FLOOD WATCH. 50 && .PREV DISCUSSION...610 PM MDT SAT AUG 1 2015... .AVIATION... 00Z TAF CYCLE THE MONSOON MOISTURE PLUME WILL REMAIN ACTIVE TONIGHT WITH SCT TO NMRS SHRA/TS THROUGH EVENING WITH WET MICROBURSTS LIKELY. A DISTURBANCE PASSING NEWD OVER THE GREAT BASIN...AND ANOTHER ONE EXITING SEWD FROM THE CENTRAL ROCKIES SHOULD KEEP SHOWERS AND STORMS ACTIVE OVER W AND NE PARTS OF NM AFTER MIDNIGHT. A TRUSTED MESOSCALE MODEL IS BRINGING ONE CLUSTER OF CELLS NEWD THROUGH THE KABQ AND KSAF AREAS AROUND MIDNIGHT. ANOTHER ROUND OF SCT TO NMRS SHRA/TS IS PROGGED TO IMPACT MUCH OF THE FORECAST AREA WITH LOWEST PROBABILITIES AT KROW AND HIGHEST PROBABILITIES AT KGUP...KFMN...KSAF AND KLVS. 44 && .PREV DISCUSSION...332 PM MDT SAT AUG 1 2015... .SYNOPSIS... AN ACTIVE MONSOON PATTERN IS EXPECTED TO PERSIST THROUGH THE REMAINDER OF THE WEEKEND. SLOW-MOVING STORMS CAPABLE OF PRODUCING TORRENTIAL RAINFALL AND FLASH FLOODING WILL REMAIN A CONCERN THIS AFTERNOON AND EARLY TONIGHT AND AGAIN SUNDAY...ESPECIALLY IN NORTH CENTRAL TO NORTHWEST PARTS OF NEW MEXICO. DRIER AND MORE STABLE AIR WILL ATTEMPT TO WORK WEST BEGINNING MONDAY...SIGNIFICANTLY LOWERING THE OVERALL COVERAGE OF STORMS AND FLASH FLOOD THREAT. FEWER STORMS WILL TRANSLATE INTO A DAY TO DAY WARMING TREND NEXT WEEK...AS WELL. && .DISCUSSION... SLOW-MOVING THUNDERSTORMS HAVE BEEN FOCUSED SQUARELY WITHIN THE FLASH FLOOD WATCH THUS FAR...WITH TREMENDOUSLY IMPRESSIVE RAINFALL RATES AS HIGH AS 3.3 INCHES PER HOUR AS MEASURED BY A PERSONAL WEATHER STATION ON THE NORTHWEST SIDE OF SANTA FE. GENERALLY 1 TO 3 INCH PER HOUR RATES LIKELY WITH JUST ABOUT ANY WELL-DEVELOPED STORM. MAY CONSIDER EXPANDING WATCH TO INCLUDE NE/EC AREAS ALTHOUGH COVERAGE EAST OF THE CENTRAL MOUNTAIN CHAIN SHOULD BE MORE ISOLATED TO SCATTERED. BUT RECENT RUNS OF THE HRRR CONTINUE TO SUGGEST SMALL MCS-LIKE FEATURE ORGANIZING BETWEEN CLAYTON AND CONCHAS DAM ROLLING TOWARD TUCUMCARI-LOGAN LATER THIS EVENING. THIS WOULD ONE AREA OF CONCERN GIVEN VERY HEAVY RAIN PAST TWO DAYS. WEAKNESS IN THE 500MB RIDGE NEAR THE NM/CO LINE ALSO A PLAYER BUT VERY DIFFICULT TO TRACK BEYOND 12 HOURS. OTHERWISE...WE`RE NOW MOVING INTO OUTFLOW BOUNDARY INTERACTION TIME OF DAY FOR VALLEY LOCATIONS CENTRAL/WEST. AIR MASS PLENTY MOIST WITH PRECIPITABLE WATER VALUES RANGING FROM 1.2 INCHES NW TO 1.5 INCHES NEAR THE NM/TX LINE. A POCKET OF RELATIVELY LOWER PWAT AIR /ONE 1 INCH OR SLIGHTLY LESS/ ANALYZED OVER THE LOWER RIO GRANDE VALLEY TO UPPER GILA HAS KEPT COVERAGE A BIT LOWER THERE BUT SUBTLE GRADIENTS. GOING INTO SUNDAY...VERY LITTLE CHANGE TO OVERALL ORIENTATION OF THE MONSOON PLUME BENEATH VERY WEAK STEERING CURRENTS. LEAST FAVORED REGION WILL CONTINUE TO BE THE SOUTHEAST CORNER...WHILE NC TO WC AREAS AGAIN FAVORED IN ADDITION TO THE SW THAT COULD SEE A BUMP IN COVERAGE AS COMPARED TO TODAY. THEREAFTER...WE HAVE BEGUN TO REFLECT A MARKED DECREASE IN STORM COVERAGE MONDAY AND ESPECIALLY TUESDAY THROUGH THURSDAY. THIS AS THE ANTICYCLONIC BELT OF WESTERLIES ELONGATES WEST-EAST AND SHIFTS SLIGHTLY SOUTH PLACING THE AREA UNDER A DRIER WESTERLY FLOW REGIME. THAT SAID...THE LAST DRYING EPISODE WAS POORLY HANDLED BY VIRTUALLY ALL THE NWP MODELS AS THEY TEND TO DRY OUR MOIST RESIDENT AIR MASS TOO QUICKLY. SO WE WILL PROCEED WITH A LITTLE PRUDENCE...BUT DEFINITELY TRENDING FORECAST TOWARD MUCH FEWER STORMS NEXT WEEK. IF THE MODELS ARE CORRECT WE WILL STRUGGLE TO DEVELOP A STORM ANYWHERE BY MID- WEEK. THAT IN TURN WILL ALLOW FOR A DAY TO DAY WARMING TREND. COULD SEE OUR NEXT BACKDOOR SURGE THUR/FRI THEN WE START THE MOISTENING CYCLE OVER. KJ && .FIRE WEATHER... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL FOCUS ON NORTHERN AND WESTERN NEW MEXICO TODAY AND SUNDAY...WITH FURTHER DEVELOPMENT EAST OF THE CENTRAL MOUNTAIN CHAIN. STEERING FLOW FROM THE UPPER LEVEL HIGH RECENTERING OVER THE SOUTHERN PORTION OF THE STATE WILL STEER SLOW MOVING NORTH TO NORTHEAST STORMS ACROSS NORTHWESTERN TO NORTH CENTRAL AREAS WHERE FLASH FLOODING WILL CONTINUE TO BE A MAJOR CONCERN THROUGHOUT THE REMAINDER OF THE WEEKEND. LOOK FOR A DRIER AIR MASS TO FILTER INTO THE STATE MONDAY THROUGH THURSDAY AS THE UPPER LEVEL HIGH OVER SOUTHERN NEW MEXICO SHIFTS WESTWARD FILTERING IN DRIER AIR FROM THE PACIFIC. SHOWER AND THUNDERSTORM ACTIVITY WILL DOWNTREND AS TEMPERATURES CREEP BACK TO NORMAL/ABOVE NORMAL READINGS. EXPECT HAINES VALUES TO INCREASE TO THE 5 AND 6 VALUES ALONG WITH DECREASING MIN RH VALUES. STORM ACTIVITY WILL BE LIMITED TO HIGHER TERRAIN AREAS AND ADJACENT LOWER ELEVATION AREAS. THE MOISTURE PLUME LOOKS TO MAKE ITS RETURN BY THE FOLLOWING WEEKEND WITH AN INCREASE IN WETTING PRECIPITATION CHANCES ACROSS THE WEST AND NORTH AS THE UPPER LEVEL HIGH STARTS TO SHIFT EASTWARD. EXPECT POOR VENT RATES ACROSS THE NORTH THE REMAINDER OF THE WEEKEND WITH IMPROVEMENTS BY MONDAY THROUGH THURSDAY. MIN RH VALUES WILL DROP INTO THE UPPER TEENS BY THE MIDWEEK BUT OVERNIGHT RECOVERIES WILL REMAIN GOOD. 32 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 50
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
610 PM MDT SAT AUG 1 2015 .AVIATION... 00Z TAF CYCLE THE MONSOON MOISTURE PLUME WILL REMAIN ACTIVE TONIGHT WITH SCT TO NMRS SHRA/TS THROUGH EVENING WITH WET MICROBURSTS LIKELY. A DISTURBANCE PASSING NEWD OVER THE GREAT BASIN...AND ANOTHER ONE EXITING SEWD FROM THE CENTRAL ROCKIES SHOULD KEEP SHOWERS AND STORMS ACTIVE OVER W AND NE PARTS OF NM AFTER MIDNIGHT. A TRUSTED MESOSCALE MODEL IS BRINGING ONE CLUSTER OF CELLS NEWD THROUGH THE KABQ AND KSAF AREAS AROUND MIDNIGHT. ANOTHER ROUND OF SCT TO NMRS SHRA/TS IS PROGGED TO IMPACT MUCH OF THE FORECAST AREA WITH LOWEST PROBABILITIES AT KROW AND HIGHEST PROBABILITIES AT KGUP...KFMN...KSAF AND KLVS. 44 && .PREV DISCUSSION...332 PM MDT SAT AUG 1 2015... .SYNOPSIS... AN ACTIVE MONSOON PATTERN IS EXPECTED TO PERSIST THROUGH THE REMAINDER OF THE WEEKEND. SLOW-MOVING STORMS CAPABLE OF PRODUCING TORRENTIAL RAINFALL AND FLASH FLOODING WILL REMAIN A CONCERN THIS AFTERNOON AND EARLY TONIGHT AND AGAIN SUNDAY...ESPECIALLY IN NORTH CENTRAL TO NORTHWEST PARTS OF NEW MEXICO. DRIER AND MORE STABLE AIR WILL ATTEMPT TO WORK WEST BEGINNING MONDAY...SIGNIFICANTLY LOWERING THE OVERALL COVERAGE OF STORMS AND FLASH FLOOD THREAT. FEWER STORMS WILL TRANSLATE INTO A DAY TO DAY WARMING TREND NEXT WEEK...AS WELL. && .DISCUSSION... SLOW-MOVING THUNDERSTORMS HAVE BEEN FOCUSED SQUARELY WITHIN THE FLASH FLOOD WATCH THUS FAR...WITH TREMENDOUSLY IMPRESSIVE RAINFALL RATES AS HIGH AS 3.3 INCHES PER HOUR AS MEASURED BY A PERSONAL WEATHER STATION ON THE NORTHWEST SIDE OF SANTA FE. GENERALLY 1 TO 3 INCH PER HOUR RATES LIKELY WITH JUST ABOUT ANY WELL-DEVELOPED STORM. MAY CONSIDER EXPANDING WATCH TO INCLUDE NE/EC AREAS ALTHOUGH COVERAGE EAST OF THE CENTRAL MOUNTAIN CHAIN SHOULD BE MORE ISOLATED TO SCATTERED. BUT RECENT RUNS OF THE HRRR CONTINUE TO SUGGEST SMALL MCS-LIKE FEATURE ORGANIZING BETWEEN CLAYTON AND CONCHAS DAM ROLLING TOWARD TUCUMCARI-LOGAN LATER THIS EVENING. THIS WOULD ONE AREA OF CONCERN GIVEN VERY HEAVY RAIN PAST TWO DAYS. WEAKNESS IN THE 500MB RIDGE NEAR THE NM/CO LINE ALSO A PLAYER BUT VERY DIFFICULT TO TRACK BEYOND 12 HOURS. OTHERWISE...WE`RE NOW MOVING INTO OUTFLOW BOUNDARY INTERACTION TIME OF DAY FOR VALLEY LOCATIONS CENTRAL/WEST. AIR MASS PLENTY MOIST WITH PRECIPITABLE WATER VALUES RANGING FROM 1.2 INCHES NW TO 1.5 INCHES NEAR THE NM/TX LINE. A POCKET OF RELATIVELY LOWER PWAT AIR /ONE 1 INCH OR SLIGHTLY LESS/ ANALYZED OVER THE LOWER RIO GRANDE VALLEY TO UPPER GILA HAS KEPT COVERAGE A BIT LOWER THERE BUT SUBTLE GRADIENTS. GOING INTO SUNDAY...VERY LITTLE CHANGE TO OVERALL ORIENTATION OF THE MONSOON PLUME BENEATH VERY WEAK STEERING CURRENTS. LEAST FAVORED REGION WILL CONTINUE TO BE THE SOUTHEAST CORNER...WHILE NC TO WC AREAS AGAIN FAVORED IN ADDITION TO THE SW THAT COULD SEE A BUMP IN COVERAGE AS COMPARED TO TODAY. THEREAFTER...WE HAVE BEGUN TO REFLECT A MARKED DECREASE IN STORM COVERAGE MONDAY AND ESPECIALLY TUESDAY THROUGH THURSDAY. THIS AS THE ANTICYCLONIC BELT OF WESTERLIES ELONGATES WEST-EAST AND SHIFTS SLIGHTLY SOUTH PLACING THE AREA UNDER A DRIER WESTERLY FLOW REGIME. THAT SAID...THE LAST DRYING EPISODE WAS POORLY HANDLED BY VIRTUALLY ALL THE NWP MODELS AS THEY TEND TO DRY OUR MOIST RESIDENT AIR MASS TOO QUICKLY. SO WE WILL PROCEED WITH A LITTLE PRUDENCE...BUT DEFINITELY TRENDING FORECAST TOWARD MUCH FEWER STORMS NEXT WEEK. IF THE MODELS ARE CORRECT WE WILL STRUGGLE TO DEVELOP A STORM ANYWHERE BY MID- WEEK. THAT IN TURN WILL ALLOW FOR A DAY TO DAY WARMING TREND. COULD SEE OUR NEXT BACKDOOR SURGE THUR/FRI THEN WE START THE MOISTENING CYCLE OVER. KJ && .FIRE WEATHER... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL FOCUS ON NORTHERN AND WESTERN NEW MEXICO TODAY AND SUNDAY...WITH FURTHER DEVELOPMENT EAST OF THE CENTRAL MOUNTAIN CHAIN. STEERING FLOW FROM THE UPPER LEVEL HIGH RECENTERING OVER THE SOUTHERN PORTION OF THE STATE WILL STEER SLOW MOVING NORTH TO NORTHEAST STORMS ACROSS NORTHWESTERN TO NORTH CENTRAL AREAS WHERE FLASH FLOODING WILL CONTINUE TO BE A MAJOR CONCERN THROUGHOUT THE REMAINDER OF THE WEEKEND. LOOK FOR A DRIER AIR MASS TO FILTER INTO THE STATE MONDAY THROUGH THURSDAY AS THE UPPER LEVEL HIGH OVER SOUTHERN NEW MEXICO SHIFTS WESTWARD FILTERING IN DRIER AIR FROM THE PACIFIC. SHOWER AND THUNDERSTORM ACTIVITY WILL DOWNTREND AS TEMPERATURES CREEP BACK TO NORMAL/ABOVE NORMAL READINGS. EXPECT HAINES VALUES TO INCREASE TO THE 5 AND 6 VALUES ALONG WITH DECREASING MIN RH VALUES. STORM ACTIVITY WILL BE LIMITED TO HIGHER TERRAIN AREAS AND ADJACENT LOWER ELEVATION AREAS. THE MOISTURE PLUME LOOKS TO MAKE ITS RETURN BY THE FOLLOWING WEEKEND WITH AN INCREASE IN WETTING PRECIPITATION CHANCES ACROSS THE WEST AND NORTH AS THE UPPER LEVEL HIGH STARTS TO SHIFT EASTWARD. EXPECT POOR VENT RATES ACROSS THE NORTH THE REMAINDER OF THE WEEKEND WITH IMPROVEMENTS BY MONDAY THROUGH THURSDAY. MIN RH VALUES WILL DROP INTO THE UPPER TEENS BY THE MIDWEEK BUT OVERNIGHT RECOVERIES WILL REMAIN GOOD. 32 && .ABQ WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR THE FOLLOWING ZONES... NMZ501>507-510>517-523-528-529-531>534. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1143 PM MDT THU JUL 30 2015 .AVIATION... 06Z TAF CYCLE SHRA/TSRA CONTINUE ACROSS MUCH OF THE EASTERN PLAINS AND PORTIONS OF NW NM. THE FORMER IS MOVING TOWARD THE N AND NE AND THE LATTER IS MOVING TOWARD THE W AND NW. THE ACTIVITY ACROSS THE NW SHOULD CONTINUE FOR ANOTHER COUPLE OF HOURS...BUT LIKE LAST NIGHT...THE ACTIVITY ACROSS THE EAST MAY PERSIST THROUGH SUNRISE. MVFR CIGS/VSBYS WILL BE POSSIBLE WITH THE STRONGEST ACTIVITY. SHOULD STORMS DIMINISH EARLIER...COULD SEE MVFR/IFR CIGS ACROSS PORTIONS OF THE NE PLAINS. ANOTHER ROUND OF SHRA/TSRA IS EXPECTED ON FRIDAY FAVORING THE HIGH TERRAIN AND PORTIONS OF NE NM. STEERING FLOW WILL BE LIGHT...PERHAPS LIGHTER THAN TODAY AS THE UPPER HIGH REMAINS OVERHEAD. MVFR CIGS AND BRIEF MT OBSCURATIONS WILL BE POSSIBLE FRI AFTN. 34 && .PREV DISCUSSION...906 PM MDT THU JUL 30 2015... .UPDATE... UPDATED POP/WEATHER GROUPINGS IN THE GRIDDED FORECAST FOR REST OF TONIGHT. ALSO UPDATED THE FLASH FLOOD WATCH BY ELIMINATING WESTERN/CENTRAL AREAS. LATEST RADAR/SATELLITE IMAGERY AND TO A CERTAIN DEGREE MODELING SHOWS THE MAIN THREAT FOR HEAVY RAIN ACROSS EASTERN AREAS. THUS LEFT THE WATCH UP THERE. MODELS SEEM TO BE OVERDOING CONDITIONS ACROSS WESTERN/CENTRAL AREAS DESPITE SOME FOCUSING WAVE FEATURES. THE LATEST HRRR HAS BACK OFF QPF NUMBERS ACROSS SW/WC HIGHLANDS ALTHOUGH THERE IS A WAVE POISED TO IMPACT THOSE AREAS TONIGHT. SUSPECT THE RAINFALL WILL BE MORE STRATIFORM WITH LESS OF A HEAVY RAIN THREAT. SIMILARLY FOR NW AREAS WHERE THERE IS SOME ONGOING RAINFALL WITHIN A MID LEVEL DEFORMATION AREA. VERY MOIST ENVIRONMENT SO IT DOESNT TAKE MUCH TO PRODUCE A RAIN SHOWER. 50 && .PREV DISCUSSION...240 PM MDT THU JUL 30 2015... .SYNOPSIS... SHOWERS AND STORMS WITH LOCALLY HEAVY RAINFALL WILL CONTINUE TO IMPACT NEW MEXICO THROUGH THE WEEKEND. THE FLASH FLOOD POTENTIAL WILL REMAIN ELEVATED AS SLOW-MOVING STORMS DROP A QUICK 1 TO 2 INCHES OF RAIN. AREAS OF STEEP TERRAIN...BURNED FORESTS...URBAN DRAINAGES...AND AREAS THAT PICK UP DAILY ROUNDS OF HEAVY RAIN WILL BE THE MOST SUSCEPTIBLE. A VERY SLOW DRYING AND WARMING TREND IS EXPECTED BEGINNING NEXT WEEK. && .DISCUSSION... THE CLIMATOLOGICAL PEAK FOR DEEP ATMOSPHERIC MOISTURE AND FLASH FLOOD POTENTIAL IS CERTAINLY DELIVERING AS WE NEAR THE END OF JULY 2015. A REMNANT CONVECTIVE VORTEX FROM LAST NIGHT MOVING SLOWLY NORTH ALONG THE CONT DVD IS FOCUSING REDEVELOPMENT TODAY. ANOTHER AREA OF MOISTURE CONVERGENCE IS FIRING UP FROM LINCOLN COUNTY NORTH INTO TORRANCE COUNTY WHERE RADAR-BASED STORM TOTAL ACCUMULATION IS ALREADY NEAR 3 INCHES IN SOME LOCALES. THE WEAKEST STEERING FLOW IS FOCUSED OVER NORTHERN NM WHERE DEFORMATION STRETCHES FROM WEST TO EAST OVER THE HIGH TERRAIN. ANY ACTIVITY THERE WILL BE NEARLY STATIONARY AND PRODUCE TORRENTIAL RAINFALL. ALL THESE AREAS ARE UNDER THE FLASH FLOOD WATCH AND NO CHANGES WILL BE MADE. SOME MINOR RIVER FLOODING IS ALSO POSSIBLE ALONG TRIBUTARIES TO MAIN STEM RIVERS SUCH AS THE RIO GRANDE AND PECOS THROUGH THE WEEKEND. EXPECT LITTLE TO NO CHANGE FRIDAY...EXCEPT PERHAPS A GREATER FOCUS FOR HEAVY RAINFALL FARTHER NORTHWEST TOWARD THE FOUR CORNERS. THIS WEEKEND WILL SEE ELEVATED FLASH FLOOD POTENTIAL AS THE UPPER HIGH ESTABLISHES FIRMLY OVERHEAD. EACH AFTERNOON OF HEAVY RAINFALL IN THE SAME AREAS WILL EXACERBATE FLASH FLOOD POTENTIAL. A SLOW WARMING AND DRYING TREND IS STILL EXPECTED AS WE HEAD INTO EARLY NEXT WEEK WITH NO ADDITIONAL INFLUX OF MOISTURE NOTED. THE RECYCLING PROCESS WILL BE THE DOMINANT PLAYER...WHICH WILL BE VERY EFFICIENT. NASA SPORT LIS SHOWS MOIST SOILS ARE EXPANDING OVER A LARGER AREA OF NM AND TO DEEPER LAYERS. OVERALL...CONDITIONS ARE LOOKING VERY TYPICAL OF A MATURE MONSOON PATTERN THROUGH EARLY AUGUST. GUYER && .FIRE WEATHER... UPPER HIGH CENTER ATTEMPTING TO BECOME ESTABLISHED OVER NEW MEXICO THIS AFTERNOON...AND MODELS PERSIST ON IT LINGERING OVER THE STATE FOR MUCH OF THE UPCOMING WEEK...ALTHOUGH IT/S LIKELY TO WOBBLE AROUND A BIT. MOISTURE TO REMAIN TRAPPED UNDER THE RIDGE...BUT SHOULD VERY SLOWLY WARM AND DRY NEXT WEEK. CELL MOTION COULD BE SOMEWHAT ERRATIC FOR THE REST OF THIS AFTERNOON AND TONIGHT...BUT GENERALLY NORTHWEST AND NORTH WEST OF THE RGV AND NORTH TO NORTHEAST EAST OF THE RGV. MOVEMENT AND SPEED WILL TREND TO SLOWER AND MORE ERRATIC FRIDAY AND INTO THE WEEKEND WITH THE HIGH CENTER OVERHEAD. THEREFORE...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AT LEAST THROUGH FRIDAY. HIGH TEMPERATURES TO VARY FROM MOSTLY BELOW AVERAGE THROUGH SUNDAY TO NEAR TO ABOVE AVERAGE NEXT MONDAY THROUGH THURSDAY. WHILE MIN RH VALUES WILL TREND DOWNWARD NEXT WEEK...OVERNIGHT RECOVERIES FORECAST TO REMAIN EXCELLENT. VENT RATES OVER PORTIONS OF THE NORTH WILL BE FAIR TO POOR THROUGH SUNDAY. POOR RATES ARE FORECAST FOR THE NORTHEAST AND SOUTHWEST MONDAY. && .ABQ WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 4 AM MDT FRIDAY FOR THE FOLLOWING ZONES... NMZ512>515-523-527>537. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1005 PM EDT SAT AUG 1 2015 .SYNOPSIS... A WEAK FRONT WILL REMAIN STALLED ACROSS THE COASTAL CAROLINAS THIS WEEKEND...PRODUCING ISOLATED SHOWERS AND THUNDERSTORMS NEAR THE COAST. THE FRONT SHOULD DISSIPATE ON MONDAY. BERMUDA HIGH PRESSURE WELL OFFSHORE WILL BUILD WESTWARD NEXT WEEK. TEMPERATURES WILL REMAIN SEASONABLE TO SLIGHTLY ABOVE NORMAL THROUGH THE WEEKEND INTO NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1000 PM SATURDAY...FORECAST SOUNDINGS FROM BOTH THE NAM AND GFS SHOW A THIN LAYER OF UNSTABLE AIR AT THE TOP OF TODAY`S DEEP MIXED LAYER ACROSS THE PEE DEE REGION. THIS IS NOT A SITUATION I WOULD HAVE ANTICIPATED CONVECTION TO DEVELOP WITHIN GIVEN ELEVATED INSTABILITY BASED AROUND 6500 FEET AGL AND BONE-DRY AIR AT AND ABOVE 700 MB. NEVERTHELESS THERE ARE SHOWERS WITH LOCALLY HEAVY RAIN DEVELOPING ALONG THE I-95 CORRIDOR FROM FLORENCE NORTHWARD TO NEAR BINGHAM IN WESTERN DILLON COUNTY. INFRARED SATELLITE SHOWS ADDITIONAL MID- LEVEL CLOUD COVER EXTENDING NORTHWARD INTO ROBESON COUNTY NC...SO I HAVE TO AT LEAST CONSIDER THE POSSIBILITY FOR SHOWERS TO DEVELOP THIS FAR NORTH AS WELL. AT THE SURFACE HIGHER DEWPOINTS HAVE RETURNED WESTWARD INTO THE INTERIOR COASTAL PLAIN WITH 70S SHOWING UP AGAIN IN LUMBERTON... MARION AND FLORENCE. THIS MOISTURE MAY BE TOO THIN TO BE FEEDING THE CONVECTION DIRECTLY...AS THE SURFACE IS LIKELY DECOUPLED FROM THE ATMOSPHERE ALOFT. LATEST HRRR MODEL RUNS DO NOT REALLY SHOW THIS CURRENT ACTIVITY WELL...ALTHOUGH INTERESTINGLY THE 00Z NAM DOES. THE NAM MOVES THE SHOWERS EASTWARD TOWARD THE COAST...DISSIPATING THE CONVECTION BETWEEN 06-09Z NEAR MYRTLE BEACH. AT 500 MB THE CAROLINAS FORM THE BASE OF A BROAD TROUGH EXTENDING DOWN FROM HUDSON BAY CANADA. PLENTY OF DRY AIR AT AND ABOVE 700 MB SHOULD CONTINUE ON WESTERLY WINDS OVERNIGHT. HIGH PRESSURE OVER THE OHIO VALLEY WILL DRIFT EASTWARD INTO THE CENTRAL APPALACHIANS SUNDAY MORNING. THIS WILL NUDGE OUR FRONT OFF THE COAST INTO THE NEARSHORE WATERS BY DAYBREAK. MOISTURE TRAPPED WITHIN THE DECOUPLED BOUNDARY LAYER WILL REMAIN TRAPPED OVERNIGHT...AND WITH GOOD RADIATIONAL COOLING I ANTICIPATE PATCHY FOG WILL DEVELOP...ESPECIALLY EAST OF I-95 WHERE DEWPOINTS ARE HIGHEST. LOWS SHOULD FALL 70-74...WARMEST AT THE BEACHES. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... AS OF 300 PM SATURDAY...STATIONARY FRONT WILL REMAIN IN AREA SUNDAY BEFORE DISSIPATING IN PLACE ON MONDAY. MEANWHILE...A BROAD...FLAT-ISH H5 TROUGH WILL REMAIN ANCHORED IN PLACE OVER EASTERN CONUS. GUIDANCE STILL SHOWING PLENTIFUL DRY AIR ALOFT WHICH WILL LIMIT EXTENT OF CONVECTION DESPITE PRESENCE OF FRONTAL BOUNDARY AND THE OCCASIONAL SHORT WAVE THAT WILL DROP INTO THE BASE OF THE UPPER TROUGH. AIR ALOFT IS DRIEST INLAND...SO WILL SHOW A DECREASING GRADIENT IN POPS NW FROM THE COAST FOR BOTH DAYS. DUE TO OVERALL LIMITED MOISTURE ALOFT...WILL KEEP POPS CAPPED AT LOW CHANCE FOR THE IMMEDIATE COAST FOR BOTH DAYS...WITH FAR INLAND AREAS BEING POSSIBLY TOO DRY TO SEE ANY SIGNIFICANT RAINFALL. TEMPERATURES WILL REMAIN ABOVE CLIMO THROUGH THE SHORT TERM AND HEAT INDEX VALUES WILL LIKELY REACH AROUND A 100 OR SO BOTH AFTERNOONS. HOWEVER...HEAT ADVISORY CRITERIA IS NOT EXPECTED TO BE EXCEEDED. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 300 PM SATURDAY... WHAT LITTLE MOISTURE THERE WILL BE IN PLACE ON TUESDAY WILL BE POOLED UP ALONG THE COAST. MINOR RAIN CHANCES WILL BE FOCUSED THERE DURING AN OTHERWISE HOT AFTERNOON PROVIDED IN PART BY A VERY WEAK RIDGE ALOFT. RAIN CHANCES REMAIN SLOW ON WEDNESDAY AS THE FLOW ALOFT STAYS WEAK THOUGH THE SENSE OF RIDGING WEAKENS. SO WILL KEEP POPS MINIMIZED BUT SHOW THEM AREA- WIDE. RAIN CHANCES RAMP UP TO SCATTERED ON THURSDAY AS SOME WEAKLY CYCLONIC CURVATURE OVERSPREADS THE REGION AND A SURFACE PIEDMONT TROUGH TAKES SHAPE. ANOTHER LITTLE PIECE OF ENERGY WILL PROVIDE SOME LIFT ON FRIDAY WHICH MAY BE ANOTHER FAIRLY ACTIVE DAY. ON SATURDAY NOT ONLY WILL THERE BE CONTINUED DISTURBANCES IMPINGING UPON THE AREA FROM THE NORTHWEST BUT A COLD FRONT WILL ALSO BE MOVING INTO THE CAROLINAS. WEDNESDAY AND THURSDAY WILL BOTH SEE RATHER HOT AFTERNOONS WHEREAS THE INCREASE IN CLOUDS LATE IN THE PERIOD SHOULD TEMPER THINGS A BIT BACK TOWARDS CLIMO. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AS OF 23Z...LATEST SFC ANALYSIS SHOWS A STATIONARY FRONT DRAPED BETWEEN THE INLAND AND COASTAL TERMINALS. CONVECTION FIRED UP ALONG THIS BOUNDARY MAINLY NEAR AND OVER KILM THIS AFTERNOON. PLENTY OF LLVL MOISTURE AVAILABLE FOR THE TONIGHT/OVERNIGHT PERIOD TRAPPED BENEATH AN INVERSION AND WITH LIGHT WINDS ALSO EXPECTED CANNOT RULE OUT MVFR CONDITIONS DUE TO FOG DEVELOPMENT...ESPECIALLY KILM. WILL MAKE MENTION AFTER 08Z IN ALL TERMINALS FOR FOG AND MVFR CONDITIONS. VFR TO RETURN AFTER 12Z AND SUNDAY WILL BE SOMEWHAT LIKE TODAY WITH THE STATIONARY FRONT DRAPED ACROSS THE REGION AND THE CHANCE OF ISOLATED SHOWER OR THUNDERSTORM POSSIBLE DURING THE DAY. WILL KEEP VFR IN ALL TERMINALS BUT CANNOT RULE OUT A BRIEF MVFR IN VSBY/CEILING IF CONVECTION OCCURS OVER A TERMINAL. EXTENDED OUTLOOK...PREDOMINANTLY VFR THROUGH THE PERIOD WITH A SLIGHT CHANCE AFTERNOON SHRA/TSRA. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 PM SATURDAY...A FRONT IS STALLED ACROSS THE COASTAL PLAIN OF THE CAROLINAS THIS EVENING. HIGH PRESSURE OVER OHIO WILL DRIFT EAST INTO THE CENTRAL APPALACHIANS LATE TONIGHT. THIS SHOULD NUDGE THE FRONT EASTWARD AND INTO THE COASTAL WATERS LATE. SOUTH TO SOUTHWEST WINDS THIS EVENING AS HIGH AS 15 KNOTS IN THE CAPE FEAR AREA SHOULD DIMINISH TO LESS THAN 10 KNOTS AFTER MIDNIGHT...THEN TURN NORTHWESTERLY LATE AS THE FRONT PUSHES OFF THE COAST. THE PRIMARY WAVE SET IS A 7-SECOND SOUTHERLY SWELL...WITH A SMALLER 10-SECOND SOUTHEASTERLY SWELL SHOWING UP. THESE TWO WAVES WILL CONTINUE INDEPENDENT OF THE WIND OVERNIGHT...WITH COMBINED SEAS 2-4 FEET...HIGHEST OFFSHORE FROM CAPE FEAR. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 PM SATURDAY...A STALLED FRONT WILL DISSIPATE OVER THE EASTERN CAROLINAS ON MONDAY AS BERMUDA HIGH PRESSURE OFFSHORE EXTENDS BACK WEST ACROSS THE WATERS. WINDS WILL SETTLE BACK INTO A SWLY DIRECTION BY SUNDAY NIGHT AS THE FRONT WEAKENS AND DISSIPATES. A SMALL CRAFT ADVISORY MAY BE REQUIRED MONDAY AFTERNOON OR EVENING AS THE GRADIENT TIGHTENS WITH HIGH PRESSURE BUILDING WEST ACROSS THE WATERS. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 300 PM SATURDAY...WIND AND SEAS RELAX ON TUESDAY AS PIEDMONT TROUGHINESS PUSHES THE TIGHTER GRADIENT CAUSED BY THE BERMUDA HIGH FURTHER OUT TO SEA. THOUGH SOME SWELL ENERGY MAY REMAIN WE SHOULD DROP BELOW ADVISORY THRESHOLDS. THEREAFTER IT LOOKS LIKE PRETTY STANDARD FARE FOR JULY WITH A SOUTHWESTERLY WIND IN THE 10 TO 15 KT RANGE AND 2 TO 4 FT SEAS...HIGHEST OFFSHORE. && .TIDES/COASTAL FLOODING... AS OF 200 AM SATURDAY...MINOR COASTAL FLOODING IS POSSIBLE DURING THE NIGHT-TIME HIGH TIDE OVER THE NEXT COUPLE OF DAYS. THESE HIGHER THAN NORMAL TIDES ARE THE RESULT OF THE PERIGEAN SPRING TIDE AND A FULL MOON WHICH OCCURRED ON FRIDAY. DEPARTURES OF PLUS 1/2 TO 1 FOOT WILL BE ENOUGH TO PRODUCE A BRIEF PERIOD OF MINOR COASTAL FLOODING. THE RISK IS HIGHEST FOR PORTIONS OF THE LOWER CAPE FEAR RIVER TO INCLUDE DOWNTOWN WILMINGTON...WITH A LIKELY PROBABILITY. THE BEACHES WILL APPROACH THE THRESHOLD FOR MINOR COASTAL FLOODING AGAIN THIS EVE...BUT THIS WILL BE THE LAST TIME THIS LUNAR CYCLE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NCZ107. MARINE...NONE. && $$ SYNOPSIS...REK NEAR TERM...TRA SHORT TERM...REK LONG TERM...MBB AVIATION...MAC TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
138 PM EDT FRI JUL 31 2015 .SYNOPSIS... A COLD FRONT WILL STALL ALONG THE COAST THROUGH THE WEEKEND. THE FRONT WEAKENS EARLY NEXT WEEK AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE ATLANTIC...AND AN INLAND TROUGH DEVELOPS TO THE WEST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1235 PM FRIDAY...FRONTAL BOUNDARY REMAINS JUST SOUTH OF THE NC COAST. HIGH-RESOLUTION MODELS SUCH AS THE HRRR AND RUC INDICATE A RATHER PROUNOUNCED SEA BREEZE WILL DEVELOP DURING THE LATE AFTERNOON HOURS. IN CONCERT WITH A DIGGING MID-LEVEL TROUGH...EXPECT A GOOD COVERAGE OF SHOWERS/THUNDERSTORMS PRIMARY OVER THE SOUTHERN HALF OF THE AREA AND MAINLY NEAR THE COAST THIS AFTERNOON INTO THIS EVENING. MODERATE INSTABILITY IS FORECAST WITH CAPES 1500-2000 J/KG AND LI`S -3 TO -5...BUT A COL IN THE MID-LEVEL FLOW WILL LEAD TO VERY SLOW MOVEMENT OF ANY ACTIVITY THAT DEVELOPS WITH POSSIBLE LOCALIZED HEAVY RAINFALL...GIVEN PRECIPITABLE WATER VALUES OF AROUND 2 INCHES FROM THE 12Z MHX SOUNDING. ONLY MINOR CHANGES MADE TO CURRENT FORECAST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... AS OF 3 AM FRIDAY...THE STALLED FRONT WILL CONT TO PROVIDE THE FOCUS FOR SCT CONVECTION ALONG THE SRN TIER TONIGHT WITH MORE ISOLD PRECIP TO THE N. SLIGHTLY COOLER TEMPS FOR INLAND AREAS TONIGHT WITH LOWS IN THE UPR 60S TO NEAR 70 COASTAL PLAINS AND THE LOWER AND MID 70S FOR COASTAL AREAS WITH PARTLY CLOUDY SKIES N AND MOSTLY CLOUDY SKIES FOR SOUTHERN SXNS WITH BTR PRECIP CHCS. && .LONG TERM /SATURDAY THROUGH FRIDAY/... AS OF 330 AM FRI...WEAK COLD FRONT WILL STALL NEAT THE COAST THROUGH THE WEEKEND WHILE BROAD TROUGHING DOMINATES ALOFT. ATLANTIC HIGH PRESSURE WILL BUILD BACK IN EARLY TO MID NEXT WEEK. SATURDAY AND SUNDAY...MODELS COMING INTO BETTER AGREEMENT WITH RESPECT TO SHOWER/STORM CHANCES THIS WEEKEND. THE 31/00Z ECM HAS CONTINUED TO TREND TOWARDS THE DRIER GFS SOLN. WILL FOLLOW TRENDS OF DECREASING POPS TO LESS THAN 20 PERCENT FOR THE NORTHERN AREAS AND 20-30 PERCENT ON THE COAST THROUGH THE WEEKEND. ANY STORMS THAT DEVELOP COULD PRODUCE HEAVY RAIN PER HIGH LAYER MIX RATIOS AND COLUMN PWATS AOA 2 INCHES ALONG THE COAST THROUGH THE WEEKEND. TEMPS WILL BE TYPICALLY HOT WITH HIGHS IN THE LOW 90S INLAND TO 80S COAST...WITH LOWS IN THE LOW/MID 70S INLAND TO UPR 70S COAST. MONDAY...SIMILAR SCENARIO TO THE WEEKEND WITH BROAD TROUGHING AND WASHED OUT FRONTAL BOUNDARY NEAR THE AREA. BEST SHOWER CHANCES WILL AGAIN BE NEAR OR JUST OFFSHORE EARLY MONDAY...THEN SEA BREEZE CONVERGENCE DURING THE AFTERNOON MAY PROMOTE SCT/ISO THUNDERSTORMS FOR THE SECOND HALF OF THE DAY INLAND. STILL HOT AND MUGGY WITH HIGHS IN THE LOW 90S INLAND TO 80S COAST. TUESDAY THROUGH THURSDAY...WARMING TEMPS AS THICKNESSES AND TEMPS BUILD WITH HIGHS CLIMBING INTO THE MID 90S (80S COAST). SOME MODEL DIFFERENCES CONTINUE MID WEEK AS 31/00Z GFS CONTINUES TROUGHING ALONG THE EAST COAST AND PUSHES A FRONT THROUGH THE AREA LATE WED/THU WITH A WAVE DEVELOPING ALONG IT... WHILE THE ECMWF HAS BERMUDA HIGH AS MAIN FEATURE AND THERMAL TROUGHING INLAND. WILL TREND WITH WPC/ECMWF AND PREVIOUS FORECAST WITH HIGH OFFSHORE AND PRED S/SW FLOW ACROSS THE AREA. WILL CONTINUE SC POPS...THINKING PRIMARILY DIURNALLY DRIVEN AT THIS TIME AND MAINLY AWAY FROM THE COAST. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 18Z SATURDAY/... AS OF 130 PM FRIDAY...VFR CONDITIONS THROUGH MUCH OF THE TAF PERIOD. SHOWERS AND THUNDERSTORMS SHOULD START TO DEVELOP LATER THIS AFTERNOON ALONG THE SEA BREEZE/STALLED FRONT. THIS ACTIVITY SHOULD STAY PRIMARILY EAST OF THE TAF SITES. BUT CAN NOT RULE OUT PRECIPITATION MIGRATING CLOSER TO OAJ/EWN. PRECIPITATION SHOULD DIMINISH THROUGH THE EVENING HOURS WITH CLOUDS ALSO ERODING THROUGH THE OVERNIGHT...LINGERING MAINLY ALONG THE COAST. THEREFORE...THIS MAY PROVIDE A BRIEF OPPORTUNITY FOR FOG TO DEVELOP ESPECIALLY ACROSS OAJ/ISO DURING THE EARLY MORNING HOURS. FEEL EWN MAY HAVE TOO MUCH CLOUD COVER STILL IN PLACE TO OBSERVE MUCH FOG. DEW POINT DEPRESSIONS ACROSS THE NW MIGHT ALSO BE A BIT HIGH. THEREFORE...HAVE EWN/PGV WITH A BIT HIGHER VSBYS AS COMPARED TO OAJ/ISO. ANY LOW LEVEL MOISTURE SHOULD MIX OUT BY MID-MORNING WITH MOSTLY CLEAR SKIES FOR MUCH OF SATURDAY. LIGHT AND VARIABLE WINDS THROUGH THE TAF PERIOD. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 330 AM FRI...PRED VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A FRONT WILL STALL NEAR THE COAST OR JUST OFFSHORE THROUGH THE WEEKEND. ISOLATED TO SCT SHOWERS/TSTMS SAT THROUGH EARLY NEXT WEEK...WITH BEST CHANCES AT EWN/OAJ. PATCHY FOG/STRATUS POSSIBLE EACH NIGHT WITH LIGHT WINDS ESP FOR AREAS THAT RECEIVE RAINFALL. && .MARINE... SHORT TERM /TODAY AND TONIGHT/... AS OF 1240 PM FRIDAY...STILL GENERALLY NORTHERLY WINDS OVER THE COASTAL WATERS AND SOUNDS...ALTHOUGH SEEING WINDS VEER TO MORE SOUTHEAST OVER THE FAR SOUTHERN WATERS. SPEEDS REMAIN LESS THAN 15 KNOTS WITH SEAS OF 3 TO 4 FEET. WILL SEE SOUTHWEST WINDS DEVELOP WITH A FAIRLY PRONOUNCED SEA BREEZE THIS AFTERNOON OVER SOUTHERN SECTIONS...WITH LIGHT NORTH WINDS CONTINUING NORTH OF OCRACOKE. WINDS GRADUALLY BECOME SE TO S TONIGHT 10 KT OR LESS. WINDS BECOME SW THROUGHOUT TOWARD SAT MORN HIGHEST SRN COASTAL WATERS. SEAS WILL RANGE 2-4 FT TONIGHT. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 330 AM FRI...THE COLD FRONT WILL WASH OUT BY SAT WITH SOUTHERLY FLOW ONCE AGAIN DEVELOPING. GRADIENT TIGHTENS THROUGH THE DAY SAT WITH INCREASING SSW WINDS 10-15KT CONT INTO SUN. A PERIOD OF MARGINAL SCA CONDITIONS LIKELY TO DEVELOP SUN NIGHT...MAINLY SOUTH OF OREGON INLET...WITH WINDS INCREASING TO 15-25KT AND SEAS BUILDING TO 4-7FT. GUSTY SW WINDS EXPECTED TO CONTINUE INTO TUE...WITH LINGERING 6FT SEAS POSSIBLE INTO TUE NIGHT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JAC NEAR TERM...CTC SHORT TERM...JAC LONG TERM...CQD/TL AVIATION...TL/LEP MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1239 PM EDT FRI JUL 31 2015 .SYNOPSIS... A COLD FRONT WILL STALL ALONG THE COAST THROUGH THE WEEKEND. THE FRONT WEAKENS EARLY NEXT WEEK AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE ATLANTIC...AND AN INLAND TROUGH DEVELOPS TO THE WEST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1235 PM FRIDAY...FRONTAL BOUNDARY REMAINS JUST SOUTH OF THE NC COAST. HIGH-RESOLUTION MODELS SUCH AS THE HRRR AND RUC INDICATE A RATHER PROUNOUNCED SEA BREEZE WILL DEVELOP DURING THE LATE AFTERNOON HOURS. IN CONCERT WITH A DIGGING MID-LEVEL TROUGH...EXPECT A GOOD COVERAGE OF SHOWERS/THUNDERSTORMS PRIMARY OVER THE SOUTHERN HALF OF THE AREA AND MAINLY NEAR THE COAST THIS AFTERNOON INTO THIS EVENING. MODERATE INSTABILITY IS FORECAST WITH CAPES 1500-2000 J/KG AND LI`S -3 TO -5...BUT A COL IN THE MID-LEVEL FLOW WILL LEAD TO VERY SLOW MOVEMENT OF ANY ACTIVITY THAT DEVELOPS WITH POSSIBLE LOCALIZED HEAVY RAINFALL...GIVEN PRECIPITABLE WATER VALUES OF AROUND 2 INCHES FROM THE 12Z MHX SOUNDING. ONLY MINOR CHANGES MADE TO CURRENT FORECAST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... AS OF 3 AM FRIDAY...THE STALLED FRONT WILL CONT TO PROVIDE THE FOCUS FOR SCT CONVECTION ALONG THE SRN TIER TONIGHT WITH MORE ISOLD PRECIP TO THE N. SLIGHTLY COOLER TEMPS FOR INLAND AREAS TONIGHT WITH LOWS IN THE UPR 60S TO NEAR 70 COASTAL PLAINS AND THE LOWER AND MID 70S FOR COASTAL AREAS WITH PARTLY CLOUDY SKIES N AND MOSTLY CLOUDY SKIES FOR SOUTHERN SXNS WITH BTR PRECIP CHCS. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 330 AM FRI...WEAK COLD FRONT WILL STALL NEAT THE COAST THROUGH THE WEEKEND WHILE BROAD TROUGHING DOMINATES ALOFT. ATLANTIC HIGH PRESSURE WILL BUILD BACK IN EARLY TO MID NEXT WEEK. SATURDAY AND SUNDAY...MODELS COMING INTO BETTER AGREEMENT WITH RESPECT TO SHOWER/STORM CHANCES THIS WEEKEND. THE 31/00Z ECM HAS CONTINUED TO TREND TOWARDS THE DRIER GFS SOLN. WILL FOLLOW TRENDS OF DECREASING POPS TO LESS THAN 20 PERCENT FOR THE NORTHERN AREAS AND 20-30 PERCENT ON THE COAST THROUGH THE WEEKEND. ANY STORMS THAT DEVELOP COULD PRODUCE HEAVY RAIN PER HIGH LAYER MIX RATIOS AND COLUMN PWATS AOA 2 INCHES ALONG THE COAST THROUGH THE WEEKEND. TEMPS WILL BE TYPICALLY HOT WITH HIGHS IN THE LOW 90S INLAND TO 80S COAST...WITH LOWS IN THE LOW/MID 70S INLAND TO UPR 70S COAST. MONDAY...SIMILAR SCENARIO TO THE WEEKEND WITH BROAD TROUGHING AND WASHED OUT FRONTAL BOUNDARY NEAR THE AREA. BEST SHOWER CHANCES WILL AGAIN BE NEAR OR JUST OFFSHORE EARLY MONDAY...THEN SEA BREEZE CONVERGENCE DURING THE AFTERNOON MAY PROMOTE SCT/ISO THUNDERSTORMS FOR THE SECOND HALF OF THE DAY INLAND. STILL HOT AND MUGGY WITH HIGHS IN THE LOW 90S INLAND TO 80S COAST. TUESDAY THROUGH THURSDAY...WARMING TEMPS AS THICKNESSES AND TEMPS BUILD WITH HIGHS CLIMBING INTO THE MID 90S (80S COAST). SOME MODEL DIFFERENCES CONTINUE MID WEEK AS 31/00Z GFS CONTINUES TROUGHING ALONG THE EAST COAST AND PUSHES A FRONT THROUGH THE AREA LATE WED/THU WITH A WAVE DEVELOPING ALONG IT... WHILE THE ECMWF HAS BERMUDA HIGH AS MAIN FEATURE AND THERMAL TROUGHING INLAND. WILL TREND WITH WPC/ECMWF AND PREVIOUS FORECAST WITH HIGH OFFSHORE AND PRED S/SW FLOW ACROSS THE AREA. WILL CONTINUE SC POPS...THINKING PRIMARILY DIURNALLY DRIVEN AT THIS TIME AND MAINLY AWAY FROM THE COAST. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 12Z SATURDAY/... AS OF 3 AM FRI...FOG/LOW CLOUD DEVELOPMENT WITH MVFR/IFR CONDITIONS PSBLE INTO THE EARLY MORN HOURS IN ADVANCE OF THE FRONT. FRONT WILL HANG UP ALONG THE COAST TODAY WITH SUB VFR CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS...MAINLY IN THE AFTERNOON FOR SOUTHERN AREAS POSSIBLY AFFECTING OAJ AND EWN. WILL HAVE VCTS FOR THE AFTN AFT 18Z AND VCSH AFT 00Z TNGT FOR THESE TAF SITES. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 330 AM FRI...PRED VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A FRONT WILL STALL NEAR THE COAST OR JUST OFFSHORE THROUGH THE WEEKEND. ISOLATED TO SCT SHOWERS/TSTMS SAT THROUGH EARLY NEXT WEEK...WITH BEST CHANCES AT EWN/OAJ. PATCHY FOG/STRATUS POSSIBLE EACH NIGHT WITH LIGHT WINDS ESP FOR AREAS THAT RECEIVE RAINFALL. && .MARINE... SHORT TERM /TODAY AND TONIGHT/... AS OF 1240 PM FRIDAY...STILL GENERALLY NORTHERLY WINDS OVER THE COASTAL WATERS AND SOUNDS...ALTHOUGH SEEING WINDS VEER TO MORE SOUTHEAST OVER THE FAR SOUTHERN WATERS. SPEEDS REMAIN LESS THAN 15 KNOTS WITH SEAS OF 3 TO 4 FEET. WILL SEE SOUTHWEST WINDS DEVELOP WITH A FAIRLY PRONOUNCED SEA BREEZE THIS AFTERNOON OVER SOUTHERN SECTIONS...WITH LIGHT NORTH WINDS CONTINUING NORTH OF OCRACOKE. WINDS GRADUALLY BECOME SE TO S TONIGHT 10 KT OR LESS. WINDS BECOME SW THROUGHOUT TOWARD SAT MORN HIGHEST SRN COASTAL WATERS. SEAS WILL RANGE 2-4 FT TONIGHT. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 330 AM FRI...THE COLD FRONT WILL WASH OUT BY SAT WITH SOUTHERLY FLOW ONCE AGAIN DEVELOPING. GRADIENT TIGHTENS THROUGH THE DAY SAT WITH INCREASING SSW WINDS 10-15KT CONT INTO SUN. A PERIOD OF MARGINAL SCA CONDITIONS LIKELY TO DEVELOP SUN NIGHT...MAINLY SOUTH OF OREGON INLET...WITH WINDS INCREASING TO 15-25KT AND SEAS BUILDING TO 4-7FT. GUSTY SW WINDS EXPECTED TO CONTINUE INTO TUE...WITH LINGERING 6FT SEAS POSSIBLE INTO TUE NIGHT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JAC NEAR TERM...CTC SHORT TERM...JAC LONG TERM...CQD/TL AVIATION...CTC/TL MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
911 PM CDT SAT AUG 1 2015 .UPDATE... ISSUED AT 853 PM CDT SAT AUG 1 2015 CONVECTION THREAT HAS ENDED OVER SOUTHEAST NORTH DAKOTA. FOCUS NOW SHIFTS TO THE NORTH. ISOLATED CONVECTION OVER THE PAST HOUR OR SO OVER SOUTHERN MANITOBA/SASKATCHEWAN IS BEGINNING TO PUSH INTO NORTHERN NORTH DAKOTA. AN ISOLATED THUNDERSTORM DEVELOPED OVER BOTTINEAU COUNTY OVER THE PAST HOUR. ML CAPES AROUND 1000-1500 J/KG WITH 50-60 KNOTS OF BULK SHEAR REMAIN OVER THE FAR NORTH CENTRAL INTO THE TURTLE MOUNTAINS AND A FEW MORE STORMS CAN NOT BE RULED OUT OVER THE NEXT FEW HOURS. THE THREAT FOR SEVERE WEATHER WILL BE MINIMAL...AND WILL SHIFT FARTHER EAST AS THE EVENING PROGRESSES. THIS IS CURRENTLY COVERED IN THE GOING FORECAST. WE DID BUMP UP WINDS OVER THE WEST AND CENTRAL THIS EVENING A NICE FALL-RISE PRESSURE BUBBLE WAS NOTED OVER THE NORTHWEST ASSOCIATED WITH THE SURFACE LOW OVER NORTHWEST NORTH DAKOTA. SOME 40 MPH WIND GUSTS WERE REPORTED OVER THE FAR NORTHWEST WITH THE 8 PM OBSERVATIONS. THE COUPLET WILL TRACK SOUTHEAST ACROSS THE FORECAST AREA TONIGHT. BUT AS WINDS DECOUPLE THIS EVENING WITH THE SETTING SUN...THE STRONGER GUST POTENTIAL WILL ALSO SUBSIDE. UPDATE ISSUED AT 543 PM CDT SAT AUG 1 2015 UNSTABLE AIRMASS REMAINS OVER SOUTHEAST NORTH DAKOTA. HOWEVER...THERE HAS BEEN ENOUGH CIN TO PRECLUDE THUNDERSTORM DEVELOPMENT FROM CU FIELD THAT DEVELOPED EARLIER THIS AFTERNOON. CAPE REMAINS HIGH BUT SHEAR IS DECREASING. WILL KEEP A MENTION OF THUNDER THROUGH 7 PM AS A FEW CU REMAIN OVER CENTRAL AND EASTERN PORTIONS OF DICKEY/LAMOURE COUNTIES. TO THE NORTHWEST...A LINE OF CU HAS DEVELOPED ALONG THE COLD FRONT MOVING INTO NORTHWEST NORTH DAKOTA. SUFFICIENT BULK SHEAR ALONG THE INTERNATIONAL BORDER BUT DEEP MOISTURE IS LACKING...ESPECIALLY RIGHT ALONG AND BEHIND THE FRONT WITH MUCH DRIED DEWPOINTS OVER THE FAR NORTHWEST AND INTO NORTHEAST NORTH DAKOTA. COULD STILL BE SOME SHOWER/THUNDERSTORM ACTIVITY HERE LATER THIS EVENING AS THE FRONT MOVES INTO CENTRAL AND EASTERN NORTH DAKOTA. THIS IS COVERED IN THE CURRENT FORECAST WITH A MENTION OF SHOWERS ACROSS THE FAR NORTH CENTRAL...AND INTO THE TURTLE MOUNTAINS AREA THIS EVENING. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 223 PM CDT SAT AUG 1 2015 SEVERE CONVECTIVE POTENTIAL ACROSS THE JAMES RIVER VALLEY THIS AFTERNOON HIGHLIGHTS THE SHORT TERM FORECAST. VISIBLE SATELLITE IMAGERY THROUGH 1920 UTC CONTINUES TO DEPICT A DEVELOPING CUMULUS FIELD BETWEEN JAMESTOWN...STEELE AND EDGELEY. THE 13-18 UTC HRRR ITERATIONS HAVE ALL DEPICTED CONVECTIVE INITIATION FOR THIS AREA BY 21 UTC IN AN ENVIRONMENT CHARACTERIZED BY ML CAPE AROUND 2000-3000 J/KG AND DEEP LAYER SHEAR OF 30-40 KTS. WITH A SHORTWAVE EVIDENT JUST UPSTREAM ON WATER VAPOR...CONVECTIVE POTENTIAL IS INCREASING ALONG WITH THE THREAT FOR LARGE HAIL AND DAMAGING WINDS IN AN ENVIRONMENT SUPPORTIVE OF SUPERCELLS...AND HAVE THUS ADDED SEVERE WORDING TO THE JAMES RIVER VALLEY FOR THIS AFTERNOON. EXPECT THE THREAT TO QUICKLY EXIT INTO THE GRAND FORKS CWA BY 00 UTC. LATER THIS EVENING A COLD FRONT WILL PROPAGATE FROM NORTHWEST TO SOUTHEAST ACROSS NORTH DAKOTA...YIELDING A COOLER BUT STILL SEASONABLE SUNDAY FOR EARLY AUGUST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 240 PM CDT SAT AUG 1 2015 NORTHWEST FLOW ALOFT THROUGH MONDAY NIGHT. DRY CONDITIONS EXPECTED WITH SURFACE HIGH PRESSURE FIRMLY IN PLACE ACROSS THE DAKOTAS. DEEP UPPER LOW MOVING SOUTH INTO THE GREAT LAKES REGION SUNDAY WILL PUSH A BACK DOOR COLD FRONT INTO THE NORTHERN PLAINS AND KEEP TEMPERATURES RELATIVELY COOL IN THE 70S TO LOW 80S MONDAY AND TUESDAY. A MORE ACTIVE PATTERN MATERIALIZES MID TO LATE NEXT WEEK WHEN OUR FLOW TRANSITIONS TO MORE ZONAL ALLOWING SEVERAL EMBEDDED WAVES TO MOVE THROUGH THE REGION. BEST THUNDERSTORM CHANCES WILL BE CONFINED TO THE SOUTH AND WEST INITIALLY...UNTIL LATER IN THE WEEK WHEN A CLOSED MID LEVEL CROSSES THE ALBERTA ROCKIES AND MOVES INTO NORTH DAKOTA FRIDAY. TEMPERATURES DO NOT RECOVER MUCH FROM EARLY IN THE WEEK...AND LOOK TO REMAIN BELOW AVERAGE FOR EARLY AUGUST WED-FRI (70S TO LOW 80S). && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 853 PM CDT SAT AUG 1 2015 VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. LIGHT WINDS WILL BECOME SOUTHERLY OR SOUTHWESTERLY AHEAD OF A COLD FRONT THAT IS HAS MOVED THROUGH KISN...AND EXPECTED THROUGH KMOT AND KDIK AROUND 03-04Z SATURDAY EVENING...REACHING KJMS AROUND 09Z. DID BUMP UP WINDS FOR A BRIEF PERIOD DIRECTLY BEHIND THE FRONT THIS EVENING. ESPECIALLY AT KISN...KMOT AND KDIK. EXPECT A NORTH TO NORTHWEST FLOW ON SUNDAY AT ALL TAF SITES BEHIND THE COLD FRONT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...AYD LONG TERM...NH AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
906 PM CDT SAT AUG 1 2015 .UPDATE... ISSUED AT 905 PM CDT SAT AUG 1 2015 QUICK UPDATE... WATCH NUMBER 460 IS CANCELLED FOR ALL AREAS NOW. UPDATE ISSUED AT 832 PM CDT SAT AUG 1 2015 HAVE CANCELLED SEVERE THUNDERSTORM WATCH 460 FOR ALL FGF COUNTIES EXCEPT GRANT COUNTY IN WEST CENTRAL MN. THE WATCH REMAINS IN EFFECT UNTIL MIDNIGHT THO GRANT COUNTY WILL LIKELY BE PULLED OUT BEFORE THEN. MEANWHILE... STORMS ARE FIRING ACROSS SOUTHERN MANITOBA AHEAD OF A FRONTAL BOUNDARY JUST BEGINNING TO DROP SOUTHWARD INTO THE US. HAVE BUMPED UP POPS JUST A BIT ACROSS THE NORTHERN COUNTIES FOR THE EVENING AND OVERNIGHT PERIOD. RISK FOR SEVERE WEATHER IS LOW DUE TO REDUCED CAPE... THOUGH SOME STRONG TSTM OUTFLOW IS POSSIBLE WITH THESE STORMS... AS 0-6KM SHEAR APPROACHES 50KTS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 325 PM CDT SAT AUG 1 2015 TWO SEPARATE SHORTWAVES WILL AFFECT THE REGION THIS EVENING/OVERNIGHT. THE FIRST WAVE WILL BRING A SEVERE THREAT TO A PORTION OF SE ND AND WC MN. CURRENT SFC ANALYSIS INDICATES A WEAK SFC LOW ACROSS SOUTH-CENTRAL NORTH DAKOTA...WITH A WARM FRONTAL FEATURE EXTENDING TO THE SOUTHEAST. DEWPOINT VALUES ALONG THESE FEATURES HAVE POOLED INTO THE MID-UPPER 60S...LEADING TO MLCAPE 3000-3500 J/KG. AS THIS SYSTEM EVOLVES AND PROPAGATES TOWARD THE FA...ANTICIPATE THUNDERSTORM DEVELOPMENT ACROSS THE FAR SOUTHERN FA. 0-6KM BULK SHEAR 35-40 KNTS COMBINED WITH THE STRONG INSTABILITY WILL LEAD TO SEVERE STORMS...ALTHOUGH COVERAGE SHOULD REMAIN ISOLATED GIVEN CONVECTIVE TEMPS NEAR 90F (SOME CAPPING ISSUES). THIS ACTIVITY WILL MOVE OUT OF THE REGION BY EARLY EVENING. DID ADD T+ (SEVERE STORMS POSSIBLE) ACROSS FAR SE ND WHERE CONFIDENCE IS HIGHER IN THUNDER DEVELOPMENT (LOW LEVEL CONVERGENCE WILL BE MAXIMIZED...AND THE HRRR HAS CONSISTENTLY INDICATED DEVELOPMENT FROM RUN TO RUN). NEXT UP WILL BE THE NORTHERN FA THIS EVENING INTO THE OVERNIGHT HOURS...AS A STRONGER UPPER WAVE BRINGS A COLD FRONT THROUGH THE REGION. THIS ACTIVITY WILL ENCOUNTER WEAK INSTABILITY (MUCAPE 500-1000 J/KG) BUT VERY STRONG DEEP LAYER SHEAR (60+ KNOTS)...ALONG WITH MID-LEVEL WINDS IN EXCESS OF 50 KNTS. THE 18Z HRRR IS INDICATING A SMALL BOW ECHO WITH SFC WIND GUSTS 50-55 KNOTS 02Z-05Z. OF COURSE THAT IS JUST ONE POSSIBLE SOLUTION...BUT IT DOES SPEAK TO THE POTENTIAL OF WHAT COULD OCCUR ACROSS THE NORTHERN FA THIS EVENING AND OVERNIGHT. THIS FORCING MAY ALSO INTERACT WITH INCREASING INSTABILITY FROM THE SOUTH AFTER MIDNIGHT...WHICH MAY BE ENOUGH FOR A FEW STRONGER STORMS INTO THE OVERNIGHT HOURS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM CDT SAT AUG 1 2015 THIS PERIOD STARTS OFF WITH A BROAD UPPER LEVEL LOW OVER ONTARIO AND COOL HIGH PRESSURE IN PLACE AT THE SURFACE OVER SASKATCHEWAN AND THE DAKOTAS. THE WEATHER WILL BE DRY AND SLIGHTLY COOLER THAN AVERAGE FOR THE START OF THE WEEK. HOWEVER...A WEAK UPPER LEVEL WAVE WILL MOVE EAST IN THE WEAK UPPER FLOW...UNDERCUTTING A WESTERN U.S. RIDGE BY MID WEEK. THE MODELS HAVE HAD A HARD TIME WITH THIS SYSTEM. PREVIOUS RUNS HAD MORE INSTABILITY AND MUCH MORE OF A PRECIPITATION SIGNAL AREA-WIDE. THE LATEST GFS HAS BEST LIFT/INSTABILITY IN THE FAR SOUTH ON WEDNESDAY NIGHT. SO...CONFIDENCE IS DECREASING IN WEDNESDAYS SYSTEM. ANOTHER WEAK WAVE WILL AFFECT PRIMARILY THE SOUTH ON THURSDAY...BUT AGAIN...THIS ONE HAS TRENDED SOUTHWARD. HOWEVER...FRIDAYS SYSTEM LOOKS TO BE THE WAVE THAT HAS THE MOST AGREEMENT REGARDING TRACK AND COULD BRING WIDESPREAD PRECIP TO THE AREA. WITH PLENTY OF UNCERTAINTY ON THESE WAVES...TOO EARLY TO TALK ABOUT SEVERE POTENTIAL. PRECIPITATION CHANCES EXIST INTO SATURDAY AS WELL AND WILL DEPEND ON SPEED OF UPPER LOW. TEMPERATURES LOOK TO BE COOL FOR MUCH OF THIS PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) UPDATED AT 835 PM CDT SAT AUG 1 2015 GENERALLY FAIR SKIES THROUGH THE EVENING AND OVERNIGHT ACROSS THESOUTHERN FA AS SEVERE THUNDERSTORM THREAT THERE IS NOW MINIMAL. MEANWHILE... A WEAK COLD FRONT WILL DROP FROM SOUTHERN SASK AND MANITOBA ACROSS THE NORTHERN HALF OF THE FA... ALG AND NORTH OF A CANDO TO GRAND FORKS AND BEMIDJI LINE... WITH SCATTERED SHOWERS AND AN ISOLATED MVFR CIG AND VSBY IN STRONG THUNDERSTORMS IN THE MIX. SCATTERED SHOWERS SHOULD PERSIST INTO THE MORNING HOURS ACROSS NORTHERN MN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...GUST SHORT TERM...TG LONG TERM...KNUTSVIG AVIATION...GUST
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
839 PM CDT SAT AUG 1 2015 .UPDATE... ISSUED AT 832 PM CDT SAT AUG 1 2015 HAVE CANCELLED SEVERE THUNDERSTORM WATCH 460 FOR ALL FGF COUNTIES EXCEPT GRANT COUNTY IN WEST CENTRAL MN. THE WATCH REMAINS IN EFFECT UNTIL MIDNIGHT THO GRANT COUNTY WILL LIKELY BE PULLED OUT BEFORE THEN. MEANWHILE... STORMS ARE FIRING ACROSS SOUTHERN MANITOBA AHEAD OF A FRONTAL BOUNDARY JUST BEGINNING TO DROP SOUTHWARD INTO THE US. HAVE BUMPED UP POPS JUST A BIT ACROSS THE NORTHERN COUNTIES FOR THE EVENING AND OVERNIGHT PERIOD. RISK FOR SEVERE WEATHER IS LOW DUE TO REDUCED CAPE... THOUGH SOME STRONG TSTM OUTFLOW IS POSSIBLE WITH THESE STORMS... AS 0-6KM SHEAR APPROACHES 50KTS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 325 PM CDT SAT AUG 1 2015 TWO SEPARATE SHORTWAVES WILL AFFECT THE REGION THIS EVENING/OVERNIGHT. THE FIRST WAVE WILL BRING A SEVERE THREAT TO A PORTION OF SE ND AND WC MN. CURRENT SFC ANALYSIS INDICATES A WEAK SFC LOW ACROSS SOUTH-CENTRAL NORTH DAKOTA...WITH A WARM FRONTAL FEATURE EXTENDING TO THE SOUTHEAST. DEWPOINT VALUES ALONG THESE FEATURES HAVE POOLED INTO THE MID-UPPER 60S...LEADING TO MLCAPE 3000-3500 J/KG. AS THIS SYSTEM EVOLVES AND PROPAGATES TOWARD THE FA...ANTICIPATE THUNDERSTORM DEVELOPMENT ACROSS THE FAR SOUTHERN FA. 0-6KM BULK SHEAR 35-40 KNTS COMBINED WITH THE STRONG INSTABILITY WILL LEAD TO SEVERE STORMS...ALTHOUGH COVERAGE SHOULD REMAIN ISOLATED GIVEN CONVECTIVE TEMPS NEAR 90F (SOME CAPPING ISSUES). THIS ACTIVITY WILL MOVE OUT OF THE REGION BY EARLY EVENING. DID ADD T+ (SEVERE STORMS POSSIBLE) ACROSS FAR SE ND WHERE CONFIDENCE IS HIGHER IN THUNDER DEVELOPMENT (LOW LEVEL CONVERGENCE WILL BE MAXIMIZED...AND THE HRRR HAS CONSISTENTLY INDICATED DEVELOPMENT FROM RUN TO RUN). NEXT UP WILL BE THE NORTHERN FA THIS EVENING INTO THE OVERNIGHT HOURS...AS A STRONGER UPPER WAVE BRINGS A COLD FRONT THROUGH THE REGION. THIS ACTIVITY WILL ENCOUNTER WEAK INSTABILITY (MUCAPE 500-1000 J/KG) BUT VERY STRONG DEEP LAYER SHEAR (60+ KNOTS)...ALONG WITH MID-LEVEL WINDS IN EXCESS OF 50 KNTS. THE 18Z HRRR IS INDICATING A SMALL BOW ECHO WITH SFC WIND GUSTS 50-55 KNOTS 02Z-05Z. OF COURSE THAT IS JUST ONE POSSIBLE SOLUTION...BUT IT DOES SPEAK TO THE POTENTIAL OF WHAT COULD OCCUR ACROSS THE NORTHERN FA THIS EVENING AND OVERNIGHT. THIS FORCING MAY ALSO INTERACT WITH INCREASING INSTABILITY FROM THE SOUTH AFTER MIDNIGHT...WHICH MAY BE ENOUGH FOR A FEW STRONGER STORMS INTO THE OVERNIGHT HOURS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM CDT SAT AUG 1 2015 THIS PERIOD STARTS OFF WITH A BROAD UPPER LEVEL LOW OVER ONTARIO AND COOL HIGH PRESSURE IN PLACE AT THE SURFACE OVER SASKATCHEWAN AND THE DAKOTAS. THE WEATHER WILL BE DRY AND SLIGHTLY COOLER THAN AVERAGE FOR THE START OF THE WEEK. HOWEVER...A WEAK UPPER LEVEL WAVE WILL MOVE EAST IN THE WEAK UPPER FLOW...UNDERCUTTING A WESTERN U.S. RIDGE BY MID WEEK. THE MODELS HAVE HAD A HARD TIME WITH THIS SYSTEM. PREVIOUS RUNS HAD MORE INSTABILITY AND MUCH MORE OF A PRECIPITATION SIGNAL AREA-WIDE. THE LATEST GFS HAS BEST LIFT/INSTABILITY IN THE FAR SOUTH ON WEDNESDAY NIGHT. SO...CONFIDENCE IS DECREASING IN WEDNESDAYS SYSTEM. ANOTHER WEAK WAVE WILL AFFECT PRIMARILY THE SOUTH ON THURSDAY...BUT AGAIN...THIS ONE HAS TRENDED SOUTHWARD. HOWEVER...FRIDAYS SYSTEM LOOKS TO BE THE WAVE THAT HAS THE MOST AGREEMENT REGARDING TRACK AND COULD BRING WIDESPREAD PRECIP TO THE AREA. WITH PLENTY OF UNCERTAINTY ON THESE WAVES...TOO EARLY TO TALK ABOUT SEVERE POTENTIAL. PRECIPITATION CHANCES EXIST INTO SATURDAY AS WELL AND WILL DEPEND ON SPEED OF UPPER LOW. TEMPERATURES LOOK TO BE COOL FOR MUCH OF THIS PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) UPDATED AT 835 PM CDT SAT AUG 1 2015 GENERALLY FAIR SKIES THROUGH THE EVENING AND OVERNIGHT ACROSS THESOUTHERN FA AS SEVERE THUNDERSTORM THREAT THERE IS NOW MINIMAL. MEANWHILE... A WEAK COLD FRONT WILL DROP FROM SOUTHERN SASK AND MANITOBA ACROSS THE NORTHERN HALF OF THE FA... ALG AND NORTH OF A CANDO TO GRAND FORKS AND BEMIDJI LINE... WITH SCATTERED SHOWERS AND AN ISOLATED MVFR CIG AND VSBY IN STRONG THUNDERSTORMS IN THE MIX. SCATTERED SHOWERS SHOULD PERSIST INTO THE MORNING HOURS ACROSS NORTHERN MN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...GUST SHORT TERM...TG LONG TERM...KNUTSVIG AVIATION...GUST
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
636 PM CDT SAT AUG 1 2015 .UPDATE... ISSUED AT 629 PM CDT SAT AUG 1 2015 SEVERE THUNDERSTORM WATCH 460 HASD BEEN ISSUED FOR EXTREME SOUTHEASTERN ND AND ADJACENT COUNTIES NORTHEASTERN SD AND WEST CENTRAL MN UNTIL MIDNIGHT. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 325 PM CDT SAT AUG 1 2015 TWO SEPARATE SHORTWAVES WILL AFFECT THE REGION THIS EVENING/OVERNIGHT. THE FIRST WAVE WILL BRING A SEVERE THREAT TO A PORTION OF SE ND AND WC MN. CURRENT SFC ANALYSIS INDICATES A WEAK SFC LOW ACROSS SOUTH-CENTRAL NORTH DAKOTA...WITH A WARM FRONTAL FEATURE EXTENDING TO THE SOUTHEAST. DEWPOINT VALUES ALONG THESE FEATURES HAVE POOLED INTO THE MID-UPPER 60S...LEADING TO MLCAPE 3000-3500 J/KG. AS THIS SYSTEM EVOLVES AND PROPAGATES TOWARD THE FA...ANTICIPATE THUNDERSTORM DEVELOPMENT ACROSS THE FAR SOUTHERN FA. 0-6KM BULK SHEAR 35-40 KNTS COMBINED WITH THE STRONG INSTABILITY WILL LEAD TO SEVERE STORMS...ALTHOUGH COVERAGE SHOULD REMAIN ISOLATED GIVEN CONVECTIVE TEMPS NEAR 90F (SOME CAPPING ISSUES). THIS ACTIVITY WILL MOVE OUT OF THE REGION BY EARLY EVENING. DID ADD T+ (SEVERE STORMS POSSIBLE) ACROSS FAR SE ND WHERE CONFIDENCE IS HIGHER IN THUNDER DEVELOPMENT (LOW LEVEL CONVERGENCE WILL BE MAXIMIZED...AND THE HRRR HAS CONSISTENTLY INDICATED DEVELOPMENT FROM RUN TO RUN). NEXT UP WILL BE THE NORTHERN FA THIS EVENING INTO THE OVERNIGHT HOURS...AS A STRONGER UPPER WAVE BRINGS A COLD FRONT THROUGH THE REGION. THIS ACTIVITY WILL ENCOUNTER WEAK INSTABILITY (MUCAPE 500-1000 J/KG) BUT VERY STRONG DEEP LAYER SHEAR (60+ KNOTS)...ALONG WITH MID-LEVEL WINDS IN EXCESS OF 50 KNTS. THE 18Z HRRR IS INDICATING A SMALL BOW ECHO WITH SFC WIND GUSTS 50-55 KNOTS 02Z-05Z. OF COURSE THAT IS JUST ONE POSSIBLE SOLUTION...BUT IT DOES SPEAK TO THE POTENTIAL OF WHAT COULD OCCUR ACROSS THE NORTHERN FA THIS EVENING AND OVERNIGHT. THIS FORCING MAY ALSO INTERACT WITH INCREASING INSTABILITY FROM THE SOUTH AFTER MIDNIGHT...WHICH MAY BE ENOUGH FOR A FEW STRONGER STORMS INTO THE OVERNIGHT HOURS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM CDT SAT AUG 1 2015 THIS PERIOD STARTS OFF WITH A BROAD UPPER LEVEL LOW OVER ONTARIO AND COOL HIGH PRESSURE IN PLACE AT THE SURFACE OVER SASKATCHEWAN AND THE DAKOTAS. THE WEATHER WILL BE DRY AND SLIGHTLY COOLER THAN AVERAGE FOR THE START OF THE WEEK. HOWEVER...A WEAK UPPER LEVEL WAVE WILL MOVE EAST IN THE WEAK UPPER FLOW...UNDERCUTTING A WESTERN U.S. RIDGE BY MID WEEK. THE MODELS HAVE HAD A HARD TIME WITH THIS SYSTEM. PREVIOUS RUNS HAD MORE INSTABILITY AND MUCH MORE OF A PRECIPITATION SIGNAL AREA-WIDE. THE LATEST GFS HAS BEST LIFT/INSTABILITY IN THE FAR SOUTH ON WEDNESDAY NIGHT. SO...CONFIDENCE IS DECREASING IN WEDNESDAYS SYSTEM. ANOTHER WEAK WAVE WILL AFFECT PRIMARILY THE SOUTH ON THURSDAY...BUT AGAIN...THIS ONE HAS TRENDED SOUTHWARD. HOWEVER...FRIDAYS SYSTEM LOOKS TO BE THE WAVE THAT HAS THE MOST AGREEMENT REGARDING TRACK AND COULD BRING WIDESPREAD PRECIP TO THE AREA. WITH PLENTY OF UNCERTAINTY ON THESE WAVES...TOO EARLY TO TALK ABOUT SEVERE POTENTIAL. PRECIPITATION CHANCES EXIST INTO SATURDAY AS WELL AND WILL DEPEND ON SPEED OF UPPER LOW. TEMPERATURES LOOK TO BE COOL FOR MUCH OF THIS PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 629 PM CDT SAT AUG 1 2015 GENERALLY FAIR SKIES THROUGH THE EVENING WITH ISOLATED STRONG TO SEVERE THUNDERSTORMS ALONG THE SOUTH DAKOTA BORDER COUNTIES... INTO ADJACENT AREAS OF WEST CENTRAL MINNESOTA. THUNDERSTORMS SHOULD EXIT THAT AREA BY 04Z. LATER TONIGHT... A WEAK COLD FRONT WILL DROP FROM SOUTHERN SASK AND MANITOBA ACROSS THE NORTHERN HALF OF THE FA... ALG AND NORTH OF A CANDO TO GRAND FORKS AND BEMIDJI LINE... WITH SCATTERED SHOWERS AND AN ISOLATED MVFR CIG AND VSBY IN STRONG THUNDERSTORMS IN THE MIX. SCTATTERED SHOWERS SHOULD PERSIST INTO TEH MORNING HOURS ACROSS NORTHERN MN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...SEVERE THUNDERSTORM WATCH 460 UNTIL MIDNIGHT. MN...SEVERE THUNDERSTORM WATCH 460 UNTIL MIDNIGHT && $$ UPDATE...GUST SHORT TERM...TG LONG TERM...KNUTSVIG AVIATION...GUST
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
937 AM EDT FRI JUL 31 2015 .SYNOPSIS... HIGH PRESSURE REMAINS OVER THE OHIO VALLEY WITH A TROUGH OVER EASTERN CANADA. A WEAK FRONT WILL SINK SOUTH ACROSS THE AREA THIS EVENING. HIGH PRESSURE WILL EXPAND OVER THE LOWER LAKES REGION ON SATURDAY...SHIFTING TO THE EAST ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST HRRR MODEL APPEARS TO BE BACKING OFF ON CHANCES FOR PRECIPITATION LATER THIS AFTERNOON. WILL KEEP THE MENTION OF A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS AS SURFACE TROUGH SLIPS EAST ACROSS THE REGION. OTHERWISE...NO MAJOR CHANGES TO THIS UPDATE. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... ALTHOUGH THE FRONT WILL BE EAST OF THE AREA BY SATURDAY MORNING...A WEAK THERMAL TROUGH IN THE VICINITY OF EASTERN LAKE ERIE COULD RESULT IN SOME CLOUDS AND MOISTURE LINGERING IN THE NE COUNTIES. WILL HOLD ONTO A SLIGHT CHANCE POP ON SATURDAY MORNING IN NW PA...EXPANDING TO NORTHWEST OHIO BY AFTERNOON AHEAD OF ANOTHER SHORTWAVE. TEMPERATURES ON SATURDAY WILL BE A LITTLE COOLER IN THE UPPER 70S/LOW 80S. SURFACE HIGH PRESSURE EXPANDS EASTWARD ON SATURDAY NIGHT AND SUNDAY AHEAD OF THE NEXT TROUGH TO APPROACH FROM THE NORTHWEST. THIS FEATURE DEVELOPS AHEAD OF A SLIGHTLY STRONGER UPPER LEVEL WAVE DROPPING SOUTH ACROSS CANADA. BETTER MOISTURE ADVECTION IS EXPECTED AHEAD OF THIS NEXT TROUGH WITH CHANCES OF SHOWERS AND THUNDERSTORMS DEVELOPING SUNDAY AFTERNOON IN THE NORTH...AND EXPANDING TO ALL AREAS FOR SUNDAY NIGHT AND MONDAY. SEASONAL TEMPERATURES WILL CONTINUE. && .LONG TERM /TUESDAY THROUGH THURSDAY/... THE MODELS LOOK SIMILAR THROUGH MID WEEK WITH THE FRONT INITIALLY STALLING SOMEWHERE NEAR THE OHIO VALLEY. THIS MAKES FOR A CHANCE FOR SOME OVER RUNNING SHOWERS...MAINLY ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. STILL NOT A LOT OF CONFIDENCE ON THE THREAT OF RAIN BUT WILL INCLUDE A SMALL CHANCE IN THE SOUTH. 850 MB TEMPERATURES MAY GET COLD ENOUGH FOR LAKE EFFECT RAIN SHOWERS ALTHOUGH THERE MAY BE ENOUGH SUBSIDENCE AND SHEAR THAT NOTHING MATERIALIZES. IT IS WORTH A MENTION BY TUESDAY NIGHT INTO WEDNESDAY. THE MODELS REMAIN FAR APART BY NEXT THURSDAY WITH THE GFS CONTINUING TO DRIVE THE FRONT WELL SOUTH OF THE AREA AND THE ECMWF DEVELOPING ANOTHER OVER RUNNING WAVE THAT COULD AT LEAST CATCH THE SOUTHERN PART OF THE FORECAST AREA. WILL CONTINUE TO FAVOR THE DRY FORECAST...ONE WOULD EXPECT THE SURFACE HIGH TO BUILD SOUTH AT SOME POINT GIVEN THE DEEPENING TROUGH ALOFT. SHAVED OFF A DEGREE OR TWO ON FORECAST HIGH TEMPERATURES MID WEEK GIVEN THE THREAT FOR CLOUDS AND SHOWERS AND THE COOL FLOW. TEMPS COULD BE COOLER THAN FORECAST...ESPECIALLY IF IT WAS TO BE CLOUDY AND RAINY BUT WITH THE DAYS SO LONG AND WARM IN EARLY AUGUST WILL STAY WITHIN 10 DEGREES OF NORMAL FOR NOW. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... A CHUNK OF HIGH PRESSURE AT THE SURFACE WAS OVER THE OHIO VALLEY SLIDING EAST. A WEAK COLD FRONT/TROUGH OVER THE NORTHERN GREAT LAKES WILL DROP ACROSS THE AREA LATE THIS AFTERNOON AND EVENING. WEST WINDS WILL GET A BIT GUSTY THIS AFTERNOON AHEAD OF THE TROUGH. MOISTURE IS VERY LIMITED BUT THERE SHOULD BE SOME CAPE DEVELOP IN THE HEATING OF THE DAY. AN INCREASE IN SHEAR IS PROGGED. A FEW THUNDERSTORMS COULD POP UP. COVERAGE WILL LIKELY BE SMALL BUT THE THREAT IS MENTIONED IN THE CURRENT TAF FORECASTS AS "VICINITY" AND WILL CONTINUE WITH THAT FORECAST LATE THIS AFTERNOON INTO TONIGHT. OUTLOOK...NON VFR POSSIBLE SUNDAY AFTERNOON AND MONDAY IN SHRA/TSRA. && .MARINE... WITH A RELATIVELY FAST FLOW ALOFT...EACH WEAK FRONT/TROUGH WILL PRODUCE THE POSSIBILITY OF SMALL CRAFT ADVISORY CONDITIONS ON LAKE ERIE...MAINLY THE EAST HALF OF THE LAKE SINCE THE FLOW IS WEST SOUTHWEST. A WEAK TROUGH IS EXPECTED THIS EVENING AND WILL POST A SMALL CRAFT ADVISORY FOR THE ERIE COUNTY PA LAKESHORE FROM EARLY AFTERNOON INTO TONIGHT. THE MAJORITY OF THE WIND WILL BE OVER THE EAST THIRD OF THE LAKE BUT 4 FOOT WAVES ARE CERTAINLY POSSIBLE AT ERIE PA LATER TODAY INTO TONIGHT. THE NEXT WEAK FRONT/TROUGH WILL BE LATER SUNDAY WITH A STRONGER COLD FRONT ON MONDAY. BOTH OF THOSE SYSTEMS MAY WELL REQUIRE A SMALL CRAFT ADVISORY...ESPECIALLY FOR THE EAST LAKESHORE. HIGH PRESSURE WILL BUILD ACROSS THE NORTHERN LAKES NEXT WEEK AND THE FLOW WILL LIKELY VEER MORE FROM THE NORTH BY MID WEEK. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...BEACH HAZARDS STATEMENT FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT FOR PAZ001. MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM EDT SATURDAY FOR LEZ149. && $$ SYNOPSIS...KEC NEAR TERM...LOMBARDY SHORT TERM...KEC LONG TERM...KOSARIK AVIATION...KOSARIK MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS NORMAN OK
1220 PM CDT FRI JUL 31 2015 .UPDATE... UPDATE TO PRECIP/WX... && .DISCUSSION... SCATTERED SHOWERS AND ISOLATED THUNDER ACROSS CENTRAL OK CONTINUES TO WEAKEN... BUT REMAIN PERSISTENT. MUCH... IF NOT ALL OF THIS ACTIVITY IS LIKELY TIED TO MODEST LOW LEVEL ASCENT ASSOCIATED WITH A WEAK 850MB TROUGH AND VARIOUS WEAKENING OUTFLOW BOUNDARIES ASSOCIATED WITH EARLIER CONVECTION. FOR THIS AFTN... PRIMARY FOCUS IS ON CONTINUOUS ACTIVITY ACROSS THE TX PH... AS NEW UPDRAFTS HAVE STARTED TO DEVELOP ON OR JUST WEST OF THE OK/TXPH BORDER. DIFFICULT TO PINPOINT EXACT FORCING FOR ASCENT... BUT IT APPEARS TIED TO SFC/LL CONVERGENCE. LATEST HRRR RUN HAS MOST OF THIS ACTIVITY DISSIPATING THROUGH EARLY/MID AFTN AS UPPER LVL SUPPORT FROM THE WEAK H500 SHORT WAVE EMBEDDED IN THE LARGER RIDGE EXITS TO THE EAST. INITIAL STORMS IN WRN OK WILL RESIDE IN A REGION OF MODEST INSTABILITY... SUPPORTIVE OF GUSTY WINDS AND LOCALLY HEAVY RAINFALL. NOT EXPECTING ANY ORGANIZED SEVERE STORMS THROUGH THIS AFTN. JTK && .PREV DISCUSSION... /ISSUED 614 AM CDT FRI JUL 31 2015/ DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. AVIATION... OVERALL...VFR CONDITIONS ARE EXPECTED. SOME MVFR...PERHAPS IFR...CONDITIONS MAY AFFECT KWWR AND KGAG THROUGH 16Z. ISO-SCT SHRA/TSRA WILL BE OVER THE AREA FOR THE NEXT 24 HOURS. ONLY INCLUDED VCTS AND VCSH NEAR KOKC AND KOUN THROUGH 16-17Z WHERE CONFIDENCE OF OCCURRENCE IS HIGHER. PINPOINTING WHERE AND WHEN SHRA/TSRA OCCUR REMAINS VERY TRICKY AND CHALLENGING...SO DID NOT MENTION IN MANY TAFS AS COVERAGE SHOULD BE LOW. BRIEF MVFR OR LOWER CONDITIONS AND VARIABLE GUSTY WINDS ARE POSSIBLE WITH SHRA/TSRA. MBS PREV DISCUSSION... /ISSUED 309 AM CDT FRI JUL 31 2015/ DISCUSSION... THE MAIN CONCERN IS DETERMINING RAIN CHANCES OVER THE NEXT SEVERAL DAYS. OVERALL...LOWERED RAIN CHANCES OVER THE NEXT SEVERAL DAYS BASED ON LATEST MODEL GUIDANCE. THE COMBINATION OF WEAK SHEAR AND WEAK FORCING AS WELL AS DECENT CAPPING SHOULD KEEP RAIN CHANCES ON THE LOW SIDE IN MOST LOCATIONS. TODAY WILL NOT BE AS HOT IN MANY LOCATIONS WITH MORE CLOUD COVER...BUT WILL BE HUMID WITH SURFACE DEWPOINTS MAINLY IN THE LOWER TO MID 70S. KEPT 20 PERCENT ACROSS THE ENTIRE AREA. ITS QUITE DIFFICULT TO PINPOINT WHERE AND WHEN STORMS WILL OCCUR TODAY. LATEST HRRR RUNS SUGGEST A FEW STORMS WILL BE NEAR I-40 THIS MORNING AND MAINLY ACROSS SOUTHERN OKLAHOMA AND NORTH TEXAS THIS AFTERNOON. COVERAGE SHOULD BE SPARSE WITHOUT A SIGNIFICANT TRIGGER FOR LIFT. STORMS WILL BE PULSE AND GENERALLY SHORT LIVED IN NATURE...BUT COULD PRODUCE LOCALLY HEAVY RAINFALL OVER AN INCH IN A SHORT PERIOD OF TIME. SEVERE POTENTIAL REMAINS LOW TODAY. INCREASED HIGHS TODAY FROM THE PREVIOUS FORECAST DUE TO LOW COVERAGE OF STORMS. TONIGHT THROUGH SUNDAY NIGHT...A FEW STORMS MAY LINGER MAINLY OVER FAR WESTERN OKLAHOMA AND FAR WESTERN NORTH TEXAS...WHICH MAY PRODUCE SOME LOCALIZED HEAVY RAINFALL. SEVERE POTENTIAL REMAINS VERY LOW. OTHERWISE...MAINLY RAINFREE CONDITIONS WILL OCCUR. HIGHS ON SATURDAY AND SUNDAY SHOULD REMAIN SLIGHTLY BELOW AVERAGE IN MANY AREAS EXCEPT POSSIBLY FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WHERE MORE SUN IS FORECAST. MONDAY THROUGH THURSDAY...GENERALLY TYPICAL SUMMERTIME HEAT IS FORECAST. LOW CHANCES FOR RAIN AND STORMS MAY OCCUR MAINLY OVER NORTHERN OKLAHOMA...BUT CONFIDENCE OF RAIN IS DECREASING AS LATEST MODELS HAVE BEEN TRENDING STRONGER WITH MID/UPPER RIDGING AND CAPPING OVER THE AREA. THIS WOULD YIELD HIGHER TEMPERATURES AS WELL. WOULD NOT BE SURPRISED IF HEAT ADVISORIES WERE NECESSARY SOMETIME DURING THIS TIME FRAME. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 71 91 71 91 / 10 10 20 10 HOBART OK 71 89 70 93 / 30 30 20 10 WICHITA FALLS TX 74 96 73 95 / 20 20 20 10 GAGE OK 68 86 67 92 / 20 20 30 10 PONCA CITY OK 71 91 72 92 / 10 10 20 10 DURANT OK 73 97 73 95 / 10 10 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS NORMAN OK
1213 PM CDT FRI JUL 31 2015 .AVIATION... ISOLATED TO SCATTERED SHOWERS AND STORMS WILL CONTINUE THROUGH THE AFTERNOON AND OVERNIGHT...BUT DID NOT MENTION IN TAFS BECAUSE CONFIDENCE IN STORMS IMPACTING ANY PARTICULAR LOCATION IS LOW. EXPECT MID CLOUDINESS TO PERSIST...THOUGH CONDITIONS SHOULD REMAIN GENERALLY VFR. LIGHT EAST WINDS WILL GRADUALLY SHIFT TO THE SOUTH OVERNIGHT. && .PREV DISCUSSION... /ISSUED 614 AM CDT FRI JUL 31 2015/ DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. AVIATION... OVERALL...VFR CONDITIONS ARE EXPECTED. SOME MVFR...PERHAPS IFR...CONDITIONS MAY AFFECT KWWR AND KGAG THROUGH 16Z. ISO-SCT SHRA/TSRA WILL BE OVER THE AREA FOR THE NEXT 24 HOURS. ONLY INCLUDED VCTS AND VCSH NEAR KOKC AND KOUN THROUGH 16-17Z WHERE CONFIDENCE OF OCCURRENCE IS HIGHER. PINPOINTING WHERE AND WHEN SHRA/TSRA OCCUR REMAINS VERY TRICKY AND CHALLENGING...SO DID NOT MENTION IN MANY TAFS AS COVERAGE SHOULD BE LOW. BRIEF MVFR OR LOWER CONDITIONS AND VARIABLE GUSTY WINDS ARE POSSIBLE WITH SHRA/TSRA. MBS PREV DISCUSSION... /ISSUED 309 AM CDT FRI JUL 31 2015/ DISCUSSION... THE MAIN CONCERN IS DETERMINING RAIN CHANCES OVER THE NEXT SEVERAL DAYS. OVERALL...LOWERED RAIN CHANCES OVER THE NEXT SEVERAL DAYS BASED ON LATEST MODEL GUIDANCE. THE COMBINATION OF WEAK SHEAR AND WEAK FORCING AS WELL AS DECENT CAPPING SHOULD KEEP RAIN CHANCES ON THE LOW SIDE IN MOST LOCATIONS. TODAY WILL NOT BE AS HOT IN MANY LOCATIONS WITH MORE CLOUD COVER...BUT WILL BE HUMID WITH SURFACE DEWPOINTS MAINLY IN THE LOWER TO MID 70S. KEPT 20 PERCENT ACROSS THE ENTIRE AREA. ITS QUITE DIFFICULT TO PINPOINT WHERE AND WHEN STORMS WILL OCCUR TODAY. LATEST HRRR RUNS SUGGEST A FEW STORMS WILL BE NEAR I-40 THIS MORNING AND MAINLY ACROSS SOUTHERN OKLAHOMA AND NORTH TEXAS THIS AFTERNOON. COVERAGE SHOULD BE SPARSE WITHOUT A SIGNIFICANT TRIGGER FOR LIFT. STORMS WILL BE PULSE AND GENERALLY SHORT LIVED IN NATURE...BUT COULD PRODUCE LOCALLY HEAVY RAINFALL OVER AN INCH IN A SHORT PERIOD OF TIME. SEVERE POTENTIAL REMAINS LOW TODAY. INCREASED HIGHS TODAY FROM THE PREVIOUS FORECAST DUE TO LOW COVERAGE OF STORMS. TONIGHT THROUGH SUNDAY NIGHT...A FEW STORMS MAY LINGER MAINLY OVER FAR WESTERN OKLAHOMA AND FAR WESTERN NORTH TEXAS...WHICH MAY PRODUCE SOME LOCALIZED HEAVY RAINFALL. SEVERE POTENTIAL REMAINS VERY LOW. OTHERWISE...MAINLY RAINFREE CONDITIONS WILL OCCUR. HIGHS ON SATURDAY AND SUNDAY SHOULD REMAIN SLIGHTLY BELOW AVERAGE IN MANY AREAS EXCEPT POSSIBLY FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WHERE MORE SUN IS FORECAST. MONDAY THROUGH THURSDAY...GENERALLY TYPICAL SUMMERTIME HEAT IS FORECAST. LOW CHANCES FOR RAIN AND STORMS MAY OCCUR MAINLY OVER NORTHERN OKLAHOMA...BUT CONFIDENCE OF RAIN IS DECREASING AS LATEST MODELS HAVE BEEN TRENDING STRONGER WITH MID/UPPER RIDGING AND CAPPING OVER THE AREA. THIS WOULD YIELD HIGHER TEMPERATURES AS WELL. WOULD NOT BE SURPRISED IF HEAT ADVISORIES WERE NECESSARY SOMETIME DURING THIS TIME FRAME. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 91 71 91 71 / 30 10 10 20 HOBART OK 94 71 89 70 / 20 30 30 20 WICHITA FALLS TX 96 74 96 73 / 20 20 20 20 GAGE OK 88 68 86 67 / 30 20 20 30 PONCA CITY OK 91 71 91 72 / 20 10 10 20 DURANT OK 96 73 97 73 / 20 10 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 04/14/14
AREA FORECAST DISCUSSION
NWS NORMAN OK
614 AM CDT FRI JUL 31 2015 .DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. && .AVIATION... OVERALL...VFR CONDITIONS ARE EXPECTED. SOME MVFR...PERHAPS IFR...CONDITIONS MAY AFFECT KWWR AND KGAG THROUGH 16Z. ISO-SCT SHRA/TSRA WILL BE OVER THE AREA FOR THE NEXT 24 HOURS. ONLY INCLUDED VCTS AND VCSH NEAR KOKC AND KOUN THROUGH 16-17Z WHERE CONFIDENCE OF OCCURRENCE IS HIGHER. PINPOINTING WHERE AND WHEN SHRA/TSRA OCCUR REMAINS VERY TRICKY AND CHALLENGING...SO DID NOT MENTION IN MANY TAFS AS COVERAGE SHOULD BE LOW. BRIEF MVFR OR LOWER CONDITIONS AND VARIABLE GUSTY WINDS ARE POSSIBLE WITH SHRA/TSRA. MBS && .PREV DISCUSSION... /ISSUED 309 AM CDT FRI JUL 31 2015/ DISCUSSION... THE MAIN CONCERN IS DETERMINING RAIN CHANCES OVER THE NEXT SEVERAL DAYS. OVERALL...LOWERED RAIN CHANCES OVER THE NEXT SEVERAL DAYS BASED ON LATEST MODEL GUIDANCE. THE COMBINATION OF WEAK SHEAR AND WEAK FORCING AS WELL AS DECENT CAPPING SHOULD KEEP RAIN CHANCES ON THE LOW SIDE IN MOST LOCATIONS. TODAY WILL NOT BE AS HOT IN MANY LOCATIONS WITH MORE CLOUD COVER...BUT WILL BE HUMID WITH SURFACE DEWPOINTS MAINLY IN THE LOWER TO MID 70S. KEPT 20 PERCENT ACROSS THE ENTIRE AREA. ITS QUITE DIFFICULT TO PINPOINT WHERE AND WHEN STORMS WILL OCCUR TODAY. LATEST HRRR RUNS SUGGEST A FEW STORMS WILL BE NEAR I-40 THIS MORNING AND MAINLY ACROSS SOUTHERN OKLAHOMA AND NORTH TEXAS THIS AFTERNOON. COVERAGE SHOULD BE SPARSE WITHOUT A SIGNIFICANT TRIGGER FOR LIFT. STORMS WILL BE PULSE AND GENERALLY SHORT LIVED IN NATURE...BUT COULD PRODUCE LOCALLY HEAVY RAINFALL OVER AN INCH IN A SHORT PERIOD OF TIME. SEVERE POTENTIAL REMAINS LOW TODAY. INCREASED HIGHS TODAY FROM THE PREVIOUS FORECAST DUE TO LOW COVERAGE OF STORMS. TONIGHT THROUGH SUNDAY NIGHT...A FEW STORMS MAY LINGER MAINLY OVER FAR WESTERN OKLAHOMA AND FAR WESTERN NORTH TEXAS...WHICH MAY PRODUCE SOME LOCALIZED HEAVY RAINFALL. SEVERE POTENTIAL REMAINS VERY LOW. OTHERWISE...MAINLY RAINFREE CONDITIONS WILL OCCUR. HIGHS ON SATURDAY AND SUNDAY SHOULD REMAIN SLIGHTLY BELOW AVERAGE IN MANY AREAS EXCEPT POSSIBLY FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WHERE MORE SUN IS FORECAST. MONDAY THROUGH THURSDAY...GENERALLY TYPICAL SUMMERTIME HEAT IS FORECAST. LOW CHANCES FOR RAIN AND STORMS MAY OCCUR MAINLY OVER NORTHERN OKLAHOMA...BUT CONFIDENCE OF RAIN IS DECREASING AS LATEST MODELS HAVE BEEN TRENDING STRONGER WITH MID/UPPER RIDGING AND CAPPING OVER THE AREA. THIS WOULD YIELD HIGHER TEMPERATURES AS WELL. WOULD NOT BE SURPRISED IF HEAT ADVISORIES WERE NECESSARY SOMETIME DURING THIS TIME FRAME. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 91 71 91 71 / 20 10 10 20 HOBART OK 94 71 89 70 / 20 30 30 20 WICHITA FALLS TX 96 74 96 73 / 20 20 20 20 GAGE OK 88 68 86 67 / 20 20 20 30 PONCA CITY OK 91 71 91 72 / 20 10 10 20 DURANT OK 96 73 97 73 / 20 10 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 84/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
309 AM CDT FRI JUL 31 2015 .DISCUSSION... THE MAIN CONCERN IS DETERMINING RAIN CHANCES OVER THE NEXT SEVERAL DAYS. OVERALL...LOWERED RAIN CHANCES OVER THE NEXT SEVERAL DAYS BASED ON LATEST MODEL GUIDANCE. THE COMBINATION OF WEAK SHEAR AND WEAK FORCING AS WELL AS DECENT CAPPING SHOULD KEEP RAIN CHANCES ON THE LOW SIDE IN MOST LOCATIONS. TODAY WILL NOT BE AS HOT IN MANY LOCATIONS WITH MORE CLOUD COVER...BUT WILL BE HUMID WITH SURFACE DEWPOINTS MAINLY IN THE LOWER TO MID 70S. KEPT 20 PERCENT ACROSS THE ENTIRE AREA. ITS QUITE DIFFICULT TO PINPOINT WHERE AND WHEN STORMS WILL OCCUR TODAY. LATEST HRRR RUNS SUGGEST A FEW STORMS WILL BE NEAR I-40 THIS MORNING AND MAINLY ACROSS SOUTHERN OKLAHOMA AND NORTH TEXAS THIS AFTERNOON. COVERAGE SHOULD BE SPARSE WITHOUT A SIGNIFICANT TRIGGER FOR LIFT. STORMS WILL BE PULSE AND GENERALLY SHORT LIVED IN NATURE...BUT COULD PRODUCE LOCALLY HEAVY RAINFALL OVER AN INCH IN A SHORT PERIOD OF TIME. SEVERE POTENTIAL REMAINS LOW TODAY. INCREASED HIGHS TODAY FROM THE PREVIOUS FORECAST DUE TO LOW COVERAGE OF STORMS. TONIGHT THROUGH SUNDAY NIGHT...A FEW STORMS MAY LINGER MAINLY OVER FAR WESTERN OKLAHOMA AND FAR WESTERN NORTH TEXAS...WHICH MAY PRODUCE SOME LOCALIZED HEAVY RAINFALL. SEVERE POTENTIAL REMAINS VERY LOW. OTHERWISE...MAINLY RAINFREE CONDITIONS WILL OCCUR. HIGHS ON SATURDAY AND SUNDAY SHOULD REMAIN SLIGHTLY BELOW AVERAGE IN MANY AREAS EXCEPT POSSIBLY FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WHERE MORE SUN IS FORECAST. MONDAY THROUGH THURSDAY...GENERALLY TYPICAL SUMMERTIME HEAT IS FORECAST. LOW CHANCES FOR RAIN AND STORMS MAY OCCUR MAINLY OVER NORTHERN OKLAHOMA...BUT CONFIDENCE OF RAIN IS DECREASING AS LATEST MODELS HAVE BEEN TRENDING STRONGER WITH MID/UPPER RIDGING AND CAPPING OVER THE AREA. THIS WOULD YIELD HIGHER TEMPERATURES AS WELL. WOULD NOT BE SURPRISED IF HEAT ADVISORIES WERE NECESSARY SOMETIME DURING THIS TIME FRAME. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 91 71 91 71 / 20 10 10 20 HOBART OK 94 71 89 70 / 20 30 30 20 WICHITA FALLS TX 96 74 96 73 / 20 20 20 20 GAGE OK 88 68 86 67 / 20 20 20 30 PONCA CITY OK 91 71 91 72 / 20 10 10 20 DURANT OK 96 73 97 73 / 20 10 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 84/17
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
143 PM EDT FRI JUL 31 2015 .SYNOPSIS... DRY HIGH PRESSURE WILL BUILD IN BEHIND A DEPARTING COLD FRONT TODAY AND REMAIN IN PLACE THROUGH THE WEEKEND. LOW LEVEL MOISTURE WILL GRADUALLY RETURN THROUGH NEXT WEEK AS ANOTHER COLD FRONT APPROACHES FROM THE NORTH. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM EDT FRIDAY...FORECAST RUNNING PRETTY MUCH ON TRACK WITH NOT MUCH IN THE WAY OF SENSIBLE WEATHER TO WRITE HOME ABOUT. DESPITE THE HEAT...A FAIRLY NICE DAY WITH DEWPOINTS LOWER IN THE WAKE OF THE WEAK FRONTAL PASSAGE. VERY LITTLE CHANGES MADE TO THE GRIDS THIS MORNING...HAVE UPDATED TEMPS AND DEWPOINTS BASED ON TRENDS AND IT IS POSSIBLE THAT HIGHS MIGHT BE JUST A TOUCH LOWER THAN FORECAST BUT WILL CONTINUE TO MONITOR. POPS LOOK GOOD FOR NOW...SPC DAY1 OUTLOOK DOES INCLUDE EXTREME SOUTHEAST PORTIONS OF THE CWA IN GENERAL THUNDER BUT LOOKING AT THE HRRR AND OTHER CAMS SEEMS WE WILL BE PRETTY HARD-PRESSED TO SEE CONVECTION TODAY. CLOUDS WILL CONTINUE TO SCATTER OUT OVER THE NEXT COUPLE OF HOURS. 1045 UTC UPDATE...SKY COVER WAS UPDATED FORM INFRARED SATELLITE IMAGERY...RESULTING IN A DECREASE. POPS WERE ADJUSTED DOWN PER TRENDS. AT 300 AM EDT FRIDAY...AN UPPER RIDGE WILL SLOWLY RETROGRESS TODAY AND TONIGHT FROM THE SOUTHERN PLAINS TO THE SOUTHERN ROCKIES...WHILE AN UPPER TROUGH AMPLIFIES OVER THE EASTERN USA. A COLD FRONT WILL MOVE SLOWLY SOUTH AND OUT OF OUR AREA...STALLING NEAR THE COAST OF THE CAROLINAS AND GA. MOISTURE ASSOCIATED WITH THIS BOUNDARY APPEARS TO GENERALLY REMAIN JUST SE OF OUR AREA...OFFERING LITTLE SUPPORT FOR CONVECTION. TEMPERATURES WILL RUN NEAR NORMAL TODAY AND TONIGHT AS WEAK COOL ADVECTION IS OFFSET BY LIMITED DOWNSLOPE WARMING FLOW IN LIGHT NORTHERLY WINDS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 150 AM FRIDAY...QUIET WEATHER EXPECTED THRU THE SHORT RANGE. AN UPPER TROF REMAINS ACROSS MUCH OF THE ERN CONUS WITH NO SIGNIFICANT SHORT WAVE ENERGY MOVING THRU THE TROF. AT THE SFC... DRY HIGH PRESSURE BUILDS IN ACROSS THE AREA SAT AND SUN. GUIDANCE BLEND SHOWS DEW POINTS MIXING OUT INTO THE 50S ACROSS THE AREA BOTH DAYS. THIS COMBINED WITH RELATIVELY WARM MID LEVEL AIR WILL LEAD TO LITTLE TO NO CAPE EACH AFTERNOON...RESULTING IN VERY LOW POTENTIAL FOR DEEP MOIST CONVECTION. A REMNANT COLD FRONT BOUNDARY WILL BE CLOSE BUT SOUTH OF THE AREA PROVIDING LITTLE TO NO LOW LEVEL CONVERGENCE FOR THE AREA. THEREFORE...HAVE GONE WITH A DRY FCST. EXPECT TEMPS TO BE NEAR TO A LITTLE ABOVE NORMAL THRU THE PERIOD. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 255 AM FRIDAY...GUIDANCE IS IN DECENT AGREEMENT THRU THE PERIOD. EAST COAST TROF FLATTENS THRU THE PERIOD WITH WLY FLOW DEVELOPING ACROSS THE AREA AS HEIGHTS RISE. THIS ALLOWS A SERIES OF SHORT WAVES TO MOVE ACROSS OR NEAR THE AREA. THE DRY HIGH PRESSURE OVER THE AREA SLOWLY MODERATES THEN DISSIPATES AS A COLD FRONT DROPS SOUTH TOWARD THE AREA. THE COLD FRONT INITIALLY STALLS...THEN MOVES INTO THE AREA THU AS A LOW PRESSURE AREA TRACKS FROM THE OH VALLEY OFF THE MID ATLANTIC COAST. THE RESULT IS AN INCREASE IN LOW LEVEL MOISTURE AND INSTABILITY THRU THE PERIOD. THE BEST FORCING...AND RESULTANT CONVECTION...WILL BE WED AND THU...WITH A DRY FCST MON AND ONLY ISOLATED CONVECTION TUE ACROSS THE MTNS. WITH THE RISING HEIGHTS AND LINGERING HIGH PRESSURE MON AND TUE...TEMPS WILL BE ABOVE NORMAL. TEMPS SLOWLY FALL WED AND THU...BUT REMAIN ABOVE NORMAL. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AT KCLT AND ELSEWHERE...VFR...WITH THE POSSIBLE EXCEPTION OF BRIEF MVFR FOG AT KHKY BETWEEN 06-12Z SATURDAY BUT CHANCE NOT HIGH ENOUGH TO INCLUDE IN TAF AT THIS TIME. VERY LITTLE MOISTURE TO WORK WITH IN THE WAKE OF THE FRONT THIS MORNING SO EXPECT AT BEST FEW TO SCT CLOUDS AROUND 5-6KFT FOR THIS AFTERNOON...WITH POSSIBLY ANOTHER ROUND SATURDAY AFTERNOON...BUT MOISTURE IS EVEN MORE LIMITED BY THAT POINT. COULD SEE PASSING CIRRUS OFF AND ON AS WELL. DO NOT EXPECT ANY CONVECTION THROUGH THE PERIOD AT THE TAF SITES. WINDS SHOULD REMAIN GENERALLY N TO NE WITH ONLY BRIEF SWINGS TOWARD E...BUT REMAINING ON THE N SIDE. COULD SEE SOME OFF-AND-ON LOW-END GUSTS THROUGH THIS AFTERNOON BUT WINDS SHOULD DIE OFF LATER THIS EVENING AND OVERNIGHT TO GENERALLY 5KT OR BELOW EVERYWHERE. OUTLOOK...EXPECTING GENERALLY DRY AND QUIET WEATHER THROUGH THE WEEKEND WITH A GRADUAL INCREASE IN CHANCES FOR SHOWERS/THUNDERSTORMS AND RESTRICTIONS FOR THE START OF THE NEW WORK WEEK. CONFIDENCE TABLE... 17-23Z 23-05Z 05-11Z 11-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...RWH NEAR TERM...TDP SHORT TERM...RWH LONG TERM...RWH AVIATION...TDP
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1044 AM EDT FRI JUL 31 2015 .SYNOPSIS... DRY HIGH PRESSURE WILL BUILD IN BEHIND A DEPARTING COLD FRONT TODAY AND REMAIN IN PLACE THROUGH THE WEEKEND. LOW LEVEL MOISTURE WILL GRADUALLY RETURN THROUGH NEXT WEEK AS ANOTHER COLD FRONT APPROACHES FROM THE NORTH. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM EDT FRIDAY...FORECAST RUNNING PRETTY MUCH ON TRACK WITH NOT MUCH IN THE WAY OF SENSIBLE WEATHER TO WRITE HOME ABOUT. DESPITE THE HEAT...A FAIRLY NICE DAY WITH DEWPOINTS LOWER IN THE WAKE OF THE WEAK FRONTAL PASSAGE. VERY LITTLE CHANGES MADE TO THE GRIDS THIS MORNING...HAVE UPDATED TEMPS AND DEWPOINTS BASED ON TRENDS AND IT IS POSSIBLE THAT HIGHS MIGHT BE JUST A TOUCH LOWER THAN FORECAST BUT WILL CONTINUE TO MONITOR. POPS LOOK GOOD FOR NOW...SPC DAY1 OUTLOOK DOES INCLUDE EXTREME SOUTHEAST PORTIONS OF THE CWA IN GENERAL THUNDER BUT LOOKING AT THE HRRR AND OTHER CAMS SEEMS WE WILL BE PRETTY HARD-PRESSED TO SEE CONVECTION TODAY. CLOUDS WILL CONTINUE TO SCATTER OUT OVER THE NEXT COUPLE OF HOURS. 1045 UTC UPDATE...SKY COVER WAS UPDATED FORM INFRARED SATELLITE IMAGERY...RESULTING IN A DECREASE. POPS WERE ADJUSTED DOWN PER TRENDS. AT 300 AM EDT FRIDAY...AN UPPER RIDGE WILL SLOWLY RETROGRESS TODAY AND TONIGHT FROM THE SOUTHERN PLAINS TO THE SOUTHERN ROCKIES...WHILE AN UPPER TROUGH AMPLIFIES OVER THE EASTERN USA. A COLD FRONT WILL MOVE SLOWLY SOUTH AND OUT OF OUR AREA...STALLING NEAR THE COAST OF THE CAROLINAS AND GA. MOISTURE ASSOCIATED WITH THIS BOUNDARY APPEARS TO GENERALLY REMAIN JUST SE OF OUR AREA...OFFERING LITTLE SUPPORT FOR CONVECTION. TEMPERATURES WILL RUN NEAR NORMAL TODAY AND TONIGHT AS WEAK COOL ADVECTION IS OFFSET BY LIMITED DOWNSLOPE WARMING FLOW IN LIGHT NORTHERLY WINDS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 150 AM FRIDAY...QUIET WEATHER EXPECTED THRU THE SHORT RANGE. AN UPPER TROF REMAINS ACROSS MUCH OF THE ERN CONUS WITH NO SIGNIFICANT SHORT WAVE ENERGY MOVING THRU THE TROF. AT THE SFC... DRY HIGH PRESSURE BUILDS IN ACROSS THE AREA SAT AND SUN. GUIDANCE BLEND SHOWS DEW POINTS MIXING OUT INTO THE 50S ACROSS THE AREA BOTH DAYS. THIS COMBINED WITH RELATIVELY WARM MID LEVEL AIR WILL LEAD TO LITTLE TO NO CAPE EACH AFTERNOON...RESULTING IN VERY LOW POTENTIAL FOR DEEP MOIST CONVECTION. A REMNANT COLD FRONT BOUNDARY WILL BE CLOSE BUT SOUTH OF THE AREA PROVIDING LITTLE TO NO LOW LEVEL CONVERGENCE FOR THE AREA. THEREFORE...HAVE GONE WITH A DRY FCST. EXPECT TEMPS TO BE NEAR TO A LITTLE ABOVE NORMAL THRU THE PERIOD. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 255 AM FRIDAY...GUIDANCE IS IN DECENT AGREEMENT THRU THE PERIOD. EAST COAST TROF FLATTENS THRU THE PERIOD WITH WLY FLOW DEVELOPING ACROSS THE AREA AS HEIGHTS RISE. THIS ALLOWS A SERIES OF SHORT WAVES TO MOVE ACROSS OR NEAR THE AREA. THE DRY HIGH PRESSURE OVER THE AREA SLOWLY MODERATES THEN DISSIPATES AS A COLD FRONT DROPS SOUTH TOWARD THE AREA. THE COLD FRONT INITIALLY STALLS...THEN MOVES INTO THE AREA THU AS A LOW PRESSURE AREA TRACKS FROM THE OH VALLEY OFF THE MID ATLANTIC COAST. THE RESULT IS AN INCREASE IN LOW LEVEL MOISTURE AND INSTABILITY THRU THE PERIOD. THE BEST FORCING...AND RESULTANT CONVECTION...WILL BE WED AND THU...WITH A DRY FCST MON AND ONLY ISOLATED CONVECTION TUE ACROSS THE MTNS. WITH THE RISING HEIGHTS AND LINGERING HIGH PRESSURE MON AND TUE...TEMPS WILL BE ABOVE NORMAL. TEMPS SLOWLY FALL WED AND THU...BUT REMAIN ABOVE NORMAL. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... AT KCLT...VFR. GUIDANCE DOES NOT FAVOR VSBY OR CIG RESTRICTIONS. WINDS WILL GENERALLY FAVOR THE N OR NE...WITH LIMITED GUST POTENTIAL. CONVECTION IS NOT EXPECTED TODAY IN DRIER AIR BEHIND A DEPARTING COLD FRONT. ELSEWHERE...RESTRICTIONS ARE NOT FAVORED AT TAF SITES BY MODEL GUIDANCE...AS DRIER AIR MOVES IN BEHIND A DEPARTING COLD FRONT. WINDS WILL GENERALLY FAVOR THE N...WITH ONLY LIMITED GUSTS. CONVECTION IS NOT EXPECTED AT TAF SITES THIS AFTERNOON. OUTLOOK...EXPECTING GENERALLY DRY AND QUIET WEATHER THROUGH THE WEEKEND WITH A GRADUAL INCREASE IN CHANCES FOR SHOWERS/THUNDERSTORMS AND RESTRICTIONS FOR THE START OF THE NEW WORK WEEK. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 95% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...RWH NEAR TERM...TDP SHORT TERM...RWH LONG TERM...RWH AVIATION...JAT/TDP
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
700 PM CDT SAT AUG 1 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...DISSIPATING SHOWERS APPROACHING SOUTH PADRE ISLAND HAVE A LOW PROBABILITY OF IMPACTING KBRO THROUGH 9 PM. NO THUNDER IS ASSOCIATED WITH THIS SMALL AREA OF RAIN AS IT DRIFTS SOUTHWEST AT AROUND 15 MPH. CEILINGS ASSOCIATED WITH THIS AREA OF RAIN AND OTHER CLOUDS THROUGH MUCH OF DEEP SOUTH TEXAS ARE IN THE VFR RANGE WITH NO MVFR OR IFR EXPECTED IN THE NEXT 24 HOURS. PROBABILITIES FROM HIGH RESOLUTION MODELS CONTINUES TO INDICATE LOW PROBABILITIES OF ANY AVIATION IMPACTS FROM LOW CLOUDS OR LOW VISIBILITIES. WINDS WILL CONTINUE TO BE LIGHT AND VARIABLE TONIGHT BECOMING SOUTHEAST LIGHT TO MODERATE SUNDAY WITH GUSTS BETWEEN 15 AND 20 KNOTS IN THE LATE MORNING AND AFTERNOON. && .PREV DISCUSSION... /ISSUED 304 PM CDT SAT AUG 1 2015/ SHORT TERM /NOW THROUGH SUNDAY NIGHT/...SATELLITE IMAGES THIS AFTERNOON INDICATE MOSTLY MID TO HIGH CLOUDS NEAR THE COAST WITH A SCATTERED CU FIELD ACROSS THE WESTERN PORTIONS OF THE DEEP SOUTH TEXAS. THE LATEST BRO RADAR CONTINUES TO SHOW SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE GULF OF MEXICO WATERS...20 TO 60 NAUTICAL MILES EAST OF PADRE ISLAND. THE WEAK 500MB LOW/INVERTED TROUGH ACROSS THE WESTERN GULF OF MEXICO THIS AFTERNOON WILL CONTINUE TO PROVIDE LOW TO MID LEVEL MOISTURE OVER THE WESTERN GULF OF MEXICO AND ALONG THE LOWER TEXAS COAST. THE 12Z BRO SOUNDING SHOWS PRECIPITABLE WATERS OF 1.97 INCHES. THIS WILL SUPPORT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL SECTIONS OF DEEP SOUTH TEXAS FOR THE REST OF THIS AFTERNOON WITH DRIER AIR FARTHER INLAND. THE LATEST HRRR KEEPS MOST...IF NOT ALL...OF THE CONVECTION OFFSHORE AND SOUTH OF THE RIO GRANDE RIVER NOW THROUGH THIS EVENING. CONVECTION IS EXPECTED TO DECREASE IN COVERAGE THIS EVENING BEFORE REDEVELOPING OVER THE GULF WATERS AFTER MIDNIGHT. THE WEAK MID TO UPPER LEVEL FEATURE IS EXPECTED TO MOVE WESTWARD ACROSS NORTHEAST MEXICO TONIGHT INTO SUNDAY. LINGERING MOISTURE COMBINED WITH DAYTIME HEATING WILL PROVIDE A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE LOWER PORTIONS OF THE RIO GRANDE VALLEY ON SUNDAY. LONG TERM /MONDAY THROUGH SATURDAY/...THE MAIN ISSUE IN THE LONGER RANGE PERIOD WILL BE THE HEAT POTENTIAL ACROSS THE RGV. THE GFS AND ECMWF BOTH RESTRENGTHEN THE 500 MB RIDGING IN PLACE OVER THE SOUTH CENTRAL PLAINS STATES NEXT WEEK. THIS WILL RESULT IN A DRIER AND MORE STABLE AIRMASS OVER DEEP SOUTH TX ONCE AGAIN YIELDING ABOVE NORMAL TEMPS THROUGH DAY 7. THE DEEPER LAYER MOISTURE VALUES REMAIN PRETTY LIMITED ACROSS THE AREA THROUGH THE EXTENDED RANGE PERIOD. ONLY A VERY SHALLOW MOISTURE LAYER MAY PERSIST ON THROUGH DAY 7 WHICH WILL ALLOW FOR SOME LOW LEVEL CLD COVER TO PERSIST ON THROUGH THE PERIOD. OTHERWISE EXPECT NEAR ZERO RAIN CHANCES TO PREVAIL. THE GFS MEX AND ECMWF MODEL HIGH/LOW TEMPS THROUGH THE PERIOD ARE IN PRETTY DECENT AGREEMENT. SO WILL GO WITH A GENERAL 50/50 BLEND OF THE TWO MODEL SETS FOR TEMPS. THE GFS MEX POPS STILL TRY TO TREND TOWARDS SOME SLGT CHC POPS LATE IN THE PERIOD. I BELIEVE THAT THIS IS MODEL TREND IS BEING SKEWED HIGH DUE TO CLIMO INFLUENCES. SO WILL GO CLOSER TO THE ECMWF POPS IN THE LONG TERM. MARINE...NOW THROUGH SUNDAY NIGHT...BUOY020 IS CURRENTLY REPORTING SEAS OF 1 FOOT WITH NORTH WINDS NEAR 4 KNOTS. LIGHT AND VARIABLE WINDS WILL PREVAIL ACROSS THE LOWER TEXAS COASTAL WATERS NOW THROUGH SUNDAY NIGHT DUE TO A WEAK PRESSURE GRADIENT ACROSS THE WESTERN GULF. WINDS AND SEAS WILL BE HIGHER IN AND NEAR THUNDERSTORMS ASSOCIATED WITH THE WEAK MID TO UPPER LEVEL DISTURBANCE OVER THE WESTERN GULF. MONDAY THROUGH THURSDAY...THE PGF WILL START OF NEXT WEEK FAIRLY WEAK ALLOWING FOR FAIRLY LOW WINDS AND SEAS TO PREVAIL. THE PGF WILL THEN START TO STRENGTHEN SOMEWHAT STARTING LATE TUES/WED AS A SURFACE LOW DEVELOPS OVER THE SOUTHERN PLAINS STATES. THIS MAY PUSH THE WINDS AND SEAS UP LATE IN THE MARINE FORECAST PERIOD TO POSSIBLY PRODUCE SOME SCEC CONDITIONS WED/THURS. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 77 92 79 94 / 10 20 10 10 BROWNSVILLE 76 94 78 95 / 10 20 10 10 HARLINGEN 75 95 77 98 / 10 40 10 10 MCALLEN 76 99 79 102 / 10 30 10 10 RIO GRANDE CITY 75 101 78 104 / 10 20 10 10 SOUTH PADRE ISLAND 78 88 80 90 / 10 20 10 10 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 59...AVIATION/SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
309 PM CDT FRI JUL 31 2015 .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...HAVE FINALLY DEVELOPED SOME ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON. HRRR MODEL HANDLING THIS REASONABLY WELL...ENDS MOST OF THE ACTIVITY BY ABOUT 02Z. HAVE 20 POPS AREA WIDE FOR THE EVENING...WITH 10S AND 20S AFTER MIDNIGHT. GLOBAL MODELS CONTINUE TO STRUGGLE WITH QPF...GFS DEFINITELY STILL TOO AGGRESSIVE. SOMETHING OF A MIX BETWEEN NAM AND ECMWF APPEARS THE BEST. THAT SAID...BOTH OF THOSE MODELS ARE QUIET ON SATURDAY...EXCEPT IN MARINE AREA. HAVE CUT POPS FOR INLAND AREAS IN THE MORNING...BUT WILL LEAVE A 20 POP AREA WIDE FOR THE AFTERNOON AS HIGH MOISTURE AIR WILL STILL BE IN PLACE AND COULD GET SOME SHOWERS TO POP UP ONCE AGAIN. WITH NO MAJOR PATTERN CHANCE...EXPECT TEMPERATURES TOMORROW TO APPROACH THE SAME VALUES WE/RE SEEING TODAY AS WE SHOULD KEEP A LIGHT AND VARIABLE WIND...NOT THE ONSHORE FLOW WE ARE USED TO THIS TIME OF YEAR. HAVE HIGHS MAINLY IN THE UPPER 90S TO AROUND 100 ACROSS THE AREA. HEAT INDEX VALUES WILL BE AT LEAST BETWEEN 100 AND 105...BUT COULD BE 105 TO 109 IF WE DON`T MIX OUT THE NEAR SURFACE MOISTURE. && .LONG TERM (SUNDAY THROUGH FRIDAY)...EXTENDED FORECAST LOOKS RELATIVELY STRAIGHTFORWARD WITH UPPER RIDGE AXIS REPOSITIONING ITSELF OVER THE SOUTHERN PLAINS AND SURFACE LEE DEVELOPMENT GENERATING TYPICAL ONSHORE FLOW REGIME ACROSS THE COASTAL BEND. ANY LINGERING PRECIPITATION CHANCES WITH A DECAYING BOUNDARY ON SUNDAY SHOULD BE CONFINED TO OFFSHORE ZONES...THEN A DRY FORECAST THROUGH THE WEEK. TEMPERATURES WILL REMAIN A CATEGORY OR SO ABOVE NORMAL THROUGH THE PERIOD. HEAT INDEX LEVELS WILL FLIRT WITH SPS CRITERIA ON A DAILY BASIS...THOUGH ACTUAL ADVISORY CRITERIA HEAT APPEARS UNLIKELY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 76 98 76 96 77 / 20 20 10 10 10 VICTORIA 74 100 74 98 75 / 20 20 10 10 10 LAREDO 78 103 78 103 78 / 20 20 10 10 0 ALICE 75 100 75 98 75 / 20 20 10 10 10 ROCKPORT 76 95 79 91 80 / 20 20 10 10 10 COTULLA 77 102 75 103 76 / 20 20 10 0 0 KINGSVILLE 75 99 76 98 76 / 20 20 10 10 10 NAVY CORPUS 78 92 79 90 80 / 20 20 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ PZ/83...SHORT TERM JV/71...LONG TERM
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1050 AM CDT FRI JUL 31 2015 .UPDATE... ONE NOTE...AFTER CHECKING THROUGH THE TEMPERATURES DECIDED TO UP THE HIGHS FOR TODAY A BIT TO BE MORE IN LINE WITH THE MAV GUIDANCE. DRIER AIR FILTERING IN FROM THE NORTHEAST WILL LIKELY AID IN A BIT HIGHER NUMBERS. 40 && .PREV DISCUSSION... /ISSUED 1036 AM CDT FRI JUL 31 2015/ DISCUSSION... A COLD FRONT WAS ENTERING INTO THE NORTHEASTERN COUNTIES OF THE FORECAST AREA AT MID MORNING...WITH A PREFRONTAL TROUGH ACROSS GALVESTON BAY THROUGH METRO HOUSTON AND INTO THE CLL AREA. ANOTHER TROUGH WAS OUT IN THE OPEN WATERS OF THE GULF. ISOLATED SHOWERS HAVE ENDEAVORED TO DEVELOP OVER THE INLAND AREAS SOUTH OF THE PREFRONTAL TROUGH WHILE SCATTERED LARGER SHOWERS WERE OVER THE OPEN WATERS OF THE GULF EAST OF THAT SURFACE TROUGH. THE HIGH RES SHORT RANGE MODELS LOOKED FAIRLY SIMILAR FOR THE OUTLOOK TODAY. LIKED THE HRRR WHICH HAS ISOLATED CONVECTION ALONG AND SOUTHWEST OF A LINE FROM ABOUT CLL TO HOUSTON TO GALVESTON LATE THIS MORNING THROUGH THE EARLY AFTERNOON. AS THE FRONT CONTINUES MOVING SOUTHWESTWARD...THE RAIN CHANCES WILL PUSH MORE OVER THE SOUTHWESTERN COUNTIES DURING THE LATE AFTERNOON AND EARLY EVENING. THE OTHER ISSUE OF NOTE WILL BE THE HEAT INDEX. VALUES ARE STILL FORECAST TO REACH ADVISORY CRITERIA OVER THE COAST DURING THE LATE AFTERNOON PERIOD. THE DRIER AIR BEHIND THE FRONT WILL LIKELY HAVE AN IMPACT OVER CHAMBERS AND MAYBE GALVESTON COUNTY. SINCE THE TIMING IS UNCERTAIN AT THIS TIME...WILL KEEP THE HEAT ADVISORY UP FOR THE IMMEDIATE COASTAL COUNTIES BUT WILL DROP COUNTIES LATER TODAY IF NEEDED. TWEAKED THE POPS AND WEATHER A BIT TO ACCOUNT FOR THE LATEST RADAR AND MODEL TRENDS. 40 PREV DISCUSSION... /ISSUED 414 AM CDT FRI JUL 31 2015/ DISCUSSION... OVERNIGHT CONVECTION OVER THE BRAZOS VALLEY CONTINUES TO DIMINISH AS IT EXITS THE FORECAST AREA...WITH VERY WARM TEMPERATURES PERSISTING ACROSS SOUTHEAST TEXAS EARLY THIS MORNING. SURFACE ANALYSIS AT 05Z SHOWED A PLUME OF 75+ DEGREE DEW POINTS DRAPED ALONG THE TEXAS COAST AND EXTENDING INTO NORTHEAST LOUISIANA. THIS... COMBINED WITH LEFTOVER CLOUDS FROM LAST NIGHT/S STORMS... WAS CONTRIBUTING TO HEAT INDICES IN THE LOW TO MID 90S AS OF 3 AM CDT AT A FEW SITES. A WEAK FRONTAL BOUNDARY WAS ALSO ANALYZED ON THIS MAP STRETCHING NORTH TEXAS AND ON INTO NORTHERN LOUISIANA. THIS FRONT WILL PLAY A MAJOR ROLE IN HOW THE WEATHER EVOLVES TODAY FOR THE REGION... BOTH IN TERMS OF THUNDERSTORM CHANCES AS WELL AS CONCERNS ABOUT HEAT. THE 00Z LAKE CHARLES SOUNDING REPORTED A PRECIPITABLE WATER VALUE OF 2.26 INCHES... WITH OVERNIGHT GPS-MET MEASUREMENTS ACROSS THE REGION SHOWING A SIMILARLY MOIST AIRMASS /2.1 TO 2.3 INCHES AROUND THE HOUSTON METRO AND ALONG THE COAST/. HIGH RESOLUTION GUIDANCE IS FAIRLY CONSISTENT WITH DEVELOPING SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE FRONT AS IT SLOWLY DROPS SOUTHWESTWARD TODAY... BUT AGREEMENT IS POOR IN THE ACTUAL TIMING OF THIS FEATURE AND CONSEQUENTLY THE LOCATION OF THE GREATEST AREAL COVERAGE. THE GFS APPEARS TO BE BY FAR THE MOST AGGRESSIVE AND SWEEPS MOISTURE AWAY FROM THE INTERSTATE 45 CORRIDOR AND POINTS EAST BY 18Z. COMPARISON OF SURFACE THETA-E FIELDS HOWEVER /WHICH REPRESENT MOISTURE AND INSTABILITY PRESENT/ REVEAL STABILIZATION FOR THE EASTERN HALF OF THE REGION CLOSER TO 00Z... WITH RELATIVELY GOOD AGREEMENT BETWEEN BOTH HIGHER RESOLUTION AND SYNOPTIC MODELS ON THIS SOLUTION. BASED ON THIS... HIGHLIGHTING HIGHEST RAIN CHANCES WEST OF THE INTERSTATE 45 CORRIDOR TODAY ALONG AND AHEAD OF THE ANTICIPATED FRONTAL POSITION. ADDITIONALLY... A DRY SUB-CLOUD LAYER AND DCAPE VALUES 1100-1300 J/KG THIS AFTERNOON RAISES CONCERNS FOR AT LEAST AN ISOLATED GUSTY WIND THREAT FROM STRONGER THUNDERSTORM ACTIVITY. A LATER FRONTAL PASSAGE ALSO MEANS THAT STIFLING CONDITIONS WILL PERSIST AHEAD OF THE FRONT TODAY AND HAVE GONE AHEAD AND ISSUED A HEAT ADVISORY FOR THE COASTAL COUNTIES OF MATAGORDA... BRAZORIA... GALVESTON... AND CHAMBERS. HEAT INDICES IN THESE AREAS REACHED 109 TO 111 DEGREES YESTERDAY. WITH THE ANTICIPATED SLOW PROGRESSION OF THE FRONT TODAY COMBINED WITH NAEFS ANOMALIES HIGHLIGHTING ANOMALOUS TEMPERATURES AGAIN ALONG THE COAST /A RETURN INTERVAL OF APPROXIMATELY ONCE EVERY 10 YEARS/... WANTED TO HIGHLIGHT THE INCREASED POTENTIAL FOR HEALTH IMPACTS. IF THE FRONT MOVES THROUGH FASTER THAN ANTICIPATED HOWEVER... DRIER AIR FILTERING IN BEHIND THE FRONT WILL ACTUALLY HELP LOWER HEAT INDEX VALUES AND ADVISORY CRITERIA MAY NOT BE MET. FOR THE REMAINDER OF THE SHORT TERM... THE FRONT IS EXPECTED TO PUSH OFF THE COAST TONIGHT. DRIER AIR FILTERING IN BEHIND THE FRONT WILL HELP LIMIT RAIN CHANCES OVER ALL BUT THE COASTAL WATERS ON SATURDAY. THIS SLIGHTLY DRIER AIR MAY ALSO ALLOW FOR SOME OVERNIGHT LOWS IN THE UPPER 60S IN THE PINEY WOODS REGION... WITH LOW 70S TO NEAR 80 POSSIBLE ELSEWHERE. HIGH TEMPERATURES ARE NOT EXPECTED TO DIFFER MUCH FROM TODAY ON SATURDAY BUT A DRIER AIRMASS IN PLACE WILL HELP MITIGATE AGAINST HIGHER HEAT INDEX VALUES. THE REGION WILL REMAIN ON THE EASTERN PERIPHERY OF THE UPPER RIDGE ON SUNDAY AND THROUGH THE REST OF THE FORECAST PERIOD... WITH THE CENTER OF THIS FEATURE SHIFTING A BIT AROUND THE SOUTHERN PLAINS DURING THIS TIME. LOW THUNDERSTORM CHANCES WILL CONTINUE IN THE VICINITY OF THE STALLED FRONTAL BOUNDARY WITH DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES INLAND PERSISTING INTO THE MIDDLE OF NEXT WEEK. HUFFMAN MARINE... STORMS HAVE DEPARTED THE WATERS BUT MORE COULD COMING LATE THIS MORNING THROUGH EVENING. WINDS WILL GENERALLY BE VARIABLE NORTHERLY TO EASTERLY ACROSS THE UPPER TEXAS COASTAL WATERS WITH AN AFTERNOON SEABREEZE FORMING. EVENTUALLY A DIFFUSE COLD FRONT SAGS OUT INTO THE GULF WATERS LATE TONIGHT AND WINDS INCREASE SLIGHTLY. 850MB FRONT APPEARS TO STALL WELL OFFSHORE AND SHOULD BECOME A FOCUS FOR REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS BUT PROBABLY JUST SE OF THE UPPER TEXAS COASTAL WATERS. WILL NEED TO KEEP AN EYE ON THE REMAINS OF THE BOUNDARY SATURDAY AFTERNOON-SUNDAY AS THE GULF IS PLENTY WARM ENOUGH AND SHEAR RELAXES. MOISTURE SURGES BACK INTO THE AREA LATE SUNDAY AND SOUTH TO SOUTHEASTERLY FLOW RETURNS AND CONTINUES THROUGH FRIDAY. 45 AVIATION... VFR FOR NOW BUT MAY GET A FEW SPOTS WITH MIFG AROUND SUNRISE MAINLY THE MORE RURAL SITES CXO NORTHWARD. CHALLENGING FORECAST FOR TODAY. DRY AIR SHOULD INTRUDE INTO THE REGION FROM THE NORTHEAST BUT A FEW OF THE MODELS APPEAR TOO QUICK TO DRY THINGS OUT. L/V WINDS WILL BE THE NORTH UNTIL THE DIFFUSE FROPA. AM THINKING THAT CLL-HOU-SGR-LBX MAY SEE SOME THUNDER CLOSE BY THIS AFTERNOON AND WILL LIKELY ADD THIS IN THE 12Z PACKAGE IF NOT SOONER. IAH MAY BE ON THE NORTHERN FRINGE OF WHERE POOLED MOISTURE AND SAGGING BOUNDARY INTERACT SO FOR NOW WILL PROBABLY LEAVE VCTS OUT BUT IT WILL BE CLOSE. DEEP MIXING AGAIN TODAY WITH LIGHT WINDS IN THE PROFILE SO STORMS SHOULD BE SLOW MOVING. DRYING NORTHEASTERLY TO EASTERLY FLOW SHOULD OVERSPREAD IAH/HOU BY LATE AFTERNOON/EARLY EVENING LEADING TO CLEAR SKIES. 45 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 99 73 98 74 99 / 30 10 10 10 10 HOUSTON (IAH) 100 74 98 75 99 / 20 10 10 10 10 GALVESTON (GLS) 95 80 94 81 92 / 30 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...MATAGORDA. GM...NONE. && $$ DISCUSSION...40 AVIATION/MARINE...33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1036 AM CDT FRI JUL 31 2015 .DISCUSSION... A COLD FRONT WAS ENTERING INTO THE NORTHEASTERN COUNTIES OF THE FORECAST AREA AT MID MORNING...WITH A PREFRONTAL TROUGH ACROSS GALVESTON BAY THROUGH METRO HOUSTON AND INTO THE CLL AREA. ANOTHER TROUGH WAS OUT IN THE OPEN WATERS OF THE GULF. ISOLATED SHOWERS HAVE ENDEAVORED TO DEVELOP OVER THE INLAND AREAS SOUTH OF THE PREFRONTAL TROUGH WHILE SCATTERED LARGER SHOWERS WERE OVER THE OPEN WATERS OF THE GULF EAST OF THAT SURFACE TROUGH. THE HIGH RES SHORT RANGE MODELS LOOKED FAIRLY SIMILAR FOR THE OUTLOOK TODAY. LIKED THE HRRR WHICH HAS ISOLATED CONVECTION ALONG AND SOUTHWEST OF A LINE FROM ABOUT CLL TO HOUSTON TO GALVESTON LATE THIS MORNING THROUGH THE EARLY AFTERNOON. AS THE FRONT CONTINUES MOVING SOUTHWESTWARD...THE RAIN CHANCES WILL PUSH MORE OVER THE SOUTHWESTERN COUNTIES DURING THE LATE AFTERNOON AND EARLY EVENING. THE OTHER ISSUE OF NOTE WILL BE THE HEAT INDEX. VALUES ARE STILL FORECAST TO REACH ADVISORY CRITERIA OVER THE COAST DURING THE LATE AFTERNOON PERIOD. THE DRIER AIR BEHIND THE FRONT WILL LIKELY HAVE AN IMPACT OVER CHAMBERS AND MAYBE GALVESTON COUNTY. SINCE THE TIMING IS UNCERTAIN AT THIS TIME...WILL KEEP THE HEAT ADVISORY UP FOR THE IMMEDIATE COASTAL COUNTIES BUT WILL DROP COUNTIES LATER TODAY IF NEEDED. TWEAKED THE POPS AND WEATHER A BIT TO ACCOUNT FOR THE LATEST RADAR AND MODEL TRENDS. 40 && .PREV DISCUSSION... /ISSUED 414 AM CDT FRI JUL 31 2015/ DISCUSSION... OVERNIGHT CONVECTION OVER THE BRAZOS VALLEY CONTINUES TO DIMINISH AS IT EXITS THE FORECAST AREA...WITH VERY WARM TEMPERATURES PERSISTING ACROSS SOUTHEAST TEXAS EARLY THIS MORNING. SURFACE ANALYSIS AT 05Z SHOWED A PLUME OF 75+ DEGREE DEW POINTS DRAPED ALONG THE TEXAS COAST AND EXTENDING INTO NORTHEAST LOUISIANA. THIS... COMBINED WITH LEFTOVER CLOUDS FROM LAST NIGHT/S STORMS... WAS CONTRIBUTING TO HEAT INDICES IN THE LOW TO MID 90S AS OF 3 AM CDT AT A FEW SITES. A WEAK FRONTAL BOUNDARY WAS ALSO ANALYZED ON THIS MAP STRETCHING NORTH TEXAS AND ON INTO NORTHERN LOUISIANA. THIS FRONT WILL PLAY A MAJOR ROLE IN HOW THE WEATHER EVOLVES TODAY FOR THE REGION... BOTH IN TERMS OF THUNDERSTORM CHANCES AS WELL AS CONCERNS ABOUT HEAT. THE 00Z LAKE CHARLES SOUNDING REPORTED A PRECIPITABLE WATER VALUE OF 2.26 INCHES... WITH OVERNIGHT GPS-MET MEASUREMENTS ACROSS THE REGION SHOWING A SIMILARLY MOIST AIRMASS /2.1 TO 2.3 INCHES AROUND THE HOUSTON METRO AND ALONG THE COAST/. HIGH RESOLUTION GUIDANCE IS FAIRLY CONSISTENT WITH DEVELOPING SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE FRONT AS IT SLOWLY DROPS SOUTHWESTWARD TODAY... BUT AGREEMENT IS POOR IN THE ACTUAL TIMING OF THIS FEATURE AND CONSEQUENTLY THE LOCATION OF THE GREATEST AREAL COVERAGE. THE GFS APPEARS TO BE BY FAR THE MOST AGGRESSIVE AND SWEEPS MOISTURE AWAY FROM THE INTERSTATE 45 CORRIDOR AND POINTS EAST BY 18Z. COMPARISON OF SURFACE THETA-E FIELDS HOWEVER /WHICH REPRESENT MOISTURE AND INSTABILITY PRESENT/ REVEAL STABILIZATION FOR THE EASTERN HALF OF THE REGION CLOSER TO 00Z... WITH RELATIVELY GOOD AGREEMENT BETWEEN BOTH HIGHER RESOLUTION AND SYNOPTIC MODELS ON THIS SOLUTION. BASED ON THIS... HIGHLIGHTING HIGHEST RAIN CHANCES WEST OF THE INTERSTATE 45 CORRIDOR TODAY ALONG AND AHEAD OF THE ANTICIPATED FRONTAL POSITION. ADDITIONALLY... A DRY SUB-CLOUD LAYER AND DCAPE VALUES 1100-1300 J/KG THIS AFTERNOON RAISES CONCERNS FOR AT LEAST AN ISOLATED GUSTY WIND THREAT FROM STRONGER THUNDERSTORM ACTIVITY. A LATER FRONTAL PASSAGE ALSO MEANS THAT STIFLING CONDITIONS WILL PERSIST AHEAD OF THE FRONT TODAY AND HAVE GONE AHEAD AND ISSUED A HEAT ADVISORY FOR THE COASTAL COUNTIES OF MATAGORDA... BRAZORIA... GALVESTON... AND CHAMBERS. HEAT INDICES IN THESE AREAS REACHED 109 TO 111 DEGREES YESTERDAY. WITH THE ANTICIPATED SLOW PROGRESSION OF THE FRONT TODAY COMBINED WITH NAEFS ANOMALIES HIGHLIGHTING ANOMALOUS TEMPERATURES AGAIN ALONG THE COAST /A RETURN INTERVAL OF APPROXIMATELY ONCE EVERY 10 YEARS/... WANTED TO HIGHLIGHT THE INCREASED POTENTIAL FOR HEALTH IMPACTS. IF THE FRONT MOVES THROUGH FASTER THAN ANTICIPATED HOWEVER... DRIER AIR FILTERING IN BEHIND THE FRONT WILL ACTUALLY HELP LOWER HEAT INDEX VALUES AND ADVISORY CRITERIA MAY NOT BE MET. FOR THE REMAINDER OF THE SHORT TERM... THE FRONT IS EXPECTED TO PUSH OFF THE COAST TONIGHT. DRIER AIR FILTERING IN BEHIND THE FRONT WILL HELP LIMIT RAIN CHANCES OVER ALL BUT THE COASTAL WATERS ON SATURDAY. THIS SLIGHTLY DRIER AIR MAY ALSO ALLOW FOR SOME OVERNIGHT LOWS IN THE UPPER 60S IN THE PINEY WOODS REGION... WITH LOW 70S TO NEAR 80 POSSIBLE ELSEWHERE. HIGH TEMPERATURES ARE NOT EXPECTED TO DIFFER MUCH FROM TODAY ON SATURDAY BUT A DRIER AIRMASS IN PLACE WILL HELP MITIGATE AGAINST HIGHER HEAT INDEX VALUES. THE REGION WILL REMAIN ON THE EASTERN PERIPHERY OF THE UPPER RIDGE ON SUNDAY AND THROUGH THE REST OF THE FORECAST PERIOD... WITH THE CENTER OF THIS FEATURE SHIFTING A BIT AROUND THE SOUTHERN PLAINS DURING THIS TIME. LOW THUNDERSTORM CHANCES WILL CONTINUE IN THE VICINITY OF THE STALLED FRONTAL BOUNDARY WITH DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES INLAND PERSISTING INTO THE MIDDLE OF NEXT WEEK. HUFFMAN MARINE... STORMS HAVE DEPARTED THE WATERS BUT MORE COULD COMING LATE THIS MORNING THROUGH EVENING. WINDS WILL GENERALLY BE VARIABLE NORTHERLY TO EASTERLY ACROSS THE UPPER TEXAS COASTAL WATERS WITH AN AFTERNOON SEABREEZE FORMING. EVENTUALLY A DIFFUSE COLD FRONT SAGS OUT INTO THE GULF WATERS LATE TONIGHT AND WINDS INCREASE SLIGHTLY. 850MB FRONT APPEARS TO STALL WELL OFFSHORE AND SHOULD BECOME A FOCUS FOR REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS BUT PROBABLY JUST SE OF THE UPPER TEXAS COASTAL WATERS. WILL NEED TO KEEP AN EYE ON THE REMAINS OF THE BOUNDARY SATURDAY AFTERNOON-SUNDAY AS THE GULF IS PLENTY WARM ENOUGH AND SHEAR RELAXES. MOISTURE SURGES BACK INTO THE AREA LATE SUNDAY AND SOUTH TO SOUTHEASTERLY FLOW RETURNS AND CONTINUES THROUGH FRIDAY. 45 AVIATION... VFR FOR NOW BUT MAY GET A FEW SPOTS WITH MIFG AROUND SUNRISE MAINLY THE MORE RURAL SITES CXO NORTHWARD. CHALLENGING FORECAST FOR TODAY. DRY AIR SHOULD INTRUDE INTO THE REGION FROM THE NORTHEAST BUT A FEW OF THE MODELS APPEAR TOO QUICK TO DRY THINGS OUT. L/V WINDS WILL BE THE NORTH UNTIL THE DIFFUSE FROPA. AM THINKING THAT CLL-HOU-SGR-LBX MAY SEE SOME THUNDER CLOSE BY THIS AFTERNOON AND WILL LIKELY ADD THIS IN THE 12Z PACKAGE IF NOT SOONER. IAH MAY BE ON THE NORTHERN FRINGE OF WHERE POOLED MOISTURE AND SAGGING BOUNDARY INTERACT SO FOR NOW WILL PROBABLY LEAVE VCTS OUT BUT IT WILL BE CLOSE. DEEP MIXING AGAIN TODAY WITH LIGHT WINDS IN THE PROFILE SO STORMS SHOULD BE SLOW MOVING. DRYING NORTHEASTERLY TO EASTERLY FLOW SHOULD OVERSPREAD IAH/HOU BY LATE AFTERNOON/EARLY EVENING LEADING TO CLEAR SKIES. 45 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 98 73 98 74 99 / 30 10 10 10 10 HOUSTON (IAH) 98 74 98 75 99 / 20 10 10 10 10 GALVESTON (GLS) 95 80 94 81 92 / 30 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...MATAGORDA. GM...NONE. && $$ DISCUSSION...40 AVIATION/MARINE...33
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1249 AM CDT FRI JUL 31 2015 .AVIATION... VFR CONDITIONS SHOULD PREVAIL FOR MOST OF THE PERIOD. DEEP MOISTURE IS ON THE INCREASE AS A WEAK DISTURBANCE MOVES IN FROM THE EAST. THIS FEATURE WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE AREA THIS AFTERNOON. WILL INCLUDE THE MENTION OF VCTS FOR THE I-35 TAF SITES. CHANCES ARE MUCH TOO LOW FOR KDRT FOR ANY MENTION. SOME OF THE THUNDERSTORMS COULD BE HEAVY...WHICH MAY CAUSE VISIBILITIES TO DROP TO MVFR CATEGORIES OR LOWER. GUSTY WINDS WILL ALSO BE POSSIBLE. && .PREV DISCUSSION... /ISSUED 937 PM CDT THU JUL 30 2015/ UPDATE...LEADING EDGE OF THE MOISTURE PLUME FROM THE EAST HAS ARRIVED INTO THE FAR EASTERN CWA THIS EVENING. HOWEVER...A GRADUAL DOWNWARD TREND IN CONVECTIVE ACTIVITY WILL TAKE PLACE THROUGH THE REMAINDER OF THE LATE EVENING WITH LOSS OF HEATING. VERY MINOR EDITS MADE TO HOURLY T/TD/APPARENT T GRIDS BASED ON TRENDS. NO OTHER UPDATES PLANNED THIS EVENING. DEEPER MOISTURE CONTINUES TO MOVE WEST AND SOUTHWEST INTO THE CWA OVERNIGHT AND FRIDAY. WITH DE-STABILIZATION TOMORROW AFTERNOON EXPECT ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS OVER THE REGION. A FEW STORMS COULD PRODUCE STRONGER DOWNDRAFTS AND WIND GUSTS GIVEN MODEL FORECAST SOUNDINGS...AND MENTIONED IN HWO. PREV DISCUSSION... /ISSUED 625 PM CDT THU JUL 30 2015/ AVIATION... /00Z TAFS/ VFR CONDITIONS ARE EXPECTED ACROSS AREA SITES THROUGH FRIDAY AFTERNOON. WINDS WILL BE FROM THE EAST AND SOUTHEAST 5 TO 10 KNOTS THIS EVENING...BECOMING LIGHT AND VARIABLE OVERNIGHT AND PICKING BACK UP TO 10 KNOTS FRIDAY AFTERNOON WITH HIGHER GUSTS MAINLY ACROSS THE RIO GRANDE PLAINS. A SURGE OF LOW TO MID LEVEL MOISTURE IS FORECAST TO PUSH ACROSS THE EASTERN HALF OF SOUTH CENTRAL TEXAS FRIDAY AFTERNOON AND EVENING. A FEW SHOWERS AND EVEN AN ISOLATED THUNDERSTORM COULD POP ALONG THE I-35 SITES MID/LATE FRIDAY AFTERNOON. THIS ACTIVITY SHOULD COME TO AN END SHORTLY AFTER SUNSET. PREV DISCUSSION... /ISSUED 142 PM CDT THU JUL 30 2015/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)... A VERY ISOLATED SHOT AT THUNDERSTORMS WILL BE POSSIBLE TONIGHT AS ENERGY AND MOISTURE WILL BE MOVING IN FROM THE EAST DUE TO A COLD FRONT PROGRESSING SOUTHWARD ACROSS THE SE CONUS. WITH THE UPPER LEVEL STEERING WINDS BEING NORTHEAST AND EAST...SOME OF THE SHOWER AND STORM DEVELOPMENT IN THE HI RES MODELS COULD MAKE IT AS FAR WEST AS THE EASTERN PERIPHERY OF THE CWA. HOWEVER...AN APPRECIABLE MOISTURE GRADIENT OVER BASICALLY THE I35 CORRIDOR SHOULD PREVENT MUCH FROM GETTING ANY FARTHER WESTWARD. ALSO...DRY LOW LEVEL CONDITIONS AS SEEN ON LAPS AND RUC SOUNDINGS WOULD CHALLENGE ANY PRECIPITATION FROM REACHING THE SURFACE SO CONFIDENCE IS NOT HIGH FOR MEASURABLE PRECIP THIS EVENING. THEREFORE LEFT THE ISOLATED MENTION IN FOR THE EASTERNMOST AREAS OF THE CWA. SHOULD SEE SOME SCATTERED LOW CLOUD DEVELOPMENT IN THE MORNING BUT LESS THAN NORMAL WITH LIGHT AND VARIABLE WINDS. THE LIGHT WINDS AND MOSTLY UNOBSTRUCTED SKY SHOULD KEEP LOWS A COUPLE DEGREES BELOW GUIDANCE AS THEY WERE THIS MORNING. BEST SHOT AT MEASURABLE PRECIP WILL BE IN THE AFTERNOON FRIDAY AS THE CONTINUING WEST COLD FRONT INTERACTS WITH THE COASTAL PLAINS SEA BREEZE. AN AREA OF ENHANCED QPF WAS NOTED IN THE NAM AND GFS WHICH MAKES SENSE AS AN AREA OF LIFT ENOUGH TO REALIZE DECENT INSTABILITY DURING THE AFTERNOON HOURS. STILL THINK PWATS ARE A BIT EXAGGERATED IN THE FORECAST SOUNDINGS BUT STILL THINK A BRIEFLY HEAVY DOWNPOUR AND GUSTY WINDS ARE STILL IN PLAY TOMORROW AFTERNOON. LONG TERM (SATURDAY THROUGH THURSDAY)... MODELS ARE TRENDING A BIT DRIER OVER THE WEEKEND BUT WITH THE BEST OPPORTUNITY FOR SOUTH CENTRAL TEXAS TO RECEIVE RAINFALL BEING SATURDAY AS A FORECAST COMPLEX DEVELOPS IN THE PANHANDLE AND NORTHERLY UPPER LEVEL FLOW CARRIES IT SOUTHWARD. UNSURE ABOUT HOW FAR SOUTH THIS WILL BE ABLE TO MAKE IT BUT CONDITIONS ARE FAVORABLE FOR A WELL SUSTAINED COLD POOL SHOULD AN ORGANIZED SYSTEM DEVELOP. THEREFORE HIGHLIGHTED THE NORTHERN PERIPHERY OF THE CWA ON THE PLATEAU FOR THE BEST SHOT AT RAINFALL SATURDAY. AFTERWARDS...THE UPPER LEVEL PATTERN RETURNS TO THE SUMMER DOLDRUMS OF HOT AND DRY THROUGH THE END OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 76 100 76 99 76 / 20 20 0 10 0 AUSTIN BERGSTROM INTL AIRPORT 74 99 73 98 75 / 20 20 0 - 0 NEW BRAUNFELS MUNI AIRPORT 76 100 74 100 75 / 20 20 10 10 0 BURNET MUNI AIRPORT 75 98 74 97 75 / 20 20 - 20 - DEL RIO INTL AIRPORT 78 101 78 101 78 / 20 20 10 10 0 GEORGETOWN MUNI AIRPORT 75 98 74 98 76 / 20 20 0 10 0 HONDO MUNI AIRPORT 76 100 75 99 74 / 20 20 10 10 0 SAN MARCOS MUNI AIRPORT 76 99 75 98 75 / 20 20 10 10 0 LA GRANGE - FAYETTE REGIONAL 76 99 75 99 76 / 20 10 10 - 0 SAN ANTONIO INTL AIRPORT 78 99 77 99 77 / 20 20 10 10 0 STINSON MUNI AIRPORT 77 100 76 100 76 / 20 20 10 - 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...HAMPSHIRE SYNOPTIC/GRIDS...OAKS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1134 PM CDT THU JUL 30 2015 .DISCUSSION... SEE 06Z AVIATION DISCUSSION. && .AVIATION... PRECIPITATION LASTED A BIT LONGER THAN EXPECTED BUT IS IN THE PROCESS OF DISSIPATING. AN ISOLATED SHOWER CAN NOT BE RULED OUT AT ANY TIME OVERNIGHT AS PW VALUES REMAIN ABOVE 2.00 INCHES. NAM12 AND THE GFS DIFFER WITH PW VALUES ON FRIDAY WITH THE NAM MORE AGGRESSIVE WITH MOISTURE. THE RAP HAS BACKED OFF SIGNIFICANTLY WITH MORNING PRECIP AND IS NOW WAITING ON HEATING TO TRIGGER SHRA/TSRA. WILL LEAN TOWARD A RAP/HRRR/GFS BLEND WHICH FOCUSES MUCH OF THE PRECIP ON FRI OVER THE SW HALF OF THE CWA. WILL CARRY VCSH FOR KLBX...KSGR...KHOU AND KGLS. DRY AIR WILL FILTER INTO THE AREA FROM THE NE LATE FRIDAY AFTN AND WILL END PRECIP FROM NE TO SW TOWARD EVENING. NUMEROUS OUTFLOW BOUNDARIES AND A WEAK PRESSURE GRADIENT MAKES FCSTING WIND DIRECTION DIFFICULT. 43 && .PREV DISCUSSION... /ISSUED 912 PM CDT THU JUL 30 2015/ DISCUSSION... SHOWERS AND THUNDERSTORMS STILL DRIFTING DOWN INTO NE ZONES AT THIS HOUR. ANOTHER IMPORTANT FEATURE...RADAR SHOWING OUTFLOW FROM LOUISIANA CONVECTION MOVING IN FROM THE EAST. THIS OUTFLOW TO BRING SOME GUSTY EAST AND NORTHEAST WINDS SHORTLY TO GALVESTON BAY AND EASTERN COASTAL GULF WATERS. WIND GUSTS WERE AS HIGH AS 40 KNOTS OVER COASTAL LOUISIANA...LIKELY 30 KNOTS OR SO FOR SOME AREAS NOW. HAVE ISSUED A MARINE WEATHER STATEMENT TO GIVE A HEADS UP FOR THIS FEATURE AND ADJUSTED WIND GRIDS AS WELL. OVERNIGHT...EXPECT A CONTINUED SLOW WEAKENING TREND IN SHOWER AND THUNDERSTORM ACTIVITY OVER LAND...BUT CANT RULE OUT AN ISOLATED SHOWER OR THUNDERSTORM ANYWHERE GIVEN THE AIRMASS CATEGORIZED BY DEEPER MOISTURE. FOR COASTAL AREAS WILL LIKELY SEE SQUALL LINE BRUSH AT LEAST OUTER WATERS...BUT OUTFLOW WILL MOVE FROM NE TO SW ALONG THE COAST WITH SOME ADDITIONAL DEVELOPMENT POSSIBLE. HAVE BUMPED UP POPS FOR COASTAL WATERS TO COVER THIS. HIGH RESOLUTION RAPID REFRESH SUPPORTS THIS SCENARIO. 46 PREV DISCUSSION... /ISSUED 304 PM CDT THU JUL 30 2015/ DISCUSSION... SCT CONVECTION IS OCCURRING ACROSS NORTHERN AND EASTERN AREAS THIS AFTERNOON. THIS ACTIVITY IS MOVING SOUTHWEST...SO CENTRAL AREAS WILL LIKELY SEE SCT CONVECTION AS WELL LATER THIS AFTERNOON AND EVENING. NORTHERN AND EASTERN AREAS ARE MOIST AND UNSTABLE...SO ISOLATED STRONG STORMS ARE POSSIBLE. MAX TEMPS ARE AROUND 100 ACROSS FAR INLAND AREAS...UPPER 90S CENTRAL AREAS...AND LOWER TO MID 90S COAST. HEAT INDICES REMAIN IN THE 100 TO 107 DEGREE RANGE THIS AFTERNOON. THE FRONTAL BOUNDARY IS NEAR THE RED RIVER AND IN SW ARK. THIS BOUNDARY WILL MOVE SOUTHWEST INTO NE PORTIONS OF SE TEXAS LATE TONIGHT/EARLY FRIDAY MORNING. BEHIND THE BOUNDARY WE WILL SEE A DRIER AIRMASS ADVECT INTO THE REGION. THE LOCATION OF BOUNDARY WILL DETERMINE WHERE THE BEST RAIN CHCS ARE TOMORROW. SOUTH OF THE BOUNDARY EXPECT SCT CONVECTION AGAIN WHERE PW VALUES ARE JUST OVER 2 INCHES. WILL TAPER POPS UPWARD FROM THE NE TO SW AREAS OF SE TX....BASED ON THE PRECIPITABLE WATER GRADIENT EXPECTATIONS ON FRI. BY SAT MORNING THE DEEP MOISTURE WILL BE OFFSHORE AND SW OF SE TX...SO RAIN CHCS WILL BE VERY SMALL AGAIN FROM SAT THROUGH MID-WEEK. NOT MUCH CHG EXPECTED IN MAX TEMPS...SOME VARIATIONS THE NEXT COUPLE OF DAYS DUE TO DIFFERENCES IN LAYER MOISTURE LEVELS. FAR INLAND AREAS ON SAT COULD SEE WIDESPREAD TEMPS OVR 100 DUE TO THE VERY DRY AIRMASS THAT WILL BE IN PLACE. MARINE...A WEAK BACKDOOR FRONT NORTH OF THE AREA WILL EFFECT THE COAST LATE THURSDAY INTO FRIDAY. HOWEVER...THE WINDS ASSOCIATED WITH THE FRONT SHOULD BE LIGHT ENOUGH TO BE INFLUENCED BY THE SEA BREEZE ON FRIDAY THROUGH THE WEEKEND. AN OFFSHORE FLOW DURING THE EARLY MORNING HOURS WILL RELAX AND BECOME ONSHORE DURING PEAK HEATING IN THE AFTERNOON BEFORE BECOMING SOUTHWESTERLY IN THE EVENING. RAIN CHANCES WILL BE ON THE INCREASE TONIGHT AND FRIDAY AS POOL OF MOISTURE OVER LA AND GULF SLIDES WESTWARD INTO THE UPPER TEXAS COASTAL WATERS. FORECAST MODELS BUILD THE HIGH PRESSURE RIDGE BACK OVER THE COASTAL WATERS LATE IN THE WEEKEND AND EARLY NEXT WEEK. 44 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 78 99 75 101 76 / 20 30 20 10 10 HOUSTON (IAH) 79 99 77 100 76 / 30 30 10 10 10 GALVESTON (GLS) 82 92 82 94 82 / 30 30 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...46 AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1036 PM CDT SAT AUG 1 2015 .UPDATE...A LARGE AREA OF INCREASING WARM ADVECTION IS OCCURRING ACROSS MN AND WI AS THE LLJ INCREASES. SOME MOISTURE TRANSPORT WITH THAT AS WELL BUT THE ELEVATED MIXED LAYER IS VERY WARM RESULTING HIGH VALUES OF CIN. MESOSCALE MODELS DO PRODUCE SOME CONVECTION OVER NORTHERN AND CENTRAL WI LATE TNT INTO SUN AM. THUS LOWERED POPS OVER SRN WI WITH BEST CHANCES TOWARD CENTRAL WI FOR THE REMAINDER OF THE NIGHT AND INTO SUN AM. FOR LATE SUN AFTERNOON AND EVENING LOW PRESSURE MOVES ACROSS CENTRAL OR NORTHERN WI AND INTO NRN LOWER MI WITH A FAIRLY STRONG COLD FRONT TO FOLLOW. THE WIND FIELD WILL INCREASE AHEAD OF THE FRONT WITH WIND GUSTS UP TO 35 TO 40 MPH BY THE MIDDLE TO LATE AFTERNOON. THE WELL MIXED AND VERY WARM AIRMASS WILL LIKELY DROP THE DEWPOINTS INTO THE LOWER 60S BY LATE AFTERNOON BUT MLCAPES MAY STILL BE 2000 J/KG. DEEP LAYER SHEAR OF 35-40 KTS AND 0-1KM HELICITIES OVER 200 M2/S2 WILL SUPPORT A SVR TSTORM THREAT DURING THIS TIME. AN APPROACHING UPPER TROUGH WILL RESULT IN 50 METER 500 MB HEIGHT FALLS FROM 18Z TO 06Z PROVIDING UPPER SUPPORT TO FAIRLY STRONG LOW LEVEL FRONTOGENESIS. THUS EXPECTED STRONG TO SVR TSTORMS FOR THIS PERIOD. && .AVIATION/06Z TAFS/...ONLY SMALL CHANCES OF TSTORMS FOR THE EARLY SUN MORNING HOURS FROM SOUTH CENTRAL WI TO SE WI AS WARM...MOIST ADVECTION INCREASES. THE CHANCES OF STORMS WILL CONTINUE ON SUNDAY BUT WILL BECOME MORE LIKELY FOR SE WI SUN EVE WHEN A STRONG COLD FRONT PASSES. VFR CONDITIONS ARE EXPECTED OUTSIDE THE TSTORMS. && .PREV DISCUSSION... /ISSUED 323 PM CDT SAT AUG 1 2015/ SHORT TERM... TONIGHT - CONFIDENCE...LOW MAIN FOCUS WILL BE PINNING DOWN CONVECTIVE TRENDS AS THE NIGHT WEARS ALONG. 850 LLJ BECOMES MORE FAVORABLE AIMING INTO CWA WITH INCREASING WAA AND MOISTURE ADVECTION. MODELS ARE SHOWING VARYING SOLUTIONS FOR MCS TRACK. 1000-500 MILLIBAR THICKNESS LINES/MCS MAINTENANCE COMPOSITE INDEX FROM SPC MESO PAGE FAVOR MORE OF A 00Z ECMWF SOLUTION. THE 12Z NAM IS THE FURTHEST NORTH WITH PRECIP INTO CNTRL/SRN WI. THE 12Z ECMWF HAS COME MORE IN LINE WITH OTHER MODELS SHOWING CONVECTION ARRIVING AFTER 6Z ACROSS THE CWA. GIVEN THE PROGGD ELEVATED CAPE/CONSENSUS OF LLJ FORCING AND MID LEVEL SHORTWAVE WILL STILL CARRY HIGH END CHANCE POPS FOR WHOLE CWA BUT WATCHING FOR A POTENTIAL SE CURVE TO ANY MCS THAT MIGHT TAKE SHAPE THAT COULD LEAVE PARTS OF SRN WI MORE ON THE NORTHERN FRINGE OF A SEWD DIVING MCS TRACK FAVORING NE IA INTO NRN IL. WATCHING AFTERNOON VSBL ANIMATION THINKING MORE LIKELY SCENARIO IS WE WILL BE SEEING OUR ACTIVITY ORIGINATE FROM WRN MN INTO ERN ND WHICH WOULD FAVOR SRN WI A BIT MORE. OVERALL MODEL SOLUTIONS INCLUDING LATEST HRRR FAVOR SOME CONVECTION A BIT LATER IN THE NIGHT ACRS SRN WI HOWEVER THERE IS SOME LOSS TO THE ORGANIZATION AND COVERAGE IN THE LATEST HRRR RUN. AND THIS REFLECTED IN THE LATEST SWODY1 WITH THE REMOVAL OF THE SLIGHT RISK FROM SRN WI. SUNDAY - CONFIDENCE...MEDIUM COULD STILL BE DEALING WITH LINGERING MORNING CONVECTION ASSOCIATED WITH THE LLJ/500 MILLIBAR SHORTWAVE. THEN WILL HAVE TO SEE HOW THE MESOSCALE DETAILS PLAY OUT. EVEN THE GFS SOUNDING IS GENERATED CAPES OVER 2K SUNDAY AFTERNOON. 850 JET IS PROGGD TO FOCUS MORE TO OUR EAST AND SOUTHEAST AS THE DAY WEARS ON. HOWEVER SURFACE/850 FRONT WILL STILL BE HANGING BACK TO THE NORTH AND A WSW LOW LEVEL FLOW WILL REINFORCE MOISTURE INSTABILITY AS THE DAY WEARS ON. CWASP SHOWING SOLID MID 70S PLUS ON ALL PROGS WITH THE GFS SHOWING 80 PLUS BY 00Z. SO GIVEN PRONOUNCED LOW LEVEL FORCING APPROACHING WITH SURFACE/850 FRONT SWODY2 SLIGHT IS WARRANTED WITH THE GREATEST THREAT LATER IN THE AFTERNOON. SUNDAY NIGHT... FORECAST CONFIDENCE MEDIUM. SYNOPTIC AND MESOSCALE MODELS ARE IN FAIR AGREEMENT WITH THUNDERSTORMS DEVELOPING ALONG THE COLD FRONT AS IT TRACKS FROM CENTRAL WI DOWN THROUGH SOUTHEAST WI AND NORTHERN IL LATE SUNDAY AFTERNOON THROUGH SUNDAY EVENING. I WENT WITH LIKELY POPS IN SOUTHEAST WI SUNDAY EVENING... BUT IT MAY JUST BE A BROKEN LINE. SHOWERS AND STORMS SHOULD WIND DOWN QUICKLY AFTER MIDNIGHT AS DRY AIR SETTLES IN BEHIND THE FRONT. EXPECTING HIGH CAPE AND SHEAR JUST AHEAD OF THE FRONT... ENOUGH TO PRODUCE LARGE HAIL AND DAMAGING WINDS WITH ANY STRONG THUNDERSTORMS. A TORNADO IS A REMOTE POSSIBILITY GIVEN THE LIMITED LOW LEVEL SHEAR. LONG TERM... MONDAY THROUGH WEDNESDAY... FORECAST CONFIDENCE HIGH. NORTHWEST FLOW WILL DOMINATE THE GREAT LAKES REGION FOR THE FIRST PART OF THE WORK WEEK AS AN UPPER LOW REMAINS STATIONED OVER QUEBEC. HIGH PRESSURE AT THE SURFACE WILL ALLOW FOR FAIRLY LIGHT WINDS. TEMPS WILL BE AROUND SEASONAL NORMAL MONDAY AND TUESDAY... THEN SLIGHTLY COOLER IN THE MID 70S WEDNESDAY DUE TO NORTHEAST BREEZE OFF THE LAKE. THURSDAY THROUGH SUNDAY... FORECAST CONFIDENCE MEDIUM. MODELS TRY TO GENERATE AN MCS OVER THE NORTHERN PLAINS THAT TRACKS SOUTHEAST THROUGH THE MIDWEST THURSDAY AND POSSIBLY ANOTHER ONE INTO FRIDAY. THE GFS IS MAINTAINING PRECIP CHANCES IN SOUTHERN WI WITH THIS SYSTEM AND APPEARS TO HAVE SOME CONVECTIVE FEEDBACK ISSUES... WHILE THE 12Z ECMWF SHIFTED THE MAIN CHANCES FARTHER SOUTH. EXPECT DRY HIGH PRESSURE TO SETTLE BACK INTO THE GREAT LAKES REGION BY FRIDAY NIGHT AND KEEP PRECIP CHANCES MINIMAL THROUGH THE WEEKEND. TEMPERATURES SHOULD BE IN THE 70S. AVIATION/00Z TAFS/...VFR CONDITIONS AT LEAST INTO THIS EVENING. MAIN FOCUS FOR CONVECTIVE DEVELOPMENT ARRIVES LATER TONIGHT INTO SUNDAY MORNING AS MORE PRONOUNCED LLJ AIMS INTO SRN WI. STILL SOME TRACK UNCERTAINTY ON MCS BUT OVERALL MOIST ADVECTION WITH 850 LLJ AND SHORTWAVE ACTIVITY WARRANTS THE CHANCE OF STORMS LATER TONIGHT INTO SUNDAY MORNING. POCKETS OF MVFR CIGS/VSBYS WITH ANY STRONGER STORMS. MESOSCALE DETAILS AFTER OVERNIGHT/EARLY MORNING STORMS WILL DICTATE STORM EVOLUTION/SEVERITY ON SUNDAY AFTERNOON/EVENING AS SURFACE LOW AND COLD FRONT INTERACT WITH POTENTIALLY VERY UNSTABLE AIRMASS. IN ADDITION WITH LOW LEVEL JET STRENGTHENING OVERNIGHT SOME LOW LEVEL WIND SHEAR IS POSSIBLE. MARINE...SMALL CRAFT ADVISORY HOISTED FOR SUNDAY AS PRESSURE GRADIENT TIGHTENS UP AHEAD OF APPROACHING SURFACE LOW PRESSURE SYSTEM. SW WINDS SHOULD RAMP UP PRETTY QUICK IN THE MORNING AND GET RATHER GUSTY. COLD FRONT MAY SPAWN SOME STRONG TSTORMS LATE AFTN/ERLY EVE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM CDT SUNDAY FOR LMZ643>646. && $$ UPDATE...GEHRING TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR SUNDAY NIGHT THROUGH SATURDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
942 PM CDT SAT AUG 1 2015 .UPDATE... ISSUED AT 942 PM CDT SAT AUG 1 2015 IT LOOKS LIKE THE CHANCES FOR STORMS THE REST OF THE NIGHT HAS BECOME PRETTY MARGINAL. THE BEST FORCING WILL BE AHEAD OF SHORT WAVE TROUGH CURRENTLY COMING OUT OF SOUTHERN MANITOBA WITH SOME STORMS AHEAD OF IT OVER NORTH DAKOTA. THE LOW LEVEL JET WILL BE FOCUSED INTO NORTHERN MINNESOTA AND WISCONSIN AHEAD OF THIS WAVE AND MAY HELP SOME ADDITIONAL STORMS FIRE THERE OVERNIGHT. THE 02.00Z HRRR-CR SEEMS TO HAVE LATCHED ONTO THIS SOLUTION AND WOULD SUGGEST THE ENTIRE AREA WILL BE DRY INTO SUNDAY MORNING. HAVE REMOVED THE RAIN CHANCES FOR ALL BUT THE INTERSTATE 94 CORRIDOR FOR LATE TONIGHT INCASE SOME ACTIVITY WITH THE LOW LEVEL JET SLIPS INTO THE AREA. NOT EXPECTING ANY SEVERE WEATHER OVERNIGHT AND HAVE UPDATED ALL PRODUCTS TO REFLECT THIS. && .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 245 PM CDT SAT AUG 1 2015 MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES TONIGHT INTO SUN EVENING...ANY SEVERE THREAT TONIGHT AND AGAIN SUN AFTERNOON/EVENING. DATA ANALYSIS AT 18Z HAD HIGH PRESSURE OVER THE MID MS VALLEY WITH RIDGING NORTH INTO MN/WI. WINDS LIGHTER ACROSS THE REGION TODAY WITH THE SFC-850MB RIDGE AXIS OVER THE UPPER MIDWEST. MOISTURE GRADUALLY INCREASING OVER IA/SOUTHERN MN AS LOWER LEVEL FLOW BECOMES MORE WEST AND SOUTHWEST. WV IMAGERY DEPICTED A SHORTWAVE MOVING SOUTHEAST ACROSS THE DAKOTAS...WITH INCREASING CLOUDS/FEW SHRA AHEAD OF IT ACROSS WESTERN MN. EARLY AFTERNOON TEMPS NEAR NORMAL FOR THE FIRST OF AUGUST. NO BIG ISSUES NOTED WITH 01.12Z MODEL INITIALIZATIONS. SOLUTIONS QUITE SIMILAR FOR TONIGHT THRU SUN NIGHT...AND VERY SIMILAR TO THEIR RUNS OF 31.12Z. THIS AS ONE PIECE OF SHORTWAVE ENERGY DROPS IA/ SOUTHERN MN TONIGHT THEN NORTHERN STREAM ENERGY DROPPING OUT OF MAN/ WESTERN ONT LOWERS HGTS ACROSS THE REGION AS IT PASSES SUN/SUN NIGHT. WITH THE TIGHT CONSENSUS...SHORT TERM FCST CONFIDENCE REMAINS GENERALLY GOOD THIS CYCLE. IN THE SHORT TERM...SHORTWAVE APPROACHING/PASSING ACROSS IA/SOUTHERN MN TONIGHT SPREADS A ROUND OF LOWER LEVEL THERMO-DYNAMIC FORCING/ LIFT ACROSS THE AREA...AHEAD OF THE SFC-700MB TROUGH/FRONT. MODEL SOUNDINGS CONTINUE TO SHOW THE BULK OF THE MOISTURE/SATURATION IS AT OR ABOVE 800MB. MUCAPE VALUES IN THE 500-1500 J/KG RANGE ARE MOSTLY LIFTING 800-700MB PARCELS...WHERE THE CIN VALUES ARE MORE IN THE 0 TO 25 RANGE. SOUNDING SHOW LIFTING SFC BASED PARCELS TONIGHT WILL GENERATE SOME CAPE...BUT NOT BEFORE ENCOUNTERING 100-400 J/KG OF CIN THAT IS 200-300MB DEEP. SFC-850MB LAYER INVOLVEMENT IN CONVECTION TONIGHT...WHERE MOST OF THE SHEAR LIES...LOOKS MINIMAL WITH MAINLY ELEVATED SHRA/TSRA AT OR ABOVE 8K-10K FT. BULK SHEAR IN THE EFFECTIVE 2KM-8KM LAYER MORE IN THE 115-20KT RANGE. GIVEN ALL THIS...CONFIDENCE IN ANY SEVERE STORM THREAT TONIGHT IS LOW. WILL MAINTAIN AN ISOLATED SEVERE TSRA MENTION TONIGHT FOR CONTINUITY SAKE. TONIGHTS ROUND OF CONVECTION IF IT DEVELOPS...AS THERE ARE A FEW HI-RES/WRF MODELS THAT KEEP THE AREA DRY TONIGHT...WOULD EXIT THE AREA EARLY SUN MORNING. SFC FRONT WORKS ITS WAY SOUTHEAST ACROSS THE FCST AREA SUN BUT MODEL SOUNDINGS SHOWING CONSIDERABLE CAPPING/ CIN BETWEEN 900-850MB MUCH OF THE DAY. LOWERED/REMOVED SHRA/TSRA CHANCES ACROSS MUCH OF THE FCST AREA FOR LATER SUN MORNING. CONTINUED SHRA/TSRA CHANCES ACROSS MAINLY THE EAST 2/3 OF THE FCST AREA SUN AFTERNOON WITH THE FRONT DROPPING THRU...EROSION OF THE CAPPING AFTER 20-21Z AND APPROACH OF THE STRONGER SHORTWAVE FROM THE NORTH. IF ANY STORMS LATER SUN AFTERNOON INTO SUN EVENING ARE SFC BASED...0-6KM BULK SHEAR WOULD BE MORE IN THE 35KT RANGE ALONG WITH MUCAPE IN THE 1.5K TO 3K J/KG RANGE. CANNOT RULE OUT A SEVERE TSRA OR TWO OVER THE EAST/SOUTH ENDS OF THE FCST AREA LATER SUN AFTERNOON/EARLY SUN EVENING. FRONT DROPS QUICKLY SOUTH OF THE FCST AREA SUN EVENING...WITH DRIER HIGH PRESSURE/SUBSIDENCE/LOW LEVEL COLD ADVECTION SPREADING IN BEHIND IT AND THE MID LEVEL TROUGH AXIS. USED A BLEND OF GUIDANCE LOWS/HIGHS FOR TONIGHT THRU SUN NIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 245 PM CDT SAT AUG 1 2015 FOR MONDAY THRU TUESDAY NIGHT... MAIN FCST CONCERNS FOR MON THRU TUE NIGHT...TEMPERATURES. 01.12Z MODELS REMAIN IN GOOD AGREEMENT AS THE EAST CAN MID LEVEL LOW AND TROUGHING OVER THE GREAT LAKES SLOWLY PROGRESS EAST MON THRU TUE NIGHT. HGTS GRADUALLY RISE THIS PERIOD...WITH THE REGION REMAINING UNDER NORTHWEST FLOW ALOFT. MODELS IN REASONABLE AGREEMENT ON SOME SHORTWAVE ENERGY COMING OUT OF THE WEST COAST TROUGHING AND MOVING INTO THE CENTRAL/NORTHERN PLAINS BY 12Z WED. FCST CONFIDENCE FOR MON THRU TUE NIGHT IS GOOD THIS CYCLE. MON THRU TUE NIGHT SHAPING UP TO BE A DRY...QUIET PERIOD WITH TEMPS A BIT BELOW NORMAL. DRIER CAN HIGH PRESSURE IN THE WAKE OF SUNDAYS COLD FRONT BUILDS SLOWLY EAST ACROSS THE UPPER MIDWEST MON THRU TUE NIGHT...UNDER THE SLOWLY RISING HGTS ALOFT. 850MB TEMPS TRENDING TO BE 0.5 TO 1 STANDARD DEVIATION BELOW NORMAL THRU THE PERIOD. NORMAL HIGHS FOR THE FIRST WEEK OF AUG ARE IN THE 79F TO 84F RANGE. MODEL/ ENSEMBLE CONSENSUS HIGHS MOSTLY IN THE 75F TO 82F RANGE MON/TUE LOOKING WELL TRENDED. WITH A DRIER AIRMASS...LIGHT WINDS AND CLEAR/ MOSTLY CLEAR SKIES...MON/TUE NIGHTS FAVORABLE FOR STRONGER RADIATIONAL COOLING. CONSENSUS LOWS MOSTLY IN THE LOW TO MID 50S BOTH NIGHTS APPEAR WELL TRENDED FOR NOW. HOWEVER WILL HAVE TO WATCH THE NORMALLY COOLER/SHELTERED LOCATIONS ALONG/NORTHEAST OF I-94 FOR SOME LOWS POTENTIALLY DIPPING INTO THE LOW TO MID 40S BOTH NIGHTS. FOR WEDNESDAY THRU SATURDAY...DAYS 4 TO 7... MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES LATER WED NIGHT INTO SAT...TEMPERATURES THRU THE PERIOD. MEDIUM RANGE MODEL RUNS OF 01.00Z AND 01.12Z IN REASONABLE AGREEMENT ON WED WITH TROUGHING NEAR THE COASTS AND A MID LEVEL RIDGE AXIS OVER CENTRAL NOAM. PLENTY OF DETAIL DIFFERENCES WITH SHORTWAVE ENERGY COMING THRU THE RIDGE ON WED. QUITE A BIT OF BETWEEN MODEL AND RUN-TO-RUN VARIABILITY ON THU AS STRONGER SHORTWAVE ENERGY WOULD TOP/FLATTEN THE RIDGING AND START TO DROP INTO THE UPPER MIDWEST. SOME CONSENSUS BETWEEN GFS/ECMWF FOR A STRONGER SHORTWAVE TROUGH TO MOVE ACROSS THE REGION THU NIGHT/FRI...WEAK SHORTWAVE RIDGING FRI NIGHT THEN ANOTHER STRONGER WAVE TO TOP THE RIDGE AND DROP SOUTHEAST INTO THE REGION SAT. GIVEN THE LARGER DETAIL DIFFERENCES WED/THU... FCST CONFIDENCE IN THE DAY 4-7 PERIOD IS BELOW AVERAGE THIS CYCLE. ANY SHORTWAVE ENERGY TO APPROACH/MOVE IN WED APPEARS WEAK. A GOOD MODEL CONSENSUS TO HOLD DRIER SFC HIGH PRESSURE OVER THE UPPER MIDWEST WED...WITH THE MAIN LOWER LEVEL MOISTURE/CAPE AXIS WELL WEST/SOUTH OF THE FCST AREA UNTIL LATER WED NIGHT INTO THU. MOISTURE INCREASES THU...AHEAD OF THE FIRST SHORTWAVE TO TOP THE RIDGE AND LOW PRESSURE ADVANCING EAST ACROSS THE PLAINS TOWARD/INTO THE MID/UPPER MS VALLEY. INCREASING SHRA/TSRA CHANCES THU INTO FRI AS THIS SFC-MID LEVEL TROUGH AXIS WOULD PASS REASONABLE AT THIS POINT. TIMING DIFFERENCES BY FRI NIGHT/SAT...BUT WITH ANOTHER SHORTWAVE LOOKING TO TOP THE RIDGE AND LOWER HGTS OVER THE REGION...SMALL CONSENSUS SHRA/TSRA CHANCES THESE PERIODS OKAY FOR NOW. NORTHWEST FLOW ALOFT AND/OR MORE CLOUDS /ESPECIALLY THU/FRI/ LOOKING TO KEEP TEMPS NEAR TO BELOW NORMAL IN THE DAY 4-7 PERIOD. MODEL/ENSEMBLE CONSENSUS WITH HIGHS/LOWS A FEW DEGREES BELOW NORMAL LOOKS TO HAVE THEM WELL TRENDED FOR NOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 610 PM CDT SAT AUG 1 2015 STILL CONSIDERABLE UNCERTAINTY ON HOW MUCH CONVECTION IS GOING TO DEVELOP THIS EVENING AND WHERE. THE LATEST REGIONAL COMPOSITE SHOWS SOME DEVELOPMENT OCCURRING OVER NORTH CENTRAL SOUTH DAKOTA...WHICH IS CLOSE TO WHERE SEVERAL OF THE HI-RES MODELS SUGGESTED THIS DEVELOPMENT WOULD OCCUR. EXPECTING THAT THIS ACTIVITY SHOULD WORK TO THE SOUTHEAST AND DISSIPATE THROUGH THE EVENING AS THE NOSE OF THE LOW LEVEL JET BECOMES FOCUSED ON A WARM FRONT OVER CENTRAL MINNESOTA. ADDITIONAL CONVECTION IS THEN EXPECTED TO FORM ALONG AND NORTH OF THIS WARM FRONT AND MOVE EAST INTO NORTHERN WISCONSIN AS THE NOSE OF THE LOW LEVEL JET FOCUSES ON THIS AREA BY LATE TONIGHT. WITH THIS OUTCOME...ALL OF THE CONVECTION WOULD STAY TO THE NORTH OF THE TAF SITES. HOWEVER...THE 01.21Z HRRR KEEPS THE DEVELOPING SOUTH DAKOTA CONVECTION GOING AND BRINGS IT INTO THE AREA LATE THIS EVENING. TO HONOR THIS SOLUTION...HAVE MAINTAINED THE VCTS MENTION IN BOTH TAF SITES BUT PUSHED THE TIMING BACK CLOSER TO 06Z. THIS CHANCE SHOULD THEN END LATE TONIGHT WITH SKIES QUICKLY CLEARING AS MID LEVEL WARM AIR MOVES IN BEHIND THE WARM FRONT TO FORM A STRONG LOW LEVEL CAP. FOR SUNDAY AFTERNOON AS A COLD FRONT SLIDES INTO THE AREA...THE 01.18Z NAM SUGGESTS THIS CAP WILL HOLD STRONG WITH THE FRONT PASSING THROUGH DRY AND WITH VERY LITTLE IF ANY CLOUD COVER. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...04 SHORT TERM...RRS LONG TERM....RRS AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CDT SAT AUG 1 2015 .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 245 PM CDT SAT AUG 1 2015 MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES TONIGHT INTO SUN EVENING...ANY SEVERE THREAT TONIGHT AND AGAIN SUN AFTERNOON/EVENING. DATA ANALYSIS AT 18Z HAD HIGH PRESSURE OVER THE MID MS VALLEY WITH RIDGING NORTH INTO MN/WI. WINDS LIGHTER ACROSS THE REGION TODAY WITH THE SFC-850MB RIDGE AXIS OVER THE UPPER MIDWEST. MOISTURE GRADUALLY INCREASING OVER IA/SOUTHERN MN AS LOWER LEVEL FLOW BECOMES MORE WEST AND SOUTHWEST. WV IMAGERY DEPICTED A SHORTWAVE MOVING SOUTHEAST ACROSS THE DAKOTAS...WITH INCREASING CLOUDS/FEW SHRA AHEAD OF IT ACROSS WESTERN MN. EARLY AFTERNOON TEMPS NEAR NORMAL FOR THE FIRST OF AUGUST. NO BIG ISSUES NOTED WITH 01.12Z MODEL INITIALIZATIONS. SOLUTIONS QUITE SIMILAR FOR TONIGHT THRU SUN NIGHT...AND VERY SIMILAR TO THEIR RUNS OF 31.12Z. THIS AS ONE PIECE OF SHORTWAVE ENERGY DROPS IA/ SOUTHERN MN TONIGHT THEN NORTHERN STREAM ENERGY DROPPING OUT OF MAN/ WESTERN ONT LOWERS HGTS ACROSS THE REGION AS IT PASSES SUN/SUN NIGHT. WITH THE TIGHT CONSENSUS...SHORT TERM FCST CONFIDENCE REMAINS GENERALLY GOOD THIS CYCLE. IN THE SHORT TERM...SHORTWAVE APPROACHING/PASSING ACROSS IA/SOUTHERN MN TONIGHT SPREADS A ROUND OF LOWER LEVEL THERMO-DYNAMIC FORCING/ LIFT ACROSS THE AREA...AHEAD OF THE SFC-700MB TROUGH/FRONT. MODEL SOUNDINGS CONTINUE TO SHOW THE BULK OF THE MOISTURE/SATURATION IS AT OR ABOVE 800MB. MUCAPE VALUES IN THE 500-1500 J/KG RANGE ARE MOSTLY LIFTING 800-700MB PARCELS...WHERE THE CIN VALUES ARE MORE IN THE 0 TO 25 RANGE. SOUNDING SHOW LIFTING SFC BASED PARCELS TONIGHT WILL GENERATE SOME CAPE...BUT NOT BEFORE ENCOUNTERING 100-400 J/KG OF CIN THAT IS 200-300MB DEEP. SFC-850MB LAYER INVOLVEMENT IN CONVECTION TONIGHT...WHERE MOST OF THE SHEAR LIES...LOOKS MINIMAL WITH MAINLY ELEVATED SHRA/TSRA AT OR ABOVE 8K-10K FT. BULK SHEAR IN THE EFFECTIVE 2KM-8KM LAYER MORE IN THE 115-20KT RANGE. GIVEN ALL THIS...CONFIDENCE IN ANY SEVERE STORM THREAT TONIGHT IS LOW. WILL MAINTAIN AN ISOLATED SEVERE TSRA MENTION TONIGHT FOR CONTINUITY SAKE. TONIGHTS ROUND OF CONVECTION IF IT DEVELOPS...AS THERE ARE A FEW HI-RES/WRF MODELS THAT KEEP THE AREA DRY TONIGHT...WOULD EXIT THE AREA EARLY SUN MORNING. SFC FRONT WORKS ITS WAY SOUTHEAST ACROSS THE FCST AREA SUN BUT MODEL SOUNDINGS SHOWING CONSIDERABLE CAPPING/ CIN BETWEEN 900-850MB MUCH OF THE DAY. LOWERED/REMOVED SHRA/TSRA CHANCES ACROSS MUCH OF THE FCST AREA FOR LATER SUN MORNING. CONTINUED SHRA/TSRA CHANCES ACROSS MAINLY THE EAST 2/3 OF THE FCST AREA SUN AFTERNOON WITH THE FRONT DROPPING THRU...EROSION OF THE CAPPING AFTER 20-21Z AND APPROACH OF THE STRONGER SHORTWAVE FROM THE NORTH. IF ANY STORMS LATER SUN AFTERNOON INTO SUN EVENING ARE SFC BASED...0-6KM BULK SHEAR WOULD BE MORE IN THE 35KT RANGE ALONG WITH MUCAPE IN THE 1.5K TO 3K J/KG RANGE. CANNOT RULE OUT A SEVERE TSRA OR TWO OVER THE EAST/SOUTH ENDS OF THE FCST AREA LATER SUN AFTERNOON/EARLY SUN EVENING. FRONT DROPS QUICKLY SOUTH OF THE FCST AREA SUN EVENING...WITH DRIER HIGH PRESSURE/SUBSIDENCE/LOW LEVEL COLD ADVECTION SPREADING IN BEHIND IT AND THE MID LEVEL TROUGH AXIS. USED A BLEND OF GUIDANCE LOWS/HIGHS FOR TONIGHT THRU SUN NIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 245 PM CDT SAT AUG 1 2015 FOR MONDAY THRU TUESDAY NIGHT... MAIN FCST CONCERNS FOR MON THRU TUE NIGHT...TEMPERATURES. 01.12Z MODELS REMAIN IN GOOD AGREEMENT AS THE EAST CAN MID LEVEL LOW AND TROUGHING OVER THE GREAT LAKES SLOWLY PROGRESS EAST MON THRU TUE NIGHT. HGTS GRADUALLY RISE THIS PERIOD...WITH THE REGION REMAINING UNDER NORTHWEST FLOW ALOFT. MODELS IN REASONABLE AGREEMENT ON SOME SHORTWAVE ENERGY COMING OUT OF THE WEST COAST TROUGHING AND MOVING INTO THE CENTRAL/NORTHERN PLAINS BY 12Z WED. FCST CONFIDENCE FOR MON THRU TUE NIGHT IS GOOD THIS CYCLE. MON THRU TUE NIGHT SHAPING UP TO BE A DRY...QUIET PERIOD WITH TEMPS A BIT BELOW NORMAL. DRIER CAN HIGH PRESSURE IN THE WAKE OF SUNDAYS COLD FRONT BUILDS SLOWLY EAST ACROSS THE UPPER MIDWEST MON THRU TUE NIGHT...UNDER THE SLOWLY RISING HGTS ALOFT. 850MB TEMPS TRENDING TO BE 0.5 TO 1 STANDARD DEVIATION BELOW NORMAL THRU THE PERIOD. NORMAL HIGHS FOR THE FIRST WEEK OF AUG ARE IN THE 79F TO 84F RANGE. MODEL/ ENSEMBLE CONSENSUS HIGHS MOSTLY IN THE 75F TO 82F RANGE MON/TUE LOOKING WELL TRENDED. WITH A DRIER AIRMASS...LIGHT WINDS AND CLEAR/ MOSTLY CLEAR SKIES...MON/TUE NIGHTS FAVORABLE FOR STRONGER RADIATIONAL COOLING. CONSENSUS LOWS MOSTLY IN THE LOW TO MID 50S BOTH NIGHTS APPEAR WELL TRENDED FOR NOW. HOWEVER WILL HAVE TO WATCH THE NORMALLY COOLER/SHELTERED LOCATIONS ALONG/NORTHEAST OF I-94 FOR SOME LOWS POTENTIALLY DIPPING INTO THE LOW TO MID 40S BOTH NIGHTS. FOR WEDNESDAY THRU SATURDAY...DAYS 4 TO 7... MAIN FCST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES LATER WED NIGHT INTO SAT...TEMPERATURES THRU THE PERIOD. MEDIUM RANGE MODEL RUNS OF 01.00Z AND 01.12Z IN REASONABLE AGREEMENT ON WED WITH TROUGHING NEAR THE COASTS AND A MID LEVEL RIDGE AXIS OVER CENTRAL NOAM. PLENTY OF DETAIL DIFFERENCES WITH SHORTWAVE ENERGY COMING THRU THE RIDGE ON WED. QUITE A BIT OF BETWEEN MODEL AND RUN-TO-RUN VARIABILITY ON THU AS STRONGER SHORTWAVE ENERGY WOULD TOP/FLATTEN THE RIDGING AND START TO DROP INTO THE UPPER MIDWEST. SOME CONSENSUS BETWEEN GFS/ECMWF FOR A STRONGER SHORTWAVE TROUGH TO MOVE ACROSS THE REGION THU NIGHT/FRI...WEAK SHORTWAVE RIDGING FRI NIGHT THEN ANOTHER STRONGER WAVE TO TOP THE RIDGE AND DROP SOUTHEAST INTO THE REGION SAT. GIVEN THE LARGER DETAIL DIFFERENCES WED/THU... FCST CONFIDENCE IN THE DAY 4-7 PERIOD IS BELOW AVERAGE THIS CYCLE. ANY SHORTWAVE ENERGY TO APPROACH/MOVE IN WED APPEARS WEAK. A GOOD MODEL CONSENSUS TO HOLD DRIER SFC HIGH PRESSURE OVER THE UPPER MIDWEST WED...WITH THE MAIN LOWER LEVEL MOISTURE/CAPE AXIS WELL WEST/SOUTH OF THE FCST AREA UNTIL LATER WED NIGHT INTO THU. MOISTURE INCREASES THU...AHEAD OF THE FIRST SHORTWAVE TO TOP THE RIDGE AND LOW PRESSURE ADVANCING EAST ACROSS THE PLAINS TOWARD/INTO THE MID/UPPER MS VALLEY. INCREASING SHRA/TSRA CHANCES THU INTO FRI AS THIS SFC-MID LEVEL TROUGH AXIS WOULD PASS REASONABLE AT THIS POINT. TIMING DIFFERENCES BY FRI NIGHT/SAT...BUT WITH ANOTHER SHORTWAVE LOOKING TO TOP THE RIDGE AND LOWER HGTS OVER THE REGION...SMALL CONSENSUS SHRA/TSRA CHANCES THESE PERIODS OKAY FOR NOW. NORTHWEST FLOW ALOFT AND/OR MORE CLOUDS /ESPECIALLY THU/FRI/ LOOKING TO KEEP TEMPS NEAR TO BELOW NORMAL IN THE DAY 4-7 PERIOD. MODEL/ENSEMBLE CONSENSUS WITH HIGHS/LOWS A FEW DEGREES BELOW NORMAL LOOKS TO HAVE THEM WELL TRENDED FOR NOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 610 PM CDT SAT AUG 1 2015 STILL CONSIDERABLE UNCERTAINTY ON HOW MUCH CONVECTION IS GOING TO DEVELOP THIS EVENING AND WHERE. THE LATEST REGIONAL COMPOSITE SHOWS SOME DEVELOPMENT OCCURRING OVER NORTH CENTRAL SOUTH DAKOTA...WHICH IS CLOSE TO WHERE SEVERAL OF THE HI-RES MODELS SUGGESTED THIS DEVELOPMENT WOULD OCCUR. EXPECTING THAT THIS ACTIVITY SHOULD WORK TO THE SOUTHEAST AND DISSIPATE THROUGH THE EVENING AS THE NOSE OF THE LOW LEVEL JET BECOMES FOCUSED ON A WARM FRONT OVER CENTRAL MINNESOTA. ADDITIONAL CONVECTION IS THEN EXPECTED TO FORM ALONG AND NORTH OF THIS WARM FRONT AND MOVE EAST INTO NORTHERN WISCONSIN AS THE NOSE OF THE LOW LEVEL JET FOCUSES ON THIS AREA BY LATE TONIGHT. WITH THIS OUTCOME...ALL OF THE CONVECTION WOULD STAY TO THE NORTH OF THE TAF SITES. HOWEVER...THE 01.21Z HRRR KEEPS THE DEVELOPING SOUTH DAKOTA CONVECTION GOING AND BRINGS IT INTO THE AREA LATE THIS EVENING. TO HONOR THIS SOLUTION...HAVE MAINTAINED THE VCTS MENTION IN BOTH TAF SITES BUT PUSHED THE TIMING BACK CLOSER TO 06Z. THIS CHANCE SHOULD THEN END LATE TONIGHT WITH SKIES QUICKLY CLEARING AS MID LEVEL WARM AIR MOVES IN BEHIND THE WARM FRONT TO FORM A STRONG LOW LEVEL CAP. FOR SUNDAY AFTERNOON AS A COLD FRONT SLIDES INTO THE AREA...THE 01.18Z NAM SUGGESTS THIS CAP WILL HOLD STRONG WITH THE FRONT PASSING THROUGH DRY AND WITH VERY LITTLE IF ANY CLOUD COVER. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
343 PM CDT FRI JUL 31 2015 .SHORT TERM...TONIGHT THROUGH MONDAY. TONIGHT AND SATURDAY - CONFIDENCE...MEDIUM STRONG NW MID LEVEL FLOW PERSISTS WITH PRIMARY SHORTWAVE OF NOTE TRAVERSING THROUGH LAKE SUPERIOR INTO LWR MI REGION TONIGHT. NAM/ARW/NMM/HRRR ALL SHOWING SOME LIGHT PRECIP DEVELOPING LATER IN THE NIGHT DUE TO LOW LEVEL CONVERGENCE ASSOCIATED WITH SURFACE/850 TROUGH. NOT MUCH SHOWING ON THIS UPSTREAM AND WITH OVERALL DRY AIRMASS AND POOR TIMING THERMODYNAMICALLY CONFIDENCE NOT GREAT IN MUCH IF ANYTHING EVOLVING. RAP SOUNDINGS ARE ALL VERY DRY WITH LITTLE IN THE WAY OF ELEVATED CAPE. HOWEVER NAM/GFS AND HRRR SOUNDINGS SHOW A LITTLE BETTER MID LEVEL MOISTENING WITH SOME ELEVATED CAPE. CONSENSUS OF MOS POPS ARE IN THE SINGLE DIGITS. WILL CARRY A A SMALL AREA OF SLGT POPS FROM LATE TONIGHT INTO EARLY SATURDAY ACROSS PORTIONS OF WRN AND SRN CWA. FROM LATER IN THE MORNING INTO THE AFTERNOON SURFACE/850 RIDGING WILL TAKE HOLD WITH A MORE RELAXED PRESSURE GRADIENT IN PLACE TO SUPPORT A LIGHTER WIND REGIME. 925 TEMPS AVERAGE 22-23C SO EXPECTING HIGHS BACK INTO THE 80S. SATURDAY NIGHT...FORECAST CONFIDENCE MEDIUM WEAK SHORT WAVE APPROACHES SATURDAY NIGHT...CENTERED OVER CWA AT 12Z SUNDAY...MOVING EAST OF AREA BY 18Z....WITH STRONGER SHORT WAVE TROUGH MOVING INTO NORTH DAKOTA BY 12Z SUNDAY. LOW-LEVEL THETA-E ADVECTION MAX CROSSES CWA BETWEEN 03Z AND 06Z SUNDAY...HOWEVER STRONGER OMEGA TIED WITH STRONGEST FRONTOGENETIC RESPONSE OVER NE WI TO FOCUSED WARM AIR ADVECTION WITH THE 35-40 KT LOW-LEVEL JET MAX AHEAD OF STRONG WAVE TO THE NORTHWEST. THIS BETTER FORCING ON THE NOSE OF THE LLJ SHIFTS EAST AS THE AXIS OF THE LLJ DROPS SOUTH THROUGH THE STATE OVERNIGHT...BRUSHING THE EASTERN CWA. WILL KEEP HIGH CHANCE POPS GOING FOR AFTER MIDNIGHT...WITH LATER SHIFTS POSSIBLY ABLE TO RAISE WITH BETTER CLARITY FROM LATER MODEL RUNS. SUNDAY...FORECAST CONFIDENCE MEDIUM PERSISTENT LOW-LEVEL FLOW CONTINUES OVER AREA AHEAD OF SECOND... STRONGER SHORT WAVE AND ASSOCIATED SURFACE LOW AND COLD FRONT DIPPING INTO NRN WI BY 00Z MONDAY. PLENTY OF FORCING ALONG/AHEAD OF 850 MB TROUGH AXIS AND SURFACE FRONT BUT STRONG AND DEEP CAPPING NOTED ON FORECAST SOUNDINGS ESPECIALLY OVER THE WESTERN CWA WITH PERSISTENT WARM AIR ADVECTION. LESS OF A CAP OVER EASTERN AREAS WITH HIGHER PW/S. WILL HAVE LOWER CHANCE POPS IN THE MORNING FOR DEPARTING WARM-AIR ADVECTION FORCING...AND KEEP THEM IN THE AFTERNOON FOR INSTABILITY AND APPROACHING LOW-LEVEL FORCING WITH THE LOW. SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM SECOND STRONGER SHORT WAVE DROPS IN SUNDAY NIGHT PUSHING LOW AND COLD FRONT THROUGH THE SOUTHERN HALF OF THE STATE. BETTER CHANCES FOR SHOWERS AND STORMS IN THE EVENING BEFORE FRONT DROPS SOUTH IN BY 06Z...WITH CAP ERODING AS MID-LEVELS COOL. KEPT A COLLABORATIVE SLIGHT CHANCE AFTER 06Z...BUT LOOKS AS IF PCPN WILL BE SOUTH OF AREA BY 06Z. MONDAY...FORECAST CONFIDENCE HIGH DRY WEATHER WITH HIGH PRESSURE BUILDING IN WITH SLIGHTLY COOLER TEMPERATURES...BUT WITH DEW POINTS FALLING INTO THE 50S WITH DEEP MIXING. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE LOW MODELS DIFFER WITH LOCATION OF STATIONARY FRONT TO THE SOUTH AND HOW FAR NORTH PRECIPITATION SHIELD WILL REACH AS WAVE MOVES ALONG STALLED BOUNDARY TUESDAY AND WEDNESDAY. MOST MODELS KEEP PCPN SOUTH OF STATE TUESDAY AND SPLIT ON HOW FAR NORTH TO BRING COVERAGE WEDNESDAY. WITH DRY BROAD HIGH IN PLACE OVER WESTERN GREAT LAKES WILL GO WITH CONSERVATIVE CONSENSUS SLIGHT CHANCE POPS FOR WEDNESDAY...WITH CHANCE POPS LIMITED TO THE IL BORDER. MORE PROGRESSIVE GFS BRINGS A STRONGER LOW ACROSS OR THURSDAY AFTERNOON/NIGHT WITH ECMWF KEEPING AREA DRY INTO FRIDAY NIGHT. RESULTING BLEND BRINGS SLIGHT/LOW CHANCES FOR SHOWERS/STORMS FOR THE END OF THE EXTENDED...THOUGH NOT EVERY PERIOD WILL EVENTUALLY HAVE PRECIPITATION. AFTER HIGHS IN THE LOW 80S TUESDAY...TEMPERATURES WILL COOL INTO THE 70S FOR THE REST OF THE EXTENDED...WITH LOWS MAINLY IN THE 50S. && .AVIATION/00Z TAFS/...WNW WINDS EXPECTED TO EASE A BIT THIS EVENING WITH LOSS OF HEATING. NAM/LATEST HRRR/ARW/NMM WANT TO GENERATE SOME LIGHT PRECIP INTO SC WI LATE TNGT/ERLY SAT BUT WILL LEAVE MENTION OUT OF TAF AT THIS TIME. WITH SURFACE/850 RIDGE DRAWING CLOSER ON SATURDAY EXPECT AN OVERALL LIGHTER WIND REGIME. && .MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH THE AFTERNOON DUE TO GUSTY WEST TO NORTHWEST WINDS OF 15 TO 25 KNOTS. A FEW GUSTS MAY REACH 30 KNOTS AT TIMES. WINDS WILL DIMINISH EARLY THIS EVENING. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646. && $$ TONIGHT/SATURDAY AND AVIATION/MARINE...COLLAR SATURDAY NIGHT THROUGH FRIDAY...REM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1021 AM CDT FRI JUL 31 2015 .AVIATION/18Z TAFS/...WNW WINDS WILL CONTINUE TO RAMP UP WITH DECENT MIXING BUT EXPECT SOME DROPOFF THIS EVENING WITH LOSS OF HEATING. NAM/LATEST HRRR WANT TO GENERATE SOME LIGHT PRECIP INTO SC WI LATE TNGT BUT WILL LEAVE MENTION OUT OF TAF AT THIS TIME. WITH SURFACE/850 RIDGE DRAWING CLOSER ON SATURDAY EXPECT AN OVERALL LIGHTER WIND REGIME. PC && .PREV DISCUSSION... /ISSUED 312 AM CDT FRI JUL 31 2015/ TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH. IN THE VERY EARLY TERM...AROUND OR JUST BEFORE 7 AM THIS MORNING...THERE IS A WEAK SURFACE TROF PASSING THROUGH COUPLED WITH A MID LEVEL TROF UP ABOVE. HIGHER DEWPOINTS ARE SNEAKING UP JUST AHEAD OF THE FRONT AND SOME OF THE HI RES MODELS QUICKLY GENERATE A FEW SHOWERS ACROSS SOUTH CENTRAL AREAS...THEN JUST AS QUICKLY WIPE THEM OUT AS THEY MOVE SOUTHEAST. THERE ISN/T MUCH ON SATELLITE RIGHT NOW...JUST A FEW CLOUDS OVER SOUTHEAST MN. SO CONFIDENCE THIS IS GOING TO HAPPEN IS VERY LOW. WILL BE KEEPING AN EYE ON IT THOUGH. OTHERWISE...LOOK FOR A VERY SIMILAR DAY TO THE LAST COUPLE. PLENTY OF SUNSHINE WITH VERY STEEP LOW LEVEL LAPSE RATES WITH DEEP MIXING. TEMPS WILL BE A FEW DEGREES COOLER THAN YESTERDAY...BUT STILL WARM. DEW POINTS WILL MIX OUT ONCE AGAIN...PRODUCING LOW HUMIDITY. QUIET AND PLEASANTLY COOL TONIGHT. SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM HIGH PRESSURE WILL SLIDE SOUTHWARD ON SATURDAY...BUT SHOULD HAVE ENOUGH OF A REMAINING INFLUENCE TO KEEP IT DRY THROUGH THE DAYTIME HOURS. SHOULD SEE A GOOD AMOUNT OF SUNSHINE...WITH HIGHS IN THE 80S ONCE AGAIN. LOOKS LIKE A DECENT CHANCE FOR STORMS AT TIMES SATURDAY NIGHT THROUGH SUNDAY NIGHT. FIRST ROUND SATURDAY EVENING AND OVERNIGHT IS EXPECTED TO COME AS LOW LEVEL JET STRENGTHENS AND MOVES OVERHEAD AHEAD OF AN APPROACHING SHORTWAVE. SPC IS HIGHLIGHTING THE SOUTHWEST HALF OF THE FORECAST ARE WITH A MARGINAL TO SLIGHT RISK OF SEVERE STORMS. NOT SURPRISING GIVEN BEST FORECAST INSTABILITY IN THE SOUTHWEST...WITH 30-40 KNOTS OF BULK SHEAR ACROSS THE FORECAST AREA. THINKING THUNDERSTORM COMPLEX WILL DEVELOP UPSTREAM AND THEN ROLL INTO THE FORECAST AREA. SUNDAY IS A BIT OF A QUESTION MARK WITH PRECIP CHANCES. MODELS SHOWING A WEAK WAVE DURING THE DAY WHICH COULD TRIGGER STORMS...DEPENDING ON HOW QUICKLY THINGS RECOVER AFTER THE OVERNIGHT ROUND OF STORMS. CURRENTLY...MODELS SHOWING QUITE A BIT OF CAPE BY AFTERNOON. BETTER CHANCE WILL PROBABLY BE IN THE EVENING HOURS AS A COLD FRONT ADVANCES INTO THE AREA. GIVEN SHEAR...INSTABILITY...AND CURRENT TIMING OF FRONT...THINKING SOME STRONG TO SEVERE STORMS POSSIBLE ONCE AGAIN. TEMPS FOR SUNDAY ARE A HEADACHE...WITH MODELS ALL OVER THE PLACE. WILL DEPEND ON TIMING OF SHORTWAVES AND PRECIP...AND RESULTANT CLOUD COVER DURING THE DAY. PRETTY GOOD SPREAD IN TEMPS ALOFT BETWEEN REALLY WARM NAM/GFS SOLUTIONS VS SOMEWHAT COOLER ECMWF. STUCK CLOSE TO CONSENSUS BLEND OF SOLUTIONS GIVEN UNCERTAINTY. MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM COULD SEE A LINGERING SHOWER OR TWO MONDAY MORNING...BUT OTHERWISE IT LOOKS DRY AS HIGH PRESSURE BEGINS TO BUILD IN FROM THE NORTHWEST. SHOULD BE DRY THEN TUESDAY UNDER THE HIGH...WITH A COUPLE SHOWERS POSSIBLY CLIPPING THE SOUTHWEST WEDNESDAY AS A WEAK WAVE SLIDES THROUGH. HAVE LOW POPS IN FOR THURSDAY AS ANOTHER WAVE TRAVERSES THE AREA. HIGH TEMPS MON/TUE LOOK TO BE WITHIN A COUPLE DEGREES OF NORMAL...COOLING A FEW DEGREES FOR WED/THU UNDER PERSISTENT NORTHWEST FLOW ALOFT. AVIATION/12Z TAFS/... VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. THERE IS A VERY SMALL CHANCE OF A SHOWER AT KMSN BEFORE 12Z THIS MORNING... ASSOCIATED WITH THE PASSING OF A WEAK SURFACE TROUGH. WINDS WILL AGAIN BE GUSTY OUT OF THE WEST TO NORTHWEST FROM LATE MORNING THROUGH THE AFTERNOON...DIMINISHING QUICKLY BY EARLY EVENING. MARINE... A SMALL CRAFT ADVISORY IS IN EFFECT FROM LATE MORNING THROUGH THE AFTERNOON DUE TO GUSTY WEST TO NORTHWEST WINDS OF 15 TO 25 KNOTS. WINDS WILL DIMINISH QUICKLY EARLY THIS EVENING. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646. && $$ TODAY/TONIGHT AND AVIATION/MARINE...DAVIS SATURDAY THROUGH THURSDAY...DDV
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1140 PM CDT THU JUL 30 2015 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 227 PM CDT THU JUL 30 2015 SEASONABLY WARM TEMPERATURES EXPECTED THROUGH THE WEEKEND. THE MAIN BAND OF WESTERLIES IS CURRENTLY ACRS SRN CANADA AND THE NRN CONUS...HAS LIMITED AMPLITUDE...AND HAS A RIDGE OVER THE W AND A TROF OVER THE HUDSON BAY RGN. THE MAIN CHG DURING THE FCST PERIOD WL BE A SLOW AND GRADUAL INCREASE IN AMPLITUDE...WITH THE UPR TROF EXPANDING SWD. THAT WL TILT THE UPR FLOW INTO THE FCST AREA MORE NWLY WITH TIME. TEMPERATURES WILL START OUT WARM...WITH DAYTIME HIGHS THROUGH THE WEEKEND 4-8F DEG ABV NORMAL. BY EARLY NEXT WK THE UPR FLOW SHOULD TILT NW ENOUGH TO BRING COOLER AIR FM CANADA INTO THE RGN...LIKELY DROPPING TEMPS TO A LITTLE BLO NORMAL BY LATE IN THE PERIOD. PCPN CHCS WILL BE LIMITED SINCE THE VERY HUMID AIR WL REMAIN TO OUR S...AND THE BEST DYNAMICS WITH THE UPR TROF WL STAY N. ALTHOUGH ALL IT TAKES AT THIS TIME OF YEAR IS ONE CONVECTIVE EVENT TO SUPPLY A NORMAL WEEKS WORTH OF PCPN...IT SEEMS LIKELY THAT MOST AREAS WL END UP RECEIVING BLO NORMAL PCPN FOR THE PERIOD. && .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 227 PM CDT THU JUL 30 2015 MILD TEMPS AND DEWPOINTS IN THE LOWER 50S MADE FOR PLEASANT CONDITIONS ACROSS NORTHEAST WISCONSIN LATE THIS AFTERNOON. HOWEVER...19Z WATER VAPOR SHOWED A SHORTWAVE TRACKING THROUGH NE MINNESOTA AND HEADING FOR NORTHERN WISCONSIN. THIS FEATURE HAS ALREADY KICKED OFF SCATTERED STORMS THAT WERE MOVING THROUGH NW WISCONSIN. WITH SOME INSTABILITY IN NORTH CENTRAL WISCONSIN...AND LAPSE RATES OF 6-7K/KM...THESE STORMS SHOULD MAINTAIN THEMSELVES THIS AFTERNOON AS THE SHORTWAVE SWINGS THROUGH. NOTHING SEVERE IS EXPECTED AS CAPES ARE ONLY 500J/KG AT BEST...BUT WITH DRY AIR ALOFT AND RAP SOUNDINGS SHOWING INVERTED-V-LIKE SIGNATURES...GUSTY WINDS AND BRIEF HEAVY RAIN IS POSSIBLE THROUGH EARLY THIS EVENING TO THE NORTH. ANY LINGERING SHOWERS AND THUNDERSTORMS THIS EVENING SHOULD QUICKLY DISSIPATE AFTER SUNSET. CLEAR SKIES SHOULD PREVAIL UNTIL ABOUT MIDNIGHT AS A WEAK FRONT PUSHES THROUGH AND SCATTERED CLOUD COVER DEVELOPS...WITH BROKEN CLOUDS TO THE NORTHAS BETTER QG FORCING GIVES SOME ADDED LIFT.WITH VERY LITTLE CHANGE TO THE OVERALL WEATHER PATTERN...STAYED CLOSE TO LAST NIGHTS LOW TEMPERATURES WITH A HINT OF THE BEST PERFORMING GUIDANCE THROWN IN. FRIDAYS SET UP LOOKS A LOT SIMILAR TO WHAT WE HAD THIS AFTERNOON. SUNNY AND DRY TO START THE DAY...WITH SOME FAIR WEATHER CU IN THE AFTERNOON. ANOTHER WEAK SHORTWAVE WILL BE DROPPING THROUGH THE MEAN FLOW WHICH COULD KICK OFF A FEW SHOWERS TO THE NORTH. WITH NE WI SITTING ON THE ANTICYCLONIC SIDE OF A BROAD UPPER LEVEL...HAVE DOUBTS SHOWERS WILL EVEN DEVELOP. FRIDAYS SHORTWAVE WILL NOT BE AS DEFINED TODAYS WITH LITTLE TO NO ADDED INSTABILITY. HOWEVER HIGH-RES MODELS CONTINUE TO SHOW ISOLATED PCPN DEVELOPING IN RESPONSE TO THE LFQ OF A STRONG 300MB JETSTREAK BRUSHING NORTHERN WISCONSIN. KEPT SLIGHT CHC POPS FRI AFTERNOON...THOUGH CONFINED PCPN TO ONLY THE FAR NORTH. HIGHS TOMORROW WILL BE A DEGREE OR TWO COOLER THAN TODAY...WITH CONTINUED BREEZY WEST WINDS THROUGH NOT AS HIGH AS WE SAW TODAY. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 227 PM CDT THU JUL 30 2015 DAYTIME TEMPS WL CONT ABV NORMAL FOR A FEW DAYS...THEN EVENTUALLY COOL AS THE UPR FLOW TILTS NWLY. STAYED CLOSE TO A BLEND OF THE TOP PERFORMING GUIDANCE PRODUCTS. HARD TO GET A HANDLE ON SPECIFICS OF THE PCPN FCST GIVEN THE PATTERN. PCPN CHCS WL BE TIED TO SML SCALE SHRTWVS ROUNDING THE BASE OF SLOWLY STRENGTHENING LNGWV TROF. CURRENT OP MODEL SUITE NOT VERY ENCOURAGING FOR THE PCPN WE/VE BEEN CARRYING FOR SAT NGT...WITH MANY OF THE MODELS NOW TAKING THAT THROUGH TO THE S OF THE FCST AREA. LATE SUN/SUN NGT LOOK BETTER FOR PCPN AT THIS POINT. BUT THEN AGAIN IN A PATTERN LIKE THIS...THINGS COULD LOOK TOTALLY DIFFERENT TOMORROW. STUCK WITH CHC POPS FOR MOST AREAS FOR SAT NGT...AND AGAIN ON SUN NGT. NO SIG CHGS MADE TO THE EXTENDED FCST INITIALIZATION GRIDS BASED ON A BROAD BLEND OF GUIDANCE PRODUCTS. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1139 PM CDT THU JUL 30 2015 EXPECT MOSTLY VFR CONDITIONS THROUGH FRIDAY EVENING. SCATTERED SHOWERS IN CYCLONIC FLOW ACROSS NORTHEAST MINNESOTA AND WESTERN ONTARIO COULD IMPACT FAR NORTHERN WISCONSIN BUT THINK THAT THERE WILL BE LITTLE OR NOTHING ON THE WISCONSIN SIDE OF THE BORDER. VFR CIGS WILL PROBABLY DEVELOP ACROSS NORTHERN WISCONSIN ALONG WITH ISOLATED/SCATTERED SHOWERS...BUT THE ODDS OF ANY OF THE SHOWERS IMPACTING THE TAF SITES SEEM LOW ENOUGH TO LEAVE THEM OUT OF THE TAFS. SHOWERS AND CLOUDS SHOULD DIMINISH AROUND SUNSET ONCE AGAIN. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....ALLEN LONG TERM......SKOWRONSKI AVIATION.......MG
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
244 AM MST SUN AUG 2 2015 .SYNOPSIS... CONSIDERABLE DRYING OCCURS STARTING TODAY AND INTO THE MIDDLE OF NEXT WEEK WITH STORM CHANCES CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX. TEMPERATURES WILL GRADUALLY WARM AND WILL HOVER NEAR NORMAL OR SLIGHTLY ABOVE THROUGH NEXT WEEK. && .DISCUSSION... PRETTY QUIET RADAR EARLY THIS MORNING SAVE FOR A SWATH OF SHOWERS AND ISOLATED THUNDERSTORMS MOVING INTO NAVAJO AND APACHE COUNTIES. FAIRLY WEEK SOUTH-SOUTHWEST STEERING FLOW THROUGH A MIXED 850-300MB LAYER OF 10-15 KTS HAS ALLOWED FOR SUFFICIENT RAINFALL AMOUNTS TO ACCUMULATE ACROSS THE HIGHER ELEVATIONS OF GILA COUNTY THIS EVENING. MOST OF THE FOCUS OF MONSOON ACTIVITY WAS ACROSS EASTERN PIMA...GILA AND GRAHAM COUNTIES SATURDAY EVENING. PER CURRENT SATELLITE IMAGERY A TONGUE OF DRY AIR IS INFILTRATING SOUTH-CENTRAL ARIZONA MOVING THE DRY AIRMASS IN FROM THE WEST AND KICKING THE MOISTURE OUT THE DOOR TO THE EAST. AN UPPER LEVEL SHORTWAVE TROUGH IS THE CULPRIT PUSHING IN FROM THE WEST BRINGING SOUTHERLY FLOW INTO THE DESERT SOUTHWEST ALONG WITH DRIER AIR /06Z SUNDAY MIXING RATIOS NEARLY 10 G/KG LESS THAN 24 HOURS AGO/. A BROAD REGION OF DIFFLUENCE STILL RESIDES ACROSS WESTERN ARIZONA THROUGH EAST CENTRAL NEW MEXICO ALONG THE MOGOLLON RIM...AND AS EXPECTED THIS WOULD BE THE REGION OF FAVORABLE STORM ACTIVITY TODAY DURING THIS TRANSITION PERIOD. CURRENT MESOSCALE HIGH RES MODEL THAT IS IN GOOD AGREEMENT APPEARS TO BE THE HRRR FOR TODAY`S ACTIVITY. PER LATEST GFS AND ECMWF...AMONG THEIR ENSEMBLE COUNTERPARTS ARE SLOW TO MOVE A CUT OFF LOW FORMING IN THE EASTERN PACIFIC TO THE EAST OVER THE NEXT 5-6 DAYS. THIS WILL ALLOW THE RIDGE OF HIGH PRESSURE TO FLOAT TO THE WEST AND FLATTEN OUT...WITH A WEAK SOUTHWESTERLY STEERING FLOW SETTLING IN THROUGH MOST OF THE UPCOMING WEEK. AN OPTIMUM TIME FOR TEMPERATURES TO GRADUALLY RISE EVEN IF SLIGHTLY ABOVE SEASONAL AVERAGE...THOUGH AT THIS TIME NONE OF THE GUIDANCE BRINGS TEMPERATURES TO THE 110 DEGREE MARK FOR PHOENIX BUT THERE ARE A FEW DAYS WITH 110 OR GREATER OUT ALONG THE LOWER COLORADO RIVER...GENERALLY A WARMER LOCALE. ALL THIS BEING SAID...STORM CHANCES OVER THE NEXT 5-6 DAYS ARE SUBSTANTIALLY LESS THAN THE PREVIOUS DAYS ACROSS THE LOWER DESERTS. A SLIGHT CHANCE WILL BE KEPT FOR HIGHER ELEVATIONS NORTH AND EAST OF PHOENIX DUE TO THE NATURE OF MOUNTAIN ACTIVITY. THE NEXT FLOW REVERSAL APPEARS TO SHAPE UP BY LATE WEEK INTO NEXT WEEKEND AS MOISTURE MAKES A RETURN APPEARANCE AND WIND FLOW RETURNS TO A SOUTH-SOUTHEASTERLY DIRECTION. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... DRY SOUTHWESTERLY FLOW ALOFT IS EXPECTED TO REDUCE CLOUD COVERAGE INTO THE CLR-FEW RANGE AT ALL OF THE TAF SITES BY SUN MORNING...WITH BASES REMAINING MAINLY AOA 10K FEET...WITH THUNDERSTORM DEVELOPMENT REMAINING WELL OFF TO THE EAST OF THE GREATER PHX AREA ON SUNDAY AFTERNOON. WINDS TO MAINLY FOLLOW TYPICAL DIURNAL TRENDS THROUGH THE TAF PERIOD. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY...DRIER AND STABLE WESTERLY FLOW ALOFT WILL PRODUCE PARTLY CLOUDY SKIES TUESDAY AND WEDNESDAY...WITH LOWER MINIMUM RELATIVE HUMIDITY GENERALLY IN THE 10 TO 15 PERCENT RANGE. MOISTURE WILL GRADUALLY INCREASE OVER SOUTHWEST AND SOUTH CENTRAL ARIZONA THURSDAY THROUGH SATURDAY...INTO THE 15 TO 25 PERCENT RANGE...WITH A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS IN SOUTHERN GILA COUNTY. AFTERNOON SOUTHWEST WINDS 10 TO 15 MPH. FAIR RECOVERY AT NIGHT. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...DEWEY AVIATION...PERCHA FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1030 PM MST SAT AUG 1 2015 .UPDATE...AVIATION DISCUSSION. && .SYNOPSIS... LINGERING STORM CHANCES THE REST OF TODAY WILL MAINLY AFFECT AREAS ACROSS HIGHER TERRAIN AREAS OF CENTRAL AND EASTERN ARIZONA WITH A SLIGHT CHANCE OF A FEW STORMS OVER THE LOWER DESERTS. CONSIDERABLE DRYING OCCURS STARTING SUNDAY AND INTO THE MIDDLE OF NEXT WEEK WITH STORM CHANCES CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX. TEMPERATURES WILL HOVER NEAR NORMAL OR SLIGHTLY ABOVE THROUGH NEXT WEEK. && .DISCUSSION... A MUCH QUIETER AFTERNOON/EVENING TODAY THAN WHAT WE SAW YESTERDAY...ESPECIALLY ACROSS THE LOWER ELEVATIONS OF SOUTH- CENTRAL AZ. DRY AIR THAT IS BEING PULLED NORTHWARD AHEAD OF AN UPPER TROF THAT IS APPROACHING THE WEST COAST HAS NOW MOVED INTO SE CA AND THE WESTERN 1/2 OF ARIZONA. THIS DRY AIR HAS PRETTY MUCH SHUT CONVECTIVE ACTIVITY DOWN AND PUSHED SFC DEWPOINTS DOWN INTO THE 50S ACROSS THE WESTERN 3/4 OF OUR CWA THIS AFTERNOON. AHEAD OF THIS DRY SURGE...THUNDERSTORMS HAVE ONCE AGAIN DEVELOPED THIS AFTERNOON ACROSS SOUTHER GILA COUNTY...WHERE DEWPOINTS ARE STILL WELL UP IN THE 60S UNDER THE MAIN MONSOON MOISTURE PLUME AND CONTINUED DIFFLUENCE ALOFT. THIS TS ACTIVITY IS NOW BEGINNING TO SLOWLY DIMINISH AND SHIFT OFF TO THE NORTH THIS EVENING AS THE MOISTURE PLUME CONTINUES TO SHIFT OFF SLOWLY TO THE EAST...WITH THE LATEST HRRR HIGH-RES MODEL RUN INDICATING THAT ANY REMAINING CONVECTIVE ACTIVITY TO END BY MIDNIGHT TONIGHT. TOMORROW STILL LOOKS LIKE IT WILL BE THE 1ST IN A SERIES OF VERY QUIET DAYS AS DRY AIR MAKES ITS WAY ACROSS ALL OF AZ. AS FAR AS THE SHORT-TERM GRIDDED AND ZONE FORECASTS ARE CONCERNED...HAVE LOWERED POPS FOR THE REST OF THIS EVENING AND TONIGHT INTO THE SINGLE-DIGIT RANGE ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ AND HAVE MADE SOME MINOR EDITS TO THE SHORT-TERM TEMPERATURE/DEWPOINT GRIDS TO BETTER REFLECT CURRENT TRENDS. && .DISCUSSION... SO FAR THIS AFTERNOON WE HAVE LITTLE SHOWER OR THUNDERSTORM ACTIVITY AS THE ATMOSPHERE JUST HAS NOT RECOVERED. SKIES HAVE REMAINED MOSTLY CLEAR SO SUNSHINE HAS NOT BEEN AN ISSUE...BUT SURFACE TEMPERATURES ARE STILL SOMEWHAT COOL FOR THIS TIME OF DAY AND GENERALLY 5-8 DEGREES COOLER THAN YESTERDAY. MESOSCALE ANALYSIS DOES SHOW AMPLE MIXED LAYER CAPE ACROSS SOUTH-CENTRAL AND SOUTHEAST ARIZONA ALONG WITH BROAD DIFFLUENCE OVER MUCH OF ARIZONA. STILL EXPECTING MORE THUNDERSTORM DEVELOPMENT THROUGH THE REST OF THIS AFTERNOON...BUT COVERAGE WILL LIKELY BE LIMITED TO MOSTLY HIGHER TERRAIN AREAS. HAVE LOWERED POPS OVER THE LOWER DESERTS INTO THE SLIGHT CHANCE CATEGORY DUE TO THE POOR CONVECTIVE START TO THE AFTERNOON...BUT WE SHOULD STILL GET A FEW STORMS IN THE DESERTS BY THE END OF THE DAY. THERE IS SOME POTENTIAL FOR SOME STRONG DOWNDRAFT WINDS WITH ANY STRONGER STORMS...BUT WITH MORE MOIST AIR IN THE BOUNDARY LAYER...OUTFLOW INTERACTIONS SHOULD BE LESS ACTIVE THAN YESTERDAY. WATER VAPOR IMAGERY SHOWS DRY AIR QUICKLY MOVING NORTHWARD THROUGH THE BAJA AREA INTO NORTHERN MEXICO AND MODELS SHOW THIS DRY AIR WORKING ACROSS ARIZONA STARTING TONIGHT AND OVERTAKING ALL OF THE STATE BY SUNDAY NIGHT. LINGERING LOWER LEVEL MOISTURE WILL ALLOW FOR SOME HIGHER TERRAIN SHOWERS AND THUNDERSTORMS...BUT LITTLE TO NO CHANCE OF ANY ACTIVITY OVER THE LOWER DESERTS. THIS DRY AIR WILL BASICALLY END OUR STORM CHANCES FOR A FEW DAYS EARLY THIS WEEK...WHILE TEMPERATURES START TO WARM UP. HIGHS ACROSS OUR SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS WILL LIKELY BREAK 110 DEGREES SUNDAY THROUGH WEDNESDAY. SOUTH-CENTRAL ARIZONA DESERT TEMPERATURES WILL PEAK ON MONDAY OR TUESDAY...BUT FALL SHORT OF HITTING 110 DEGREES. THE SUBTROPICAL HIGH POSITIONED OVER THE DESERT SOUTHWEST FOR MONDAY AND TUESDAY IS FORECAST TO SHIFT EASTWARD INTO NEW MEXICO SOMETIME WEDNESDAY AND THURSDAY AND REDIRECTING OUR FLOW OUT OF THE SOUTHEAST. THIS WILL BRING A RETURN TO AT LEAST SOME LIMITED MONSOONAL MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS OVER MAINLY THE EASTERN HALF OF ARIZONA. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... DRY SOUTHWESTERLY FLOW ALOFT IS EXPECTED TO REDUCE CLOUD COVERAGE INTO THE CLR-FEW RANGE AT ALL OF THE TAF SITES BY SUN MORNING...WITH BASES REMAINING MAINLY AOA 10K FEET...WITH THUNDERSTORM DEVELOPMENT REMAINING WELL OFF TO THE EAST OF THE GREATER PHX AREA ON SUNDAY AFTERNOON. WINDS TO MAINLY FOLLOW TYPICAL DIURNAL TRENDS THROUGH THE TAF PERIOD. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY...DRIER AND STABLE WESTERLY FLOW ALOFT WILL PRODUCE PARTLY CLOUDY SKIES TUESDAY AND WEDNESDAY...WITH LOWER MINIMUM RELATIVE HUMIDITY GENERALLY IN THE 10 TO 15 PERCENT RANGE. MOISTURE WILL GRADUALLY INCREASE OVER SOUTHWEST AND SOUTH CENTRAL ARIZONA THURSDAY THROUGH SATURDAY...INTO THE 15 TO 25 PERCENT RANGE...WITH A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS IN SOUTHERN GILA COUNTY. AFTERNOON SOUTHWEST WINDS 10 TO 15 MPH. FAIR RECOVERY AT NIGHT. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/KUHLMAN AVIATION...PERCHA FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
901 PM MST SAT AUG 1 2015 .SYNOPSIS...A GRADUAL DAILY REDUCTION IN THUNDERSTORM COVERAGE WILL THEN OCCUR SUNDAY THROUGH TUESDAY. SCATTERED AFTERNOON AND EVENING THUNDERSTORMS MAINLY FROM TUCSON EAST AND SOUTH WILL RETURN DURING THE LATTER PART OF THE UPCOMING WEEK. && .DISCUSSION...SHOWERS AND THUNDERSTORMS CONTINUED TO DIMINISH LATE THIS EVENING AFTER A RATHER ACTIVE AFTERNOON. LATEST HRRR SOLUTION SUGGESTED THAT THE REMAINING SHOWERS WILL DISSIPATE BY MIDNIGHT WITH SKIES CLEARING OVERNIGHT. CURRENT FORECAST LOOKED ON TRACK...SO JUST SOME MINOR ADJUSTMENTS TO THE GRIDDED POP FIELD THIS EVENING. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR MORE DETAILS. && .AVIATION...VALID THRU 03/06Z. EXPECT CLEARING SKIES LATE TONIGHT INTO SUNDAY MORNING BEFORE REDEVELOPMENT OF ISO-SCT SHRA/TSRA DURING THE EARLY AFTERNOON...MAINLY E OF KTUS/KOLS AND ESP NEAR TERRAIN. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SOUTHWEST WINDS ALOFT ON SUNDAY WILL USHER DRIER AIR INTO THE REGION...WHICH WILL LIMIT PRECIPITATION CHANCES ON MONDAY AND ESPECIALLY ON TUESDAY. HIGH PRESSURE RETURNS TO A MORE FAVORABLE LOCATION FOR DAILY CHANCES OF MONSOON SHOWERS AND THUNDERSTORMS FROM WEDNESDAY ONWARD. OUTSIDE OF THUNDERSTORM WIND GUSTS...20-FT WINDS WILL GENERALLY BE TERRAIN DRIVEN AND LESS THAN 15 MPH. HOWEVER SOME AFTERNOON AND EARLY EVENING BREEZINESS IS LIKELY DUE TO DAYTIME HEATING... ESPECIALLY THROUGH THE GILA VALLEY NEAR SAFFORD. && .PREV DISCUSSION...01/12Z NAM/GFS/ECMWF/CMC WERE IN GOOD AGREEMENT WITH DEPICTING A DRYING TREND TO COMMENCE SUNDAY AND CONTINUE INTO TUE...AT LEAST. HIGH PRESSURE ALOFT IS PROGGED TO BE CENTERED OVER FAR WEST TEXAS SUN MORNING...WITH A SHORTWAVE TROUGH OVER THE GREAT BASIN AND NWRN ARIZONA. 700-300 MB SWLY FLOW SUN WILL BECOME INCREASINGLY WLY MON AND CONTINUE WITH GENERALLY LIGHT WLY FLOW TUE AS THE UPPER HIGH BECOMES POSITIONED JUST SOUTH OF THIS FORECAST AREA OVER NRN SONORA. THIS WIND REGIME WILL TRANSLATE INTO ISOLATED TO SCATTERED SHOWERS/ TSTMS FROM TUCSON EWD/SWD SUN AND MON. BY TUE...THERE IS ONLY A SLIGHT CHANCE OF SHOWERS/TSTMS MAINLY NEAR THE MOUNTAINS WITH DRY CONDITIONS ELSEWHERE. A SIMILAR PRECIP REGIME MAY ACTUALLY OCCUR WED...AT LEAST BASED ON THE GFS/ECMWF/CMC SOLUTIONS. FOR NOW... OPTED TO CONTINUE WITH A SLIGHT CHANCE OF SHOWERS/TSTMS ACROSS MUCH OF SE ARIZONA WED. THEREAFTER...THE GFS/ECMWF WERE FAIRLY SIMILAR WITH DEPICTING DEEPER MOISTURE TO RETURN TO THIS FORECAST AREA STARTING THUR AND CONTINUING INTO NEXT SAT. THESE SOLUTIONS SEEM PLAUSIBLE AS THE MID- LEVEL STEERING FLOW BECOMES INCREASINGLY SLY IN RESPONSE TO THE UPPER HIGH BECOMING POSITIONED AGAIN OVER WEST TEXAS...AND AN UPPER TROUGH ADJACENT THE CALIFORNIA COAST. THUS...SCATTERED SHOWERS/TSTMS WILL RETURN THUR-SAT MAINLY FROM TUCSON EWD/SWD TO THE NEW MEXICO/ INTERNATIONAL BORDERS. EXPECT ABOUT A DEGREE-OR-TWO OF DAILY WARMING SUN-TUE FOLLOWED BY A VERY GRADUAL REDUCTION IN DAYTIME TEMPS DURING THE LATTER PART OF THE UPCOMING WEEK. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1124 PM MDT SAT AUG 1 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 238 PM MDT SAT AUG 1 2015 ...TYPICAL AUGUST WEATHER CONTINUES ON SUNDAY... FAIRLY TYPICAL SUMMER PATTERN REMAINS IN PLACE OVER SE CO. WITH MONSOONAL PLUME CIRCULATING CLOCKWISE AROUND THE UPPER HIGH CENTERED OVER NM...BEST T-STORM COVERAGE CONTINUES TO BE OVER WRN AND SRN PORTIONS OF THE CWA. NEWLY OPERATIONAL RADAR IN THE SAN JUANS SHOWS WIDESPREAD CONVECTION OVER THE SW MTS...JUSTIFYING LIKELY POPS FOR THE BALANCE OF THE AFTERNOON AND INTO EARLY EVE. MORE QUESTIONABLE WHETHER STORMS WILL SURVIVE MOVING ONTO THE SERN PLAINS E OF I- 25...BUT ISOLD POPS LOOK APPROPRIATE THERE. TEMPS CONTINUE TO BE IN THE LOWER 90S FOR THE PLAINS...70S FOR THE HIGH VALLEY AREAS. EXPECT MOST OF THE T-STORM ACTIVITY TO WANE AFTER SUNSET...HOWEVER LATEST HRRR AND OTHER GUIDANCE SUGGESTS CONTINUED ISOLD ACTIVITY OVER THE SW MTS AND SURROUNDING AREAS...SO WILL MAINTAIN AT LEAST LOW POPS THROUGH THE NIGHT FOR THIS AREA. SOME MODEL SOUNDINGS STILL SUPPORT LOW CLOUDS OR POSSIBLY EVEN SOME FOG FOR THE SAN LUIS VALLEY IF SUFFICIENT PRECIP CAN FALL THIS AFTERNOON OR EVE. TOMORROW...MORE OF THE SAME...BUT A WEAK SHORTWAVE PASSING THROUGH NW FLOW ON THE E SIDE OF THE UPPER RIDGE COULD SPARK A FEW MORE STORMS THAN WE ARE CURRENTLY SEEING...ESPECIALLY OVER THE SERN MTS. SFC WINDS SHIFT TO A STRONGER UPSLOPE COMPONENT SUN AFTERNOON... WHICH WILL KEEP THE BEST FORCING FOR STORMS ANCHORED ALONG THE MTS AND ADJACENT LOWLANDS ALONG THE I-25 CORRIDOR. TEMPS AGAIN SHOULD BE IN THE LOWER TO MID 90S OVER THE PLAINS. ROSE .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 238 PM MDT SAT AUG 1 2015 SUN NIGHT AN UPR TROF IS FORECAST TO EXTEND FROM THE GREAT BASIN REGION AND ACRS CO. BOTH THE NAM AND GFS SHOW A SHORTWAVE TROF MOVING INTO THE SERN CORNER OF CO OVERNIGHT AND INTO MON MORNING...BUT THEY DISAGREE ON ITS IMPACT. BOT MODELS SHOW PCPN CONTINUING THRU THE NIGHT OVR THE CONTDVD WITH THE POTENTIAL FOR SOME ISOLD PCPN OVR THE ERN MTNS. FOR FAR ERN PORTIONS OF THE FORECAST AREA...THE NAM HAS MAINLY SOME ISOLD PCPN OVR THE SERN CORNER THRU THE NIGHT AND MON MORNING...BUT THE GFS HAS MORE WIDESPREAD CHANCES OVR THE SERN PLAINS. SINCE THERE IS A DISTURBANCE IN THE AREA...WL KEEP SOME ISOLD POPS ACRS THE SERN PLAINS THRU THE NIGHT. THRU THE DAY MON...THAT UPR TROF CONTINUES WORKING ITS WAY NORTHEASTWARD INTO ID...WY AND NERN CO. THE GFS AND NAM HAVE SCT PCPN OVR THE HYR TRRN ON MON...WHILE THE NAM IS MAINLY DRY OVR THE SERN PLAINS IN THE AFTERNOON AND EVENING...BUT THE GFS HINTS AT ISOLD TO SCT PCPN. MON NIGHT THE NAM SHOWS PCPN ACRS THE FORECAST AREA ENDING BY LATE EVENING...BUT THE GFS CONTINUES PCPN OVR THE FAR ERN BORDER AREA INTO THE LATE NIGHT HOURS. TUE AN UPR RIDGE BUILDS OVR THE AREA AND REMAINS IN PLACE ON WED...WHICH WL KEEP THE MONSOON MSTR TO THE SOUTH OF THE FORECAST AREA. SO...DRIER CONDITIONS CAN BE EXPECTED ALTHOUGH THERE MAY STILL BE ENOUGH MSTR OVR THE AREA FOR A FEW AFTERNOON AND EVENING MTN AREA SHOWERS/TSTMS. ON THU A DISTURBANCE IS FORECAST TO MOVE ACRS WY...THEN PUSHING A FRONT THRU ERN CO. THE ECMWF DEVELOPS AND MCS OVR ERN FOR THU NIGHT...WHILE THE GFS DOES NOT AND LEAVES THE AREA RATHER DRY. FOR NOW WL GO WITH THE DRY SOLUTION AND SEE HOW THE SITUATION DEVELOPS. FRI THE UPR RIDGE WL BE CENTERED TO THE SOUTH OF CO. THE ECMWF SHOWS THE POTENTIAL FOR A LITTLE MORE MSTR TO WORK ITS WAY BACK TOWARD CO...BUT THE GFS IS STILL FAIRLY DRY THROUGH SAT. && .AVIATION... ISSUED AT 1124 PM MDT SAT AUG 1 2015 VFR CONDITIONS ARE ANTICIPATED OVER THE KALS...KCOS AND KPUB TAF SITES INTO SUNDAY MORNING. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
328 AM EDT SUN AUG 2 2015 .DISCUSSION... ...LOCALLY HEAVY RAINFALL AND GUSTY WINDS WITH STORMS AGAIN TODAY... CURRENT...KMLB NEXRAD 88D SHOWS SPOTTY LIGHT RAIN ECHOES MOVING FROM SOUTHWEST TO NORTHEAST ACROSS EAST CENTRAL FL EARLY THIS MORNING. WATER VAPOR IMAGERY AGAIN SHOWS A BLANKET OF MID/UPPER LEVEL MOISTURE ACROSS THE REGION ALL SOUTH OF A WEAK QUASI-STATIONARY FRONTAL BOUNDARY SITUATED OVER THE DEEP SOUTH AND SOUTHEAST U.S. MSAS/SURFACE OBS SHOW THAT THE SURFACE RIDGE AXIS HAS CREPT NORTH TO NEAR SOUTH-CENTRAL FL. MID TO UPPER LEVEL TROUGHINESS AGAIN LIES ACROSS THE AREA. CAPE 915 MHZ PROFILER WINDS OUT OF THE S/SSW AVERAGE BETWEEN 20 AND 30 KTS OFF THE DECK UP TO AROUND 10.0 KFT. SURFACE S/SSW WINDS ARE BETWEEN 5 AND 10 MPH WITH TEMPERATURES AND DEWPOINTS IN THE 70S. TODAY-TONIGHT...PRECIPITABLE WATER VALUES WILL CONTINUE AROUND 2 INCHES AREAWIDE EARLY...BUT THE GFS SUGGESTS SOME DRIER AIR FILTERING INTO THE AREA SOUTH OF I-4 LATER IN THE DAY. THE AFOREMENTIONED SURFACE BOUNDARY TO THE NORTH WILL REMAIN NORTH OF THE AREA WITH THE SURFACE RIDGE AXIS NEAR LAKE OKEECHOBEE. S/SSW WINDS WILL INCREASE THIS MORNING AND EARLY AFTERNOON TOWARD AROUND 15 MPH...POSSIBLY FLIRTING WITH 15-20 MPH (BREEZY) AT TIMES AND SOME HIGHER GUSTS LIKELY. THE IMMEDIATE TREASURE COAST MAY SEE WINDS BACK TO SSE/SE IN THE AFTERNOON. CONTINUED DEEP MOISTURE WILL MAKE CLOUD COVER HARD TO OVERCOME FOR MUCH OF THE AREA AGAIN TODAY. AFTERNOON HIGHS WILL CONTINUE IN THE U80S TO AROUND 90 DEGREES. THE DEEP/STOUT SOUTHWESTERLY FLOW WILL ALLOW SCT SHRA/ISOLD TSRA LATER THIS MORNING AND EARLY AFTERNOON TO TRAVERSE THE PENINSULA WITH SHOWER COVERAGE FORECAST TO BECOME NUMEROUS THIS AFTERNOON WITH SCATTERED LIGHTNING STORMS. 500 MB TEMPERATURES WILL BE A BIT WARMER WITH MODELS SHOWING A RANGE BETWEEN -5.5 AND -6.5 DEGREES CELSIUS ACROSS ECFL. THE 00Z GFS CONTINUES TO HIGHLIGHT FAIRLY GOOD UPPER LEVEL DIFFLUENCE ACROSS THE EAST COAST/COASTAL WATERS LATER THIS AFTERNOON/EARLY EVENING. STORM MOVEMENT WILL BE FAIRLY QUICK AND OUT OF THE SW AT 15 TO 20 KTS. THE MAIN THREATS WITH STRONGER ACTIVITY CONTINUES TO BE HEAVY DOWNPOURS...GUSTY WINDS TO AROUND 50 MPH AND FREQUENT LIGHTNING IN A FEW CELLS. MARINERS ON INLAND LAKES AS WELL AS ACROSS THE INTRACOASTAL/NEAR SHORE ATLANTIC WATERS WILL NEED TO KEEP AN EYE TO THE SKY WESTWARD FOR DEVELOPING/APPROACHING STORMS. CONVECTION WILL GRADUALLY DECREASE THROUGH THE EVENING...THOUGH A SCHC FOR A SHOWER WILL CONTINUE OVERNIGHT ALMOST EVERYWHERE. CONSIDERABLE CLOUDINESS TO MOSTLY CLOUDY SKIES WILL CONTINUE THIS EVENING AND OVERNIGHT. OVERNIGHT LOWS IN THE 70S. S/SSW WINDS WILL GRADUALLY DECREASE TO AROUND 5 MPH THIS EVENING AND OVERNIGHT. MONDAY...SFC LOW IS FORECAST TO TRACK ACROSS SE GA AND MOVE NE THROUGH THE AFTERNOON WITH A TRAILING AREA OF DEEP MOISTURE STRETCHING SOUTH OF THE LOW ACROSS NRN SECTIONS MONDAY MORNING AND DROPPING SLOWLY SE INTO LATE AFTERNOON. THIS SHOULD ALLOW FOR MOSTLY CLOUDY SKIES ACROSS NRN SECTIONS IN THE MORNING WITH SOME EARLY MORNING SHOWERS. EXPECT CONVECTION TO BECOME LIKELY ACROSS THE NRN ZONES INTO MID DAY INTO THE AFTERNOON WITH SCATTERED SHOWERS AND STORMS ACROSS SRN SECTIONS BY MID TO LATE AFTERNOON. LOCALLY HEAVY RAINFALL IS LIKELY WITH STORMS AND GUSTY WINDS AS STORMS APPROACH THE EAST COAST MAINLY NORTH OF FT PIERCE. HIGHS WILL BE IN THE MID TO UPPER 80S NORTH TO LOWER 90S ACROSS SRN ZONES WHERE MORE MORNING SUN IS EXPECTED BEFORE SCATTERED STORMS DEVELOP INTO THE AFTERNOON. TUESDAY...THE SFC AND LOW LVL RIDGE WILL WORK SLOWLY NORTHWARD TWD FAR SRN SECTIONS OF THE FORECAST AREA AS WE BEGIN TO LOSE THE INFLUENCE OF THE SFC LOW AND FRONTAL BOUNDARY THAT HAD BEEN NORTH OF THE AREA FOR THE LAST WEEK OR SO. OVERALL WILL SEE LIGHTER WINDS IN THE SFC TO 850 LAYER WITH LATE DAY BOUNDARY INTERACTIONS FAVORING INTERIOR SECTIONS ESPEC INLAND FROM THE TREASURE COAST. WILL FORECAST 30-40 POPS NEAR THE EAST COAST AND 40-50 PCT OVER THE INTERIOR. HIGHS FROM 89 TO 92 DEGS. WED...SOUTHERLY LOW LVL FLOW IS FORECAST AROUND THE ATLC RIDGE WITH INLAND MOVING SEA BREEZE BOUNDARIES MOVING TWD THE NRN INTERIOR LATE IN THE AFTERNOON INTO THE EARLY EVENING. LOWEST POPS AROUND 30 PCT WILL BE ALONG THE TREASURE COAST WHERE THE SEA BREEZE SHOULD MOVE INLAND INTO MID AFTERNOON. WILL FORECAST 40-50 PCT ACROSS THE INTERIOR FOR MID TO LATE AFTERNOON SCATTERED STORMS. HIGHS NEAR 90 COASTAL TO THE LOWER 90S FOR THE INTERIOR. THU...THE LOW LVL RIDGE WILL SHIFT A BIT SOUTHWARD AGAIN BY THU AFTN AS A 500 MB S/W TROUGH MOVES INTO THE SE STATES. MOISTURE LEVELS APPEAR SUFFICIENT FOR SCATTERED STORMS WHICH WILL MOVE TWD THE EAST COAST LATE IN THE DAY WITH STEERING FLOW FROM THE WEST INTO THE EVENING. RAIN CHANCES 40 PCT CSTL TO 50 PCT FROM ORLANDO SOUTH ACROSS THE INTERIOR. HIGHS 90-92 DEGS. FRI-SUN...A DEEPENING L/W TROUGH ACROSS THE ERN STATES FOR THE UPCOMING WEEKEND WILL PRODUCE DEEP LAYER WESTERLY FLOW AND INCREASING MOISTURE LEVELS WHICH WILL ALLOW FOR EASTWARD MOVING SCATTERED SHOWERS AND STORMS EACH DAY...LIKELY ALONG A PROGRESSIVE WEST COAST SEA BREEZE AND POSSIBLY ALONG AN EAST COAST BREEZE PINNED NEAR THE EAST COAST IF THE WESTERLY FLOW IS NOT TOO STRONG. WILL KEEP RAIN CHANCES MAINLY IN THE 40-50 PCT RANGE FOR THE UPCOMING WEEKEND. HIGHS WILL REMAIN MAINLY IN THE LOWER 90S. && .AVIATION...A SIMILAR PATTERNS SITS IN PLACE FROM THE PREVIOUS COUPLE OF DAYS. THE HRRR HINTS AGAIN AT CONVECTION ACROSS THE WESTERN PENINSULA MOVING INTO ECFL LATE MORNING/EARLY AFTERNOON MOVING OFF OF THE COAST EARLY TO MID AFTERNOON (NORTH TO SOUTH). MOIST CONDITIONS CONTINUE IN A DEEP SWRLY FLOW PATTERN WITH SHRA/TSRA BECOMING SCT-NMRS AGAIN AT TIMES THROUGH THE AFTN/EARLY EVENING. SKIES TO REMAIN CONSIDERABLY TO MOSTLY CLOUDY THROUGH THE PERIOD. S/SSW SFC WINDS A BIT STRONGER AS WITH YESTERDAY AND GUSTY AT TIMES. ALONG THE TREASURE COAST WINDS MAY BACK TO S/SSE AS THE SFC RIDGE AXIS LIES NEAR LAKE OKEECHOBEE. AS WITH PREVIOUS DAYS...PRECIPITATION LATE THIS MORNING/EARLY THIS AFTERNOON MAY DISTORT THE WIND FIELD WITH OCCASIONAL LIGHTER SURFACE WINDS THAN FORECAST WITH VARYING DIRECTION. TEMPO IFR/MVFR IN SHRA/TSRA. CELL MOVEMENT TOWARD THE NE AT 15 TO 20 KTS. FOR TAFS...VCSH/VCTS FROM LATE MORNING/EARLY AFTERNOON WITH TEMPO GROUPS ADDED AS CONFIDENCE PERMITS. THREATS FROM CONVECTION CONTINUES TO BE LIGHTNING... TORRENTIAL DOWNPOURS AND GUSTY WINDS. ACTIVITY WILL WIND DOWN THROUGH THE EVENING AND WINDS WILL DECREASE. && .MARINE...TODAY-TONIGHT...THE SURFACE RIDGE AXIS IS OVER THE SOUTH- CENTRAL FL PENINSULA WHERE IT WILL LIKELY REMAIN OVER THE NEXT 24 HRS. CAUTIONARY STATEMENTS SEEM APPROPRIATE AGAIN FOR GUSTY S/SSW WINDS OFFSHORE/NORTH OF SEBASTIAN INLET. WILL ALLOW FUTURE SHIFTS TO MONITOR AND ADJUST AS NECESSARY. SLIGHTLY LOWER WIND SPEEDS ARE FORECAST THIS EVENING/OVERNIGHT HERE. WIND SPEEDS MAINLY 10-15 KTS ELSEWHERE. SEAS 2-3 FT NEAR SHORE AND 3-4 FT OFFSHORE. WINDS/SEAS WILL BE LOCALLY HIGHER INVOF QUICK MOVING OFFSHORE SHOWERS/STORMS. OFFSHORE MOVING LIGHTNING STORMS REMAIN A THREAT THROUGH THE DAY/EVENING AND COVERAGE WILL BE FAIRLY HIGH LATER TODAY. MARINERS SHOULD REMEMBER THAT STRONG WINDS MAY ARRIVE WELL AHEAD OF RAIN AND LIGHTNING. MONDAY...SW WINDS MAINLY 10-15 KNOTS WITH OFFSHORE MOVING SHOWERS AND STORMS DURING THE AFTERNOON AND EARLY EVENING HOURS. A FEW COULD BE STRONG WITH GUSTY WINDS GREATER THAN 35 KNOTS. SEAS MAINLY 2-3 FT TO 4 FT ACROSS THE NRN OFFSHORE WATERS. TUE-THU...S-SW WINDS TUE WILL BECOME SOUTHERLY AROUND THE ATLC RIDGE BY WED/THU AND DECREASE TO AROUND 10 KNOTS. SEAS 2 FT NEAR SHORE TO 3 FT OFFSHORE. A LOWER COVERAGE OF ATLC SHOWERS/STORMS IS EXPECTED INTO MID WEEK. && .PRELIMINARY POINT TEMPS/POPS... DAB 89 73 87 73 / 60 30 60 20 MCO 89 74 88 73 / 60 20 60 20 MLB 91 76 89 75 / 50 20 60 30 VRB 91 72 91 72 / 50 30 50 30 LEE 86 75 87 74 / 60 30 60 20 SFB 89 75 88 73 / 60 20 60 20 ORL 89 75 88 75 / 60 20 60 20 FPR 91 73 91 73 / 50 30 50 30 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM/AVIATION...SEDLOCK LONG TERM....VOLKMER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
142 AM EDT SUN AUG 2 2015 .SYNOPSIS... A WEAK PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA THROUGH MONDAY. DEEPER MOISTURE WILL REMAIN SUPPRESSED EAST AND SOUTH OF THE AREA. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THE UPPER-LEVEL PATTERN FEATURES A RIDGE OUT WEST WITH A BROAD TROUGH FROM THE GREAT LAKES TO THE EAST COAST. WATER VAPOR SATELLITE IMAGERY SHOWED DRY AIR ALOFT ACROSS THE MIDLANDS AND CSRA. WEAK FRONTAL BOUNDARY NEAR THE SOUTHERN TIP OF THE FORECAST AREA THIS EVENING. SHARP MOISTURE GRADIENT ACROSS THE REGION LATE THIS EVENING AS SEABREEZE HAD PUSHED INTO THE CENTRAL MIDLANDS AND CSRA BRINGING WITH IT DEWPOINT TEMPERATURES IN THE UPPER 60S/LOWER 70S. AHEAD OF THIS BOUNDARY DEWPOINT TEMPERATURES REMAIN IN THE MID 50S/MID 60S. MODELS SHOWING POOL OF MOISTURE NEAR THE SURFACE WITH DRY AIR ALOFT. WV LOOP CONTINUES TO SHOW DRY AIR ALOFT ACROSS THE AREA. EXPECT SOME FOG TO FORM TOWARD MORNING GIVEN MOSTLY CLEAR SKIES AND LOW LEVEL MOISTURE. BEST CHANCE FOR FOG WILL BE ACROSS THE EASTERN MIDLANDS/CSRA WHERE HIGHEST DEWPOINTS CURRENTLY RESIDE. MET MOS GUIDANCE HAS COOL BIAS OVERNIGHT MINS HAVE STAYED WITH SLIGHTLY WARMER OVERNIGHT TEMPERATURES WITH LOWS IN THE UPPER 60S TO LOWER 70S TONIGHT. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... THE WEAK FRONTAL BOUNDARY WILL REMAIN ACROSS EASTERN SOUTH CAROLINA THROUGH THE PERIOD. MODELS APPEARS TO BE DRIER ACROSS CENTRAL SOUTH CAROLINA AND CSRA AND SOUNDINGS LIKELY CAPPED. WIDELY SCATTERED CONVECTION CONFINED MAINLY IN THE EAST MIDLANDS...LOWER CSRA. MAX TEMPERATURES MAINLY IN THE MID 90S...LOWS UPPER 60S TO MID 70S. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... MODELS HAVE BEEN CONSISTENT SHOWING A RIDGE OVER THE CENTRAL US WITH A BROAD TROUGH ALONG THE EAST COAST. THE FRONTAL BOUNDARY WILL REMAIN ALONG THE COAST THROUGH EARLY NEXT WEEK BEFORE DISSIPATING. THE GFS KEEPS THE AREA DRY THROUGH WEDNESDAY. MOISTURE RETURNS TO THE REGION LATER IN THE WEEK. RAISED POPS INTO THE 30-40 PERCENT THURSDAY THROUGH SATURDAY. HIGH TEMPERATURES IN THE MID 90S THROUGH MID-WEEK...LOWERING INTO THE LOWER 90S THURSDAY THROUGH SATURDAY. OVERNIGHT LOWS GENERALLY IN THE LOWER TO MID 70S. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... MOSTLY CLEAR SKIES AND LIGHT WINDS EXPECTED OVERNIGHT...WHICH LEADS TO FOG CONCERNS. SATELLITE WATER VAPOR IMAGERY INDICATES DRY AIR ALOFT WHICH TENDS TO AID IN RADIATIONAL COOLING AND FOG DEVELOPMENT. DESPITE SHALLOW SEA BREEZE OR OUTFLOW BOUNDARY THAT MOVED THROUGH EARLIER THIS EVENING...DRIER LOW LEVEL AIR EXISTS ACROSS THE NORTHER NAND CENTRAL FA NEAR CAE/CUB AND IS EXPECTED TO LIMIT FOG POTENTIAL THERE. HOWEVER...TO THE SOUTH WHERE BETTER LOW LEVEL MLOISTURE EXISTS...THE FOG POTENTIAL IS GREATER...ESPECIALLY AT THE FOG PRONE SITES AGS AND OGB. LATEST HRRR INDICATES SOME STRATUS POTENTIAL NEAR AGS AND DNL AS WELL NEAR WHERE BETTER PRECIP COVERAGE OCCURRED SATURDAY. WILL INDICATE PREDOMINATE IFR FOG POTENTIAL FOR THE FOG PRONE SITES AGS AND OGB...AND MVFR FOG AT DNL...AND WILL INDICATE TEMPO IFR CIGS POSSIBLE AT DNL AND AGS. WILL MAINTAIN VFR CONDITIONS AT CAE/CUB. SURFACE BOUNDARY WILL REMAIN NEARLY STATIONARY OVER THE SOUTHERN FA TODAY. A DRY AND CAPPED ATMOSPHERE WILL REMAIN IN PLACE OVER MOST OF THE NORTHERN AND CENTRAL FA...AND IS EXPECTED TO PRECLUDE CONVECTION THERE. AN ISOLATED MAINLY DIURNAL SHOWER OR THUNDERSTORM MAY OCCUR MAINLY SOUTH POSSIBLY NEAR DNL/AGS/OGB...BUT CHANCES TOO LOW TO INCLUDE MENTION IN THE TAFS AT THIS TIME. EXTENDED AVIATION OUTLOOK... RESTRICTIONS POSSIBLE IN LATE NIGHT/EARLY MORNING FOG. OTHERWISE...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
...UPDATE TO AVIATION FORECAST DISCUSSION...

.SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 326 PM CDT SAT AUG 1 2015 19Z WATER VAPOR IMAGERY SHOWS NORTHWEST FLOW ACROSS THE NORTHERN AND CENTRAL PLAINS WHILE THE CENTER OF A MID LEVEL RIDGE SITS OVER WEST TX. THE RIDGE AXIS EXTENDED NORTHWEST INTO OR. THE RAP ANALYSIS SUGGESTS THERE ARE ONLY A COUPLE WEAK VORT MAXIMUM UPSTREAM. ONE OVER EASTERN NEB AND ANOTHER MOVING INTO SD. AT THE SURFACE, A MESO HIGH REMAIN OVER CENTRAL NEB WHILE OUTFLOW BOUNDARIES FROM MORNING CONVECTION HAVE BECOME MORE DIFFUSE ACROSS CENTRAL AND EASTERN KS. FOR THIS AFTERNOON AND THIS EVENING, THERE REMAINS AN OUTSIDE CHANCE FOR A STORM TO DEVELOP AS OBJECTIVE ANALYSIS SHOWS MORE THAN ENOUGH INSTABILITY. HOWEVER SURFACE FLOW HAS BEEN RATHER WEAK SO CONVERGENCE AND LIFT ALONG ANY OF THE BOUNDARIES HAS ALSO BEEN RATHER WEAK. SATELLITE SHOWS LITTLE DEVELOPMENT TO THE CU FIELD ACROSS THE AREA INDICATING THERE HASN`T BEEN MUCH FORCING AS WELL. AND ANY WEAK VORTICITY ADVECTION FROM THE LEFT OVER CONVECTION IN EASTERN NEB IS LIKELY PROPAGATING INTO MO. BECAUSE OF THIS THINK THE CHANCES FOR ANY SPOT TO RECEIVE RAIN IS ONLY ABOUT 10 PERCENT AND NOT HIGH ENOUGH TO MENTION IN THE FORECAST. ONCE THE BOUNDARY LAYER STARTS TO COOL, THE THREAT FOR THUNDERSTORMS SHOULD DIMINISH. OVERNIGHT, MODELS SHOW THE LOW LEVEL JET SETTING UP ACROSS NEB AND IA WITH NO REAL ORGANIZED ISENTROPIC LIFT ACROSS THE FORECAST AREA. BECAUSE OF THIS HAVE A DRY FORECAST GOING THROUGH THE NIGHT. THERE SHOULD BE MOSTLY CLEAR SKIES, SO THINK WITH SOME RADIATIONAL COOLING LOWS WILL FALL INTO THE UPPER 60S TO AROUND 70. FOR SUNDAY, THE SETUP LOOKS VERY SIMILAR TO TODAY WITH DECENT SURFACE BASED INSTABILITY DEVELOPING AND NOT MUCH INHIBITION TO CONVECTION. WITH A LACK OF LARGE SCALE FORCING, PRECIP CHANCES LOOK UNLIKELY UNTIL A TROUGH AXIS APPROACHES NORTH CENTRAL KS LATE IN THE DAY. MOST MODEL SOLUTIONS SHOW THIS BOUNDARY MOVING INTO THE FORECAST AREA LATE IN THE AFTERNOON BUT THE GFS IS REALLY THE ONLY ONE THAT DEVELOPS CONVECTION. THE GFS ALSO IS THE WARMEST SOLUTION AND MAY BE A LITTLE EAGER TO BREAK WHAT CAP THERE IS. WHILE PRECIP CHANCES DON`T LOOK GREAT, IT`S DIFFICULT TO RULE OUT A CHANCE SO HAVE SLIGHT CHANCE POPS IN THE FORECAST FOR THE LATE AFTERNOON. WITH 850 TEMPS SLIGHTLY WARMER THAN TODAY, HAVE HIGHS A DEGREE OR SO WARMER WITH GENERALLY MID 90S EXPECTED. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 326 PM CDT SAT AUG 1 2015 SUNDAY EVENING WILL CONTINUE TO KEEP LOW PRECIPITATION CHANCES ALONG THE WEAK FRONTAL BOUNDARY AS WELL AS THE INSTABILITY AXIS ACROSS THE NORTHERN CWA. WILL LITTLE TO NO UPPER SUPPORT AND WEAK SURFACE CONVERGENCE EXPECT ANY CONVECTION TO BE ON THE WANE AFTER SUNSET. LOWS SUNDAY NIGHT WILL COOL INTO THE UPPER 60S TO LOWER 70S. MONDAY FOR MUCH OF THE DAY LOOKS DRY WITH INCREASING CHANCES FROM LATE AFTERNOON THROUGH EARLY MORNING HOURS ON TUESDAY ESPECIALLY NEAR THE NEBRASKA BORDER NEAR THE VICINITY OF THE SURFACE FRONTAL BOUNDARY IN SOUTHERN NEBRASKA. LOW LEVEL JET WILL INCREASE FROM THE SOUTH AND SOUTHWEST MONDAY NIGHT BEFORE WEAKENING TUESDAY MORNING. MODELS CONTINUE TO SHOW MID LEVEL SHORTWAVE MOVING THROUGH THE PLAINS TUESDAY AND TUESDAY NIGHT. WEDNESDAY THROUGH SATURDAY WILL BE MARKED BY COOLER TEMPERATURES WITH PRECIPITATION CHANCES OFF AND ON AS WAVES MOVE THROUGH THE NEARLY ZONAL FLOW ACROSS THE CENTRAL PLAINS. HIGH PRESSURE NOSES INTO EASTERN KANSAS ON THURSDAY WITH A FRONTAL BOUNDARY SOUTH OF THE FORECAST AREA. APPROACHING SHORTWAVE TROUGH AND INCREASING ISENTROPIC LIFT OVER THE FRONT WILL KEEP A CHANCE FOR ELEVATED THUNDERSTORMS THURSDAY NIGHT THEN CONTINUE ON FRIDAY WITH PASSAGE OF THE UPPER TROUGH. COOLER HIGH PRESSURE BUILDS IN SATURDAY. COOLER HIGH TEMPERATURES ARE EXPECTED FROM WEDNESDAY THROUGH SATURDAY IN THE 80S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1147 PM CDT SAT AUG 1 2015 VFR CONDITIONS ARE LIKELY THROUGH THE TAF PERIOD. SOUTH TO SOUTHWEST WINDS AT 10 TO 15 KTS ARE EXPECTED FOR MUCH OF THE DAY SUNDAY BEFORE TAPERING IN THE EVENING. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARJENBRUCH SHORT TERM...WOLTERS LONG TERM...53 AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
350 AM EDT SUN AUG 2 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 350 AM EDT SUN AUG 2 2015 07Z SFC ANALYSIS SHOWS HIGH PRESSURE IN PLACE OVER CENTRAL KENTUCKY. THIS IS HELPING TO KEEP THE SKY MOSTLY CLEAR ACROSS THE STATE...BUT A SMATTERING OF MID LEVEL CLOUDS ARE DRIFTING OVER EAST KENTUCKY AND OUT OF THE AREA ATTM. SIMILAR TO THE PAST FEW NIGHTS...AN INVERSION HAS SET UP WHILE GOOD RADIATIONAL COOLING IS UNDERWAY. THIS HAS LED TO ANOTHER NIGHT OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES WITH SOME UPPER 50S FOUND IN THE DEEPER SPOTS WHILE HILLTOPS ARE RUNNING IN THE MID 60S. WINDS REMAIN LIGHT TO CALM ACROSS EAST KENTUCKY WITH NOT MUCH EVIDENCE OF FOG OUT THERE YET. HOWEVER...AGAIN SIMILAR TO THE PAST FEW NIGHTS... EXPECT THE FOG TO FORM IN THE RIVER VALLEYS BEFORE DAWN ALONG WITH LOCALLY DENSE PATCHES. THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT AS A BROAD AREA OF TROUGHING CONTINUES OVER SOUTH CENTRAL CANADA AND DOWN INTO THE OHIO VALLEY ACROSS TO NEW ENGLAND. A WIGGLE AT THE CORE OF THE TROUGH TO THE NORTH WILL SEND A LARGE AMOUNT OF ENERGY INTO THE GREAT LAKES ON MONDAY ALONG WITH A MID LEVEL GRADIENT THAT TIGHTENS...RESULTING IN FASTER FLOW THROUGH THE OHIO VALLEY. GIVEN THE AGREEMENT ALOFT WILL FOLLOW A BLENDED SOLUTION WITH EMPHASIS ON THE HRRR AND NAM12 EARLY ON AND THE BROADER CONSENSUS LATER. SENSIBLE WEATHER WILL FEATURE ANOTHER PLEASANT DAY WITH FAIRLY LOW AND COMFORTABLE HUMIDITY LEVELS AND HIGHS GENERALLY IN THE MID 80S UNDER MOSTLY SUNNY SKIES. THIS WILL LEAD INTO ONE MORE NIGHT OF GOOD RADIATIONAL COOLING AND RIDGE TO VALLEY TEMPERATURE DIFFERENCES INTO MONDAY MORNING...ALONG WITH PATCHY VALLEY FOG TOWARDS DAWN. BY MONDAY...THOUGH...THE SFC PATTERN WILL CHANGE WITH A COLD FRONT PRESSING SOUTH THROUGH THE OHIO VALLEY AND TOWARD EAST KENTUCKY. THIS WILL LIKELY KICK OFF SHOWERS AND THUNDERSTORMS NORTH OF THE STATE THAT SHOULD HELP TO SPAWN ADDITIONAL STORMS TO THE SOUTH WITH TIME THROUGH THE DAY. ANY STORMS THAT MANAGE TO DEVELOP OUT AHEAD OF THE FRONT IN EAST KENTUCKY WILL HAVE THE POTENTIAL TO BECOME STRONG TO SEVERE OWING TO HIGH CAPES AND STRENGTHENING MID LEVEL WINDS. THE BEST CHANCES WILL BE OVER OUR NORTHERN ZONES CLOSER TO THE FRONT AND SPC HAS INDICATED A SLIGHT RISK FOR SEVERE STORMS THERE. WILL HIGHLIGHT THIS CONCERN IN THE FORTHCOMING HWO. STARTED WITH THE SHORTBLEND MODEL FOR THE T/TD/WIND GRIDS THROUGH THE DAY FOLLOWED BY THE SUPERBLEND INTO MONDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENTS TO TEMPERATURES THIS MORNING AND TONIGHT WITH RESPECT TO RIDGE AND VALLEY DIFFERENCES. AS FOR POPS...KEPT THEM LOW AND IN LINE WITH THE DRY GUIDANCE INTO MONDAY MORNING. DID GO A BIT HIGHER THAN THE MET AND MAV NUMBERS FOR MONDAY AFTERNOON TO ACCOUNT FOR THE POTENTIAL INTRUSION OF STORMS... ORGANIZED OR OTHERWISE...FROM THE NORTH BY EVENING. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 340 AM EDT SUN AUG 2 2015 THE EXTENDED FORECAST PERIOD BEGINS ON MONDAY NIGHT WITH THE UPPER LEVEL PATTERN MAINTAINING A RIDGE OVER THE WEST AND THE LONGWAVE TROUGH OVER THE EASTERN CONUS. A CLOSED LOW OVER THE HUDSON BAY AREA WILL GRADUALLY SHIFT OFF TO THE EAST THROUGH THE EXTENDED AS BY THURSDAY...A SERIES OF STRONGER TROUGHS COME ASHORE OVER THE WEST AS THE WESTERN RIDGE BEGINS TO WEAKEN A BIT AND SHIFT EAST. THIS THROUGH THE LAST PORTION OF THE EXTENDED WILL BE THE FORECAST CHALLENGE AS THE BASE OF THE EASTERN TROUGH SETS UP OVER THE MID MS VALLEY AND THROUGH KY. THE GFS AND EURO DOES ALIGN A BIT WITH THIS SOLUTION. CLOSER TO THE SURFACE...THE FRONT THAT HAS PASSED THROUGH ON MONDAY WILL LAG ACROSS NORTHERN KENTUCKY AS A STATIONARY BOUNDARY DEVELOPS. THIS AREA BECOMES A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT AS THE BOUNDARY SLIDES FURTHER SOUTH THROUGH THE DAY ON TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...NORTHWEST FLOW SETS UP OVER THE AREA AS A SERIES OF UPPER LEVEL WAVES TOPPLE OVER THE THE TOP OF THE WESTERN RIDGE AND TRACK SOUTHEAST INTO THE OH VALLEY. THE SUPER BLEND HAS THIS IN IT/S SOLUTION AS WELL WITH THE PATTERN FAVORABLE FOR NOCTURNAL THUNDERSTORMS AS WELL...ESPECIALLY IF THIS PATTERN FOR MCS/S REMAIN...WHICH SEEMS LIKELY BASED UPON THE GFS AND EURO SOLUTIONS . THUS WILL STAY CLOSE TO THE SUPER BLENDS SOLUTION WEDNESDAY THROUGH FRIDAY KEEPING HIGH CHANCE TO LIKELY POPS DURING THIS PERIOD. TOWARDS THE END OF THE EXTENDED ON FRIDAY AND SATURDAY...THE UPPER LEVEL PATTERN LOSES A BIT AMPLITUDE AND BECOMES MORE ACTIVE AS ANOTHER SHORTWAVE TAKES AIM AT THE OH VALLEY. HOWEVER...THE GFS AND EURO DO DIVERGE TOWARDS THE END OF THE EXTENDED. THUS...LACKING CONFIDENCE...WILL GO NEAR OR SLIGHTLY BELOW THE SUPER BLEND ON POPS. THE LINGERING TROUGH OVER THE EAST AND SAGGING SOUTH THROUGH THE EXTENDED WILL KEEP HIGHS AT OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. IN SHORT...THE WEDNESDAY THROUGH FRIDAY PERIOD SEEMS TO BE QUITE ACTIVE AND WET WITH THE END OF THE FORECAST POSSIBLY CONTINUING THIS TREND WITH A COOLING TREND AS WELL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 220 AM EDT SUN AUG 2 2015 A RIDGE OF HIGH PRESSURE WILL KEEP MOSTLY CLEAR SKIES AND LIGHT WINDS IN PLACE ACROSS THE AREA FOR THE TAF PERIOD. THE BULK OF ANY FOG THAT FORMS OVERNIGHT SHOULD BE CONFINED TO VALLEY FLOORS AND NEAR BODIES OF WATER. AS SUCH...THE MAJORITY OF THE TAF SITES SHOULD ALL REMAIN FREE OF FOG INTO SUNDAY MORNING. THE EXCEPTION MAY BE SME AND SYM...BOTH WITH THE SMALLEST DEWPOINT DEPRESSION CURRENTLY...WHERE A PERIOD OF MVFR FOG HAS BEEN FORECAST LATER TONIGHT. ADDITIONALLY...SOME IFR FOG WILL BE POSSIBLE LOCALLY IN THE DEEPER VALLEYS THROUGH EARLY SUNDAY MORNING. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD ALONG WITH LIGHT AND VARIABLE WINDS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...SHALLENBERGER AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
526 AM EDT SUN AUG 2 2015 .UPDATE... A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING. IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE 07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING WORDING IN THE HWO AND OTHER PRODUCTS. FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS 18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP LAPSE RATE ENVIRONMENT. && .PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015 SHORT TERM...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85 TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED AREAS. SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT, LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z. BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION. LONG TERM... UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER 12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80 DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S. A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID 50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY. MARINE... SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE SEVERE...PRODUCING WINDS OF 50 KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS TIME FRAME AS WELL. && .AVIATION...ISSUED 1147 PM EDT SAT AUG 1 2015 SW WINDS WILL INCREASE LATE SUN MORNING INTO SUN AFTERNOON DUE BOTH TO DIURNAL MIXING AND A STRENGTHENING WSW GRADIENT IN ADVANCE OF AN APPROACHING COLD FRONT. AN INFLUX OF INSTABILITY DURING THE DAY WILL LEAD TO INCREASING CHANCES FOR THUNDERSTORMS...TIMING OF WHICH CARRIES A GOOD DEAL OF UNCERTAINTY AT THIS EARLY STAGE IN THE FORECAST. FOR DTW...THE TWO MOST PROBABLE TIME PERIOD FOR THUNDERSTORM IMPACTING METRO WILL BE SUN AFTERNOON WITH THE INFLUX OF INSTABILITY AND LATE SUN EVENING/NIGHT AHEAD OF A COLD FRONT. //DTW THRESHOLD PROBABILITIES... * MEDIUM IN THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM NOON EDT TODAY THROUGH THIS EVENING FOR MIZ049. LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LHZ421-422-441>443. LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LCZ460. MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LEZ444. && $$ UPDATE.......JVC AVIATION.....SC SHORT TERM...JVC LONG TERM....SF MARINE.......SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
252 AM EDT SUN AUG 2 2015 .SHORT TERM...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85 TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED AREAS. SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT, LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z. BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION. && .LONG TERM... UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER 12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80 DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S. A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID 50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY. && .MARINE... SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE SEVERE...PRODUCING WINDS OF 50 KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS TIME FRAME AS WELL. && .AVIATION...ISSUED 1147 PM EDT SAT AUG 1 2015 SW WINDS WILL INCREASE LATE SUN MORNING INTO SUN AFTERNOON DUE BOTH TO DIURNAL MIXING AND A STRENGTHENING WSW GRADIENT IN ADVANCE OF AN APPROACHING COLD FRONT. AN INFLUX OF INSTABILITY DURING THE DAY WILL LEAD TO INCREASING CHANCES FOR THUNDERSTORMS...TIMING OF WHICH CARRIES A GOOD DEAL OF UNCERTAINTY AT THIS EARLY STAGE IN THE FORECAST. FOR DTW...THE TWO MOST PROBABLE TIME PERIOD FOR THUNDERSTORM IMPACTING METRO WILL BE SUN AFTERNOON WITH THE INFLUX OF INSTABILITY AND LATE SUN EVENING/NIGHT AHEAD OF A COLD FRONT. //DTW THRESHOLD PROBABILITIES... * MEDIUM IN THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LHZ421-422-441>443. LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LCZ460. MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LEZ444. && $$ SHORT TERM...JVC LONG TERM....SF MARINE.......SF AVIATION.....SC YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
121 AM EDT SUN AUG 2 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 323 PM EDT SAT AUG 1 2015 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALOFT OVER THE GREAT LKS BTWN CLOSED UPR LO OVER HUDSON BAY AND RDG ACROSS THE WRN CONUS. THE 12Z INL/GRB RAOBS SHOW A RELATIVELY DRY...CAPPED ENVIRONMENT...SO THE DIURNAL CU THAT POPPED UP HAVE BEEN FAIRLY SHALLOW WITH LARGE SCALE DEEP LYR QVECTOR DVGC/SUBSIDENCE DOMINATING. THE ONLY EXCEPTION IS OVER THE SE CWA E OF ESCANABA... WHERE RADAR INDICATES A FEW SHOWERS HAVE POPPED UP IN AN AREA CLOSER TO SOME DEEPER MSTR/LESS CAPPED ENVIRONMENT SHOWN ON THE 12Z APX RAOB AND WHERE LLVL CNVGC HAS BEEN ENHANCED BY LK BREEZE CNVGC. LOOKING UPSTREAM...A SHRTWV IS DROPPING SEWD THRU MANITOBA. THERE IS A BAND OF CLDS AND A FEW SHOWERS ASSOCIATED WITH AXIS OF HIER H7 RH IN AREA OF DPVA/H7-5 QVECTOR CNVGC MOVING INTO NW ONTARIO AHEAD OF THIS FEATURE. FARTHER AWAY...ANOTHER SHRTWV TOPPING WRN RDG IS MOVING ESEWD THRU SASKATCHEWAN. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON SHOWER/TS CHANCES ASSOCIATED MAINLY WITH THE TWO SHRTWVS NOTED ABOVE. TNGT...FIRST SHRTWV OVER MANITOBA IS FCST TO SLIDE SEWD THRU NW ONTARIO...WITH SHARPER DPVA/DEEP LYR QVECTOR CNVGC REMAINING TO THE N. ALTHOUGH THE LLVL FLOW IS FCST TO BACK TOWARD THE WSW TO THE S OF THE TRACK OF THIS DISTURBANCE...GUIDANCE INDICATES THE MOST IMPRESSIVE MSTR CNVGC WL REMAIN TO THE S IN WI...JUST BRUSHING THE BORDER. WITH THE DISCONNECT BTWN THIS MOISTENING TO THE S AND THE MORE IMPRESSIVE DYNAMIC SUPPORT REMAINING TO THE N...SUSPECT PCPN OVER MUCH OF UPR MI WL BE RATHER LIMITED BTWN AXES OF HIER POPS TO THE N AND ALONG THE SRN CWA/WI. INCRSG PWAT AND WSW FLOW WL TEND TO LIMIT THE DIURNAL TEMP DROP. SUN...DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV NOW MOVING THRU SASKATCHEWAN IS FCST TO ARRIVE OVER SLOW MOVING...WEAKENING COLD FNT THAT WL BE DROPPING SLOWLY SE ACRS THE CWA ATTENDANT TO FIRST DISTURBANCE EXITING INTO QUEBEC. SOME OF THE MODELS... ESPECIALLY THE 12Z GFS...ALSO HINT AT THE POTENTIAL FOR SOME ENHANCED UPR DVGC IN RRQ OF EXITING H3 JET MAX SUPPORTING THE FIRST DISTURBANCE AND EXIT REGION OF INCOMING JET STREAK ASSOCIATED WITH 2ND SHRTWV. SINCE THIS FORCING WL BE ARRIVING DURING PERIOD OF DAYTIME HEATING...SUSPECT SHOWERS/TS WL BECOME MORE NUMEROUS. SO TENDED TO BUMP POPS UP INTO THE LIKELY RANGE OVER MUCH OF THE CWA. WITH INCRSG H85-5 RH...THERE ARE CONCERNS ABOUT HOW MORE CLDS WL IMPACT SFC DESTABILIZATION. THE 12Z NAM SHOWS MUCAPE AS HI AS 2500- 3000 J/KG OVER THE SCENTRAL UNDER AREA OF STEEP H7-5 LAPSE RATES APRCHG 8C/KM PER THE THE 12Z GFS. ALTHOUGH MOST OF THE GUIDANCE SUGGESTS THE BULK OF THE PCPN WL FALL ON THE COOL SIDE OF THE FNT AND THERE WL BE A GOOD DEAL OF CLD COVER THAT SUG THE NAM FCST MUCAPE IS TOO HI...TS THAT FORM ALONG AND AHEAD OF THE FNT ESPECIALLY OVER THE SCENTRAL COULD TURN STRONG TO SEVERE WITH DEEP LYR SHEAR NEAR 40 KTS. IN FACT...THE NEW SPC OUTLOOK FOR SUN AS SHIFTED THE NRN EDGE OF MARGINAL RISK FOR SVR STORMS AS FAR N AS SRN MNM COUNTY. POPS WL DIMINISH FM THE NW BY MID/LATE AFTN FOLLOWING ARRIVAL OF SUBSIDENCE/MID LVL DRYING FOLLOWING THE SHRTWV. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 317 PM EDT SAT AUG 1 2015 IMPACTS...COOLER TEMPERATURES AND GREATER MOISTURE WILL HAVE A POSITIVE IMPACT ON FIRE WEATHER...AT LEAST SOMEWHAT LOWERING CONCERNS. A TROUGH/COLD FRONT AND ASSOCIATED PRECIPITATION WILL BE MOSTLY OUT OF THE AREA BY 00Z MON AS THE UPPER LOW THAT HAS BEEN SITTING OVER HUDSON BAY MOVES S INTO ONTARIO. AS THE LOW MOVES FROM EXTREME NRN ONTARIO AT 00Z MON TO THE ONTARIO/QUEBEC BORDER E OF LAKE SUPERIOR BY 00Z WED...THE CORE OF COLDEST AIR (850MB TEMPS OF 3-4C) WILL SLIDE INTO THE CWA. THE COLDER MID LEVELS WILL ALLOW FOR CONVECTIVE SHOWERS MON THROUGH TUE AS LOW LEVEL MOISTURE WILL BE INCREASED AND SUBTLE SHORTWAVES WILL BE MOVING THROUGH. SFC TEMPS WILL BE 7-10 DEGREES BELOW NORMAL WITH HIGHS IN THE MID 60S TO MID 70S. LOWS WILL BE FROM THE MID 40S INLAND TO THE MID 50S NEAR THE GREAT LAKES. TUE NIGHT THROUGH WED NIGHT WILL SEE A SFC RIDGE MOVE OVERHEAD...WITH NO PRECIP EXPECTED. TEMPS MAY BE A DEGREE OR TWO WARMER THAN TUE WITH HIGHS IN THE UPPER 60S TO LOW 70S. THERE WILL STILL BE ENOUGH MOISTURE TUE NIGHT TO KEEP TEMPS FROM FALLING INTO THE 30S AND WED NIGHT MAY SEE INCREASING CLOUD COVER AND RETURN FLOW TO KEEP TEMPS FROM FALLING TO CONCERNING LEVELS. THE REST OF THE PERIOD THU THROUGH SAT IS QUITE A BIT MORE UNCERTAIN IN EXACT DETAILS AS CONDITIONS LOOK TO BE DRIVEN LARGELY BY SHORTWAVES. SLIGHT CHANCES OF PRECIP EACH DAY AS GIVEN BY CONSENSUS GUIDANCE IS REASONABLE...SO WILL LEAVE THAT IN THE FORECAST. ALSO...TEMPERATURES LOOK TO REMAIN BELOW NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 120 AM EDT SUN AUG 2 2015 LOW-LEVEL DRY AIR WILL ALLOW VFR CONDITIONS TO CONTINUE OVERNIGHT AT KIWD/KCMX/KSAW. AN APPROACHING DISTURBANCE SHOULD BEGIN TO SPREAD SHRA AND SOME TS INTO THE AREA LATE TONIGHT WITH COVERAGE INCREASING DURING THE MORNING. CONFIDENCE IN TS OCCURRING AT ANY OF THE TERMINALS REMAINS LOW ENOUGH AT THIS POINT TO PRECLUDE A MENTION. VFR CONDITIONS SHOULD CONTINUE TODAY...BUT IF THERE IS ANY MDT/HVY RAINFALL...MVFR AND PERHAPS EVEN IFR CONDITIONS COULD OCCUR FOR A VERY BRIEF TIME. SHRA WILL END NW TO SE IN THE LATE AFTN/EARLY EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 323 PM EDT SAT AUG 1 2015 A LOW SPINNING OVER SOUTHERN HUDSON BAY WILL SWEEP A PAIR OF TROFS ACROSS LAKE SUPERIOR TONIGHT AND SUN. WINDS WILL GENERALLY BE IN THE 10-20KT RANGE. HI PRES FROM THE CANADIAN PRAIRIES WILL MOVE OVER THE REGION THROUGH MOST OF NEXT WEEK...KEEPING WINDS UNDER 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
358 AM CDT SUN AUG 2 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 354 AM CDT SUN AUG 2 2015 CHANCE FOR THUNDERSTORMS AND WARM TEMPERATURES TODAY...THEN OFF AND ON STORM CHANCES THROUGH TUESDAY...ARE THE PRIMARY FORECAST CONCERNS. SCATTERED THUNDERSTORMS POPPED UP EARLY THIS MORNING JUST AHEAD OF MID LEVEL WAVE DROPPING SOUTHEAST THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA AS PER WATER VAPOR AND RAP ANALYSIS. THIS WAVE WILL TRACK EAST OF OUR CWA EARLY IN THE DAYLIGHT HOURS...WITH SUBSIDENCE BEHIND WAVE KEEPING MUCH OF THE REST OF THE MORNING DRY. ANOTHER SHORTWAVE IN THE NORTHERN PLAINS INTO THE NORTHERN GREAT LAKES IS FORECAST TO SWEEP SOUTHEAST LATER TODAY...WITH SURFACE REFLECTION IN THE FORM OF A FRONT/WIND SHIFT SETTLING INTO NORTHEAST NEBRASKA THIS AFTERNOON. SURFACE DEW POINTS NEAR OR ABOVE 70F AHEAD OF THIS BOUNDARY ARE EXPECTED TO POOL IN EASTERN NEBRASKA AND WESTERN IOWA DURING PEAK HEATING. CONVERGENCE ALONG BOUNDARY SHOULD BE ENOUGH TO GET AT LEAST ISOLATED THUNDERSTORMS FIRING IN UNSTABLE ATMOSPHERE CHARACTERIZED BY MUCAPES OVER 2500 J/KG. MEANWHILE MODERATE MID LEVEL FLOW WILL HELP GENERATE NEAR 40KT OF BULK SHEAR WITH VECTORS NORMAL TO SURFACE CONVERGENCE...SUGGESTING DISCRETE AND ROTATING STORMS ARE LIKELY...SUPPORTING HAIL AND WIND POTENTIAL. ONLY MARGINAL RISK IN SPC OUTLOOK...AND CAN NOT ARGUE GIVEN EXPECTED SCANT COVERAGE. INITIATION LOOKS TO BE FARTHER NORTH THAN PREVIOUS MODEL RUNS WITH LATER ARRIVAL OF FRONT...MOSTLY LIKELY FIRING NEAR OR SOUTH OF A WAYNE TO ALBION LINE BETWEEN 3 AND 4 PM. EXPECT ISOLATED TO SCATTERED STORMS TO PROGRESS SOUTH THROUGH THE REST OF THE AFTERNOON INTO THE EVENING WITH FRONTAL BOUNDARY BEFORE EXITING SOUTHEAST NEBRASKA AND SOUTHWEST AROUND MIDNIGHT WHEN LAST OF 850 MOISTURE PLUME FINALLY DROPS SOUTH. AHEAD OF FRONT...TEMPERATURES ARE EXPECTED WELL INTO THE 90S ESPECIALLY IF CLOUD COVER FROM MORNING CONVECTION DISSIPATES AS EXPECTED. WILL LIKELY SEE SOME HEAT INDICES TOPPING 100 FOR A COUPLE OF HOURS THIS AFTERNOON. SHOULD SEE A DRY PERIOD AFTER MIDNIGHT TONIGHT...BUT LOWERING PRESSURES IN THE HIGH PLAINS WILL DRAW 850 MOISTURE BACK NORTH RATHER QUICKLY BY LATER MONDAY MORNING AS NORTHWEST MID LEVEL FLOW CONTINUES. WILL KEEP OUR SMALL POPS FOR OUR WESTERN CWA DURING THAT TIME PERIOD...WITH CHANCES/COVERAGE GRADUALLY INCREASING MONDAY AFTERNOON...BUT ESPECIALLY OVERNIGHT AND TUESDAY AS MAGNITUDE OF MOISTURE RETURN INCREASES. WILL MAINTAIN 30 TO 50 PERCENT STORM CHANCES DURING THE DAY TUESDAY. SEVERE THREAT SHOULD BE MINIMAL THEN AS INSTABILITY REMAINS WEAK DUE TO MUCH COOLER SURFACE TEMPERATURES. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 354 AM CDT SUN AUG 2 2015 UNSETTLED WEATHER PATTERN WITH OCCASIONAL RAIN/STORM CHANCES WILL CONTINUE THROUGH MUCH OF THE REST OF THE WEEK. MID LEVEL RIDGE IS FORECAST TO REMAIN FROM TEXAS WEST TO THE SOUTHWESTERN STATES AT LEAST THROUGH THURSDAY...KEEPING STORM TRACK ROLLING FROM THE CENTRAL/NORTHERN ROCKIES ACROSS THE PLAINS. SEVERAL SHORTWAVES COULD TRIGGER CONVECTION AT JUST ABOUT ANY TIME...WITH MORE POTENT WAVES MOVING THROUGH OUR AREA WEDNESDAY DURING THE DAY AND THURSDAY NIGHT AS PER ECMWF/GFS. WE SHOULD REMAIN ON THE COOL SIDE OF SURFACE FRONTAL SYSTEM...SO INSTABILITY PROGS SUGGEST SEVERE CHANCE WILL BE MINIMAL OVERALL WITH TEMPERATURES REMAINING IN THE 70S AND 80S MUCH OF THE WEEK. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1152 PM CDT SAT AUG 1 2015 NOT MUCH CHANGE FROM PREVIOUS THINKING. ISOLATED TSTMS POSSIBLE THE NEXT 24 HOURS BUT CHANCES TOO LOW TO MENTION IN TAFS AT THIS TIME. LOOK FOR VFR CONDITIONS WITH ANY CEILINGS EXPECTED TO BE ABOVE 8000 FEET. BEST CHANCE OF TSRA WOULD BE WITH WIND SHIFT SUNDAY AFTERNOON/EVENING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS ELKO NV
215 AM PDT SUN AUG 2 2015 .SYNOPSIS...MONSOON MOISTURE WILL INFLUENCE THE LOCAL REGION. PORTIONS OF NORTHERN AND CENTRAL NEVADA WILL RECEIVE RAIN SHOWERS AND THUNDERSTORMS TODAY. CONVECTION WILL LINGER THROUGH THE MIDDLE OF THE WEEK THEN EXPECT DRIER CONDITIONS. TEMPERATURES WILL BE NEAR NORMAL. && .SHORT TERM...TODAY THROUGH MONDAY. THE LONGWAVE PATTERN FEATURES RIDGING FROM NEW MEXICO TO WASHINGTON...WITH A PLUME OF MOISTURE OVER THE EASTERN GREAT BASIN. THERE IS A WEAK VORTEX EMBEDDED IN THE H5 FLOW...WHICH WILL ENABLE CONVECTION TO FLARE UP. THE CONVECTIVE TEMPERATURE FOR ELKO AT 21Z IS 82F...WITH PWS CLIMBING ABOVE .75 OF AN INCH. THE VORTEX IS MOVING AT A GLACIAL PACE AND WILL CONTINUE TO BE THE MAIN EVENT WITH THIS MONSOON EPISODE. SIMILAR TO YESTERDAY`S RUNS...THE NAM AND THE HRRR BOTH DEPICT MOIST AND UNSTABLE AIR IMPACTING THE LKN CWA THIS FORECAST PERIOD...WITH THE NAM BEING A BIT MORE AGGRESSIVE WITH THE QPF. THIS DISTURBANCE HAS MULTIPLE IMPULSES ROTATING ABOUT...AND THE MODELS SHOW TWO DISTINCT AREAS OF ACTIVITY...ONE PUSHING UP THROUGH CENTRAL NV...AND THE OTHER IMPACTING WESTERN NV. FOR THE POPS THIS PACKAGE ...USED AN ALL BLEND WITH TERRAIN ENHANCEMENT. AS TIME ELAPSES THIS PERTURBATION WILL SHIFT NORTHEASTWARD...SHIFTING THE QPF FOCUS TO THE NORTHERN ZONES NEAR THE IDAHO BORDER ON MONDAY. .LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. MODELS AGREE WELL ON LARGE PICTURE OF SOUTHWEST RIDGE FLATTENING AND DRIFTING EAST AS PACIFIC LOW MOVES INTO COAST. THIS COMBO PRODUCED A RELATIVELY DRY AIRMASS WITH SPOTTY MOISTURE. BEST CHANCES FOR PRECIP ARE EARLY IN THE PERIOD. TOOK OUT ONE PERIOD OF SHOWERS ONLY AND LEFT ALL POTENTIAL CONVECTION AS -TRW. AIRMASS DRIES AS WEEK PROGRESSES SO POPS AND THUNDER COVERAGE LOWER EACH PERIOD UNTIL LATE WHEN MODELS BEGIN TO DIVERGE AGAIN AND SOME CONVECTION MAY FIRE AGAIN. WARMING TREND WILL BE GENERAL AFTER A SLIGHT COOLING DUE TO CLOUDS AND CONVECTION. IT IS THE DOG DAYS...AFTER ALL. && .AVIATION...INCREASING SOUTHERLY MOISTURE WILL START A FEW VCSH AROUND KTPH AND KELY. BY LATE MORNING...EXPECTING VCTS AT ALL SITES WITH GUSTY ERRATIC WINDS. KWMC HAS A FEW ODD WIND SHIFTS LIKELY RELATED TO LOCAL VIRGA WHICH ARE STIRRING UP DUST (HZ) AND SO HAVE INCLUDED A TEMPO LOWER VISBY THIS MORNING. AS THE AFTERNOON WARMS...THIS SHOULD IMPROVE. STORMS/SHOWERS PERSIST INTO EARLY EVENING BEFORE WANING. A FEW SHOWERS IN CENTRAL AND EASTERN NEVADA COULD BE BRIEFLY HEAVY. && .FIRE WEATHER...THE NAM PLACES THE BEST LI`S SQUARELY OVER 454 THIS MORNING AND THEN SHIFTING TO THE NORTH THIS AFTERNOON. WHILE THE MODELS ARE IN GOOD AGREEMENT ABOUT THE GENERAL PATTERN...THE OVERALL CONFIDENCE HAS TO BE TEMPERED WITH THE LACK OF AGREEMENT IN THE SMALL DETAILS. GENERALLY EXPECTING A CONVECTIVE PATTERN TODAY...WETTING RAINS POSSIBLE. ANOTHER ROUND OF TSRA IS EXPECTED ON MONDAY. && .LKN WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 97/98/98/97
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1146 PM MDT SAT AUG 1 2015 .AVIATION... 06Z TAF CYCLE MESOSCALE MODELS DEPICT A BROAD AREA OF LIGHT TO MODERATE TS/SHRA PERSISTING INTO THE EARLY MORNING HOURS ACROSS CENTRAL NM FROM THE CONTDVD TO THE CENTRAL MT CHAIN. THIS SHOULD IMPACT MAINLY THE MIDDLE AND LOWER RIO GRANDE VALLEY...BUT COULD TRACK NORTHWARD TO AROUND SANTA FE. ANOTHER ROUND OF SCT TO NMRS TS/SHRA IS PROGGED TO IMPACT MUCH OF THE FORECAST AREA SUNDAY AFTN/EVENING WITH LOWEST PROBABILITIES AT KROW AND HIGHEST PROBABILITIES AT KGUP...KFMN...KSAF AND KLVS. 44 && .PREV DISCUSSION...952 PM MDT SAT AUG 1 2015... .UPDATE... HEAVY RAIN THREAT IS ENDING ACROSS N/C NEW MEXICO. MAINLY STRATIFORM TYPE OF EVENT WITH EMBEDDED CONVECTION DURING THE REST OF THE OVERNIGHT. LOOKS LIKE THE MAIN BAND ACROSS WESTERN/CENTRAL NM SHOULD SHIFT NORTHWARD DURING THE OVERNIGHT ALTHOUGH MAY JUST DIE OUT OVER CENTRAL AREAS. UPDATED POPS AND ENDED THE FLASH FLOOD WATCH. 50 && .PREV DISCUSSION...332 PM MDT SAT AUG 1 2015... .SYNOPSIS... AN ACTIVE MONSOON PATTERN IS EXPECTED TO PERSIST THROUGH THE REMAINDER OF THE WEEKEND. SLOW-MOVING STORMS CAPABLE OF PRODUCING TORRENTIAL RAINFALL AND FLASH FLOODING WILL REMAIN A CONCERN THIS AFTERNOON AND EARLY TONIGHT AND AGAIN SUNDAY...ESPECIALLY IN NORTH CENTRAL TO NORTHWEST PARTS OF NEW MEXICO. DRIER AND MORE STABLE AIR WILL ATTEMPT TO WORK WEST BEGINNING MONDAY...SIGNIFICANTLY LOWERING THE OVERALL COVERAGE OF STORMS AND FLASH FLOOD THREAT. FEWER STORMS WILL TRANSLATE INTO A DAY TO DAY WARMING TREND NEXT WEEK...AS WELL. && .DISCUSSION... SLOW-MOVING THUNDERSTORMS HAVE BEEN FOCUSED SQUARELY WITHIN THE FLASH FLOOD WATCH THUS FAR...WITH TREMENDOUSLY IMPRESSIVE RAINFALL RATES AS HIGH AS 3.3 INCHES PER HOUR AS MEASURED BY A PERSONAL WEATHER STATION ON THE NORTHWEST SIDE OF SANTA FE. GENERALLY 1 TO 3 INCH PER HOUR RATES LIKELY WITH JUST ABOUT ANY WELL-DEVELOPED STORM. MAY CONSIDER EXPANDING WATCH TO INCLUDE NE/EC AREAS ALTHOUGH COVERAGE EAST OF THE CENTRAL MOUNTAIN CHAIN SHOULD BE MORE ISOLATED TO SCATTERED. BUT RECENT RUNS OF THE HRRR CONTINUE TO SUGGEST SMALL MCS-LIKE FEATURE ORGANIZING BETWEEN CLAYTON AND CONCHAS DAM ROLLING TOWARD TUCUMCARI-LOGAN LATER THIS EVENING. THIS WOULD ONE AREA OF CONCERN GIVEN VERY HEAVY RAIN PAST TWO DAYS. WEAKNESS IN THE 500MB RIDGE NEAR THE NM/CO LINE ALSO A PLAYER BUT VERY DIFFICULT TO TRACK BEYOND 12 HOURS. OTHERWISE...WE`RE NOW MOVING INTO OUTFLOW BOUNDARY INTERACTION TIME OF DAY FOR VALLEY LOCATIONS CENTRAL/WEST. AIR MASS PLENTY MOIST WITH PRECIPITABLE WATER VALUES RANGING FROM 1.2 INCHES NW TO 1.5 INCHES NEAR THE NM/TX LINE. A POCKET OF RELATIVELY LOWER PWAT AIR /ONE 1 INCH OR SLIGHTLY LESS/ ANALYZED OVER THE LOWER RIO GRANDE VALLEY TO UPPER GILA HAS KEPT COVERAGE A BIT LOWER THERE BUT SUBTLE GRADIENTS. GOING INTO SUNDAY...VERY LITTLE CHANGE TO OVERALL ORIENTATION OF THE MONSOON PLUME BENEATH VERY WEAK STEERING CURRENTS. LEAST FAVORED REGION WILL CONTINUE TO BE THE SOUTHEAST CORNER...WHILE NC TO WC AREAS AGAIN FAVORED IN ADDITION TO THE SW THAT COULD SEE A BUMP IN COVERAGE AS COMPARED TO TODAY. THEREAFTER...WE HAVE BEGUN TO REFLECT A MARKED DECREASE IN STORM COVERAGE MONDAY AND ESPECIALLY TUESDAY THROUGH THURSDAY. THIS AS THE ANTICYCLONIC BELT OF WESTERLIES ELONGATES WEST-EAST AND SHIFTS SLIGHTLY SOUTH PLACING THE AREA UNDER A DRIER WESTERLY FLOW REGIME. THAT SAID...THE LAST DRYING EPISODE WAS POORLY HANDLED BY VIRTUALLY ALL THE NWP MODELS AS THEY TEND TO DRY OUR MOIST RESIDENT AIR MASS TOO QUICKLY. SO WE WILL PROCEED WITH A LITTLE PRUDENCE...BUT DEFINITELY TRENDING FORECAST TOWARD MUCH FEWER STORMS NEXT WEEK. IF THE MODELS ARE CORRECT WE WILL STRUGGLE TO DEVELOP A STORM ANYWHERE BY MID- WEEK. THAT IN TURN WILL ALLOW FOR A DAY TO DAY WARMING TREND. COULD SEE OUR NEXT BACKDOOR SURGE THUR/FRI THEN WE START THE MOISTENING CYCLE OVER. KJ && .FIRE WEATHER... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL FOCUS ON NORTHERN AND WESTERN NEW MEXICO TODAY AND SUNDAY...WITH FURTHER DEVELOPMENT EAST OF THE CENTRAL MOUNTAIN CHAIN. STEERING FLOW FROM THE UPPER LEVEL HIGH RECENTERING OVER THE SOUTHERN PORTION OF THE STATE WILL STEER SLOW MOVING NORTH TO NORTHEAST STORMS ACROSS NORTHWESTERN TO NORTH CENTRAL AREAS WHERE FLASH FLOODING WILL CONTINUE TO BE A MAJOR CONCERN THROUGHOUT THE REMAINDER OF THE WEEKEND. LOOK FOR A DRIER AIR MASS TO FILTER INTO THE STATE MONDAY THROUGH THURSDAY AS THE UPPER LEVEL HIGH OVER SOUTHERN NEW MEXICO SHIFTS WESTWARD FILTERING IN DRIER AIR FROM THE PACIFIC. SHOWER AND THUNDERSTORM ACTIVITY WILL DOWNTREND AS TEMPERATURES CREEP BACK TO NORMAL/ABOVE NORMAL READINGS. EXPECT HAINES VALUES TO INCREASE TO THE 5 AND 6 VALUES ALONG WITH DECREASING MIN RH VALUES. STORM ACTIVITY WILL BE LIMITED TO HIGHER TERRAIN AREAS AND ADJACENT LOWER ELEVATION AREAS. THE MOISTURE PLUME LOOKS TO MAKE ITS RETURN BY THE FOLLOWING WEEKEND WITH AN INCREASE IN WETTING PRECIPITATION CHANCES ACROSS THE WEST AND NORTH AS THE UPPER LEVEL HIGH STARTS TO SHIFT EASTWARD. EXPECT POOR VENT RATES ACROSS THE NORTH THE REMAINDER OF THE WEEKEND WITH IMPROVEMENTS BY MONDAY THROUGH THURSDAY. MIN RH VALUES WILL DROP INTO THE UPPER TEENS BY THE MIDWEEK BUT OVERNIGHT RECOVERIES WILL REMAIN GOOD. 32 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
145 AM EDT SUN AUG 2 2015 .SYNOPSIS... A WEAK FRONT WILL REMAIN STALLED ACROSS THE COASTAL CAROLINAS... PRODUCING ISOLATED SHOWERS AND THUNDERSTORMS NEAR THE COAST. THE FRONT SHOULD DISSIPATE ON MONDAY. BERMUDA HIGH PRESSURE WELL OFFSHORE WILL BUILD WESTWARD THIS WEEK. TEMPERATURES WILL REMAIN SEASONABLE TO SLIGHTLY ABOVE NORMAL THROUGH THE WEEKEND INTO NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1000 PM SATURDAY...FORECAST SOUNDINGS FROM BOTH THE NAM AND GFS SHOW A THIN LAYER OF UNSTABLE AIR AT THE TOP OF TODAY`S DEEP MIXED LAYER ACROSS THE PEE DEE REGION. THIS IS NOT A SITUATION I WOULD HAVE ANTICIPATED CONVECTION TO DEVELOP WITHIN GIVEN ELEVATED INSTABILITY BASED AROUND 6500 FEET AGL AND BONE-DRY AIR AT AND ABOVE 700 MB. NEVERTHELESS THERE ARE SHOWERS WITH LOCALLY HEAVY RAIN DEVELOPING ALONG THE I-95 CORRIDOR FROM FLORENCE NORTHWARD TO NEAR BINGHAM IN WESTERN DILLON COUNTY. INFRARED SATELLITE SHOWS ADDITIONAL MID- LEVEL CLOUD COVER EXTENDING NORTHWARD INTO ROBESON COUNTY NC...SO I HAVE TO AT LEAST CONSIDER THE POSSIBILITY FOR SHOWERS TO DEVELOP THIS FAR NORTH AS WELL. AT THE SURFACE HIGHER DEWPOINTS HAVE RETURNED WESTWARD INTO THE INTERIOR COASTAL PLAIN WITH 70S SHOWING UP AGAIN IN LUMBERTON... MARION AND FLORENCE. THIS MOISTURE MAY BE TOO THIN TO BE FEEDING THE CONVECTION DIRECTLY...AS THE SURFACE IS LIKELY DECOUPLED FROM THE ATMOSPHERE ALOFT. LATEST HRRR MODEL RUNS DO NOT REALLY SHOW THIS CURRENT ACTIVITY WELL...ALTHOUGH INTERESTINGLY THE 00Z NAM DOES. THE NAM MOVES THE SHOWERS EASTWARD TOWARD THE COAST...DISSIPATING THE CONVECTION BETWEEN 06-09Z NEAR MYRTLE BEACH. AT 500 MB THE CAROLINAS FORM THE BASE OF A BROAD TROUGH EXTENDING DOWN FROM HUDSON BAY CANADA. PLENTY OF DRY AIR AT AND ABOVE 700 MB SHOULD CONTINUE ON WESTERLY WINDS OVERNIGHT. HIGH PRESSURE OVER THE OHIO VALLEY WILL DRIFT EASTWARD INTO THE CENTRAL APPALACHIANS SUNDAY MORNING. THIS WILL NUDGE OUR FRONT OFF THE COAST INTO THE NEARSHORE WATERS BY DAYBREAK. MOISTURE TRAPPED WITHIN THE DECOUPLED BOUNDARY LAYER WILL REMAIN TRAPPED OVERNIGHT...AND WITH GOOD RADIATIONAL COOLING I ANTICIPATE PATCHY FOG WILL DEVELOP...ESPECIALLY EAST OF I-95 WHERE DEWPOINTS ARE HIGHEST. LOWS SHOULD FALL 70-74...WARMEST AT THE BEACHES. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... AS OF 300 PM SATURDAY...STATIONARY FRONT WILL REMAIN IN AREA SUNDAY BEFORE DISSIPATING IN PLACE ON MONDAY. MEANWHILE...A BROAD...FLAT-ISH H5 TROUGH WILL REMAIN ANCHORED IN PLACE OVER EASTERN CONUS. GUIDANCE STILL SHOWING PLENTIFUL DRY AIR ALOFT WHICH WILL LIMIT EXTENT OF CONVECTION DESPITE PRESENCE OF FRONTAL BOUNDARY AND THE OCCASIONAL SHORT WAVE THAT WILL DROP INTO THE BASE OF THE UPPER TROUGH. AIR ALOFT IS DRIEST INLAND...SO WILL SHOW A DECREASING GRADIENT IN POPS NW FROM THE COAST FOR BOTH DAYS. DUE TO OVERALL LIMITED MOISTURE ALOFT...WILL KEEP POPS CAPPED AT LOW CHANCE FOR THE IMMEDIATE COAST FOR BOTH DAYS...WITH FAR INLAND AREAS BEING POSSIBLY TOO DRY TO SEE ANY SIGNIFICANT RAINFALL. TEMPERATURES WILL REMAIN ABOVE CLIMO THROUGH THE SHORT TERM AND HEAT INDEX VALUES WILL LIKELY REACH AROUND A 100 OR SO BOTH AFTERNOONS. HOWEVER...HEAT ADVISORY CRITERIA IS NOT EXPECTED TO BE EXCEEDED. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 300 PM SATURDAY...WHAT LITTLE MOISTURE THERE WILL BE IN PLACE ON TUESDAY WILL BE POOLED UP ALONG THE COAST. MINOR RAIN CHANCES WILL BE FOCUSED THERE DURING AN OTHERWISE HOT AFTERNOON PROVIDED IN PART BY A VERY WEAK RIDGE ALOFT. RAIN CHANCES REMAIN SLOW ON WEDNESDAY AS THE FLOW ALOFT STAYS WEAK THOUGH THE SENSE OF RIDGING WEAKENS. SO WILL KEEP POPS MINIMIZED BUT SHOW THEM AREA- WIDE. RAIN CHANCES RAMP UP TO SCATTERED ON THURSDAY AS SOME WEAKLY CYCLONIC CURVATURE OVERSPREADS THE REGION AND A SURFACE PIEDMONT TROUGH TAKES SHAPE. ANOTHER LITTLE PIECE OF ENERGY WILL PROVIDE SOME LIFT ON FRIDAY WHICH MAY BE ANOTHER FAIRLY ACTIVE DAY. ON SATURDAY NOT ONLY WILL THERE BE CONTINUED DISTURBANCES IMPINGING UPON THE AREA FROM THE NORTHWEST BUT A COLD FRONT WILL ALSO BE MOVING INTO THE CAROLINAS. WEDNESDAY AND THURSDAY WILL BOTH SEE RATHER HOT AFTERNOONS WHEREAS THE INCREASE IN CLOUDS LATE IN THE PERIOD SHOULD TEMPER THINGS A BIT BACK TOWARDS CLIMO. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...EARLIER CONVECTION HAS DISSIPATED ACROSS THE CWA AND SKIES HAVE TRENDED CLEAR FOR THE MOST PART. WITH SUFFICIENT LOW- LEVEL MOISTURE...AN INVERSION AND LIGHT WINDS...PATCHY FOG IS FORECAST ACROSS THE INLAND TERMINALS WITH MVFR VSBY BETWEEN 09-12Z. MAIN WEATHER FEATURE FOR TODAY WILL BE THE STATIONARY FRONT/SEA BREEZE WHICH WILL TRIGGER ISOLATED SHOWERS OR TSTMS ACROSS THE COASTAL TERMINALS THIS AFTERNOON AND EVE. WILL KEEP VFR AT ALL THE TERMINALS...BUT CANNOT RULE OUT BRIEF MVFR VSBY/ CEILING IF CONVECTION OCCURS DIRECTLY OVER KILM/KCRE/KMYR. EXTENDED OUTLOOK...PREDOMINANTLY VFR THROUGH THE PERIOD WITH A SLIGHT CHANCE AFTERNOON SHRA/TSRA. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 PM SATURDAY...A FRONT IS STALLED ACROSS THE COASTAL PLAIN OF THE CAROLINAS THIS EVENING. HIGH PRESSURE OVER OHIO WILL DRIFT EAST INTO THE CENTRAL APPALACHIANS LATE TONIGHT. THIS SHOULD NUDGE THE FRONT EASTWARD AND INTO THE COASTAL WATERS LATE. SOUTH TO SOUTHWEST WINDS THIS EVENING AS HIGH AS 15 KNOTS IN THE CAPE FEAR AREA SHOULD DIMINISH TO LESS THAN 10 KNOTS AFTER MIDNIGHT...THEN TURN NORTHWESTERLY LATE AS THE FRONT PUSHES OFF THE COAST. THE PRIMARY WAVE SET IS A 7-SECOND SOUTHERLY SWELL...WITH A SMALLER 10-SECOND SOUTHEASTERLY SWELL SHOWING UP. THESE TWO WAVES WILL CONTINUE INDEPENDENT OF THE WIND OVERNIGHT...WITH COMBINED SEAS 2-4 FEET...HIGHEST OFFSHORE FROM CAPE FEAR. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 PM SATURDAY...A STALLED FRONT WILL DISSIPATE OVER THE EASTERN CAROLINAS ON MONDAY AS BERMUDA HIGH PRESSURE OFFSHORE EXTENDS BACK WEST ACROSS THE WATERS. WINDS WILL SETTLE BACK INTO A SWLY DIRECTION BY SUNDAY NIGHT AS THE FRONT WEAKENS AND DISSIPATES. A SMALL CRAFT ADVISORY MAY BE REQUIRED MONDAY AFTERNOON OR EVENING AS THE GRADIENT TIGHTENS WITH HIGH PRESSURE BUILDING WEST ACROSS THE WATERS. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 300 PM SATURDAY...WIND AND SEAS RELAX ON TUESDAY AS PIEDMONT TROUGHINESS PUSHES THE TIGHTER GRADIENT CAUSED BY THE BERMUDA HIGH FURTHER OUT TO SEA. THOUGH SOME SWELL ENERGY MAY REMAIN WE SHOULD DROP BELOW ADVISORY THRESHOLDS. THEREAFTER IT LOOKS LIKE PRETTY STANDARD FARE FOR JULY WITH A SOUTHWESTERLY WIND IN THE 10 TO 15 KT RANGE AND 2 TO 4 FT SEAS...HIGHEST OFFSHORE. && .TIDES/COASTAL FLOODING... AS OF 200 AM SATURDAY...MINOR COASTAL FLOODING IS POSSIBLE DURING THE NIGHT-TIME HIGH TIDE OVER THE NEXT COUPLE OF DAYS. THESE HIGHER THAN NORMAL TIDES ARE THE RESULT OF THE PERIGEAN SPRING TIDE AND A FULL MOON WHICH OCCURRED ON FRIDAY. DEPARTURES OF PLUS 1/2 TO 1 FOOT WILL BE ENOUGH TO PRODUCE A BRIEF PERIOD OF MINOR COASTAL FLOODING. THE RISK IS HIGHEST FOR PORTIONS OF THE LOWER CAPE FEAR RIVER TO INCLUDE DOWNTOWN WILMINGTON...WITH A LIKELY PROBABILITY. THE BEACHES WILL APPROACH THE THRESHOLD FOR MINOR COASTAL FLOODING AGAIN THIS EVE...BUT THIS WILL BE THE LAST TIME THIS LUNAR CYCLE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...REK LONG TERM...MBB AVIATION...MAC/RJD TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1204 AM EDT SUN AUG 2 2015 .SYNOPSIS... A WEAK FRONT WILL REMAIN STALLED ACROSS THE COASTAL CAROLINAS... PRODUCING ISOLATED SHOWERS AND THUNDERSTORMS NEAR THE COAST. THE FRONT SHOULD DISSIPATE ON MONDAY. BERMUDA HIGH PRESSURE WELL OFFSHORE WILL BUILD WESTWARD THIS WEEK. TEMPERATURES WILL REMAIN SEASONABLE TO SLIGHTLY ABOVE NORMAL THROUGH THE WEEKEND INTO NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1000 PM SATURDAY...FORECAST SOUNDINGS FROM BOTH THE NAM AND GFS SHOW A THIN LAYER OF UNSTABLE AIR AT THE TOP OF TODAY`S DEEP MIXED LAYER ACROSS THE PEE DEE REGION. THIS IS NOT A SITUATION I WOULD HAVE ANTICIPATED CONVECTION TO DEVELOP WITHIN GIVEN ELEVATED INSTABILITY BASED AROUND 6500 FEET AGL AND BONE-DRY AIR AT AND ABOVE 700 MB. NEVERTHELESS THERE ARE SHOWERS WITH LOCALLY HEAVY RAIN DEVELOPING ALONG THE I-95 CORRIDOR FROM FLORENCE NORTHWARD TO NEAR BINGHAM IN WESTERN DILLON COUNTY. INFRARED SATELLITE SHOWS ADDITIONAL MID- LEVEL CLOUD COVER EXTENDING NORTHWARD INTO ROBESON COUNTY NC...SO I HAVE TO AT LEAST CONSIDER THE POSSIBILITY FOR SHOWERS TO DEVELOP THIS FAR NORTH AS WELL. AT THE SURFACE HIGHER DEWPOINTS HAVE RETURNED WESTWARD INTO THE INTERIOR COASTAL PLAIN WITH 70S SHOWING UP AGAIN IN LUMBERTON... MARION AND FLORENCE. THIS MOISTURE MAY BE TOO THIN TO BE FEEDING THE CONVECTION DIRECTLY...AS THE SURFACE IS LIKELY DECOUPLED FROM THE ATMOSPHERE ALOFT. LATEST HRRR MODEL RUNS DO NOT REALLY SHOW THIS CURRENT ACTIVITY WELL...ALTHOUGH INTERESTINGLY THE 00Z NAM DOES. THE NAM MOVES THE SHOWERS EASTWARD TOWARD THE COAST...DISSIPATING THE CONVECTION BETWEEN 06-09Z NEAR MYRTLE BEACH. AT 500 MB THE CAROLINAS FORM THE BASE OF A BROAD TROUGH EXTENDING DOWN FROM HUDSON BAY CANADA. PLENTY OF DRY AIR AT AND ABOVE 700 MB SHOULD CONTINUE ON WESTERLY WINDS OVERNIGHT. HIGH PRESSURE OVER THE OHIO VALLEY WILL DRIFT EASTWARD INTO THE CENTRAL APPALACHIANS SUNDAY MORNING. THIS WILL NUDGE OUR FRONT OFF THE COAST INTO THE NEARSHORE WATERS BY DAYBREAK. MOISTURE TRAPPED WITHIN THE DECOUPLED BOUNDARY LAYER WILL REMAIN TRAPPED OVERNIGHT...AND WITH GOOD RADIATIONAL COOLING I ANTICIPATE PATCHY FOG WILL DEVELOP...ESPECIALLY EAST OF I-95 WHERE DEWPOINTS ARE HIGHEST. LOWS SHOULD FALL 70-74...WARMEST AT THE BEACHES. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... AS OF 300 PM SATURDAY...STATIONARY FRONT WILL REMAIN IN AREA SUNDAY BEFORE DISSIPATING IN PLACE ON MONDAY. MEANWHILE...A BROAD...FLAT-ISH H5 TROUGH WILL REMAIN ANCHORED IN PLACE OVER EASTERN CONUS. GUIDANCE STILL SHOWING PLENTIFUL DRY AIR ALOFT WHICH WILL LIMIT EXTENT OF CONVECTION DESPITE PRESENCE OF FRONTAL BOUNDARY AND THE OCCASIONAL SHORT WAVE THAT WILL DROP INTO THE BASE OF THE UPPER TROUGH. AIR ALOFT IS DRIEST INLAND...SO WILL SHOW A DECREASING GRADIENT IN POPS NW FROM THE COAST FOR BOTH DAYS. DUE TO OVERALL LIMITED MOISTURE ALOFT...WILL KEEP POPS CAPPED AT LOW CHANCE FOR THE IMMEDIATE COAST FOR BOTH DAYS...WITH FAR INLAND AREAS BEING POSSIBLY TOO DRY TO SEE ANY SIGNIFICANT RAINFALL. TEMPERATURES WILL REMAIN ABOVE CLIMO THROUGH THE SHORT TERM AND HEAT INDEX VALUES WILL LIKELY REACH AROUND A 100 OR SO BOTH AFTERNOONS. HOWEVER...HEAT ADVISORY CRITERIA IS NOT EXPECTED TO BE EXCEEDED. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 300 PM SATURDAY...WHAT LITTLE MOISTURE THERE WILL BE IN PLACE ON TUESDAY WILL BE POOLED UP ALONG THE COAST. MINOR RAIN CHANCES WILL BE FOCUSED THERE DURING AN OTHERWISE HOT AFTERNOON PROVIDED IN PART BY A VERY WEAK RIDGE ALOFT. RAIN CHANCES REMAIN SLOW ON WEDNESDAY AS THE FLOW ALOFT STAYS WEAK THOUGH THE SENSE OF RIDGING WEAKENS. SO WILL KEEP POPS MINIMIZED BUT SHOW THEM AREA- WIDE. RAIN CHANCES RAMP UP TO SCATTERED ON THURSDAY AS SOME WEAKLY CYCLONIC CURVATURE OVERSPREADS THE REGION AND A SURFACE PIEDMONT TROUGH TAKES SHAPE. ANOTHER LITTLE PIECE OF ENERGY WILL PROVIDE SOME LIFT ON FRIDAY WHICH MAY BE ANOTHER FAIRLY ACTIVE DAY. ON SATURDAY NOT ONLY WILL THERE BE CONTINUED DISTURBANCES IMPINGING UPON THE AREA FROM THE NORTHWEST BUT A COLD FRONT WILL ALSO BE MOVING INTO THE CAROLINAS. WEDNESDAY AND THURSDAY WILL BOTH SEE RATHER HOT AFTERNOONS WHEREAS THE INCREASE IN CLOUDS LATE IN THE PERIOD SHOULD TEMPER THINGS A BIT BACK TOWARDS CLIMO. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AS OF 23Z...LATEST SFC ANALYSIS SHOWS A STATIONARY FRONT DRAPED BETWEEN THE INLAND AND COASTAL TERMINALS. CONVECTION FIRED UP ALONG THIS BOUNDARY MAINLY NEAR AND OVER KILM THIS AFTERNOON. PLENTY OF LLVL MOISTURE AVAILABLE FOR THE TONIGHT/OVERNIGHT PERIOD TRAPPED BENEATH AN INVERSION AND WITH LIGHT WINDS ALSO EXPECTED CANNOT RULE OUT MVFR CONDITIONS DUE TO FOG DEVELOPMENT...ESPECIALLY KILM. WILL MAKE MENTION AFTER 08Z IN ALL TERMINALS FOR FOG AND MVFR CONDITIONS. VFR TO RETURN AFTER 12Z AND SUNDAY WILL BE SOMEWHAT LIKE TODAY WITH THE STATIONARY FRONT DRAPED ACROSS THE REGION AND THE CHANCE OF ISOLATED SHOWER OR THUNDERSTORM POSSIBLE DURING THE DAY. WILL KEEP VFR IN ALL TERMINALS BUT CANNOT RULE OUT A BRIEF MVFR IN VSBY/CEILING IF CONVECTION OCCURS OVER A TERMINAL. EXTENDED OUTLOOK...PREDOMINANTLY VFR THROUGH THE PERIOD WITH A SLIGHT CHANCE AFTERNOON SHRA/TSRA. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 PM SATURDAY...A FRONT IS STALLED ACROSS THE COASTAL PLAIN OF THE CAROLINAS THIS EVENING. HIGH PRESSURE OVER OHIO WILL DRIFT EAST INTO THE CENTRAL APPALACHIANS LATE TONIGHT. THIS SHOULD NUDGE THE FRONT EASTWARD AND INTO THE COASTAL WATERS LATE. SOUTH TO SOUTHWEST WINDS THIS EVENING AS HIGH AS 15 KNOTS IN THE CAPE FEAR AREA SHOULD DIMINISH TO LESS THAN 10 KNOTS AFTER MIDNIGHT...THEN TURN NORTHWESTERLY LATE AS THE FRONT PUSHES OFF THE COAST. THE PRIMARY WAVE SET IS A 7-SECOND SOUTHERLY SWELL...WITH A SMALLER 10-SECOND SOUTHEASTERLY SWELL SHOWING UP. THESE TWO WAVES WILL CONTINUE INDEPENDENT OF THE WIND OVERNIGHT...WITH COMBINED SEAS 2-4 FEET...HIGHEST OFFSHORE FROM CAPE FEAR. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 PM SATURDAY...A STALLED FRONT WILL DISSIPATE OVER THE EASTERN CAROLINAS ON MONDAY AS BERMUDA HIGH PRESSURE OFFSHORE EXTENDS BACK WEST ACROSS THE WATERS. WINDS WILL SETTLE BACK INTO A SWLY DIRECTION BY SUNDAY NIGHT AS THE FRONT WEAKENS AND DISSIPATES. A SMALL CRAFT ADVISORY MAY BE REQUIRED MONDAY AFTERNOON OR EVENING AS THE GRADIENT TIGHTENS WITH HIGH PRESSURE BUILDING WEST ACROSS THE WATERS. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 300 PM SATURDAY...WIND AND SEAS RELAX ON TUESDAY AS PIEDMONT TROUGHINESS PUSHES THE TIGHTER GRADIENT CAUSED BY THE BERMUDA HIGH FURTHER OUT TO SEA. THOUGH SOME SWELL ENERGY MAY REMAIN WE SHOULD DROP BELOW ADVISORY THRESHOLDS. THEREAFTER IT LOOKS LIKE PRETTY STANDARD FARE FOR JULY WITH A SOUTHWESTERLY WIND IN THE 10 TO 15 KT RANGE AND 2 TO 4 FT SEAS...HIGHEST OFFSHORE. && .TIDES/COASTAL FLOODING... AS OF 200 AM SATURDAY...MINOR COASTAL FLOODING IS POSSIBLE DURING THE NIGHT-TIME HIGH TIDE OVER THE NEXT COUPLE OF DAYS. THESE HIGHER THAN NORMAL TIDES ARE THE RESULT OF THE PERIGEAN SPRING TIDE AND A FULL MOON WHICH OCCURRED ON FRIDAY. DEPARTURES OF PLUS 1/2 TO 1 FOOT WILL BE ENOUGH TO PRODUCE A BRIEF PERIOD OF MINOR COASTAL FLOODING. THE RISK IS HIGHEST FOR PORTIONS OF THE LOWER CAPE FEAR RIVER TO INCLUDE DOWNTOWN WILMINGTON...WITH A LIKELY PROBABILITY. THE BEACHES WILL APPROACH THE THRESHOLD FOR MINOR COASTAL FLOODING AGAIN THIS EVE...BUT THIS WILL BE THE LAST TIME THIS LUNAR CYCLE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...REK LONG TERM...MBB AVIATION...MAC TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1222 AM CDT SUN AUG 2 2015 .UPDATE... ISSUED AT 1221 AM CDT SUN AUG 2 2015 A LINE OF THUNDERSTORMS CONTINUED MOVING SOUTH OUT OF MANITOBA INTO NORTHEASTERN NORTH DAKOTA AND NORTHERN MINNESOTA. THIS CONVECTION WAS ASSOCIATED WITH AN UPPER LEVEL VORT ENERGY IMPULSE MOVING THROUGH THE NORTHWEST FLOW ALOFT IN THAT AREA...ALONG WITH A SURFACE FRONT MOVING SOUTH ACROSS NORTH DAKOTA. THE WESTERN EDGE OF THE CONVECTION WAS AS FAR WEST AS BOTTINEAU COUNTY...AND HAVE INCREASED COVERAGE OF SLIGHT CHANCE OF THUNDERSTORMS DUE TO THE MORE ISOLATED NATURE OF THE CELLS ON THE WESTERN EDGE OF THIS DISTURBANCE. BULK SHEAR IS STILL QUITE HIGH...WITH THE BEST MIXED LAYER CAPE OVER EASTERN NORTH DAKOTA. EXPECT RAIN SHOWERS/THUNDER TO SKIM THE BOTTINEAU/TURTLE MOUNTAIN AREA...AND INTO RUGBY/TOWNER - MAINLY EAST OF MINOT. SHORT TERM MODELS DIFFER ON HOW LONG CONVECTION WILL LINGER...BUT ALL AGREE ON ACTIVITY REMAINING UNTIL AROUND 09Z (4 AM CDT). THUS HAVE A MENTION OF ISOLATED STORMS UNTIL THEN. WILL RE-EVALUATE LATER TO SEE WHICH OF THE MODELS HANDLED CONVECTION THE BEST. UPDATE ISSUED AT 853 PM CDT SAT AUG 1 2015 CONVECTION THREAT HAS ENDED OVER SOUTHEAST NORTH DAKOTA. FOCUS NOW SHIFTS TO THE NORTH. ISOLATED CONVECTION OVER THE PAST HOUR OR SO OVER SOUTHERN MANITOBA/SASKATCHEWAN IS BEGINNING TO PUSH INTO NORTHERN NORTH DAKOTA. AN ISOLATED THUNDERSTORM DEVELOPED OVER BOTTINEAU COUNTY OVER THE PAST HOUR. ML CAPES AROUND 1000-1500 J/KG WITH 50-60 KNOTS OF BULK SHEAR REMAIN OVER THE FAR NORTH CENTRAL INTO THE TURTLE MOUNTAINS AND A FEW MORE STORMS CAN NOT BE RULED OUT OVER THE NEXT FEW HOURS. THE THREAT FOR SEVERE WEATHER WILL BE MINIMAL...AND WILL SHIFT FARTHER EAST AS THE EVENING PROGRESSES. THIS IS CURRENTLY COVERED IN THE GOING FORECAST. WE DID BUMP UP WINDS OVER THE WEST AND CENTRAL THIS EVENING A NICE FALL-RISE PRESSURE BUBBLE WAS NOTED OVER THE NORTHWEST ASSOCIATED WITH THE SURFACE LOW OVER NORTHWEST NORTH DAKOTA. SOME 40 MPH WIND GUSTS WERE REPORTED OVER THE FAR NORTHWEST WITH THE 8 PM OBSERVATIONS. THE COUPLET WILL TRACK SOUTHEAST ACROSS THE FORECAST AREA TONIGHT. BUT AS WINDS DECOUPLE THIS EVENING WITH THE SETTING SUN...THE STRONGER GUST POTENTIAL WILL ALSO SUBSIDE. UPDATE ISSUED AT 543 PM CDT SAT AUG 1 2015 UNSTABLE AIRMASS REMAINS OVER SOUTHEAST NORTH DAKOTA. HOWEVER...THERE HAS BEEN ENOUGH CIN TO PRECLUDE THUNDERSTORM DEVELOPMENT FROM CU FIELD THAT DEVELOPED EARLIER THIS AFTERNOON. CAPE REMAINS HIGH BUT SHEAR IS DECREASING. WILL KEEP A MENTION OF THUNDER THROUGH 7 PM AS A FEW CU REMAIN OVER CENTRAL AND EASTERN PORTIONS OF DICKEY/LAMOURE COUNTIES. TO THE NORTHWEST...A LINE OF CU HAS DEVELOPED ALONG THE COLD FRONT MOVING INTO NORTHWEST NORTH DAKOTA. SUFFICIENT BULK SHEAR ALONG THE INTERNATIONAL BORDER BUT DEEP MOISTURE IS LACKING...ESPECIALLY RIGHT ALONG AND BEHIND THE FRONT WITH MUCH DRIED DEWPOINTS OVER THE FAR NORTHWEST AND INTO NORTHEAST NORTH DAKOTA. COULD STILL BE SOME SHOWER/THUNDERSTORM ACTIVITY HERE LATER THIS EVENING AS THE FRONT MOVES INTO CENTRAL AND EASTERN NORTH DAKOTA. THIS IS COVERED IN THE CURRENT FORECAST WITH A MENTION OF SHOWERS ACROSS THE FAR NORTH CENTRAL...AND INTO THE TURTLE MOUNTAINS AREA THIS EVENING. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 223 PM CDT SAT AUG 1 2015 SEVERE CONVECTIVE POTENTIAL ACROSS THE JAMES RIVER VALLEY THIS AFTERNOON HIGHLIGHTS THE SHORT TERM FORECAST. VISIBLE SATELLITE IMAGERY THROUGH 1920 UTC CONTINUES TO DEPICT A DEVELOPING CUMULUS FIELD BETWEEN JAMESTOWN...STEELE AND EDGELEY. THE 13-18 UTC HRRR ITERATIONS HAVE ALL DEPICTED CONVECTIVE INITIATION FOR THIS AREA BY 21 UTC IN AN ENVIRONMENT CHARACTERIZED BY ML CAPE AROUND 2000-3000 J/KG AND DEEP LAYER SHEAR OF 30-40 KTS. WITH A SHORTWAVE EVIDENT JUST UPSTREAM ON WATER VAPOR...CONVECTIVE POTENTIAL IS INCREASING ALONG WITH THE THREAT FOR LARGE HAIL AND DAMAGING WINDS IN AN ENVIRONMENT SUPPORTIVE OF SUPERCELLS...AND HAVE THUS ADDED SEVERE WORDING TO THE JAMES RIVER VALLEY FOR THIS AFTERNOON. EXPECT THE THREAT TO QUICKLY EXIT INTO THE GRAND FORKS CWA BY 00 UTC. LATER THIS EVENING A COLD FRONT WILL PROPAGATE FROM NORTHWEST TO SOUTHEAST ACROSS NORTH DAKOTA...YIELDING A COOLER BUT STILL SEASONABLE SUNDAY FOR EARLY AUGUST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 240 PM CDT SAT AUG 1 2015 NORTHWEST FLOW ALOFT THROUGH MONDAY NIGHT. DRY CONDITIONS EXPECTED WITH SURFACE HIGH PRESSURE FIRMLY IN PLACE ACROSS THE DAKOTAS. DEEP UPPER LOW MOVING SOUTH INTO THE GREAT LAKES REGION SUNDAY WILL PUSH A BACK DOOR COLD FRONT INTO THE NORTHERN PLAINS AND KEEP TEMPERATURES RELATIVELY COOL IN THE 70S TO LOW 80S MONDAY AND TUESDAY. A MORE ACTIVE PATTERN MATERIALIZES MID TO LATE NEXT WEEK WHEN OUR FLOW TRANSITIONS TO MORE ZONAL ALLOWING SEVERAL EMBEDDED WAVES TO MOVE THROUGH THE REGION. BEST THUNDERSTORM CHANCES WILL BE CONFINED TO THE SOUTH AND WEST INITIALLY...UNTIL LATER IN THE WEEK WHEN A CLOSED MID LEVEL CROSSES THE ALBERTA ROCKIES AND MOVES INTO NORTH DAKOTA FRIDAY. TEMPERATURES DO NOT RECOVER MUCH FROM EARLY IN THE WEEK...AND LOOK TO REMAIN BELOW AVERAGE FOR EARLY AUGUST WED-FRI (70S TO LOW 80S). && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1221 AM CDT SUN AUG 2 2015 VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. AT 05Z A COLD FRONT EXTENDED FROM BETWEEN KDIK/KISN TO BETWEEN KMOT/KN60 TO NEAR GRAND FORKS. THIS FRONT WILL CONTINUE MOVING SOUTH EARLY THIS MORNING...REACHING THE SOUTH DAKOTA BORDER BY/BEFORE SUNRISE. NORTHERLY WINDS 10-15 KNOTS ALONG/BEHIND THE FRONT SHOULD LOWER TO BELOW 10 KNOTS WITHIN AN HOUR OR TWO OF FRONTAL PASSAGE. THUNDERSTORMS ALONG THE FRONT EXTENDED FROM LAKE SUPERIOR ACROSS NORTHERN MINNESOTA AS FAR WEST AS BOTTINEAU. EXPECT THESE CONVECTIVE CELLS TO REMAIN EAST OF MINOT. WILL NOT MENTION IN KJMS JUST YET AS EXPECT CONVECTION TO BE EAST OF KJMS AS THE FRONT MOVES SOUTH. AFTER 15Z/16Z NORTH WINDS SHOULD INCREASE AS SURFACE WINDS LINK TO THE MIXING WINDS ALOFT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JV SHORT TERM...AYD LONG TERM...NH AVIATION...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1140 PM CDT SAT AUG 1 2015 .UPDATE... ISSUED AT 1133 PM CDT SAT AUG 1 2015 QUICK UPDATE... THUNDERSTORM CELLS DROPPING FROM MANITOBA INTO FAR NORTHEAST ND AND FAR NORTHWEST MN AT THIS TIME... WITH LARGE HAIL INDICATED IN CELLS FROM HUMBOLDT...ACROSS CARIBOU INTO THE LAKE OF THE WOODS AREA. EXPECT THESE STORMS TO PERSIST A BIT INTO THE OVERNIGHT AS THEY PUSH FURTHER EAST-SOUTHEAST. SOME STRONG TSTM OUTFLOW IS ALSO POSSIBLE WITH THESE STORMS... AS 0-6KM SHEAR APPROACHES 50KTS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 325 PM CDT SAT AUG 1 2015 TWO SEPARATE SHORTWAVES WILL AFFECT THE REGION THIS EVENING/OVERNIGHT. THE FIRST WAVE WILL BRING A SEVERE THREAT TO A PORTION OF SE ND AND WC MN. CURRENT SFC ANALYSIS INDICATES A WEAK SFC LOW ACROSS SOUTH-CENTRAL NORTH DAKOTA...WITH A WARM FRONTAL FEATURE EXTENDING TO THE SOUTHEAST. DEWPOINT VALUES ALONG THESE FEATURES HAVE POOLED INTO THE MID-UPPER 60S...LEADING TO MLCAPE 3000-3500 J/KG. AS THIS SYSTEM EVOLVES AND PROPAGATES TOWARD THE FA...ANTICIPATE THUNDERSTORM DEVELOPMENT ACROSS THE FAR SOUTHERN FA. 0-6KM BULK SHEAR 35-40 KNTS COMBINED WITH THE STRONG INSTABILITY WILL LEAD TO SEVERE STORMS...ALTHOUGH COVERAGE SHOULD REMAIN ISOLATED GIVEN CONVECTIVE TEMPS NEAR 90F (SOME CAPPING ISSUES). THIS ACTIVITY WILL MOVE OUT OF THE REGION BY EARLY EVENING. DID ADD T+ (SEVERE STORMS POSSIBLE) ACROSS FAR SE ND WHERE CONFIDENCE IS HIGHER IN THUNDER DEVELOPMENT (LOW LEVEL CONVERGENCE WILL BE MAXIMIZED...AND THE HRRR HAS CONSISTENTLY INDICATED DEVELOPMENT FROM RUN TO RUN). NEXT UP WILL BE THE NORTHERN FA THIS EVENING INTO THE OVERNIGHT HOURS...AS A STRONGER UPPER WAVE BRINGS A COLD FRONT THROUGH THE REGION. THIS ACTIVITY WILL ENCOUNTER WEAK INSTABILITY (MUCAPE 500-1000 J/KG) BUT VERY STRONG DEEP LAYER SHEAR (60+ KNOTS)...ALONG WITH MID-LEVEL WINDS IN EXCESS OF 50 KNTS. THE 18Z HRRR IS INDICATING A SMALL BOW ECHO WITH SFC WIND GUSTS 50-55 KNOTS 02Z-05Z. OF COURSE THAT IS JUST ONE POSSIBLE SOLUTION...BUT IT DOES SPEAK TO THE POTENTIAL OF WHAT COULD OCCUR ACROSS THE NORTHERN FA THIS EVENING AND OVERNIGHT. THIS FORCING MAY ALSO INTERACT WITH INCREASING INSTABILITY FROM THE SOUTH AFTER MIDNIGHT...WHICH MAY BE ENOUGH FOR A FEW STRONGER STORMS INTO THE OVERNIGHT HOURS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM CDT SAT AUG 1 2015 THIS PERIOD STARTS OFF WITH A BROAD UPPER LEVEL LOW OVER ONTARIO AND COOL HIGH PRESSURE IN PLACE AT THE SURFACE OVER SASKATCHEWAN AND THE DAKOTAS. THE WEATHER WILL BE DRY AND SLIGHTLY COOLER THAN AVERAGE FOR THE START OF THE WEEK. HOWEVER...A WEAK UPPER LEVEL WAVE WILL MOVE EAST IN THE WEAK UPPER FLOW...UNDERCUTTING A WESTERN U.S. RIDGE BY MID WEEK. THE MODELS HAVE HAD A HARD TIME WITH THIS SYSTEM. PREVIOUS RUNS HAD MORE INSTABILITY AND MUCH MORE OF A PRECIPITATION SIGNAL AREA-WIDE. THE LATEST GFS HAS BEST LIFT/INSTABILITY IN THE FAR SOUTH ON WEDNESDAY NIGHT. SO...CONFIDENCE IS DECREASING IN WEDNESDAYS SYSTEM. ANOTHER WEAK WAVE WILL AFFECT PRIMARILY THE SOUTH ON THURSDAY...BUT AGAIN...THIS ONE HAS TRENDED SOUTHWARD. HOWEVER...FRIDAYS SYSTEM LOOKS TO BE THE WAVE THAT HAS THE MOST AGREEMENT REGARDING TRACK AND COULD BRING WIDESPREAD PRECIP TO THE AREA. WITH PLENTY OF UNCERTAINTY ON THESE WAVES...TOO EARLY TO TALK ABOUT SEVERE POTENTIAL. PRECIPITATION CHANCES EXIST INTO SATURDAY AS WELL AND WILL DEPEND ON SPEED OF UPPER LOW. TEMPERATURES LOOK TO BE COOL FOR MUCH OF THIS PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING) ISSUED AT 1135 PM CDT SAT AUG 1 2015 GENERALLY FAIR SKIES THROUGH THE EVENING AND OVERNIGHT ACROSS THE SOUTHERN FA... WITH WIND SHIFT TURNING FROM THE NORTHWEST THROUGH THE MORNING HOURS ALONG WITH SOME MID LEVEL CLOUDS. ACROSS THE NORTHERN FA... A WEAK COLD FRONT DROPPING SOUTHWARD ACROSS THE CANAM BORDER WILL DEVELOP SCATTERED THUNDERSTORMS AND AN ISOLATED MVFR CIGS AND VSBYS WITH OCCASIONAL LARGE HAIL IN STRONG TO SEVERE STORMS... ALG AND NORTH OF A CANDO TO GRAND FORKS AND BEMIDJI LINE. SCATTERED SHOWERS SHOULD PERSIST INTO THE MORNING HOURS ACROSS NORTHERN MN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...GUST SHORT TERM...TG LONG TERM...KNUTSVIG AVIATION...GUST
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1241 AM CDT SUN AUG 2 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE A FEW HIGH CLOUDS ACROSS EXTREME SOUTHEAST PORTIONS OF THE CWA LATE TONIGHT. EXPECT VFR CONDITIONS TO PREVAIL THE REST OF TONIGHT THROUGH EARLY SUNDAY MORNING. CONVECTION IS EXPECTED TO DEVELOP ACROSS THE COASTAL SECTIONS SUNDAY AND MOVE INLAND AS A WEAK 500MB INVERTED TROUGH MOVES ACROSS NORTHEAST MEXICO SUN AFTERNOON. EXPECT SHOWERS IN THE VICINITY OF LOCAL AERODROMES THROUGH 18Z SUNDAY AND THUNDERSTORMS IN THE VICINITY OF LOCAL AERODROMES 18Z THROUGH 24Z SUNDAY AS A RESULT. && .PREV DISCUSSION... /ISSUED 700 PM CDT SAT AUG 1 2015/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...DISSIPATING SHOWERS APPROACHING SOUTH PADRE ISLAND HAVE A LOW PROBABILITY OF IMPACTING KBRO THROUGH 9 PM. NO THUNDER IS ASSOCIATED WITH THIS SMALL AREA OF RAIN AS IT DRIFTS SOUTHWEST AT AROUND 15 MPH. CEILINGS ASSOCIATED WITH THIS AREA OF RAIN AND OTHER CLOUDS THROUGH MUCH OF DEEP SOUTH TEXAS ARE IN THE VFR RANGE WITH NO MVFR OR IFR EXPECTED IN THE NEXT 24 HOURS. PROBABILITIES FROM HIGH RESOLUTION MODELS CONTINUES TO INDICATE LOW PROBABILITIES OF ANY AVIATION IMPACTS FROM LOW CLOUDS OR LOW VISIBILITIES. WINDS WILL CONTINUE TO BE LIGHT AND VARIABLE TONIGHT BECOMING SOUTHEAST LIGHT TO MODERATE SUNDAY WITH GUSTS BETWEEN 15 AND 20 KNOTS IN THE LATE MORNING AND AFTERNOON. PREV DISCUSSION... /ISSUED 304 PM CDT SAT AUG 1 2015/ SHORT TERM /NOW THROUGH SUNDAY NIGHT/...SATELLITE IMAGES THIS AFTERNOON INDICATE MOSTLY MID TO HIGH CLOUDS NEAR THE COAST WITH A SCATTERED CU FIELD ACROSS THE WESTERN PORTIONS OF THE DEEP SOUTH TEXAS. THE LATEST BRO RADAR CONTINUES TO SHOW SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE GULF OF MEXICO WATERS...20 TO 60 NAUTICAL MILES EAST OF PADRE ISLAND. THE WEAK 500MB LOW/INVERTED TROUGH ACROSS THE WESTERN GULF OF MEXICO THIS AFTERNOON WILL CONTINUE TO PROVIDE LOW TO MID LEVEL MOISTURE OVER THE WESTERN GULF OF MEXICO AND ALONG THE LOWER TEXAS COAST. THE 12Z BRO SOUNDING SHOWS PRECIPITABLE WATERS OF 1.97 INCHES. THIS WILL SUPPORT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL SECTIONS OF DEEP SOUTH TEXAS FOR THE REST OF THIS AFTERNOON WITH DRIER AIR FARTHER INLAND. THE LATEST HRRR KEEPS MOST...IF NOT ALL...OF THE CONVECTION OFFSHORE AND SOUTH OF THE RIO GRANDE RIVER NOW THROUGH THIS EVENING. CONVECTION IS EXPECTED TO DECREASE IN COVERAGE THIS EVENING BEFORE REDEVELOPING OVER THE GULF WATERS AFTER MIDNIGHT. THE WEAK MID TO UPPER LEVEL FEATURE IS EXPECTED TO MOVE WESTWARD ACROSS NORTHEAST MEXICO TONIGHT INTO SUNDAY. LINGERING MOISTURE COMBINED WITH DAYTIME HEATING WILL PROVIDE A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE LOWER PORTIONS OF THE RIO GRANDE VALLEY ON SUNDAY. LONG TERM /MONDAY THROUGH SATURDAY/...THE MAIN ISSUE IN THE LONGER RANGE PERIOD WILL BE THE HEAT POTENTIAL ACROSS THE RGV. THE GFS AND ECMWF BOTH RESTRENGTHEN THE 500 MB RIDGING IN PLACE OVER THE SOUTH CENTRAL PLAINS STATES NEXT WEEK. THIS WILL RESULT IN A DRIER AND MORE STABLE AIRMASS OVER DEEP SOUTH TX ONCE AGAIN YIELDING ABOVE NORMAL TEMPS THROUGH DAY 7. THE DEEPER LAYER MOISTURE VALUES REMAIN PRETTY LIMITED ACROSS THE AREA THROUGH THE EXTENDED RANGE PERIOD. ONLY A VERY SHALLOW MOISTURE LAYER MAY PERSIST ON THROUGH DAY 7 WHICH WILL ALLOW FOR SOME LOW LEVEL CLD COVER TO PERSIST ON THROUGH THE PERIOD. OTHERWISE EXPECT NEAR ZERO RAIN CHANCES TO PREVAIL. THE GFS MEX AND ECMWF MODEL HIGH/LOW TEMPS THROUGH THE PERIOD ARE IN PRETTY DECENT AGREEMENT. SO WILL GO WITH A GENERAL 50/50 BLEND OF THE TWO MODEL SETS FOR TEMPS. THE GFS MEX POPS STILL TRY TO TREND TOWARDS SOME SLGT CHC POPS LATE IN THE PERIOD. I BELIEVE THAT THIS IS MODEL TREND IS BEING SKEWED HIGH DUE TO CLIMO INFLUENCES. SO WILL GO CLOSER TO THE ECMWF POPS IN THE LONG TERM. MARINE...NOW THROUGH SUNDAY NIGHT...BUOY020 IS CURRENTLY REPORTING SEAS OF 1 FOOT WITH NORTH WINDS NEAR 4 KNOTS. LIGHT AND VARIABLE WINDS WILL PREVAIL ACROSS THE LOWER TEXAS COASTAL WATERS NOW THROUGH SUNDAY NIGHT DUE TO A WEAK PRESSURE GRADIENT ACROSS THE WESTERN GULF. WINDS AND SEAS WILL BE HIGHER IN AND NEAR THUNDERSTORMS ASSOCIATED WITH THE WEAK MID TO UPPER LEVEL DISTURBANCE OVER THE WESTERN GULF. MONDAY THROUGH THURSDAY...THE PGF WILL START OF NEXT WEEK FAIRLY WEAK ALLOWING FOR FAIRLY LOW WINDS AND SEAS TO PREVAIL. THE PGF WILL THEN START TO STRENGTHEN SOMEWHAT STARTING LATE TUES/WED AS A SURFACE LOW DEVELOPS OVER THE SOUTHERN PLAINS STATES. THIS MAY PUSH THE WINDS AND SEAS UP LATE IN THE MARINE FORECAST PERIOD TO POSSIBLY PRODUCE SOME SCEC CONDITIONS WED/THURS. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 61/64
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
853 AM MST SUN AUG 2 2015 .SYNOPSIS... CONSIDERABLE DRYING WILL OCCUR TODAY AND INTO THE MIDDLE OF NEXT WEEK WITH STORM CHANCES CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX. TEMPERATURES WILL GRADUALLY WARM AND WILL HOVER NEAR NORMAL OR SLIGHTLY ABOVE THROUGH NEXT WEEK. && .DISCUSSION... WHAT A STARK CONTRAST COMPARED TO THE LAST COUPLE OF DAYS. EVEN THOUGH YESTERDAY ENDED BEING SOMEWHAT QUIET OVER MOST OF THE AREA...TODAY WILL BE EVEN MORE QUIET. LITTLE MOISTURE IS LEFT FROM PHOENIX WESTWARD AND WATER VAPOR IMAGERY CONTINUES TO SHOW EVEN DRIER AIR WORKING IN FROM THE SOUTH. SOME LINGERING LOW LEVEL MOISTURE SHOULD ALLOW FOR SOME SPORADIC AFTERNOON CU ACROSS THE DESERTS...BUT DRIER AIR MIXING DOWN WILL QUICKLY DROP SURFACE DEW POINTS FROM THE CURRENT MID 50S TO LOWER 60S DOWN CLOSER TO 50 DEGREES BY LATE AFTERNOON. SLIGHT CHANCES OF SHOWERS AND MAYBE A FEW THUNDERSTORMS WILL BE POSSIBLE OVER HIGHER TERRAIN AREAS EAST OF PHOENIX...BUT AM NOT ANTICIPATING MUCH ACTIVITY TODAY. TEMPERATURES WILL AGAIN TOP OUT NEAR 110 DEGREES OR SLIGHTLY WARMER OVER THE DESERTS OF SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA...WHILE HIGHS SHOULD PEAK OUT IN A 104-108 RANGE OVER THE SOUTH-CENTRAL ARIZONA DESERTS. THE CURRENT FORECAST LOOKS TO BE ON TRACK AND NO SIGNIFICANT CHANGES ARE NEEDED. && .PREVIOUS DISCUSSION... PRETTY QUIET RADAR EARLY THIS MORNING SAVE FOR A SWATH OF SHOWERS AND ISOLATED THUNDERSTORMS MOVING INTO NAVAJO AND APACHE COUNTIES. FAIRLY WEEK SOUTH-SOUTHWEST STEERING FLOW THROUGH A MIXED 850-300MB LAYER OF 10-15 KTS HAS ALLOWED FOR SUFFICIENT RAINFALL AMOUNTS TO ACCUMULATE ACROSS THE HIGHER ELEVATIONS OF GILA COUNTY THIS EVENING. MOST OF THE FOCUS OF MONSOON ACTIVITY WAS ACROSS EASTERN PIMA...GILA AND GRAHAM COUNTIES SATURDAY EVENING. PER CURRENT SATELLITE IMAGERY A TONGUE OF DRY AIR IS INFILTRATING SOUTH-CENTRAL ARIZONA MOVING THE DRY AIRMASS IN FROM THE WEST AND KICKING THE MOISTURE OUT THE DOOR TO THE EAST. AN UPPER LEVEL SHORTWAVE TROUGH IS THE CULPRIT PUSHING IN FROM THE WEST BRINGING SOUTHERLY FLOW INTO THE DESERT SOUTHWEST ALONG WITH DRIER AIR /06Z SUNDAY MIXING RATIOS NEARLY 10 G/KG LESS THAN 24 HOURS AGO/. A BROAD REGION OF DIFFLUENCE STILL RESIDES ACROSS WESTERN ARIZONA THROUGH EAST CENTRAL NEW MEXICO ALONG THE MOGOLLON RIM...AND AS EXPECTED THIS WOULD BE THE REGION OF FAVORABLE STORM ACTIVITY TODAY DURING THIS TRANSITION PERIOD. CURRENT MESOSCALE HIGH RES MODEL THAT IS IN GOOD AGREEMENT APPEARS TO BE THE HRRR FOR TODAY`S ACTIVITY. PER LATEST GFS AND ECMWF...AMONG THEIR ENSEMBLE COUNTERPARTS ARE SLOW TO MOVE A CUT OFF LOW FORMING IN THE EASTERN PACIFIC TO THE EAST OVER THE NEXT 5-6 DAYS. THIS WILL ALLOW THE RIDGE OF HIGH PRESSURE TO FLOAT TO THE WEST AND FLATTEN OUT...WITH A WEAK SOUTHWESTERLY STEERING FLOW SETTLING IN THROUGH MOST OF THE UPCOMING WEEK. AN OPTIMUM TIME FOR TEMPERATURES TO GRADUALLY RISE EVEN IF SLIGHTLY ABOVE SEASONAL AVERAGE...THOUGH AT THIS TIME NONE OF THE GUIDANCE BRINGS TEMPERATURES TO THE 110 DEGREE MARK FOR PHOENIX BUT THERE ARE A FEW DAYS WITH 110 OR GREATER OUT ALONG THE LOWER COLORADO RIVER...GENERALLY A WARMER LOCALE. ALL THIS BEING SAID...STORM CHANCES OVER THE NEXT 5-6 DAYS ARE SUBSTANTIALLY LESS THAN THE PREVIOUS DAYS ACROSS THE LOWER DESERTS. A SLIGHT CHANCE WILL BE KEPT FOR HIGHER ELEVATIONS NORTH AND EAST OF PHOENIX DUE TO THE NATURE OF MOUNTAIN ACTIVITY. THE NEXT FLOW REVERSAL APPEARS TO SHAPE UP BY LATE WEEK INTO NEXT WEEKEND AS MOISTURE MAKES A RETURN APPEARANCE AND WIND FLOW RETURNS TO A SOUTH-SOUTHEASTERLY DIRECTION. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... DRIER AND MORE STABLE AIR WILL TRANSITION INTO THE AREA FROM THE WEST-SOUTHWEST...SHUNTING THE BEST CHANCES FOR ANY STORMS TODAY INTO THE MOUNTAINS NORTH-EAST-SOUTHEAST OF THE PHX AREA. SKY COVERAGE TO RANGE FROM SKC TO SCT WITH ANY DAYTIME CU GNLY AOA 10KFT. WINDS WILL FOLLOW TYPICAL SUMMERTIME PATTERNS...WITH SLIGHTLY ENHANCED WESTERLY AFTN AND EVENING FLOW FOR KIPL AND THE PHX AREA TERMINALS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... DRIER AND STABLE WESTERLY FLOW ALOFT WILL PRODUCE PARTLY CLOUDY SKIES TUESDAY AND WEDNESDAY...WITH LOWER MINIMUM RELATIVE HUMIDITY GENERALLY IN THE 10 TO 15 PERCENT RANGE. MOISTURE WILL GRADUALLY INCREASE OVER SOUTHWEST AND SOUTH CENTRAL ARIZONA THURSDAY THROUGH SATURDAY...INTO THE 15 TO 25 PERCENT RANGE...WITH A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS IN SOUTHERN GILA COUNTY. AFTERNOON SOUTHWEST WINDS 10 TO 15 MPH. FAIR RECOVERY AT NIGHT. MOISTURE WILL BEGIN TO THIN TOWARDS THE END OF THE WEEK...WITH DAILY STORM CHANCES PERSISTING FOR THE HIGHER TERRAIN AND DAYTIME HUMIDITIES STILL RANGING FROM 10 TO 20 PERCENT IN THE LOWER DESERTS AND 30 TO 35 PERCENT FOR THE HIGHER TERRAIN. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...KUHLMAN PREVIOUS DISCUSSION...DEWEY AVIATION...NOLTE FIRE WEATHER...NOLTE/VASQUEZ
AREA FORECAST DISCUSSION
NWS RENO NV
303 AM PDT SUN AUG 2 2015 .SYNOPSIS... PLENTY OF MOISTURE WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TODAY TO NORTHEAST CALIFORNIA AND WESTERN NEVADA, WITH LIGHTNING AND LOCALLY HEAVY RAINFALL THE MAIN THREATS FROM THUNDERSTORMS. THUNDERSTORM COVERAGE IS EXPECTED TO WANE MONDAY THROUGH WEDNESDAY AS DRIER AIR WORKS INTO THE REGION. AFTERNOON TEMPERATURES WILL REMAIN AROUND AVERAGE THIS WEEK. && .SHORT TERM... MAIN CHANGES TO THE SHORT TERM FORECAST TO CUT BACK THUNDERSTORMS TO MORE DIURNALLY-DRIVEN (AFTERNOON AND EVENING) TIMING FOR MONDAY AND TUESDAY. THE COMPLEX OF SHOWERS AND THUNDERSTORMS WHICH MOVED THROUGH WESTERN NEVADA LAST EVENING HAS PUSHED OFF TO WEST OF THE SIERRA CREST THIS MORNING, WITH JUST A FEW SHOWERS LEFT OVER NORTH OF HIGHWAY 70 IN NORTHEAST CALIFORNIA. LOOKING DOWN INTO SOUTHERN AND CENTRAL NEVADA, ANOTHER UPPER DISTURBANCE IS WORKING NORTH PER INFRARED SATELLITE INDICATIONS OF COOLING CLOUD TOPS OVER ESMERALDA AND NYE COUNTIES. THE IMPULSE IS PROGGED BY THE 08Z HRRR TO FIRE UP SHOWERS SOUTH OF HIGHWAY 50 IN THE NEXT FEW HOURS, WHICH MAKES SENSE GIVEN THE APPROACHING COOLING CLOUD TOPS AND THE RATHER MOIST ATMOSPHERE. ELSEWHERE SOUTH AND WEST OF AN ALTURAS TO RENO TO FALLON LINE, A FEW STRAY SHOWERS OR EVEN A VERY ISOLATED LIGHTNING STRIKE CANNOT BE RULED OUT THIS MORNING. THIS AFTERNOON, THE HRRR AND NAM HAVE TRENDED TOWARDS FOCUSING THE BEST SHOT AT CONVECTION NORTH OF HIGHWAY 50 AHEAD THE INCOMING UPPER DISTURBANCE. THOSE MODELS HAVE ALSO REDUCED THEIR AFTERNOON PRECIPITATION FORECAST FOR MONO AND MINERAL COUNTIES AS THEY FOCUS THE FORCING FARTHER NORTH. HOWEVER, PLENTY OF MOISTURE REMAINS FOR AREAS SOUTH OF HIGHWAY 50 AND THE NAM SHOWS SOME WESTERLY WINDS IN THE AFTERNOON WHICH COULD PROVIDE FOCUS FOR SCATTERED DEEP CONVECTION. THEREFORE, I HAVE HELD OFF ON REDUCING POP WHOLESALE FOR MONO/MINERAL COUNTIES FOR THIS AFTERNOON AND EVENING. AS FAR AS THE NATURE OF THUNDERSTORMS THIS AFTERNOON, THE RELATIVELY HIGH MOISTURE BROUGHT INTO THE REGION SINCE YESTERDAY (PWAT NEAR 1" IN RENO CURRENTLY) SHOULD ALLOW FOR MODERATE TO HEAVY RAIN UNDER STORM CORES DESPITE SOME MODEST STORM MOTION OF UP TO 10-15 KTS. IN FACT, IF STORMS GET HUNG UP ON TERRAIN OR TRAIN OVER THE SAME AREA LOCALIZED FLOODING WILL BE POSSIBLE GIVEN THE HEAVY RAIN POTENTIAL WITH THE HIGH PWATS. LATE TONIGHT, AS THE UPPER DISTURBANCE CONTINUES TO TREK SLOWLY THROUGH NORTHERN NEVADA, SHOWERS AND A FEW THUNDERSTORMS WILL BE POSSIBLE IN THE BASIN AND RANGE AND OVER EXTREME NORTHEAST CALIFORNIA. MONDAY AND TUESDAY, THUNDERSTORM COVERAGE SHOULD WANE AS PWATS FALL OFF SOME WITH DRIER WESTERLY FLOW IMPINGING ON THE REGION. ALSO, WITH WEAKER UPPER FORCING AS COMPARED TO THE PAST COUPLE DAYS, STORMS WILL NEED TO RELY ON DAYTIME HEATING TO DEVELOP. THEREFORE, I HAVE CUT BACK THE THUNDERSTORM TIMING TO MORE DIURNALLY-DEPENDENT TIMES. STORM FLOW WILL INCREASE FOR MONDAY AND TUESDAY, WHICH MAY BRING HYBRID WET/DRY STORMS BACK INTO PLAY VERSUS THE WETTER STORMS EXPECTED FOR TODAY. SEE THE FIRE WEATHER SECTION FOR MORE ON THE CONCERNS WITH CONVECTION ON MONDAY AND TUESDAY. SNYDER .LONG TERM...WEDNESDAY THROUGH SATURDAY... FEW CHANGES MADE TO THE LONG TERM WITH THE FIRST PART OF THE UPPER LOW EXITING ON WEDNESDAY WITH THE MAIN LOW NOW FORECAST TO MOVE THROUGH FRIDAY INTO SATURDAY. HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS NORTH OF SUSANVILLE AND GERLACH WEDNESDAY WITH RESIDUAL MOISTURE AND INSTABILITY. AREAS FURTHER SOUTH WILL BE TOO STABLE. A BREAK IS EXPECTED THURSDAY BEFORE THE MAIN LOW MOVES IN LATE FRIDAY INTO SATURDAY. THIS LOW WILL TRACK FURTHER SOUTH AND IT WILL BE COOLER ALOFT WITH IT. WHILE MOISTURE WILL NOT BE GREAT, THE COOLER TEMPS ALOFT WILL BE CONDUCIVE FOR CONVECTION AT LEAST NORTH OF HIGHWAY 50. ADDED THUNDERSTORMS FRIDAY AND FRIDAY NIGHT FOR THESE AREAS. STRONG FORCING WILL CONTINUE OVERNIGHT WITH ANOTHER ROUND OF CONVECTION POSSIBLE. THE STORMS MAY CONTINUE INTO SATURDAY AS THE UPPER LOW MOVES ACROSS. TEMPERATURES WILL REMAIN NEAR TO A LITTLE BELOW AVERAGE FOR EARLY AUGUST. THE WARMEST TEMPERATURES ARE LIKELY THURSDAY BETWEEN SYSTEMS WITH HIGHS ONLY IN THE 80S FRIDAY AND SATURDAY FOR WESTERN NV AND 70S IN THE SIERRA. A TYPICAL AFTERNOON ZEPHYR IS EXPECTED WEDNESDAY BEHIND THE FIRST SYSTEM ONLY TO SEE THE FLOW BACK TO THE SOUTH AHEAD OF THE MAIN UPPER LOW. THE WINDS WILL BE LIGHTER WITH PERHAPS A LIGHT AFTERNOON ZEPHYR FOR THURSDAY. WALLMANN && .AVIATION... SCATTERED THUNDERSTORMS HAVE MOVED WEST OF THE SIERRA CREST EARLY THIS MORNING. ABUNDANT MID AND HIGH CLOUDS ALONG WITH ISOLATED SHOWERS REMAIN, BUT CONDITIONS WILL STILL BE VFR. A FEW THUNDERSTORMS ARE POSSIBLE THIS MORNING 13-18Z NEAR KMMH AND KHTH, ABOUT A 10% CHANCE. FOR THE AFTERNOON, EXPECT STORMS TO FIRE AROUND 19Z AND LAST THRU 02Z NEAR HIGHWAY 395 AND 05Z FURTHER EAST. CHANCE OF IMPACT AT KTRK/KTVL/KRNO/KCXP ABOUT 35% WITH SMALL HAIL AND SFC WND GUSTS TO 40 KTS. LESSER CHANCE FOR KMMH THIS AFTERNOON AT AROUND 25%. EXPECT VFR CONDITIONS OVERNIGHT WITH LESS STORMS FOR MONDAY. ONLY A 20% CHANCE OF STORMS AFFECTING TERMINALS AND LESS THAN 10% FOR KTRK/KTVL. WALLMANN && .FIRE WEATHER... ISOLATED SHOWERS CONTINUE AFTER THE SCATTERED STORMS FROM EARLIER THIS MORNING HAVE MOVED WEST OF THE SIERRA CREST. MORE STORMS ARE EXPECTED TO FIRE THIS AFTERNOON AND WITH MOISTURE UP, STORMS ARE EXPECTED TO BE WET. SOME AREAS ALREADY RECEIVED UP TO 3/4" OF RAIN YESTERDAY FROM STORMS AND THE SAME IS POSSIBLE TODAY. EVEN SO, A FEW SMALL FIRES OUTSIDE STORM CORES ARE POSSIBLE FROM LIGHTNING STRIKES. A LITTLE DRIER MONDAY AS SOUTHWEST FLOW INCREASES. IT ALSO APPEARS TO STABILIZE A BIT WITH ONLY ISOLATED THUNDERSTORMS AT BEST EXCEPT OVER MINERAL COUNTY. STORMS WILL BE MORE HYBRID WET/DRY, BUT WITH LOWER COVERAGE DO NOT THINK ANY WATCHES/WARNINGS ARE NECESSARY. TUESDAY MORNING INTO TUESDAY NIGHT A PIECE OF THE UPPER LOW OFF THE COAST WILL MOVE THROUGH AND THE FORCING WILL BE STRONG MOISTURE REMAINS WITH PW AROUND 0.6", BUT LAPSE RATES ALOFT ARE ACTUALLY SOMEWHAT STABLE. THERE ARE DIFFERENCES IN THE MODELS WITH THE EC/GFS DRIER AND MORE STABLE WHILE THE NAM SHOWS A SLUG OF MOISTURE NEAR 600 MB THAT WOULD BE ENOUGH TO GENERATE CONVECTION AS EARLY AS TUESDAY MORNING. IF THE NAM IS RIGHT, A DECENT DRY LIGHTNING OUTBREAK IS POSSIBLE FOR WESTERN NV, WHILE IT WOULD BE ONLY ISOLATED AT BEST WITH THE EC/GFS. LEANING TOWARD THE EC/GFS FOR NOW, BUT WILL BE MONITORED. THE NEXT CONCERN WOULD BE WHEN THE UPPER LOW FINALLY MOVES ONSHORE LATER THURSDAY NIGHT INTO FRIDAY. IT WILL BE MORE UNSTABLE WITH COOLER TEMPS ALOFT WITH ONLY MARGINAL MOISTURE. MORE DRY LIGHTNING IS POSSIBLE WITH THIS LOW AS WELL. WALLMANN && .REV WATCHES/WARNINGS/ADVISORIES... NV...NONE. CA...NONE. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
936 AM MDT SUN AUG 2 2015 .UPDATE... ISSUED AT 926 AM MDT SUN AUG 2 2015 LIGHT PRECIPITATION COMING TO AN END OVER THE FAR NE CORNER WITH THE HELP OF HIGH DEWPOINTS AND THE EDGE OF AN UPPER LEVEL JET. EXPECT DEVELOPMENT TO CONTINUE OVER THE MOUNTAINS WITH INCREASED MOISTURE AND AN UPPER LEVEL WAVE. INCREASED POPS OVER THE PLAINS WITH THE CLOUD COVER AND A FRONT NORTH OF NEBRASKA THAT IS STILL PROGGED TO TRACK INTO NE COLORADO BY THIS EVENING/EARLY MONDAY MORNING. LATEST RUN OF THE HRRR HAS SOME GUSTY WINDS MOVING SOUTH OUT OF WY FROM OUTFLOWS PROVIDED BY STORM DEVELOPMENT TO THE NORTH. MAINTAINED SLIGHT CHANCE INTO THE EVENING. MAIN THREATS STILL LOOK TO BE MODERATE TO HEAVY RAIN AND GUSTY WINDS WITH THE STORMS. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 340 AM MDT SUN AUG 2 2015 WATER VAPOR IMAGERY SHOWING ELONGATED UPPER RIDGE FROM THE PACIFIC NORTHWEST AND EXTENDING SOUTHEAST INTO COLORADO WITH A WEST TO NORTHWEST FLOW ALOFT OVER NORTHERN COLORADO. OVERALL NOT MUCH CHANGE IN MOISTURE LEVELS OVER EASTERN COLORADO WITH INTEGRATED PW VALUES JUST UNDER AN INCH OVER THE FRONT RANGE AND A BIT HIGHER OVER WESTERN COLORADO. THERE IS QUITE A BIT OF MIDDLE AND HIGH LEVEL CLOUD COVER NOW OVER THE SOUTHERN 2/3 OF COLORADO. THERE IS AN UPPER WAVE OVER SOUTHERN NEVADA WHICH WILL SLOWLY ROTATE INTO WESTERN COLORADO TONIGHT WHICH WILL AID IN ADDITIONAL MOISTURE AND WEAK QG LIFT. INITIALLY...SHOWER ACTIVITY WILL BE CONFINED TO THE MOUNTAINS BY EARLY AFTERNOON BUT SLOWLY SNEAK OUT ONTO THE PLAINS DURING THE LATE AFTERNOON. A WEAK MID LEVEL CAPPING INVERSION REMAINS WHICH WILL LIMIT CONVECTION ON THE PLAINS WITH OVERALL SURFACE BASED CAPE VALUES UNDER 700J/KG. APPEARS A WEAK FRONTAL BOUNDARY WILL APPROACH THE FAR NE PLAINS TOWARDS EVENING WITH A SLIGHT CHANCE4 OF THUNDERSTORMS SPARKING THERE. TEMPERATURES EXPECTED TO BE VERY SIMILAR TO SATURDAYS READINGS BUT MAYBE A DEGREE OR TWO DOWN CLOSER TO THE FRONT RANGE WITH MORE CLOUD COVER. WILL KEEP LOW POPS IN THE MOUNTAINS THROUGH THE NIGHT AS THE UPPER TROF WILL APPROACH WITH AIDED MOISTURE AND LIFT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 318 AM MDT SUN AUG 2 2015 MID-LEVEL SHORTWAVE TROUGH IS STILL FORECAST TO SWING NEWRD ACROSS N- CNTRL/NERN CO MON AFTERNOON/EVENING...THEN SEWRD ACRS ERN WY/WRN SD/WRN NE ON TUE AS THE UPPER RIDGE BUILDS OVER THE 4-CORNERS RGN. SHOULD SEE SCATTERED TO NUMEROUS SHWRS/T-STORMS IN THE HIGH COUNTRY DURING THE DAY MON AND SCATTERED T-STORMS ON THE PLAINS DURING THE AFTERNOON AND EVENING HOURS. SYSTEM APPEARS MOST ROBUST ON THE NAM AND ONLY LACK LUSTER ON THE ECMWF. NAM GENERATES SOME RIDICULOUSLY HIGH CAPES ACRS THE NERN CORNER OF CO IN THE VCNTY OF A STALLED SFC FRONTAL ZONE STRADDLING THE NERN CORNER OF THE STATE AND A LOW-LEVEL JET ALIGNED WITH THE STATE`S ERN BORDER MON NIGHT AND TUE. GFS... ECMWF AND SREF INDICATE FAR LESS INSTABILITY BUT STILL INDICATE DECENT SHEAR IN THE VCNTY OF THE LOW-LEVEL JET. MEANWHILE THE CANADIAN MODEL GOES SO FAR AS TO SPIN UP A CLOSED 700-500MB LOW OVER NERN CO LATE MON AND THEN DEEPENS IT AS IT SLOWLY TRACKS E/SEWRD ACRS NWRN KS OVERNIGHT. PREFER A BLEND OF THE MODELS...EXCLUDING THE CANADIAN GEM...CENTERED ON THE GFS SOLUTION. FOR THE PLAINS...PLAN ON GOING WITH HIGHER POPS UP AGAINST THE NRN FRONT RANGE AND ALONG THE WY BORDER DURING THE AFTERNOON...AND OUT ACRS THE NERN CORNER OF THE STATE MON NIGHT. STORMS FORMING IN THE VICINITY OF THE STALLED FRONTAL BOUNDARY AND LOW-LEVEL JET ARE MORE LIKELY TO PRODUCE HVY RAINFALL...STG GUSTY WNDS AND HAIL. HIGH TEMPS ON MON EXPECTED TO BE SEVERAL DEGS LOWER THAN THOSE ON SUNDAY DUE IN LARGE PART TO CONSIDERABLE MORE CLOUDINESS. ON TUE...SHOULD SEE PRECIP CHANCES QUICKLY DECREASE FROM WEST-TO- EAST AS DRIER/COOLER AIR SWEEPS IN ON W/NWLY FLOW BEHIND THE EXITING SHORTWAVE. HOWEVER COULD SEE A MODEST UPTICK IN SHOWER/T-STORM ACTIVITY ACRS THE NERN CORNER OF THE CWA TUE AFTERNOON WITH THE SHORT-WAVE DYNAMICS BRUSHING THE AREA. HIGHS ON TUESDAY SLIGHTLY WARMER THAN THE DAY BEFORE BUT STILL BELOW THE SEASONAL AVERAGE. WED THROUGH SAT...A STRONG UPPER RIDGE TAKES HOLD OF THE REGION ON WED RETURNING TEMPS TO SLIGHTLY ABOVE AVERAGE. MODELS SHOW A WEAK MID-LEVEL PERTABATION ROUNDING THE TOP OF THIS RIDGE AND POSSIBLY GENERATING A FEW T-STORMS ACROSS THE FAR NERN CORNER OF THE CWA WED AFTERNOON AND EVENING. OTHERWISE A DRY DAY WITH MORE SUNSHINE AND LOWER HUMIDITY. ON THU...MODELS SHOW YET ANOTHER SOMEWHAT STRONGER MID-LEVEL DISTURBANCE MOVING OUT OF THE NRN ROCKIES AND DOWN ACRS THE CENTRAL GREAT PLAINS. THE TAIL END OF THE DISTURBANCE APPEARS TO CLIP THE NERN CORNER OF FCST AREA THU AFTERNOON AND EVENING AND POTENTIALLY PRODUCING ANOTHER ROUND OF T-STORMS. MORE CLOUDS AND SLIGHT COOLER ALOFT SHOULD RESULT IN SLIGHTLY COOLER TEMPS ON THU. ON FRI...RIDGE REGAINS ITS GRIP ON COLORADO RESULTING IN WARMER TEMPS AND MORE SUNSHINE. HOWEVER WITH THE WARMER TEMPS AND SUNSHINE COULD SEE WIDELY SCATTERED AFTERNOON T-STORMS FORMING OVER THE FRONT RANGE AND MOVING OUT OVER THE PLAINS BY THE EVENING. ON SAT...MODELS SHOW THE UPPER RIDGE MOVING EAST ALLOWING SWLY FLOW ALOFT TO USHER IN SUBTROPICAL MOISTURE AND SHORTWAVE TROUGH FROM THE DESERT SOUTHWEST. TOO SOON TO KNOW WITH ANY CERTAINTY HOW WET AND STORMY SAT MAY TURN OUT. WILL NEED TO KEEP AN EYE THIS LATE WEEK SYSTEM. && .AVIATION...(FOR THE TAFS THROUGH 18Z MONDAY MORNING) ISSUED AT 926 AM MDT SUN AUG 2 2015 VFR EXPECTED FOR THE NEXT 24 HOURS. ADDED SOME LIGHT SHRA IN A TEMPO WITH LATEST MODEL GUIDANCE AND A WEAK CAP WITH INCREASED INSTABILITY. COULD SEE SOME OUTFLOWS FROM THE NORTH THAT WILL HELP TO BRING IN SOME GUSTY WINDS ALONG WITH A LINE OF RAINSHOWERS AROUND 23Z. WINDS WILL BE LIGHT THROUGH THE DAY THEN TRANSITION TO THE NW BEFORE GOING TO DRAINAGE BY THIS EVENING AS STORMS CLEAR OUT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BOWEN SHORT TERM...ENTREKIN LONG TERM...BAKER AVIATION...BOWEN
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1031 AM EDT SUN AUG 2 2015 .SYNOPSIS... A WEAK PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA THROUGH TUESDAY. DEEPER MOISTURE WILL REMAIN SUPPRESSED EAST AND SOUTH OF THE AREA. ABOVE NORMAL TEMPERATURES EXPECTED THROUGH MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE UPPER-LEVEL PATTERN FEATURES A RIDGE OUT WEST WITH A BROAD TROUGH FROM THE GREAT LAKES TO THE EAST COAST. WATER VAPOR SATELLITE IMAGERY SHOWED DRY AIR ALOFT ACROSS THE MIDLANDS AND CSRA. WEAKENING FRONTAL BOUNDARY ACROSS THE SOUTHERN MIDLANDS THIS MORNING SHOULD SHIFT TO THE COAST THIS AFTERNOON. FOG/STRATUS RAPIDLY MIXING OUT ACROSS THE SOUTHERN MIDLANDS AND CSRA AT 14Z. SKIES BECOMING MOSTLY SUNNY. MODELS SOUNDINGS INDICATE A DRY AND CAPPED AIR MASS OVER CENTRAL SOUTH CAROLINA TODAY. AIR MASS WEAKLY UNSTABLE IN THE EAST AND SOUTH MIDLANDS/CSRA. POSSIBLE SEA BREEZE/OUTFLOW FROM COASTAL CONVECTION COULD TRIGGER A FEW ISOLATED THUNDERSTORMS THERE THIS AFTERNOON. MAX TEMPERATURES MAINLY IN THE MID TO UPPER 90S. THE NAM AND RAP MODELS SUGGEST FOG/STRATUS DEVELOPING AGAIN LATE TONIGHT. KEPT LOWS IN THE LOW/MID 70S. && .SHORT TERM /MONDAY THROUGH TUESDAY/... MODELS SUGGEST WEAK LOW PRESSURE OVER FLORIDA PANHANDLE AREA WILL MOVE NORTHEAST ALONG THE SOUTH CAROLINA COASTAL FRONT MONDAY AND MONDAY NIGHT. MOISTURE FLUX CONFINED TO THE COASTAL SOUTH CAROLINA AS AIR MASS INLAND REMAINS MAINLY DRY. THERE IS SOME UNCERTAINTY IN THE ENSEMBLE GUIDANCE...HOWEVER THE BULK OF GUIDANCE SUGGESTS LOW POPS ACROSS CWA. WILL CONTINUE LOW CHANCE POPS MONDAY IN THE EXTREME EAST MIDLANDS...MAINLY DIURNAL CONVECTION. DRY AIR MASS EXPECTED TUESDAY WITH WARMING CONDITIONS...POSSIBLY NEAR 100 DEGREES IN A FEW AREAS AS 850MB WARM ADVECTION/DOWN SLOPE FLOW DEVELOPS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS HAVE BEEN CONSISTENT SHOWING A RIDGE OVER THE CENTRAL US WITH A BROAD TROUGH ALONG THE EAST COAST. ISOLATED AFTERNOON CONVECTION AT MOST WEDNESDAY AFTERNOON. MOISTURE RETURNS TO THE REGION LATER IN THE WEEK. RAISED POPS INTO THE 30-40 PERCENT THURSDAY THROUGH SATURDAY. HIGH TEMPERATURES IN THE MID 90S THROUGH MID- WEEK...LOWERING INTO THE LOWER 90S THURSDAY THROUGH SATURDAY. OVERNIGHT LOWS GENERALLY IN THE LOWER TO MID 70S. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... VFR THROUGH THE EVENING HOURS AT CAE/CUB. MORNING FOG/STRATUS AFFECTING AGS/DNL/OGB LIFTING. ALL TAF SITES SHOULD BE VFR BY 16Z. A WEAK SURFACE BOUNDARY ACROSS THE AREA WITH DRY AIR NORTH AND PLENTY OF LOW LEVEL MOISTURE TO THE SOUTH. A DRY AND CAPPED ATMOSPHERE WILL REMAIN IN PLACE OVER MOST OF THE NORTHERN AND CENTRAL MIDLANDS...AND IS EXPECTED TO PRECLUDE CONVECTION. AN ISOLATED DIURNAL SHOWER OR THUNDERSTORM MAY OCCUR MAINLY SOUTH POSSIBLY NEAR DNL/AGS/OGB...BUT CHANCES TOO LOW TO INCLUDE MENTION IN THE TAFS AT THIS TIME. FOG/STRATUS...POSSIBLE LATE TONIGHT/EARLY MONDAY MORNING. EXTENDED AVIATION OUTLOOK... RESTRICTIONS POSSIBLE IN LATE NIGHT/EARLY MORNING FOG. OTHERWISE...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
559 AM CDT SUN AUG 2 2015 .UPDATE... ISSUED AT 514 AM CDT SUN AUG 2 2015 THE VORT MAX MOVING INTO OUR AREA ALONG WITH THE H85 THETAE PUSH....SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS WESTERN AND SOUTHERN IA EARLY THIS AM. HRRR SUGGESTS THAT THESE STORMS CONTINUE TO FIRE CLOSER TO US AND THEN MOVE THROUGH OUR AREA. AS A RESULT OF THE TRENDS AND GUIDANCE...DECIDED TO INCREASE POPS AFTER 12Z ACROSS MY WESTERN ZONES. MAY NEED TO INCREASE TO LIKELYS IF CURRENT HRRR IS CORRECT. && .SYNOPSIS... ISSUED AT 329 AM CDT SUN AUG 2 2015 AN AGITATED ACCAS DECK ASSOCIATED WITH A QUICK MOVING VORT MAX IN THE STEERING FLOW WAS LOCATED FROM ESCANABA MI TO HASTINGS NE. EXTREMELY ISOLATED CONVECTION HAS FORMED IN THIS BAND AS IT MARCHES TO THE SE AT AROUND 20 KTS. AT THE SFC...DEWPOINTS ARE POOLING ACROSS THE AREA AND RELATIVELY CLEAR SKIES REMAIN ACROSS THE AREA. WITH THE POOLING MOISTURE....TEMPS HAVE BEEN SLOW TO DROP ACROSS THE AREA. GUIDANCE SUGGESTS AN H85 THETAE PUSH OF NEAR 50 DEGREES INTO THE AREA NEAR 12Z. THIS AND THE VORT MAX WILL DOMINATE OUR WEATHER IN THE NEXT 6 TO 12 HOURS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT SUN AUG 2 2015 MAIN FORECAST CONCERN FOR THE SHORT ARE THE CHANCES FOR THUNDERSTORMS AND RAIN TODAY. THERE ARE TWO CHANCES WITH THE FIRST ONE EITHER ONGOING AT 12Z OR STARTING SHORTLY THEREAFTER. THE OTHER IS ASSOCIATED WITH A COLD FRONT THAT WILL MOVE THROUGH THE AREA TODAY AND INTO TONIGHT. SOME OF THE STORMS LATER THIS AFTERNOON AND EVENING COULD BE STRONG TO SEVERE. THIS MORNING THE ACCAS DECK MOVING INTO THE AREA WILL ENCOUNTER AN H85 THETAE PUSH. THESE TWO ARE FORECAST TO BE COINCIDENT ACROSS THE CWA NEAR 12Z. THIS COULD LEAD TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA. LARGE SCALE MODELS HINT AT THIS POSSIBLY HAPPENING...HOWEVER THE MESOSCALE NATURE OF THE FORCINGS ARE DIFFICULT FOR THE MODELS TO HANDLE CORRECTLY. PERUSING THE CAMS...WHICH DO BETTER WITH MESOSCALE FEATURES...IT IS CLEAR THAT THESE MODELS DO SUGGEST ADDITIONAL THUNDERSTORM DEVELOPMENT THIS MORNING WITH THE WAVE. AT THIS TIME...THESE STORMS ARE NOT EXPECTED TO BE SEVERE. A STRONG STORM WITH SMALL HAIL COULD BE POSSIBLE. I DO NOT HAVE HIGH CONFIDENCE IN THIS OCCURRING SO DECIDED TO GO WITH SCHC POPS UNTIL THE ACCAS BECOMES BETTER AGITATED. ANY STORMS THIS AM COULD LEAVE OFBS THAT MAY INFLUENCE CONVECTION LATER. THIS AFTERNOON...GUIDANCE SUGGESTS THAT MIXING WILL RESULT IN HIGH TEMPS IN THE 90S ACROSS THE AREA. SOUNDINGS INDICATE THE EML HAS RESULTED IN DRIER AIR ALOFT. AS THIS DRIER AIR IS MIXED DOWN...THE TEMPS SHOULD INCREASE AND DEWPOINTS SHOULD LOWER. USED MOSGUIDE FOR THE DEWPOINTS AS THEY SEEMED TO HAVE A BETTER HANDLE ON WHAT WAS GOING ON NOW AND MIXING THE DEWPOINTS LOWER THIS PM. AS A RESULT...HEAT INDICES WILL REMAIN BELOW CRITERIA. LATE THIS AFTERNOON A COLD FRONT WILL MOVE THROUGH THE AREA. LOOKING AT THE THUNDERSTORM POTENTIAL...THERE WILL BE SUFFICIENT DEEP LAYER SHEAR FOR ISOLATED CELLS. WITH THE MAIN FORCING TO THE NORTH...THESE STORMS MAY BE SLOWER TO GROW UPSCALE INTO A MCS. LAPSE RATES IN THE MID LEVELS SUGGEST THAT HAIL WILL BE THE MAIN THREAT. WITH THE HIGH TEMPS AND LIKELY HIGHER STORM BASES...DAMAGING WINDS COULD ALSO BE POSSIBLE. LOW LEVEL SHEAR AND HODOS ARE INDICATIVE OF THE POSSIBILITY OF TORNADOES AS WELL. IN FACT THEY ARE VERY FAVORABLE FOR POSSIBLE TORNADOES. HOWEVER...THE THERMODYNAMIC ENVIRONMENT IS NOT. I THINK THE THREAT OF TORNADOES IS HIGHER WITH AN MCS INSTEAD OF A SUPERCELL STORM THAT MAY BE THE FIRST MODE OF DEVELOPMENT. REGARDLESS THERE IS A THREAT FOR SEVERE WEATHER FROM THESE STORMS. LOOKING AT THE CAMS...THE NAM 4KM HAS THE BULK OF THE STORMS AND BOWING STRUCTURES ACROSS WI AND E IL. THIS MODEL POPS SHORT LIVED ISOLATED CELLS THAT STRUGGLE TO GROW UPSCALE INTO A MCS STRUCTURES. THE WRFNMM AND ARW ARE EERILY SIMILAR IN WHICH A FRONTAL MCS COMES THROUGH OUR AREA INSTEAD OF TO THE EAST. REGARDLESS THESE MODELS PRODUCE STORMS AND THUS GIVE ME HIGHER CONFIDENCE THAT CONVECTION WILL OCCUR. DID NOT GO HIGHER THAN CHC AS I DO NOT HAVE AN IDEA OF WHICH OF THE SOLUTIONS WILL OCCUR. LATER SHIFTS MAY BE ABLE TO INCREASE POPS ACROSS THE AREA AS THE DAY PROGRESSES AND A CLEARER SOLUTION IS SEEN. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN AUG 2 2015 MONDAY AND MONDAY NIGHT... NORTHWEST FLOW ALOFT WILL DOMINATE EARLY IN THE WEEK AS ANOMALOUSLY DEEP UPPER LOW (500 MB HEIGHTS OF 550-555 DECAMETERS EQUATING TO ROUGHLY 2+ STANDARD DEVIATIONS BELOW CLIMO PER NAEFS) REMAINS PARKED NEAR QUEBEC. THIS FLOW PATTERN COUPLED WITH HIGH PRESSURE RIDGE BUILDING IN WILL RESULT IN COOLER (NEAR NORMAL) AND DRIER CONDITIONS TO START THE WEEK. A SURFACE FRONT IS ANTICIPATED TO STALL OUT FROM THE CENTRAL PLAINS TO THE APPALACHIANS BY MONDAY EVENING. ISENTROPIC LIFT AND WEAK LOW AMPLITUDE SHORTWAVES WILL PROVIDE FOCUS FOR PRECIPITATION CHANCES NEAR AND ON COOL SIDE OF BOUNDARY...WITH THE FAR SOUTHERN CWA POTENTIALLY IN CLOSE PROXIMITY TO SOME OF THIS ACTIVITY. TUESDAY AND TUESDAY NIGHT... OVERALL PATTERN NOT SHOWING MUCH CHANGE DURING THIS PERIOD WITH UPPER LOW SLOW MOVING THROUGH ONTARIO... AND CWA STAYING ON COOL SIDE OF STALLED FRONTAL ZONE FROM THE PLAINS THROUGH THE MID-MISSISSIPPI VALLEY. THUS... MORE OF THE SAME WITH PLEASANT CONDITIONS WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS AND COMFORTABLE HUMIDITY LEVELS... AND ANY RAIN CHANCES MAINLY TO OUR SOUTH/WEST IN VICINITY OF STALLED FRONT WITH SOUTHERN CWA STANDING ANY CHANCES FOR RAIN BEING IN CLOSER PROXIMITY TO BOUNDARY. WEDNESDAY THROUGH SATURDAY... CONTINUED GRADUAL DRAWN DOWN ON TEMPS TO BELOW NORMAL EXPECTED INTO LATE WEEK WITH INFLUX OF COOLER AIR (850 MB TEMPS LOWERING INTO RANGE OF 12-16C) IN WAKE OF DEPARTING ONTARIO UPPER LOW. IN ADDITION...LIKELIHOOD OF INTERVALS OF CLOUDINESS WITH SERIES OF UPPER LEVEL DISTURBANCES PROPAGATING THROUGH REGION IN THE SEMI-ZONAL TO NORTHWEST FLOW TO AID IN KEEPING TEMPS BELOW NORMAL. WITH SURFACE FRONT NEARBY WILL MAINTAIN RAIN CHANCES THROUGH THURSDAY THEN TRENDS SUPPORT DRYING OUT LATE WEEK INTO THE WEEKEND WITH ANOTHER BOUT OF GREAT LAKES RIDGING AND INFLUX OF COOLER...DRIER AIR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 553 AM CDT SUN AUG 2 2015 VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN TWO ROUNDS TODAY. THE FIRST ROUND WILL BE THIS MORNING AND MAY AFFECT BRL AND MLI. THIS AFTERNOON A COLD FRONT MOVES IN FROM THE NORTH. THUNDERSTORMS COULD BE STRONG TO SEVERE WITH THIS FRONT. AT THIS TIME ONLY USED PROB30 AS NOT SURE WHETHER OR NOT THIS AM CONVECTION WILL AFFECT TONIGHTS. COULD SEE MVFR RESTRICTIONS WITH THUNDERSTORMS TONIGHT. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...GIBBS SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...05 AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
516 AM CDT SUN AUG 2 2015 .UPDATE... ISSUED AT 514 AM CDT SUN AUG 2 2015 THE VORT MAX MOVING INTO OUR AREA ALONG WITH THE H85 THETAE PUSH....SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS WESTERN AND SOUTHERN IA EARLY THIS AM. HRRR SUGGESTS THAT THESE STORMS CONTINUE TO FIRE CLOSER TO US AND THEN MOVE THROUGH OUR AREA. AS A RESULT OF THE TRENDS AND GUIDANCE...DECIDED TO INCREASE POPS AFTER 12Z ACROSS MY WESTERN ZONES. MAY NEED TO INCREASE TO LIKELYS IF CURRENT HRRR IS CORRECT. && .SYNOPSIS... ISSUED AT 329 AM CDT SUN AUG 2 2015 AN AGITATED ACCAS DECK ASSOCIATED WITH A QUICK MOVING VORT MAX IN THE STEERING FLOW WAS LOCATED FROM ESCANABA MI TO HASTINGS NE. EXTREMELY ISOLATED CONVECTION HAS FORMED IN THIS BAND AS IT MARCHES TO THE SE AT AROUND 20 KTS. AT THE SFC...DEWPOINTS ARE POOLING ACROSS THE AREA AND RELATIVELY CLEAR SKIES REMAIN ACROSS THE AREA. WITH THE POOLING MOISTURE....TEMPS HAVE BEEN SLOW TO DROP ACROSS THE AREA. GUIDANCE SUGGESTS AN H85 THETAE PUSH OF NEAR 50 DEGREES INTO THE AREA NEAR 12Z. THIS AND THE VORT MAX WILL DOMINATE OUR WEATHER IN THE NEXT 6 TO 12 HOURS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT SUN AUG 2 2015 MAIN FORECAST CONCERN FOR THE SHORT ARE THE CHANCES FOR THUNDERSTORMS AND RAIN TODAY. THERE ARE TWO CHANCES WITH THE FIRST ONE EITHER ONGOING AT 12Z OR STARTING SHORTLY THEREAFTER. THE OTHER IS ASSOCIATED WITH A COLD FRONT THAT WILL MOVE THROUGH THE AREA TODAY AND INTO TONIGHT. SOME OF THE STORMS LATER THIS AFTERNOON AND EVENING COULD BE STRONG TO SEVERE. THIS MORNING THE ACCAS DECK MOVING INTO THE AREA WILL ENCOUNTER AN H85 THETAE PUSH. THESE TWO ARE FORECAST TO BE COINCIDENT ACROSS THE CWA NEAR 12Z. THIS COULD LEAD TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA. LARGE SCALE MODELS HINT AT THIS POSSIBLY HAPPENING...HOWEVER THE MESOSCALE NATURE OF THE FORCINGS ARE DIFFICULT FOR THE MODELS TO HANDLE CORRECTLY. PERUSING THE CAMS...WHICH DO BETTER WITH MESOSCALE FEATURES...IT IS CLEAR THAT THESE MODELS DO SUGGEST ADDITIONAL THUNDERSTORM DEVELOPMENT THIS MORNING WITH THE WAVE. AT THIS TIME...THESE STORMS ARE NOT EXPECTED TO BE SEVERE. A STRONG STORM WITH SMALL HAIL COULD BE POSSIBLE. I DO NOT HAVE HIGH CONFIDENCE IN THIS OCCURRING SO DECIDED TO GO WITH SCHC POPS UNTIL THE ACCAS BECOMES BETTER AGITATED. ANY STORMS THIS AM COULD LEAVE OFBS THAT MAY INFLUENCE CONVECTION LATER. THIS AFTERNOON...GUIDANCE SUGGESTS THAT MIXING WILL RESULT IN HIGH TEMPS IN THE 90S ACROSS THE AREA. SOUNDINGS INDICATE THE EML HAS RESULTED IN DRIER AIR ALOFT. AS THIS DRIER AIR IS MIXED DOWN...THE TEMPS SHOULD INCREASE AND DEWPOINTS SHOULD LOWER. USED MOSGUIDE FOR THE DEWPOINTS AS THEY SEEMED TO HAVE A BETTER HANDLE ON WHAT WAS GOING ON NOW AND MIXING THE DEWPOINTS LOWER THIS PM. AS A RESULT...HEAT INDICES WILL REMAIN BELOW CRITERIA. LATE THIS AFTERNOON A COLD FRONT WILL MOVE THROUGH THE AREA. LOOKING AT THE THUNDERSTORM POTENTIAL...THERE WILL BE SUFFICIENT DEEP LAYER SHEAR FOR ISOLATED CELLS. WITH THE MAIN FORCING TO THE NORTH...THESE STORMS MAY BE SLOWER TO GROW UPSCALE INTO A MCS. LAPSE RATES IN THE MID LEVELS SUGGEST THAT HAIL WILL BE THE MAIN THREAT. WITH THE HIGH TEMPS AND LIKELY HIGHER STORM BASES...DAMAGING WINDS COULD ALSO BE POSSIBLE. LOW LEVEL SHEAR AND HODOS ARE INDICATIVE OF THE POSSIBILITY OF TORNADOES AS WELL. IN FACT THEY ARE VERY FAVORABLE FOR POSSIBLE TORNADOES. HOWEVER...THE THERMODYNAMIC ENVIRONMENT IS NOT. I THINK THE THREAT OF TORNADOES IS HIGHER WITH AN MCS INSTEAD OF A SUPERCELL STORM THAT MAY BE THE FIRST MODE OF DEVELOPMENT. REGARDLESS THERE IS A THREAT FOR SEVERE WEATHER FROM THESE STORMS. LOOKING AT THE CAMS...THE NAM 4KM HAS THE BULK OF THE STORMS AND BOWING STRUCTURES ACROSS WI AND E IL. THIS MODEL POPS SHORT LIVED ISOLATED CELLS THAT STRUGGLE TO GROW UPSCALE INTO A MCS STRUCTURES. THE WRFNMM AND ARW ARE EERILY SIMILAR IN WHICH A FRONTAL MCS COMES THROUGH OUR AREA INSTEAD OF TO THE EAST. REGARDLESS THESE MODELS PRODUCE STORMS AND THUS GIVE ME HIGHER CONFIDENCE THAT CONVECTION WILL OCCUR. DID NOT GO HIGHER THAN CHC AS I DO NOT HAVE AN IDEA OF WHICH OF THE SOLUTIONS WILL OCCUR. LATER SHIFTS MAY BE ABLE TO INCREASE POPS ACROSS THE AREA AS THE DAY PROGRESSES AND A CLEARER SOLUTION IS SEEN. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN AUG 2 2015 MONDAY AND MONDAY NIGHT... NORTHWEST FLOW ALOFT WILL DOMINATE EARLY IN THE WEEK AS ANOMALOUSLY DEEP UPPER LOW (500 MB HEIGHTS OF 550-555 DECAMETERS EQUATING TO ROUGHLY 2+ STANDARD DEVIATIONS BELOW CLIMO PER NAEFS) REMAINS PARKED NEAR QUEBEC. THIS FLOW PATTERN COUPLED WITH HIGH PRESSURE RIDGE BUILDING IN WILL RESULT IN COOLER (NEAR NORMAL) AND DRIER CONDITIONS TO START THE WEEK. A SURFACE FRONT IS ANTICIPATED TO STALL OUT FROM THE CENTRAL PLAINS TO THE APPALACHIANS BY MONDAY EVENING. ISENTROPIC LIFT AND WEAK LOW AMPLITUDE SHORTWAVES WILL PROVIDE FOCUS FOR PRECIPITATION CHANCES NEAR AND ON COOL SIDE OF BOUNDARY...WITH THE FAR SOUTHERN CWA POTENTIALLY IN CLOSE PROXIMITY TO SOME OF THIS ACTIVITY. TUESDAY AND TUESDAY NIGHT... OVERALL PATTERN NOT SHOWING MUCH CHANGE DURING THIS PERIOD WITH UPPER LOW SLOW MOVING THROUGH ONTARIO... AND CWA STAYING ON COOL SIDE OF STALLED FRONTAL ZONE FROM THE PLAINS THROUGH THE MID-MISSISSIPPI VALLEY. THUS... MORE OF THE SAME WITH PLEASANT CONDITIONS WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS AND COMFORTABLE HUMIDITY LEVELS... AND ANY RAIN CHANCES MAINLY TO OUR SOUTH/WEST IN VICINITY OF STALLED FRONT WITH SOUTHERN CWA STANDING ANY CHANCES FOR RAIN BEING IN CLOSER PROXIMITY TO BOUNDARY. WEDNESDAY THROUGH SATURDAY... CONTINUED GRADUAL DRAWN DOWN ON TEMPS TO BELOW NORMAL EXPECTED INTO LATE WEEK WITH INFLUX OF COOLER AIR (850 MB TEMPS LOWERING INTO RANGE OF 12-16C) IN WAKE OF DEPARTING ONTARIO UPPER LOW. IN ADDITION...LIKELIHOOD OF INTERVALS OF CLOUDINESS WITH SERIES OF UPPER LEVEL DISTURBANCES PROPAGATING THROUGH REGION IN THE SEMI-ZONAL TO NORTHWEST FLOW TO AID IN KEEPING TEMPS BELOW NORMAL. WITH SURFACE FRONT NEARBY WILL MAINTAIN RAIN CHANCES THROUGH THURSDAY THEN TRENDS SUPPORT DRYING OUT LATE WEEK INTO THE WEEKEND WITH ANOTHER BOUT OF GREAT LAKES RIDGING AND INFLUX OF COOLER...DRIER AIR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1145 PM CDT SAT AUG 1 2015 VFR CONDITIONS WILL BE SEEN THROUGH 15Z/02. THE PROBABILITY OF A SHRA OR TSRA AFFECTING A TAF SITE THROUGH SUNRISE IS UNDER 10 PERCENT. IF A SHRA/TSRA WOULD AFFECT A TAF SITE...KDBQ WOULD HAVE A SLIGHTLY BETTER CHANCE...AND ONLY A BRIEF PERIOD OF MVFR CONDITIONS MIGHT BE SEEN. AFT 15Z/02 VFR CONDITIONS ARE EXPECTED TO CONTINUE. A NEW ROUND OF CONVECTION IS EXPECTED AFT 18Z/02 ACROSS NORTHERN ILLINOIS. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...GIBBS SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...05 AVIATION...08
AREA FORECAST DISCUSSION
NWS JACKSON KY
1038 AM EDT SUN AUG 2 2015 .UPDATE... ISSUED AT 1038 AM EDT SUN AUG 2 2015 MUCH OF THE FOG THAT DEVELOPED ACROSS THE RIVER VALLEYS THIS MORNING HAS DISSIPATED. WE ARE LEFT WITH MOSTLY SUNNY TO SUNNY SKIES UNDER SURFACE HIGH PRESSURE. FORECAST IS ON TRACK AT THIS POINT WITH ONLY MINOR ADJUSTMENTS MADE OVERALL TOWARDS LATEST OBS AND TRENDS. UPDATE ISSUED AT 700 AM EDT SUN AUG 2 2015 TOUCHED UP THE GRIDS THIS MORNING BASED ON THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 350 AM EDT SUN AUG 2 2015 07Z SFC ANALYSIS SHOWS HIGH PRESSURE IN PLACE OVER CENTRAL KENTUCKY. THIS IS HELPING TO KEEP THE SKY MOSTLY CLEAR ACROSS THE STATE...BUT A SMATTERING OF MID LEVEL CLOUDS ARE DRIFTING OVER EAST KENTUCKY AND OUT OF THE AREA ATTM. SIMILAR TO THE PAST FEW NIGHTS...AN INVERSION HAS SET UP WHILE GOOD RADIATIONAL COOLING IS UNDERWAY. THIS HAS LED TO ANOTHER NIGHT OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES WITH SOME UPPER 50S FOUND IN THE DEEPER SPOTS WHILE HILLTOPS ARE RUNNING IN THE MID 60S. WINDS REMAIN LIGHT TO CALM ACROSS EAST KENTUCKY WITH NOT MUCH EVIDENCE OF FOG OUT THERE YET. HOWEVER...AGAIN SIMILAR TO THE PAST FEW NIGHTS... EXPECT THE FOG TO FORM IN THE RIVER VALLEYS BEFORE DAWN ALONG WITH LOCALLY DENSE PATCHES. THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT AS A BROAD AREA OF TROUGHING CONTINUES OVER SOUTH CENTRAL CANADA AND DOWN INTO THE OHIO VALLEY ACROSS TO NEW ENGLAND. A WIGGLE AT THE CORE OF THE TROUGH TO THE NORTH WILL SEND A LARGE AMOUNT OF ENERGY INTO THE GREAT LAKES ON MONDAY ALONG WITH A MID LEVEL GRADIENT THAT TIGHTENS...RESULTING IN FASTER FLOW THROUGH THE OHIO VALLEY. GIVEN THE AGREEMENT ALOFT WILL FOLLOW A BLENDED SOLUTION WITH EMPHASIS ON THE HRRR AND NAM12 EARLY ON AND THE BROADER CONSENSUS LATER. SENSIBLE WEATHER WILL FEATURE ANOTHER PLEASANT DAY WITH FAIRLY LOW AND COMFORTABLE HUMIDITY LEVELS AND HIGHS GENERALLY IN THE MID 80S UNDER MOSTLY SUNNY SKIES. THIS WILL LEAD INTO ONE MORE NIGHT OF GOOD RADIATIONAL COOLING AND RIDGE TO VALLEY TEMPERATURE DIFFERENCES INTO MONDAY MORNING...ALONG WITH PATCHY VALLEY FOG TOWARDS DAWN. BY MONDAY...THOUGH...THE SFC PATTERN WILL CHANGE WITH A COLD FRONT PRESSING SOUTH THROUGH THE OHIO VALLEY AND TOWARD EAST KENTUCKY. THIS WILL LIKELY KICK OFF SHOWERS AND THUNDERSTORMS NORTH OF THE STATE THAT SHOULD HELP TO SPAWN ADDITIONAL STORMS TO THE SOUTH WITH TIME THROUGH THE DAY. ANY STORMS THAT MANAGE TO DEVELOP OUT AHEAD OF THE FRONT IN EAST KENTUCKY WILL HAVE THE POTENTIAL TO BECOME STRONG TO SEVERE OWING TO HIGH CAPES AND STRENGTHENING MID LEVEL WINDS. THE BEST CHANCES WILL BE OVER OUR NORTHERN ZONES CLOSER TO THE FRONT AND SPC HAS INDICATED A SLIGHT RISK FOR SEVERE STORMS THERE. WILL HIGHLIGHT THIS CONCERN IN THE FORTHCOMING HWO. STARTED WITH THE SHORTBLEND MODEL FOR THE T/TD/WIND GRIDS THROUGH THE DAY FOLLOWED BY THE SUPERBLEND INTO MONDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENTS TO TEMPERATURES THIS MORNING AND TONIGHT WITH RESPECT TO RIDGE AND VALLEY DIFFERENCES. AS FOR POPS...KEPT THEM LOW AND IN LINE WITH THE DRY GUIDANCE INTO MONDAY MORNING. DID GO A BIT HIGHER THAN THE MET AND MAV NUMBERS FOR MONDAY AFTERNOON TO ACCOUNT FOR THE POTENTIAL INTRUSION OF STORMS... ORGANIZED OR OTHERWISE...FROM THE NORTH BY EVENING. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 340 AM EDT SUN AUG 2 2015 THE EXTENDED FORECAST PERIOD BEGINS ON MONDAY NIGHT WITH THE UPPER LEVEL PATTERN MAINTAINING A RIDGE OVER THE WEST AND THE LONGWAVE TROUGH OVER THE EASTERN CONUS. A CLOSED LOW OVER THE HUDSON BAY AREA WILL GRADUALLY SHIFT OFF TO THE EAST THROUGH THE EXTENDED AS BY THURSDAY...A SERIES OF STRONGER TROUGHS COME ASHORE OVER THE WEST AS THE WESTERN RIDGE BEGINS TO WEAKEN A BIT AND SHIFT EAST. THIS THROUGH THE LAST PORTION OF THE EXTENDED WILL BE THE FORECAST CHALLENGE AS THE BASE OF THE EASTERN TROUGH SETS UP OVER THE MID MS VALLEY AND THROUGH KY. THE GFS AND EURO DOES ALIGN A BIT WITH THIS SOLUTION. CLOSER TO THE SURFACE...THE FRONT THAT HAS PASSED THROUGH ON MONDAY WILL LAG ACROSS NORTHERN KENTUCKY AS A STATIONARY BOUNDARY DEVELOPS. THIS AREA BECOMES A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT AS THE BOUNDARY SLIDES FURTHER SOUTH THROUGH THE DAY ON TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...NORTHWEST FLOW SETS UP OVER THE AREA AS A SERIES OF UPPER LEVEL WAVES TOPPLE OVER THE THE TOP OF THE WESTERN RIDGE AND TRACK SOUTHEAST INTO THE OH VALLEY. THE SUPER BLEND HAS THIS IN IT/S SOLUTION AS WELL WITH THE PATTERN FAVORABLE FOR NOCTURNAL THUNDERSTORMS AS WELL...ESPECIALLY IF THIS PATTERN FOR MCS/S REMAIN...WHICH SEEMS LIKELY BASED UPON THE GFS AND EURO SOLUTIONS . THUS WILL STAY CLOSE TO THE SUPER BLENDS SOLUTION WEDNESDAY THROUGH FRIDAY KEEPING HIGH CHANCE TO LIKELY POPS DURING THIS PERIOD. TOWARDS THE END OF THE EXTENDED ON FRIDAY AND SATURDAY...THE UPPER LEVEL PATTERN LOSES A BIT AMPLITUDE AND BECOMES MORE ACTIVE AS ANOTHER SHORTWAVE TAKES AIM AT THE OH VALLEY. HOWEVER...THE GFS AND EURO DO DIVERGE TOWARDS THE END OF THE EXTENDED. THUS...LACKING CONFIDENCE...WILL GO NEAR OR SLIGHTLY BELOW THE SUPER BLEND ON POPS. THE LINGERING TROUGH OVER THE EAST AND SAGGING SOUTH THROUGH THE EXTENDED WILL KEEP HIGHS AT OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. IN SHORT...THE WEDNESDAY THROUGH FRIDAY PERIOD SEEMS TO BE QUITE ACTIVE AND WET WITH THE END OF THE FORECAST POSSIBLY CONTINUING THIS TREND WITH A COOLING TREND AS WELL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 715 AM EDT SUN AUG 2 2015 A RIDGE OF HIGH PRESSURE WILL KEEP MOSTLY CLEAR SKIES AND LIGHT WINDS IN PLACE ACROSS THE AREA FOR THE TAF PERIOD. THE BULK OF ANY FOG AROUND THIS MORNING AND AGAIN TOWARD DAWN MONDAY SHOULD BE CONFINED TO VALLEY FLOORS AND NEAR BODIES OF WATER. AS SUCH...THE MAJORITY OF THE TAF SITES SHOULD ALL REMAIN FREE OF FOG THIS MORNING AND INTO MONDAY MORNING. THE EXCEPTION WILL PROBABLY BE AT SME AND SYM WHERE SOME MVFR OR BRIEF IFR FOG WILL BE POSSIBLE. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD ALONG WITH LIGHT AND VARIABLE WINDS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...DJ SHORT TERM...GREIF LONG TERM...SHALLENBERGER AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
715 AM EDT SUN AUG 2 2015 .UPDATE... ISSUED AT 700 AM EDT SUN AUG 2 2015 TOUCHED UP THE GRIDS THIS MORNING BASED ON THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 350 AM EDT SUN AUG 2 2015 07Z SFC ANALYSIS SHOWS HIGH PRESSURE IN PLACE OVER CENTRAL KENTUCKY. THIS IS HELPING TO KEEP THE SKY MOSTLY CLEAR ACROSS THE STATE...BUT A SMATTERING OF MID LEVEL CLOUDS ARE DRIFTING OVER EAST KENTUCKY AND OUT OF THE AREA ATTM. SIMILAR TO THE PAST FEW NIGHTS...AN INVERSION HAS SET UP WHILE GOOD RADIATIONAL COOLING IS UNDERWAY. THIS HAS LED TO ANOTHER NIGHT OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES WITH SOME UPPER 50S FOUND IN THE DEEPER SPOTS WHILE HILLTOPS ARE RUNNING IN THE MID 60S. WINDS REMAIN LIGHT TO CALM ACROSS EAST KENTUCKY WITH NOT MUCH EVIDENCE OF FOG OUT THERE YET. HOWEVER...AGAIN SIMILAR TO THE PAST FEW NIGHTS... EXPECT THE FOG TO FORM IN THE RIVER VALLEYS BEFORE DAWN ALONG WITH LOCALLY DENSE PATCHES. THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT AS A BROAD AREA OF TROUGHING CONTINUES OVER SOUTH CENTRAL CANADA AND DOWN INTO THE OHIO VALLEY ACROSS TO NEW ENGLAND. A WIGGLE AT THE CORE OF THE TROUGH TO THE NORTH WILL SEND A LARGE AMOUNT OF ENERGY INTO THE GREAT LAKES ON MONDAY ALONG WITH A MID LEVEL GRADIENT THAT TIGHTENS...RESULTING IN FASTER FLOW THROUGH THE OHIO VALLEY. GIVEN THE AGREEMENT ALOFT WILL FOLLOW A BLENDED SOLUTION WITH EMPHASIS ON THE HRRR AND NAM12 EARLY ON AND THE BROADER CONSENSUS LATER. SENSIBLE WEATHER WILL FEATURE ANOTHER PLEASANT DAY WITH FAIRLY LOW AND COMFORTABLE HUMIDITY LEVELS AND HIGHS GENERALLY IN THE MID 80S UNDER MOSTLY SUNNY SKIES. THIS WILL LEAD INTO ONE MORE NIGHT OF GOOD RADIATIONAL COOLING AND RIDGE TO VALLEY TEMPERATURE DIFFERENCES INTO MONDAY MORNING...ALONG WITH PATCHY VALLEY FOG TOWARDS DAWN. BY MONDAY...THOUGH...THE SFC PATTERN WILL CHANGE WITH A COLD FRONT PRESSING SOUTH THROUGH THE OHIO VALLEY AND TOWARD EAST KENTUCKY. THIS WILL LIKELY KICK OFF SHOWERS AND THUNDERSTORMS NORTH OF THE STATE THAT SHOULD HELP TO SPAWN ADDITIONAL STORMS TO THE SOUTH WITH TIME THROUGH THE DAY. ANY STORMS THAT MANAGE TO DEVELOP OUT AHEAD OF THE FRONT IN EAST KENTUCKY WILL HAVE THE POTENTIAL TO BECOME STRONG TO SEVERE OWING TO HIGH CAPES AND STRENGTHENING MID LEVEL WINDS. THE BEST CHANCES WILL BE OVER OUR NORTHERN ZONES CLOSER TO THE FRONT AND SPC HAS INDICATED A SLIGHT RISK FOR SEVERE STORMS THERE. WILL HIGHLIGHT THIS CONCERN IN THE FORTHCOMING HWO. STARTED WITH THE SHORTBLEND MODEL FOR THE T/TD/WIND GRIDS THROUGH THE DAY FOLLOWED BY THE SUPERBLEND INTO MONDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENTS TO TEMPERATURES THIS MORNING AND TONIGHT WITH RESPECT TO RIDGE AND VALLEY DIFFERENCES. AS FOR POPS...KEPT THEM LOW AND IN LINE WITH THE DRY GUIDANCE INTO MONDAY MORNING. DID GO A BIT HIGHER THAN THE MET AND MAV NUMBERS FOR MONDAY AFTERNOON TO ACCOUNT FOR THE POTENTIAL INTRUSION OF STORMS... ORGANIZED OR OTHERWISE...FROM THE NORTH BY EVENING. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 340 AM EDT SUN AUG 2 2015 THE EXTENDED FORECAST PERIOD BEGINS ON MONDAY NIGHT WITH THE UPPER LEVEL PATTERN MAINTAINING A RIDGE OVER THE WEST AND THE LONGWAVE TROUGH OVER THE EASTERN CONUS. A CLOSED LOW OVER THE HUDSON BAY AREA WILL GRADUALLY SHIFT OFF TO THE EAST THROUGH THE EXTENDED AS BY THURSDAY...A SERIES OF STRONGER TROUGHS COME ASHORE OVER THE WEST AS THE WESTERN RIDGE BEGINS TO WEAKEN A BIT AND SHIFT EAST. THIS THROUGH THE LAST PORTION OF THE EXTENDED WILL BE THE FORECAST CHALLENGE AS THE BASE OF THE EASTERN TROUGH SETS UP OVER THE MID MS VALLEY AND THROUGH KY. THE GFS AND EURO DOES ALIGN A BIT WITH THIS SOLUTION. CLOSER TO THE SURFACE...THE FRONT THAT HAS PASSED THROUGH ON MONDAY WILL LAG ACROSS NORTHERN KENTUCKY AS A STATIONARY BOUNDARY DEVELOPS. THIS AREA BECOMES A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT AS THE BOUNDARY SLIDES FURTHER SOUTH THROUGH THE DAY ON TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...NORTHWEST FLOW SETS UP OVER THE AREA AS A SERIES OF UPPER LEVEL WAVES TOPPLE OVER THE THE TOP OF THE WESTERN RIDGE AND TRACK SOUTHEAST INTO THE OH VALLEY. THE SUPER BLEND HAS THIS IN IT/S SOLUTION AS WELL WITH THE PATTERN FAVORABLE FOR NOCTURNAL THUNDERSTORMS AS WELL...ESPECIALLY IF THIS PATTERN FOR MCS/S REMAIN...WHICH SEEMS LIKELY BASED UPON THE GFS AND EURO SOLUTIONS . THUS WILL STAY CLOSE TO THE SUPER BLENDS SOLUTION WEDNESDAY THROUGH FRIDAY KEEPING HIGH CHANCE TO LIKELY POPS DURING THIS PERIOD. TOWARDS THE END OF THE EXTENDED ON FRIDAY AND SATURDAY...THE UPPER LEVEL PATTERN LOSES A BIT AMPLITUDE AND BECOMES MORE ACTIVE AS ANOTHER SHORTWAVE TAKES AIM AT THE OH VALLEY. HOWEVER...THE GFS AND EURO DO DIVERGE TOWARDS THE END OF THE EXTENDED. THUS...LACKING CONFIDENCE...WILL GO NEAR OR SLIGHTLY BELOW THE SUPER BLEND ON POPS. THE LINGERING TROUGH OVER THE EAST AND SAGGING SOUTH THROUGH THE EXTENDED WILL KEEP HIGHS AT OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. IN SHORT...THE WEDNESDAY THROUGH FRIDAY PERIOD SEEMS TO BE QUITE ACTIVE AND WET WITH THE END OF THE FORECAST POSSIBLY CONTINUING THIS TREND WITH A COOLING TREND AS WELL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 715 AM EDT SUN AUG 2 2015 A RIDGE OF HIGH PRESSURE WILL KEEP MOSTLY CLEAR SKIES AND LIGHT WINDS IN PLACE ACROSS THE AREA FOR THE TAF PERIOD. THE BULK OF ANY FOG AROUND THIS MORNING AND AGAIN TOWARD DAWN MONDAY SHOULD BE CONFINED TO VALLEY FLOORS AND NEAR BODIES OF WATER. AS SUCH...THE MAJORITY OF THE TAF SITES SHOULD ALL REMAIN FREE OF FOG THIS MORNING AND INTO MONDAY MORNING. THE EXCEPTION WILL PROBABLY BE AT SME AND SYM WHERE SOME MVFR OR BRIEF IFR FOG WILL BE POSSIBLE. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD ALONG WITH LIGHT AND VARIABLE WINDS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...SHALLENBERGER AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1153 AM EDT SUN AUG 2 2015 .UPDATE... FORECAST REMAINS IN GOOD SHAPE AS CONVECTIVE EVOLUTION TO OUR NORTH HAS BEEN FAIRLY PREDICTABLE TO THIS POINT. SEVERAL CLUSTERS OF STORMS CONTINUE TO PEEL EASTWARD ACROSS NORTHERN WISCONSIN ON INTO THE UP AND NORTHERN LOWER MICHIGAN. THUNDERSTORM CHANCES WILL INCREASE OVER THE NORTHERN CWA THIS AFTERNOON AS THE FLOW OF WARM AND MOIST AIR PERSISTS AND A LARGE OUTFLOW BOUNDARY ALONG THE SOUTHERN EDGE OF STORM COMPLEXES TO THE NORTH SETTLES INTO THE FORECAST AREA AND PROVIDES FOCUS FOR THIS INCREASINGLY UNSTABLE AIRMASS. WHILE AN ISOLATED STORM CANNOT BE RULED OUT AS FAR SOUTH AS M 59 LATER THIS AFTERNOON...MOST ACTIVITY WILL REMAIN NORTH OF THE I-69 CORRIDOR. IT LOOKS INCREASINGLY LIKE THE NEXT ROUND OF THUNDERSTORMS WILL ACTUALLY OVERLAP WITH THIS ONGOING ACTIVITY AS OPPOSED TO BEING A MORE DISTINCT EPISODE. A CONTINUED FLOW OF MOIST/UNSTABLE AIR ALONG THE AFOREMENTIONED OUTFLOW BOUNDARY SHOULD MAINTAIN FAIRLY CONSISTENT CONVECTION ALONG/NORTH OF THE CWA INTO EARLY THIS EVENING WITH ADDITIONAL DEVELOPING ACTIVITY ALONG APPROACHING COLD FRONT THEN SPREADING INTO THE AREA FROM NORTHERN LOWER MICHIGAN AND WISCONSON DURING THE COURSE OF THE EVENING...WHICH WILL ACT TO DRAG EXISTING CONVECTION ALONG THE NORTHERN BORDER SOUTHWARD INTO THE AREA. NET RESULT WILL BE THE SAME AS STORM CHANCES INCREASE FROM NORTH TO SOUTH ACROSS THE AREA FROM MID TO LATE EVENING. TIMING FOR LARGEST THREAT OF STORMS FOR METRO DETROIT STILL APPEARS TO BE MAINLY AFTER 10 PM AND PERHAPS CLOSER TO MIDNIGHT FOR MANY LOCALES. WITH ANY LUCK...DECLINING INSTABILITY AT THIS LATER HOUR WILL TAKE SOME PUNCH OUT OF THE LINE OF STORMS THAT EVENTUALLY EVOLVES AND PROGRESSES INTO THE AREA LATER THIS EVENING. THAT SAID...THE THREAT OF SEVERE WEATHER WILL PERSIST GIVEN THE STRONG WIND FIELD AND AT LEAST A MODERATELY UNSTABLE AIRMASS AT THAT POINT. && .AVIATION...ISSUED 633 AM EDT SUN AUG 2 2015 STRENGTHENING SWLY WINDS WILL GUST TO AROUND 25 KTS LATE THIS MORNING INTO AFTN IN ADVANCE OF AN APPROACHING TROUGH AND COLD FRONT. INCREASING INSTABILITY WILL SUPPORT POTENTIAL FOR TSTORMS TO IMPACT MAINLY KMBS/KFNT THIS AFTERNOON WHILE REMAINING TERMINALS SHOULD REMAIN CAPPED WITH NOTHING MORE THAN HIGH BASED CU. MORE SIGNIFICANT TSTORM EPISODE POSSIBLE 00Z-06Z TONIGHT AS UPSTREAM CONVECTION ORGANIZES AND MOVES DOWNSTREAM CARRYING AN ELEVATED SEVERE THREAT...PARTICULARLY FOR NW AREAS. UNCERTAINTY IS HIGHER IN DETROIT AREA GIVEN EXPECTED TSTORM ARRIVAL WELL AFTER SUNSET AND LOSS OF DIURNAL HEATING. FOR DTW...VERY LOW CHANCE FOR A TSTORM INVOF KDTW 18-00Z WITH CAPPING EXPECTED TO PREVAIL WARRANTING REMOVAL OF PRIOR PROB30 GROUP. MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE OF THE COLD FRONT. //DTW THRESHOLD PROBABILITIES... * LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT. && .PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015 UPDATE... A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING. IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE 07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING WORDING IN THE HWO AND OTHER PRODUCTS. FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS 18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP LAPSE RATE ENVIRONMENT. && .PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015 SHORT TERM...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85 TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED AREAS. SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT, LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z. BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION. LONG TERM... UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER 12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80 DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S. A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID 50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY. MARINE... SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE SEVERE...PRODUCING WINDS OF 50 KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS TIME FRAME AS WELL. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049. LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443. LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460. MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444. && $$ UPDATE.......DG AVIATION.....JVC SHORT TERM...JVC LONG TERM....SF MARINE.......SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
633 AM EDT SUN AUG 2 2015 .AVIATION... STRENGTHENING SWLY WINDS WILL GUST TO AROUND 25 KTS LATE THIS MORNING INTO AFTN IN ADVANCE OF AN APPROACHING TROUGH AND COLD FRONT. INCREASING INSTABILITY WILL SUPPORT POTENTIAL FOR TSTORMS TO IMPACT MAINLY KMBS/KFNT THIS AFTERNOON WHILE REMAINING TERMINALS SHOULD REMAIN CAPPED WITH NOTHING MORE THAN HIGH BASED CU. MORE SIGNIFICANT TSTORM EPISODE POSSIBLE 00Z-06Z TONIGHT AS UPSTREAM CONVECTION ORGANIZES AND MOVES DOWNSTREAM CARRYING AN ELEVATED SEVERE THREAT...PARTICULARLY FOR NW AREAS. UNCERTAINTY IS HIGHER IN DETROIT AREA GIVEN EXPECTED TSTORM ARRIVAL WELL AFTER SUNSET AND LOSS OF DIURNAL HEATING. FOR DTW...VERY LOW CHANCE FOR A TSTORM INVOF KDTW 18-00Z WITH CAPPING EXPECTED TO PREVAIL WARRANTING REMOVAL OF PRIOR PROB30 GROUP. MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE OF THE COLD FRONT. //DTW THRESHOLD PROBABILITIES... * LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT. && .PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015 UPDATE... A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING. IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE 07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING WORDING IN THE HWO AND OTHER PRODUCTS. FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS 18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP LAPSE RATE ENVIRONMENT. PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015 SHORT TERM...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85 TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED AREAS. SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT, LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z. BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION. LONG TERM... UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER 12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80 DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S. A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID 50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY. MARINE... SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE SEVERE...PRODUCING WINDS OF 50 KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS TIME FRAME AS WELL. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM NOON EDT TODAY THROUGH THIS EVENING FOR MIZ049. LAKE HURON...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LHZ421-422-441>443. LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LCZ460. MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 AM EDT MONDAY FOR LEZ444. && $$ AVIATION.....JVC UPDATE.......JVC SHORT TERM...JVC LONG TERM....SF MARINE.......SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
623 AM CDT SUN AUG 2 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 455 AM CDT SUN AUG 2 2015 THUNDERSTORMS HAVE DEVELOPED EARLY THIS MORNING OVER SOUTH CENTRAL IOWA IN AN AREA OF LOW LEVEL MOISTURE CONVERGENCE ON THE NOSE OF A 30KT LOW LEVEL JET. RAP SHOWS THAT THIS LOW LEVEL CONVERGENCE WILL MOVE ACROSS THE NORTHERN PART OF THE CWA THIS MORNING. WILL KEEP ISOLATED THUNDERSTORMS GOING OVER THIS AREA THROUGH AT LEAST THE MORNING HOURS. WENT WITH A BLEND OF THE MOS GUIDANCE FOR HIGHS TODAY WHICH IS SUPPORTED BY MIXING DOWN THE 850MB TEMPERATURES. BRITT .LONG TERM: (TONIGHT THROUGH SATURDAY) ISSUED AT 455 AM CDT SUN AUG 2 2015 (TONIGHT THROUGH TUESDAY) COLD FRONT WILL MOVE DOWN INTO THE AREA TONIGHT AHEAD OF A WEAK SHORTWAVE IN NORTHWESTERLY FLOW ALOFT. STILL EXPECT SCATTERED THUNDERSTORMS TO DEVELOP IN THE WEAK MOISTURE CONVERGENCE ALONG THE COLD FRONT IN AREAS ALONG AND NORTH OF I-70. ISOLATED THUNDERSTORMS WILL CONTINUE INTO MONDAY OVER THE SOUTHERN HALF OF THE CWA AS THE COLD FRONT SHIFTS TO THE SOUTH. CHANCES FOR STORMS WILL INCREASE MONDAY NIGHT INTO TUESDAY NIGHT AS THE FRONT STALLS OVER THE AREA AS STRONGER SHORTWAVE TROUGH MOVES ACROSS THE AREA. (WEDNESDAY THROUGH SATURDAY) THE CHANCE OF THUNDERSTORMS WILL CONTINUE OVER THE AREA THROUGH FRIDAY AS THE FRONT WILL REMAINED STALLED MISSOURI AND ILLINOIS. BOTH THE ECMWF AND GFS ARE SHOWING A SERIES OF SHORTWAVES MOVING OVER THE STALLED FRONT DURING THIS PERIOD. HIGH PRESSURE WILL FINALLY MOVE INTO THE AREA BY SATURDAY PROVIDING A DRY DAY. WENT WITH BELOW TEMPERATURES BECAUSE OF EXPECTED CLOUDS AND RAIN CHANCES. BRITT && .AVIATION: (FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 616 AM CDT SUN AUG 2 2015 TSRA OVER N CENTRAL MO ARE EXPECTED TO CONTINUE MOVING SEWD. THESE STORMS ARE NOT CURRENTLY ANTICIPATED TO IMPACT UIN...BUT CAN NOT BE RULED OUT AND WILL BE IN THE REGION. OTHERWISE, TSRA MAY ALSO IMPACT UIN THIS EVENING AS A CDFNT APPROACHES THE REGION. HOWEVER...TSRA SHUD DISSIPATE AS THEY APPROACH THE UIN REGION AND WILL THEREFORE KEEP OUT OF TAF ATTM. OTHERWISE, WINDS WILL BECOME SWLY THIS MORNING AND WLY AS THE FNT APPROACHES. LATEST MODEL GUIDANCE SUGGESTS ISOD TO SCT TSRA WILL BE POSSIBLE THIS AFTERNOON INTO EARLY EVENING ACROSS PORTIONS OF ERN OZARKS...POSSIBLY AS FAR N AS THE STL/SUS/CPS REGION. CHANCES OF DEVELOPMENT AND IMPACTING THESE TERMINALS IS TOO LOW TO MENTION IN THE TAF ATTM. TILLY && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
501 AM CDT SUN AUG 2 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 455 AM CDT SUN AUG 2 2015 THUNDERSTORMS HAVE DEVELOPED EARLY THIS MORNING OVER SOUTH CENTRAL IOWA IN AN AREA OF LOW LEVEL MOISTURE CONVERGENCE ON THE NOSE OF A 30KT LOW LEVEL JET. RAP SHOWS THAT THIS LOW LEVEL CONVERGENCE WILL MOVE ACROSS THE NORTHERN PART OF THE CWA THIS MORNING. WILL KEEP ISOLATED THUNDERSTORMS GOING OVER THIS AREA THROUGH AT LEAST THE MORNING HOURS. WENT WITH A BLEND OF THE MOS GUIDANCE FOR HIGHS TODAY WHICH IS SUPPORTED BY MIXING DOWN THE 850MB TEMPERATURES. BRITT .LONG TERM: (TONIGHT THROUGH SATURDAY) ISSUED AT 455 AM CDT SUN AUG 2 2015 (TONIGHT THROUGH TUESDAY) COLD FRONT WILL MOVE DOWN INTO THE AREA TONIGHT AHEAD OF A WEAK SHORTWAVE IN NORTHWESTERLY FLOW ALOFT. STILL EXPECT SCATTERED THUNDERSTORMS TO DEVELOP IN THE WEAK MOISTURE CONVERGENCE ALONG THE COLD FRONT IN AREAS ALONG AND NORTH OF I-70. ISOLATED THUNDERSTORMS WILL CONTINUE INTO MONDAY OVER THE SOUTHERN HALF OF THE CWA AS THE COLD FRONT SHIFTS TO THE SOUTH. CHANCES FOR STORMS WILL INCREASE MONDAY NIGHT INTO TUESDAY NIGHT AS THE FRONT STALLS OVER THE AREA AS STRONGER SHORTWAVE TROUGH MOVES ACROSS THE AREA. (WEDNESDAY THROUGH SATURDAY) THE CHANCE OF THUNDERSTORMS WILL CONTINUE OVER THE AREA THROUGH FRIDAY AS THE FRONT WILL REMAINED STALLED MISSOURI AND ILLINOIS. BOTH THE ECMWF AND GFS ARE SHOWING A SERIES OF SHORTWAVES MOVING OVER THE STALLED FRONT DURING THIS PERIOD. HIGH PRESSURE WILL FINALLY MOVE INTO THE AREA BY SATURDAY PROVIDING A DRY DAY. WENT WITH BELOW TEMPERATURES BECAUSE OF EXPECTED CLOUDS AND RAIN CHANCES. BRITT && .AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1119 PM CDT SAT AUG 1 2015 STILL EXPECTING DEVELOPMENT OF SHOWERS AND THUNDERSTORMS LIKELY OVER CENTRAL IOWA IN THE PREDAWN HOURS OF SUNDAY MORNING. QUINCY MAY BE ON SOUTHERN EDGE AND MAINTAINED A VC GROUP FOR EARLY SUNDAY MORNING. ALTHOUGH CANNOT TOTALLY RULE OUT ACTIVITY FURTHER SOUTH LATE SUNDAY MORNING/EARLY AFTERNOON CHANCES ARE PRETTY LOW SO KEPT REMAINING SITES DRY. WEST/SOUTHWEST WINDS WILL PICK UP AND GUST AT KCOU AND KUIN AS SFC PRESSURE GRADIENT TIGHTENS BUT WILL RELAX A BIT WITH APPROACH OF NEXT COLD FRONT SUNDAY NIGHT. SPECIFICS FOR KSTL: VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH SUNDAY NIGHT. LIGHT/VARIABLE WINDS WILL BECOME PREDOMINANTLY SOUTHWESTERLY BY LATE SUNDAY MORNING. NEXT COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE SUNDAY NIGHT BUT PRECIPITATION CHANCES ONCE AGAIN DO NOT LOOK TOO HIGH WITH IT AND PASSAGE OF SAID ACTUAL FRONT LOOKS TO BE ACTUALLY ON MONDAY MORNING. GOSSELIN && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
621 AM CDT SUN AUG 2 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 354 AM CDT SUN AUG 2 2015 CHANCE FOR THUNDERSTORMS AND WARM TEMPERATURES TODAY...THEN OFF AND ON STORM CHANCES THROUGH TUESDAY...ARE THE PRIMARY FORECAST CONCERNS. SCATTERED THUNDERSTORMS POPPED UP EARLY THIS MORNING JUST AHEAD OF MID LEVEL WAVE DROPPING SOUTHEAST THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA AS PER WATER VAPOR AND RAP ANALYSIS. THIS WAVE WILL TRACK EAST OF OUR CWA EARLY IN THE DAYLIGHT HOURS...WITH SUBSIDENCE BEHIND WAVE KEEPING MUCH OF THE REST OF THE MORNING DRY. ANOTHER SHORTWAVE IN THE NORTHERN PLAINS INTO THE NORTHERN GREAT LAKES IS FORECAST TO SWEEP SOUTHEAST LATER TODAY...WITH SURFACE REFLECTION IN THE FORM OF A FRONT/WIND SHIFT SETTLING INTO NORTHEAST NEBRASKA THIS AFTERNOON. SURFACE DEW POINTS NEAR OR ABOVE 70F AHEAD OF THIS BOUNDARY ARE EXPECTED TO POOL IN EASTERN NEBRASKA AND WESTERN IOWA DURING PEAK HEATING. CONVERGENCE ALONG BOUNDARY SHOULD BE ENOUGH TO GET AT LEAST ISOLATED THUNDERSTORMS FIRING IN UNSTABLE ATMOSPHERE CHARACTERIZED BY MUCAPES OVER 2500 J/KG. MEANWHILE MODERATE MID LEVEL FLOW WILL HELP GENERATE NEAR 40KT OF BULK SHEAR WITH VECTORS NORMAL TO SURFACE CONVERGENCE...SUGGESTING DISCRETE AND ROTATING STORMS ARE LIKELY...SUPPORTING HAIL AND WIND POTENTIAL. ONLY MARGINAL RISK IN SPC OUTLOOK...AND CAN NOT ARGUE GIVEN EXPECTED SCANT COVERAGE. INITIATION LOOKS TO BE FARTHER NORTH THAN PREVIOUS MODEL RUNS WITH LATER ARRIVAL OF FRONT...MOSTLY LIKELY FIRING NEAR OR SOUTH OF A WAYNE TO ALBION LINE BETWEEN 3 AND 4 PM. EXPECT ISOLATED TO SCATTERED STORMS TO PROGRESS SOUTH THROUGH THE REST OF THE AFTERNOON INTO THE EVENING WITH FRONTAL BOUNDARY BEFORE EXITING SOUTHEAST NEBRASKA AND SOUTHWEST AROUND MIDNIGHT WHEN LAST OF 850 MOISTURE PLUME FINALLY DROPS SOUTH. AHEAD OF FRONT...TEMPERATURES ARE EXPECTED WELL INTO THE 90S ESPECIALLY IF CLOUD COVER FROM MORNING CONVECTION DISSIPATES AS EXPECTED. WILL LIKELY SEE SOME HEAT INDICES TOPPING 100 FOR A COUPLE OF HOURS THIS AFTERNOON. SHOULD SEE A DRY PERIOD AFTER MIDNIGHT TONIGHT...BUT LOWERING PRESSURES IN THE HIGH PLAINS WILL DRAW 850 MOISTURE BACK NORTH RATHER QUICKLY BY LATER MONDAY MORNING AS NORTHWEST MID LEVEL FLOW CONTINUES. WILL KEEP OUR SMALL POPS FOR OUR WESTERN CWA DURING THAT TIME PERIOD...WITH CHANCES/COVERAGE GRADUALLY INCREASING MONDAY AFTERNOON...BUT ESPECIALLY OVERNIGHT AND TUESDAY AS MAGNITUDE OF MOISTURE RETURN INCREASES. WILL MAINTAIN 30 TO 50 PERCENT STORM CHANCES DURING THE DAY TUESDAY. SEVERE THREAT SHOULD BE MINIMAL THEN AS INSTABILITY REMAINS WEAK DUE TO MUCH COOLER SURFACE TEMPERATURES. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 354 AM CDT SUN AUG 2 2015 UNSETTLED WEATHER PATTERN WITH OCCASIONAL RAIN/STORM CHANCES WILL CONTINUE THROUGH MUCH OF THE REST OF THE WEEK. MID LEVEL RIDGE IS FORECAST TO REMAIN FROM TEXAS WEST TO THE SOUTHWESTERN STATES AT LEAST THROUGH THURSDAY...KEEPING STORM TRACK ROLLING FROM THE CENTRAL/NORTHERN ROCKIES ACROSS THE PLAINS. SEVERAL SHORTWAVES COULD TRIGGER CONVECTION AT JUST ABOUT ANY TIME...WITH MORE POTENT WAVES MOVING THROUGH OUR AREA WEDNESDAY DURING THE DAY AND THURSDAY NIGHT AS PER ECMWF/GFS. WE SHOULD REMAIN ON THE COOL SIDE OF SURFACE FRONTAL SYSTEM...SO INSTABILITY PROGS SUGGEST SEVERE CHANCE WILL BE MINIMAL OVERALL WITH TEMPERATURES REMAINING IN THE 70S AND 80S MUCH OF THE WEEK. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 614 AM CDT SUN AUG 2 2015 CONDITIONS SHOULD REMAIN VFR THROUGHOUT THE MAJORITY OF THE PERIOD. WINDS WILL GRADUALLY VEER TO THE NORTH TODAY AS A WEAK COLD FRONT MOVES THROUGH THE REGION. A FEW STORMS COULD FIRE ALONG THE BOUNDARY THIS EVENING AND TONIGHT. HOWEVER CONFIDENCE IN EXACT TIMING AND LOCATION OF STORMS REMAINS LOW AT THIS TIME...SO OPTED TO CONTINUE TO LEAVE PRECIP OUT OF THIS ISSUANCE. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...KG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
949 AM EDT SUN AUG 2 2015 .SYNOPSIS... A STATIONARY FRONT LINGERING ALONG THE COAST OF THE SOUTHEAST STATES WILL DISSIPATE MONDAY. THE NEXT FRONT WILL AFFECT THE AREA LATE THIS WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 945 AM SUNDAY...SOMEWHAT DRIER AIR ACROSS THE REGION THIS MORNING AS PRECIPITABLE WATER VALUES HAVE DROP TO 1.29 INCHES WITH DEWPOINTS IN THE UPPER 60S INLAND. WHILE MOST AREAS WILL REMAIN DRY...THE HIGH-RESOLUTION HRRR AND ENSEMBLE WRF FROM NCAR SHOWING SOME ISOLATED SHOWERS JUST INLAND ALONG THE SEA BREEZE DURING THE MID-AFTERNOON HOURS. COVERAGE WILL BE VERY LIMITED AND WILL CONTINUE WITH JUST SLIGHT CHANCE POPS. QUITE WARM INLAND WITH PLENTY OF SUNSHINE PUSHING TEMPERATURES WELL INTO THE 90S WITH UPPER 80S COASTAL AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AS OF 3 AM SUN...BOTH MODELS INCREASE MOISTURE FROM THE SOUTH IN RESPONSE TO BROAD UPPER TROF ALONG EASTERN SEABOARD SHARPENING UP. WILL NUDGE POPS A BIT FURTHER NORTH AND INCREASE TO CHANCE SOUTH OF A LINE FROM OREGON INLET TO MOREHEAD CITY. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 3 AM SUN...GFS/ECMWF TRENDING A BIT WETTER COAST MON INTO MON NIGHT AS MOISTURE INCREASES AHEAD OF WEAK LOW LIFTING NE ALONG REMNANT FRONTAL BOUNDARY. FOR NOW KEPT POPS IN CHC RANGE CST BUT IF CURRENT MDL TRENDS CONT THEY MAY NEED TO BE INCREASED IN LATER FCSTS. DEEP INLAND LOOKS MAINLY DRY AS BEST MOISTURE STAYS ALONG THE CST. HIGHS MON LOWER 90S INLAND TO 80S CST WITH 70S AREAS WIDE MON NIGHT. MAIN STORY FOR THE TUE AND WED WILL BE THE HEAT AS TYPICAL SUMMERTIME PATTERN RE-DEVELOPS WITH HIGH PRESSURE OFFSHORE AND STRENGTHENING TROUGH INLAND. HEIGHTS BUILD THROUGH MID WEEK...WITH LOW LEVEL THICKNESS VALUES AND 850MB TEMPS SUPPORTING HIGHS IN THE UPPER 80S/LOW 90S ALONG THE COAST...AND MID 90S/POSSIBLY A FEW UPPER 90S INLAND. FOR NOW FCST DEWPTS KEEP APPARENT TEMPS BELOW 105 BUT WILL BE CLOSE TO HEAT ADVRY. MAINLY SLIGHT CHC POPS TUE AND WED WITH BEST CHC CST EARLY MORN AND INLAND DURING AFTN AND EVENING. CHANCE OF SHRA AND TSRA INCREASE LATE WEEK AS UPR TRF DEVELOPS TO THE W WITH WEAK COLD FRONT APPROACHING FROM THE NW THU AND STALLING NEAR THE AREA FRI INTO SAT. HAVE CHC POPS THRU THE PERIOD. WILL REMAIN MUGGY HOWEVER TEMPS WONT BE QUITE A S HOT WITH MAINLY UPR 80S AND LOWER 90S. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... SHORT TERM /THROUGH TONIGHT/ AS OF 7 AM SUN...THE MIXTURE OF CIGS/VSBYS WILL BECOME ALL VFR IN THE NEXT COUPLE OF HOURS AFTER SUNRISE AND ATMOSPHERIC MIXING BEGINS. OTHERWISE...MOSTLY VFR THROUGH THE PERIOD. LIGHT SOUTHEAST WINDS AROUND 5 KNOTS THIS AFTERNOON VEER TO SOUTH TONIGHT. ISOLATED CONVECTION POSSIBLE AT TERMINALS EWN AND OAJ...DRY ELSEWHERE. PATCHY IFR/MVFR FOG POSSIBLE AGAIN IN PREDAWN HOURS MONDAY. LONG TERM /MON THROUGH THURSDAY/... AS OF 3 AM SUN...DECENT CVRG OF SHRA/TSRA NEAR CST MON INTO MON NIGHT BUT BEST BET FOR REDUCED CIGS/VSBYS WILL BE MAINLY E OF TERMINALS ESPCLY ISO/PGV WITH POSS SOME MVFR OAJ/EWN. MAINLY VFR TUE AND WED WITH LIMITED PRECIP AND LOW LVL SW FLOW LIMITING FOG/ST THREAT. COULD SEE BETTER CVRG OF SHRA AND TSRA THU AHEAD OF NEXT FRONT WITH BRIEF SUB VFR POSS MAINLY IN THE AFTN. && .MARINE... SHORT TERM /THROUGH TONIGHT/ AS OF 950 AM SUNDAY...LIGHT W/NW WINDS ON ALL THE WATERS THIS MORNING WITH ONLY DIAMOND BUOY GUSTING ABOVE 10 KNOTS. SEAS ARE 1 TO 3 FEET...WITH SOME LONG PERIOD SWELL OVER NORTHERN AREAS. WINDS SHOULD GRADUALLY BECOME MORE SOUTHERLY BY LATE TODAY. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 3 AM SUN...SSW WINDS WILL INCREASE MON AS WEAK LOW LIFTS NE ALONG FRONT/TRF INLAND TIGHTENING GRDNT. WINDS SHLD REACH 15 TO 20 KTS MOST WTRS MON AFTN WITH SEAS BUILDING TO 4 TO 6 FEET HIGHEST OUTER CNTRL AND SRN WTRS. SSW WINDS THEN EXPECTED AT 10 TO 20 KTS REST OF THE FCST PERIOD AS TRF CONTS INLAND WITH HIGH OFFSHORE. THESE WINDS WILL KEEP SEAS ELEVATED ESPCLY OUTER WTRS FROM HAT S WHERE WILL BE MAINLY 5 TO 6 FT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...HSA NEAR TERM...CTC SHORT TERM...HSA LONG TERM...RF AVIATION...RF/HSA MARINE...RF/CTC
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1059 AM EDT SUN AUG 2 2015 .SYNOPSIS... DRY HIGH PRESSURE WILL REMAIN IN PLACE ACROSS THE AREA THROUGH MONDAY. LOW LEVEL MOISTURE WILL GRADUALLY RETURN THROUGH THE WEEK AS ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN MOVES INTO THE AREA AND STALLS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1045 AM EDT SUNDAY...DEWPOINTS ARE RUNNING A BIT LOWER THAN FORECAST SO HAVE MADE SOME ADJUSTMENTS ACCORDINGLY. OTHER GRIDS IN GOOD SHAPE FOR THE MOST PART. HRRR AND OTHER HIRES GUIDANCE DO STILL WANT TO DEVELOP SOME CONVECTION OVER THE MOUNTAINS THIS AFTERNOON DESPITE THE DRY DEWPOINTS...BUT ENOUGH LAPSE RATE ALOFT FOR SOME MINIMAL CAPE VALUES...SO HAVE KEPT THE SLIGHT CHANCE POPS FOR THIS AFTERNOON. 1045 UTC UPDATED...SKY COVER HAS BEEN UPDATED TO ACCOUNT FOR CIRRUS CROSSING THE INTERSTATE 77 CORRIDOR AND MOVING INTO SW SN AND NE GA. WINDS WERE UPDATED FROM THE LATEST NAM GUIDANCE. AT 230 AM EDT SUNDAY...AN UPPER RIDGE WILL REMAIN OVER THE WESTERN USA TODAY AND TONIGHT...WHILE A TROUGH PERSISTS OVER THE EAST. WEAK...CHANNELED SHORTWAVE ENERGY WILL MOVE THROUGH BASE OF THE TROUGH OVER VA TODAY. AT THE SURFACE...A STATIONARY FRONT WILL REMAIN NEAR THE COASTS OF NC...SC AND GA. THE BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE WILL REMAIN SOUTHEAST OF OUR AREA...AS WILL ASSOCIATED PRECIPITATION. MOISTURE IS EXPECTED TO INCREASE OVER OUR AREA HOWEVER...AND FORECAST MODEL SOUNDINGS WILL BE SUPPORTIVE OF CONVECTION THIS AFTERNOON AND EVENING IN THE MOUNTAINS. TEMPERATURES WILL SLIGHTLY ABOVE NORMAL. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 205 AM SUNDAY...EXPECT ANOTHER QUITE DAY MONDAY BEFORE A PATTERN CHANGE AND A RETURN THE MORE TYPICAL DIURNAL THUNDERSTORM REGIME. AN UPPER TROF WILL BE OVER THE ERN US WITH DRY HIGH PRESSURE IN PLACE AT THE SFC. EXPECT THE DEWPOINTS TO MIX OUT ONCE AGAIN INTO THE 50S MOST PLACES...KEEPING INSTABILITY AT A MINIMUM. THE GUIDANCE SHOWS A LOW PRESSURE SYSTEM FORMING OVER THE GULF AND MOVING NE NEAR THE ATLANTIC COAST ALONG AN OLD FRONTAL BOUNDARY. HOWEVER...MOST MDLS KEEP THE LOW SOUTH AND EAST OF THE AREA WITH MINIMAL EFFECT OVER THE CWFA. THEREFORE...NO SIGNIFICANT CONVECTION IS EXPECTED. TEMPERATURES WILL BE WELL ABOVE NORMAL. THE UPPER TROF BEGINS TO LIFT TUE WITH A WLY FLOW DEVELOPING. AT THE SFC...A WEAK FRONTAL SYSTEM SAGS INTO THE AREA FROM THE NORTH. A MOIST LOW LEVEL FLOW RETURNS BRINGING INCREASE LOW LEVEL MOISTURE. DEWPOINTS WILL MIX OUT...BUT ONLY TO AROUND 60. THIS WILL BRING AN INCREASE IN INSTABILITY AND POTENTIAL FOR AFTERNOON CONVECTION. STILL...COVERAGE APPEARS TO BE LIMITED TO ISOLATED...AND MAINLY OVER NC. TEMPS WILL RISE A COUPLE OF DEGREES FROM MON. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 320 AM SUNDAY...THE PATTERN CHANGE IS FULLY UNDERWAY AT THE BEGINNING OF THE MEDIUM RANGE. ZONAL FLOW ALOFT BRINGS A SERIES OF SHORTWAVES ACROSS THE AREA THRU THU. STRONGER SHORT WAVES MOVE IN BEGINNING FRI BRINGING A RETURN TO THE UPPER TROF TO THE EASTERN CONUS. ANOTHER SHORTWAVE MOVES THRU ON SAT REINFORCING THE TROF. AT THE SFC...A WEAK COLD FRONT SAGS SOUTH AND STALLS ACROSS THE AREA. THE SHORTWAVES HELP DEVELOP A SERIES OF LOW PRESSURE CENTERS WHICH THEN MOVE ALONG THE FRONT AND ACROSS THE AREA THRU FRI. THIS WILL BRING INCREASING CHANCES OF MAINLY DIURNAL CONVECTION. THAT SAID... CONVECTION COULD LINGER THRU THE NITE AS THE CWFA WILL BE IN THE PATH OF ANY POTENTIAL MCS ACTIVITY. A STRONGER LOW PRESSURE CENTER DEVELOPS ON SAT AND MOVES EAST OF THE AREA POSSIBLY DRAGGING THE FRONT SOUTH OF THE AREA. HOWEVER...THE MOIST UNSTABLE AIR MASS WILL LINGER...KEEPING THE CHC OF CONVECTION IN PLACE...ALTHOUGH WITH A LOWER RESULTING POP. TEMPS SHOW A SLOW BUT STEADY COOLING TREND THRU THE PERIOD...ENDING UP NEAR NORMAL BY SAT. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... AT KCLT...VFR. FEW TO OCCASIONALLY SCT CU GENERALLY 8-9KFT LATE THIS MORNING AND WILL LIKELY LOWER SOME AS MIXING INCREASES...BUT COVERAGE IS GENERALLY NOT EXPECTED TO BE SUFFICIENT FOR A CIG. INSTABILITY WILL BE TOO LIMITED FOR CONVECTION. LIGHT WINDS WILL BE FROM THE NE TODAY....VEERING SE TONIGHT. SOME GUIDANCE IS LEANING TOWARD DAYBREAK FOG MONDAY MORNING AT SURROUNDING SITES...BUT OTHER GUIDANCE IS LESS PESSIMISTIC. ELSEWHERE...VFR. SO FAR MOUNTAIN FOG HAS BEEN LIMITED TO VALLEYS WELL SW OF KAVL. HIGH VFR CIGS ARE POSSIBLE EARLY TODAY AS CIRRUS MOVES OVERHEAD. LOW VFR CIGS LATER TODAY WILL BE POSSIBLE IN THE NC MOUNTAINS WHERE CONVECTION WILL COULD OCCUR IN BETTER INSTABILITY. LIGHT WINDS WILL BE FROM THE NE MORNING...EXCEPT AT KAVL WHERE THEY WILL VEER FROM NW TO SE TODAY AND RETURN TO NW TONIGHT...AND KHKY WHERE THEY BACK FROM NE TO N TONIGHT. GUIDANCE IS BECOMING MORE SUPPORTIVE OF DAYBREAK FOG ON MONDAY...BUT THE BEST BET IS INITIALLY IN MOUNTAIN VALLEYS WHERE COOL AIR WILL POOL. OUTLOOK...GRADUALLY INCREASING PRECIPITATION/RESTRICTION CHANCES THROUGH MID WEEK AS MOIST SOUTHERLY FLOW RETURNS. CONFIDENCE TABLE... 15-21Z 21-03Z 03-09Z 09-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% MED 66% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 94% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 94% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...RWH NEAR TERM...TDP SHORT TERM...RWH LONG TERM...RWH AVIATION...JAT/TDP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
455 AM MDT SUN AUG 2 2015 .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 300 AM MDT SUN AUG 2 2015 TODAY...FLOW ALOFT REMAINS NORTHWEST. LOOKS LIKE THE NAM PROJECTS A LOW LEVEL BOUNDARY TO SET UP THIS AFTERNOON ALONG THE WYOMING AND COLORADO STATE LINE WITH A NICE 850/700 MB THETA-E RIDGE AXIS OVER NORTHERN COLORADO. THUS...AS NAM DEPICTS...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP ALONG AND NEAR THE COLORADO STATE LINE...THEN SLOWLY DIMINISH THIS EVENING ALONG THE LARAMIE RANGE. TONIGHT/MONDAY...MODELS CONSISTENT IN SHOWING MORE MONSOONAL MOISTURE BEING TAPPED INTO AND MOVING ACROSS OUR COUNTIES MONDAY AFTERNOON...THOUGH NOW FURTHER WEST THAN PREVIOUS RUNS INDICATED. STILL THOUGH...WITH A SHORTWAVE TROUGH ALOFT MOVING OVERHEAD AND INCREASING LOW AND MID LEVEL MOISTURE...WILL CONTINUE OUR FORECAST WITH ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ALONG AND WEST OF INTERSTATE 25...WITH LESSER ACTIVITY FURTHER EAST. MONDAY NIGHT/TUESDAY/TUESDAY NIGHT...SHORTWAVE TROUGH ALOFT MOVES SLOWLY EASTWARD ACROSS OUR NORTHERN COUNTIES...AND WITH PLENTY OF LOW AND MID LEVEL MOISTURE...WILL SEE SCATTERED SHOWERS AND THUNDERSTORMS ACROSS OUR NORTHERN COUNTIES...LESS ACTIVITY FURTHER SOUTH WITH DRIER AIRMASS AND NEGATIVE THETA-E ADVECTION. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 300 AM MDT SUN AUG 2 2015 MONSOONAL MOISTURE TO REMAIN OVER THE AREA THROUGH AT LEAST THURSDAY. DEPENDING ON WHICH MEDIUM RANGE GUIDANCE USED...IT COULD BE LONGER. FORECAST BASED OFF THE MORE MOIST ECMWF THIS FORECAST CYCLE. STARTING OFF WEDNESDAY...WE ARE LOOKING AT THE SEMI-PERMANENT THATS BEEN IN THE AREA TO LAY ALONG THE NEBRASKA PANHANDLE...MAYBE SLIGHTLY FURTHER EAST. GFS SHOWING THE BOUNDARY FURTHER EAST AND THUS THE ENTIRE CWFA DRY. ECMWF ON THE OTHER HAND HAS THE BOUNDARY REMAINING ALONG THE EAST SLOPES OF THE LARAMIE RANGE...WITH NORTHEAST UPSLOPE FLOW ACROSS THE PANHANDLE. THIS WOULD GIVE MOST LOCATIONS ALONG AND EAST OF THE LARAMIE RANGE WITH AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON. THURSDAY AFTERNOON...A FAIRLY STRONG SHORTWAVE TRACKS ACROSS NORTHERN WYOMING INTO SOUTH DAKOTA. STRONG SOUTH TO SOUTHEASTERLY 850MB WINDS IN THE PANHANDLE AND A 70KT 250MB JET COULD BE SETTING US UP FOR ANOTHER ROUND OF SEVERE THUNDERSTORMS AT LEAST FOR THE SOUTHERN HALF OF THE PANHANDLE AS WELL AS EASTERN LARAMIE COUNTY...UP INTO GOSHEN COUNTY. SHOWERS AND THUNDERSTORMS LOOK TO PERSIST INTO THE LATE EVENING HOURS THURSDAY. AFTER A DRY FRIDAY WITH A TRANSITORY RIDGE MOVING THROUGH THE CWFA...SATURDAY LOOKS TO BE A REPEAT OF THURSDAY AS ANOTHER SHORTWAVE MOVES INTO THE AREA FROM THE SOUTHWEST. SHOULD SEE AT LEAST SLIGHT CHANCE POPS FOR MUCH OF THE AREA WITH BEST CHANCES ALONG THE WYOMING COLORADO STATE LINE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 450 AM MDT SUN AUG 2 2015 LOOKS LIKE A REPEAT IN THE FORECAST FOR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE AIRPORTS AS WAS THE CASE SATURDAY. HRRR USED FOR TIMING OF CONVECTION...MAINLY ALONG THE I-80 CORRIDOR FROM KSNY TO KLAR. TIMING LOOKS TO BE FROM 20Z THROUGH 01Z. && .FIRE WEATHER... ISSUED AT 145 AM MDT SUN AUG 2 2015 HUMIDITIES INCREASING THE NEXT FEW DAYS AS LOW AND MID LEVEL MOISTURE INCREASES ALONG WITH INCREASING CHANCES FOR LATE DAY SHOWERS AND THUNDERSTORMS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RUBIN LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
955 AM MST SUN AUG 2 2015 .SYNOPSIS...A DRYING TREND WILL LEAD TO LESS THUNDERSTORM ACTIVITY TODAY AND MONDAY...WITH THUNDERSTORMS CONFINED TO MAINLY NEAR THE NEW MEXICO BORDER TUESDAY. PRECIPITATION CHANCES WILL THEN INCREASE AROUND THURSDAY FOLLOWED BY A CHANCE OF THUNDERSTORMS ACROSS MUCH OF SOUTHEAST ARIZONA FRIDAY AND SATURDAY. EXPECT ABOVE NORMAL DAYTIME TEMPERATURES THIS WEEK. && .DISCUSSION...IR/VISIBLE SATELLITE IMAGERY INDICATED MOSTLY CLOUDY SKIES NEAR THE NEW MEXICO BORDER AT THIS TIME...WHILE SUNNY SKIES WERE THE RULE WEST OF TUCSON. WATER VAPOR IMAGERY DEPICTED THE DEEPER MOISTURE TO BE ACROSS FAR ERN SECTIONS. MEANWHILE...A A DISTINCTLY DRIER MID/UPPER LEVEL REGIME WAS DEPICTED VIA WATER VAPOR IMAGERY FROM TUCSON WWD INTO WRN PIMA COUNTY. 02/12Z KTWC SOUNDING ALSO DEPICTED A MARKEDLY DRIER REGIME ABOVE 400 MB VERSUS 24 HOURS AGO. HOWEVER...THE PROFILE WAS STILL QUITE MOIST...WITH TOTAL PRECIP WATER VALUE OF 1.52 INCHES. 02/12Z UPPER AIR PLOTS DEPICTED LIGHT TO MODERATE GENERALLY WLY FLOW ACROSS MUCH OF THIS FORECAST AREA...AS A RIDGE AXIS EXTENDED FROM THE PERMIAN BASIN OF WEST TEXAS SWWD TO WEST OF THE BAJA CALIFORNIA SPUR. 02/12Z NAM/GFS...02/00Z ECMWF AND VARIOUS RUC HRRR SOLUTIONS AGREE THAT SCATTERED SHOWERS/TSTMS WILL FAVOR GREENLEE/GRAHAM/COCHISE COUNTIES EAST OF TUCSON THIS AFTERNOON AND EARLY THIS EVENING. THERE APPEARS TO BE ENOUGH MOISTURE TO SUPPORT AT LEAST A SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON/EVENING FROM THE VICINITY OF NOGALES NWD ACROSS ERN PIMA COUNTY...INCLUDING TUCSON...AND FURTHER NWD INTO SOUTHEASTERN PINAL COUNTY. PRECIP-FREE CONDITIONS SHOULD OCCUR ACROSS WRN PIMA COUNTY...AND MUCH OF THE TOHONO O`ODHAM NATION AND SOUTH CENTRAL PINAL COUNTY. IF THE VARIOUS RUC HRRR SOLUTIONS BECOME REALITY...SHOWERS/TSTMS WILL QUICKLY DISSIPATE THIS EVENING. FOR NOW...WILL MAINTAIN A SLIGHT CHANCE OF SHOWERS/TSTMS LATE TONIGHT ACROSS FAR ERN SECTIONS WITH DRY CONDITIONS ELSEWHERE. HIGH TEMPS THIS AFTERNOON WILL BE QUITE CLOSE TO TEMPS ACHIEVED SAT...OR WILL BE A FEW DEGREES WARMER DEPENDING UPON LOCATION. A WARMING TREND WILL THEN OCCUR MON-TUE AS THE DRYING TREND CONTINUES ACROSS THE AREA. THERE ARE NO UPDATES NECESSARY FOR THE INHERITED OFFICIAL FORECAST. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL. && .AVIATION...VALID THRU 03/18Z. EXPECT SCATTERED -TSRA/-SHRA EAST AND SOUTH OF KTUS THIS AFTERNOON AND EVENING. THERE IS A 10-20 PERCENT CHANCE OF -TSRA/-SHRA AT KTUS THIS AFTERNOON AND EVENING...BUT THIS CHANCE IS TOO LOW TO INCLUDE IN THE TAF. THE BULK OF ANY -TSRA/-SHRA WILL BE EAST OF THE NEW MEXICO BORDER BY AROUND 03/06Z. HOWEVER...ISOLATED MAINLY -SHRA WILL BE POSSIBLE EAST OF KTUS LATE TONIGHT INTO MONDAY MORNING. OTHERWISE...WEST OF KTUS EXPECT CLEAR SKIES OR A FEW CLOUDS ABOVE 10K FT AGL THROUGH THE PERIOD. EAST AND SOUTH OF KTUS...A FEW TO BROKEN CLOUDS MAINLY AT 7-11K FT AGL THIS AFTERNOON AND EVENING... THEN CLOUD DECKS MOSTLY ABOVE 10K FT AGL LATE TONIGHT INTO MONDAY MORNING. SURFACE WIND WILL GENERALLY BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SOUTHWEST WINDS ALOFT TODAY WILL BEGIN TO USHER DRIER AIR INTO THE REGION. PRECIPITATION CHANCES TODAY WILL GENERALLY BE CONFINED TO AREAS EAST OF TUCSON AND NEAR HIGH TERRAIN...BEFORE BEING RELEGATED TO FAR SOUTHEASTERN PORTIONS OF ARIZONA AND MOUNTAINS ON MONDAY. THE LOWEST PRECIPITATION CHANCES WILL OCCUR ON TUESDAY. HIGH PRESSURE RETURNS TO A MORE FAVORABLE LOCATION FOR DAILY CHANCES OF SHOWERS AND THUNDERSTORMS THURSDAY INTO SATURDAY. OUTSIDE OF THUNDERSTORM WIND GUSTS...20-FT WINDS WILL GENERALLY BE TERRAIN DRIVEN AND LESS THAN 15 MPH. HOWEVER SOME AFTERNOON AND EARLY EVENING BREEZINESS IS LIKELY DUE TO DAYTIME HEATING...ESPECIALLY THROUGH THE GILA VALLEY NEAR SAFFORD. && .PREV DISCUSSION...THE DRY PUSH WILL CONTINUE IN EARNEST ON MONDAY...AIDED BY DEEPENING SOUTHWESTERLY/WESTERLY FLOW. THIS WILL RELEGATE THUNDERSTORMS TO NEAR THE AZ/NM BORDER AND THE WHITE MOUNTAINS. TUESDAY MAY BE THE MOST INACTIVE DAY IN THIS FORECAST PACKAGE...AS THE MID-LEVEL HIGH CENTER PIVOTS ALMOST DIRECTLY OVERHEAD. MODEL DIFFERENCES BEGIN TO INCREASE STARTING WEDNESDAY AND REVOLVE AROUND THE DEGREE OF MOISTURE RETURN WE SEE AS THE SUBTROPICAL HIGH BEGINS TO MIGRATE EAST INTO NM...THE GFS BEING THE QUICKEST OF THE 00Z GFS/ECMWF/CMC NWP SUITE. AT THIS TIME...HAVE OPTED TO MAINTAIN SLIGHT CHANCE POPS SOUTH OF TUCSON...ALTHOUGH BASED ON THE TIMING OF THE EASTWARD-MOVING HIGH CENTER...THIS MAY STILL BE OVERDONE. FOR THURSDAY THROUGH SATURDAY...PRECIPITATION CHANCES WILL INCREASE AS WELL AS SHIFT FROM WEST-TO-EAST ACROSS THE CWA AS THE MID-LEVEL HIGH TEMPORARILY MOVES TO A MORE TYPICAL AUGUST POSITION ACROSS CENTRAL AND NORTHERN NM. ALAS...THIS INCREASE IN CONVECTIVE COVERAGE MAY BE SHORT-LIVED AS ANOTHER TROUGH AXIS IS POISED TO SWING INTO THE THE GREAT BASIN. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON FRANCIS PREVIOUS DISCUSSION...CARLAW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
237 PM MDT SUN AUG 2 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 235 PM MDT SUN AUG 2 2015 ...HEAVY RAIN POSSIBLE OVER THE MOUNTAINS TONIGHT... ...ANOTHER ROUND OF STORMS TOMORROW...SOME ON THE STRONG SIDE... MAIN CONCERN FOR THE SHORT TERM IS POTENTIAL FOR FLASH FLOODING OVER THE MOUNTAINS THROUGH TONIGHT. SCT TO NMRS SHOWERS AND STORMS HAVE ALREADY DEVELOPED THIS AFTERNOON...AND AS A STRONG SHORTWAVE NOW MOVING THROUGH AZ AND UT CONTINUES TO TRANSLATE TO THE NE THIS EVENING...THE THREAT FOR LOCALLY HEAVY RAINFALL WILL PERSIST. LATEST GUIDANCE SHOWS THE ASSOCIATED UPPER LOW OVER UT MOVING INTO NW CO BY 12-15Z MON MORNING. AM PARTICULARLY CONCERNED BY THE LATEST HIGH RES WRF AND HRRR RUNS...WHICH BOTH SHOW A STRONG BAND OF HEAVY PRECIP MOVING THROUGH SW-CENTRAL CO BETWEEN 03Z AND 09Z TONIGHT. THIS WOULD COINCIDE WITH STRONGEST UPPER FORCING FROM THE SHORT WAVE. IN COORDINATION WITH KGJT AND KABQ HAVE EXPANDED OUR FLASH FLOOD WATCH FOR THE SAN JUANS TO INCLUDE THE REST OF THE CONTDVD...ALONG WITH THE SANGRE DE CRISTO RANGE...THROUGH 09Z TONIGHT. THIS MAY HAVE TO BE EXTENDED SLIGHTLY IF THE BANDED HEAVY PRECIP GETS A DELAYED START...BUT THERE IS STILL SOME UNCERTAINTY ON HOW INTENSE THE PRECIP WILL BE...ESPECIALLY SINCE THE STRONGEST FORCING WILL OCCUR DURING THE OVERNIGHT HOURS WHEN CONVECTION IS GENERALLY LESS INTENSE. NEVERTHELESS...ANYONE PLANNING ON BEING IN OR TRAVELING THROUGH THE MTS THIS EVE AND OVERNIGHT NEEDS TO BE AWARE OF THE POTENTIAL FOR FLOOD-PRODUCING RAINS...WHICH COULD LEAD TO SUDDEN SMALL STREAM RISES...FLOODED ROADWAYS...AND MUD OR ROCK SLIDES IN THE STEEPER TERRAIN. TOMORROW...THE UPPER WAVE WILL CONTINUE TO MOVE TO THE NE DURING THE DAY...INTO SRN WY BY 00Z TUE. THIS WILL BRING SEVERAL MORE ROUNDS OF CONVECTION TO THE AREA...PARTICULARLY OVER THE HIGHER TERRAIN. LOW LEVEL MOISTURE WILL ALSO INCREASE OVER THE PLAINS. ALONG WITH INCREASED SHEAR...THIS WILL RAISE THE THREAT OF SOME STRONG TO POSSIBLY SVR STORMS OVER THE AREA. IT LOOKS LIKE THE GREATEST INSTABILITY WILL BE OVER THE SERN PLAINS GENERALLY SOUTH OF HGWY 50 AND E OF I-25...AND THIS IS WHERE THE STRONGEST STORMS LIKELY WILL BE DURING THE AFTERNOON. LOWER TEMPS ALOFT ALONG WITH INCREASED LLVL MOISTURE AND PRECIP/CLOUDS WILL HOLD HIGH TEMPS A GOOD 5-10 DEGREES BELOW THE HIGH TEMPS FROM TODAY...SO WILL SEE MAINLY TEMPS IN THE 70S AND 80S MON AFTERNOON. ROSE .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 235 PM MDT SUN AUG 2 2015 MON NIGHT...AS AN UPR DISTURBANCE MOVES NORTHEASTWARD OUT OF SERN CO AND AN UPR TROF MOVES NORTHWARD INTO WY...THE ISOLD TO SCT PCPN ACRS THE FORECAST SHOULD COME TO AN END AROUND MIDNIGHT. ON TUE AN UPR RIDGE AXIS WL LIE FROM AZ INTO THE GREAT BASIN REGION... RESULTING IN W TO NW FLOW ALOFT OVR THE FORECAST AREA. THE LATEST RUN OF THE NAM AND GFS SHOWS DRIER CONDITIONS FOR TUE...WITH MAINLY JUST SOME ISOLD PCPN CHANCES. TUE NIGHT SFC HIGH PRESSURE BACKS INTO ERN CO AND IS EXPECTED TO BRING INCREASING LOW LEVEL MSTR AND THE POTENTIAL FOR SOME LOW CLOUDS. AS A RESULT...THE NAM PRINTS OUT THE POTENTIAL FOR SOME LIGHT PCPN OVR THE FAR SERN PLAINS LATE TUE NIGHT AND EARLY WED MORNING...HOWEVER WL LEAVE THE FORECAST DRY FOR NOW. ON WED THE UPR RIDGE AXIS SHIFTS EASTWARD OVR CO WITH RELATIVELY DRY CONDITIONS EXPECTED THRU MUCH OF THE DAY WITH MAINLY JUST SOME ISOLD PCPN OVR AND NR THE MTN AREAS. HOWEVER A WEAK DISTURBANCE MAY ROUND THE TOP OF THE RIDGE AND MOVE THRU ERN CO IN THE EVENING HOURS TO HELP KICK OFF SOME CONVECTION ACRS THE PLAINS. ON THU THE UPR RIDGE GETS FLATTENED ACRS THE FORECAST AREA AS A SHORTWAVE TROF MOVES THRU MT WY AND NRN CO. ONLY SOME ISOLD PCPN IS EXPECTED THU AFTERNOON...BUT THEN AS THAT DISTURBANCE MOVES OFF INTO THE PLAINS STATES THE ECMWF IS STILL SHOWING AN MCS DEVELOPING AND AFFECTING PORTIONS OF ERN CO BY THU EVENING. FRI AN UPR TROF IS EXPECTED TO MOVE OVR CA...WITH AN UPR RIDGE BEING OVR CO. MSTR STILL LOOKS TO BE SOMEWHAT LIMITED DURING THE DAY...WITH MAYBE JUST SOME ISOLD TO SCT PCPN OVR THE FORECAST AREA. THEN FRI NIGHT AND SAT AS THAT UPR TROF MOVES EAST-NORTHEASTWARD INTO ID AND UT...MONSOON MSTR IS EXPECTED TO BE DRAWN NORTHWARD INTO WESTERN CO AGAIN WHICH WL INCREASE THE CHANCES FOR PCPN...ESPECIALLY OVR THE MTNS AND HIGH VALLEYS. AS THE UPR DISTURBANCE MOVES EASTWARD ACRS MT AND WY SAT NIGHT...PCPN IS EXPECTED TO SPREAD ACRS THE ERN CO PLAINS. THEN BY SUN IT LOOKS LIKE THE FORECAST AREA WL AGAIN BE CUTOFF FROM THE MONSOON MSTR...LEADING TO DRIER CONDITIONS AGAIN. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 235 PM MDT SUN AUG 2 2015 MAIN CONCERN CONTINUES TO BE STORMS THIS AFTERNOON AND THIS EVE. AT KCOS AND KPUB THIS THREAT WILL BE HIGHEST THROUGH AROUND 03Z...ALTHOUGH ISOLD STORMS WILL BE POSSIBLE THROUGH TONIGHT. AT KALS...SEVERAL ROUNDS OF MODT TO HEAVY PRECIP WILL BE POSSIBLE THROUGH TONIGHT. COULD SEE SEVERAL ROUNDS OF MVFR TO OCCASIONALLY IFR DEVELOP FOR THE SAN LUIS VALLEY DUE TO LOW CIGS AND/OR VIS. AS AN UPPER LEVEL DISTURBANCE CONTINUES TO MOVE NEWD FROM UT INTO NW CO AND SW WY...THIS WILL KEEP THE THREAT OF PRECIP AND LOW CIGS GOING THROUGH MON MORNING FOR MUCH OF SE CO. STORMS COULD REDEVELOP MON AFTERNOON BEFORE DISSIPATING FROM SW TO NE MON EVENING. ROSE && .PUB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR COZ058-060-061-063- 066>068-072>075. && $$ SHORT TERM...ROSE LONG TERM...28 AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1119 AM MDT SUN AUG 2 2015 .UPDATE... ISSUED AT 1047 AM MDT SUN AUG 2 2015 UPDATED TO DELAY TIMING OF HIGHER POPS BY A FEW HOURS. STILL NOT SEEING THE PRECIP OVER SW CO MOVE INTO OUR AREA...BUT SHOULD SEE FAIRLY STEADY INCREASE IN PRECIP THIS AFTERNOON. LATEST HRRR AND OTHER GUIDANCE IS SHOWING SIGNIFICANT QPF OVER THE WRN CWA THIS EVENING. WILL CONSIDER EXPANDING THE FLOOD WATCH BASED ON TRENDS EARLY THIS AFTERNOON. ROSE && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 341 AM MDT SUN AUG 2 2015 CURRENTLY...QUIET WEATHER HAS SPREAD ACROSS SOUTHERN COLORADO EARLY THIS MORNING. TEMPERATURES HAVE REMAINED MILD WITH 60S OVER THE LOWER ELEVATIONS UNDER LIGHT WINDS. TODAY AND TONIGHT...A STRONG UPPER LEVEL DISTURBANCE UNDER A BROAD AREA OF HIGH PRESSURE ALOFT IS FORECAST TO ROTATE NORTHWARD ACROSS UTAH AND WESTERN COLORADO THIS AFTERNOON AND TONIGHT. ABUNDANT MOISTURE IS IN PLACE...AND MODELS DEVELOP LOW LEVEL SOUTHEASTERLY UPSLOPE FLOW ACROSS THE SAN LUIS VALLEY INTO THE EASTERN SAN JUANS FOR THIS AFTERNOON. ALL WILL COMBINE TO PROVIDE THE FOCUS FOR THUNDERSTORMS THIS AFTERNOON OVER THE SAN JUAN RANGE...NORTH INTO THE LA GARITA MOUNTAINS. LOCALLY HEAVY RAINFALL IS EXPECTED WITH THESE THUNDERSTORMS...AND FLASH FLOODING WILL BE OF CONCERN...ESPECIALLY FOR THE WEST FORK COMPLEX BURN SCAR. A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE BURN SCAR AREA FOR THIS AFTERNOON AND EVENING. ELSEWHERE...EXPECT WIDESPREAD SHOWERS AND THUNDERSTORMS OVER ALL THE MOUNTAIN AREAS AND THE SAN LUIS VALLEY THIS AFTERNOON AND EVENING. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH STRONGER CORES ALONG WITH LIGHTNING. THERE IS LESS CERTAINTY OVER THE EASTERN PLAINS. MOST HIGH-RES MODELS BRING DRIER AIR INTO THE PLAINS THIS AFTERNOON LIMITING AFTERNOON INSTABILITY ALONG WITH THE SHOWER AND THUNDERSTORM POTENTIAL. THAT BEING SAID...MOST HIGH-RES SOLUTIONS DO BRING SHOWERS AND THUNDERSTORMS INTO THE PALMER DIVIDE AND RATON MESA REGIONS THIS AFTERNOON AND HAVE THE HIGHEST POPS OVER THESE LOCATIONS. THERE ARE A COUPLE OF SOLUTIONS...NAMELY THE ARW AND THE NSSL WRF...WHICH DO BRING A ROUND OF SHOWERS AND THUNDERSTORMS INTO THE I-25 CORRIDOR BY THIS EVENING...AND HAVE LOW POPS IN THIS AREA TO ACCOUNT FOR THE UNCERTAINTY. THE FAR EASTERN PLAINS WILL MOST LIKELY REMAIN DRY THROUGH TONIGHT. MODELS IN GOOD AGREEMENT WITH SHOWERS AND THUNDERSTORMS DISSIPATING ACROSS MUCH OF THE AREA AROUND MIDNIGHT. THE EXCEPTION LOOKS TO BE ALONG THE CONTINENTAL DIVIDE WHERE INFLUENCES OF THE UPPER DISTURBANCE OVER UTAH INTO WESTERN COLORADO WILL REMAIN FELT INTO MONDAY MORNING. MOZLEY .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 341 AM MDT SUN AUG 2 2015 ...MONSOON EARLY IN THE WEEK...DRIER FOR A COUPLE DAYS...THEN MONSOON RETURNING BY WEEKS END... ON MONDAY...SOUTHERN COLORADO WILL BE UNDER THE INFLUENCE OF A SUBTROPICAL DISTURBANCE...CARRYING MONSOON MOISTURE THROUGH THE REGION. WATER CONTENT OF THE ATMOSPHERE WILL BE HIGH WITH THUNDERSTORM INITIATION AIDED BY LIFT FROM THE DISTURBANCE. SO...ANOTHER ACTIVE DAY ACROSS THE REGION...WITH PRIMARY THREATS OF LIGHTNING AND HEAVY RAIN...ALONG WITH GUSTY WINDS AND SOME SMALL HAIL. FLASH FLOODING WILL CONTINUE TO BE A CONCERN. TUESDAY IS NOT CURRENTLY LOOKING AS MOIST AS IT ONCE DID. MODELS ARE INDICATING...NOW...THAT DRIER AIR FROM THE WEST WILL ALREADY BE MAKING ITS WAY INTO THE REGION. THERE WILL LIKELY STILL BE ENOUGH MOISTURE AROUND FOR CONVECTION THIS DAY...BUT MUCH LESS SO THAN ON MONDAY. STILL THREATS OF LIGHTNING AND LOCALLY HEAVY RAIN THIS DAY...BUT STARTING TO TREND TOWARD MORE OF A GUSTY WIND THREAT AS DRIER AIR MOVES IN. WEDNESDAY AND THURSDAY LOOK LIKE MOSTLY DRY AND WARM DAYS...AS DRY WESTERLY FLOW PREVAILS OVER THE REGION...AND THE MONSOON GETS SUPPRESSED WELL TO THE SOUTH. MOSTLY ISOLATED STORMS OVER THE HIGHER TERRAIN ON THESE DAYS WITH PRIMARILY A LIGHTNING AND GUSTY WIND THREAT. A LITTLE TRICKY THURSDAY EVENING...THOUGH...AS SOME MODEL RUNS ARE CLIPPING THE FAR EASTERN PLAINS WITH AN MCS MOVING THROUGH THE CENTRAL HIGH PLAINS. ON FRIDAY AND SATURDAY...IT LOOKS LIKE WE WILL TRANSITION BACK INTO THE MONSOON. MODELS INDICATE AN INTENSE LOW PRESSURE SYSTEM WILL MOVE ONSHORE OVER CENTRAL CALIFORNIA LATE FRIDAY AND TRACK INTO THE GREAT BASIN ON SATURDAY. AS THE SYSTEM MOVES INLAND...IT LOOKS LIKE IT WILL PULL ANOTHER STRONG SURGE OF MONSOON MOISTURE NORTH INTO COLORADO. THE MOISTURE STARTS TO SHOW UP ON FRIDAY...BUT REALLY BLANKETS THE REGION ON SATURDAY. WITH THE RETURN OF THE MONSOON MOISTURE PLUME...THE THREAT OF HEAVY RAIN AND FLASH FLOODING WILL RETURN...ALONG WITH CONTINUED THREATS OF LIGHTNING AND GUSTY WINDS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1114 AM MDT SUN AUG 2 2015 MAIN AVN CONCERN TODAY IS POTENTIAL FOR HEAVY RAIN WITH TS THIS AFTERNOON AND EVENING. SCT TO NMRS TS OVER THE CONTDVD WILL BUILD THROUGH THIS AFTERNOON AND EVE. KALS HAS THE BEST CHANCE OF SEEING PRECIP LATER THIS AFTERNOON THROUGH TONIGHT. COULD SEE MVFR OR BRIEF IFR DEVELOP AFTER 21-22Z AND PERSISTING AT TIMES THROUGH TONIGHT. DEPENDING ON EXTENT OF PRECIP COULD POTENTIALLY SEE SOME LOCALIZED LOW CIGS MON MORNING OVER THE SAN LUIS VALLEY. AT KCOS AND KPUB...TIMING OF STORMS WILL BE LATER AND LESS LIKELY...AS THE MORE WIDESPREAD PRECIP REMAINS OVER THE MTS. HOWEVER...ISOLD STORMS COULD AFFECT THE I-25 CORRIDOR THROUGH EARLY EVE. SFC WINDS SHOULD SHIFT TO AN ERLY DIRECTION DURING THIS TIME BEFORE DIMINISHING LATE THIS EVENING. ROSE && .PUB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THIS EVENING FOR COZ067-068. && $$ UPDATE...ROSE SHORT TERM...MOZLEY LONG TERM...LW AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1050 AM MDT SUN AUG 2 2015 .UPDATE... ISSUED AT 1047 AM MDT SUN AUG 2 2015 UPDATED TO DELAY TIMING OF HIGHER POPS BY A FEW HOURS. STILL NOT SEEING THE PRECIP OVER SW CO MOVE INTO OUR AREA...BUT SHOULD SEE FAIRLY STEADY INCREASE IN PRECIP THIS AFTERNOON. LATEST HRRR AND OTHER GUIDANCE IS SHOWING SIGNIFICANT QPF OVER THE WRN CWA THIS EVENING. WILL CONSIDER EXPANDING THE FLOOD WATCH BASED ON TRENDS EARLY THIS AFTERNOON. ROSE && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 341 AM MDT SUN AUG 2 2015 CURRENTLY...QUIET WEATHER HAS SPREAD ACROSS SOUTHERN COLORADO EARLY THIS MORNING. TEMPERATURES HAVE REMAINED MILD WITH 60S OVER THE LOWER ELEVATIONS UNDER LIGHT WINDS. TODAY AND TONIGHT...A STRONG UPPER LEVEL DISTURBANCE UNDER A BROAD AREA OF HIGH PRESSURE ALOFT IS FORECAST TO ROTATE NORTHWARD ACROSS UTAH AND WESTERN COLORADO THIS AFTERNOON AND TONIGHT. ABUNDANT MOISTURE IS IN PLACE...AND MODELS DEVELOP LOW LEVEL SOUTHEASTERLY UPSLOPE FLOW ACROSS THE SAN LUIS VALLEY INTO THE EASTERN SAN JUANS FOR THIS AFTERNOON. ALL WILL COMBINE TO PROVIDE THE FOCUS FOR THUNDERSTORMS THIS AFTERNOON OVER THE SAN JUAN RANGE...NORTH INTO THE LA GARITA MOUNTAINS. LOCALLY HEAVY RAINFALL IS EXPECTED WITH THESE THUNDERSTORMS...AND FLASH FLOODING WILL BE OF CONCERN...ESPECIALLY FOR THE WEST FORK COMPLEX BURN SCAR. A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE BURN SCAR AREA FOR THIS AFTERNOON AND EVENING. ELSEWHERE...EXPECT WIDESPREAD SHOWERS AND THUNDERSTORMS OVER ALL THE MOUNTAIN AREAS AND THE SAN LUIS VALLEY THIS AFTERNOON AND EVENING. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH STRONGER CORES ALONG WITH LIGHTNING. THERE IS LESS CERTAINTY OVER THE EASTERN PLAINS. MOST HIGH-RES MODELS BRING DRIER AIR INTO THE PLAINS THIS AFTERNOON LIMITING AFTERNOON INSTABILITY ALONG WITH THE SHOWER AND THUNDERSTORM POTENTIAL. THAT BEING SAID...MOST HIGH-RES SOLUTIONS DO BRING SHOWERS AND THUNDERSTORMS INTO THE PALMER DIVIDE AND RATON MESA REGIONS THIS AFTERNOON AND HAVE THE HIGHEST POPS OVER THESE LOCATIONS. THERE ARE A COUPLE OF SOLUTIONS...NAMELY THE ARW AND THE NSSL WRF...WHICH DO BRING A ROUND OF SHOWERS AND THUNDERSTORMS INTO THE I-25 CORRIDOR BY THIS EVENING...AND HAVE LOW POPS IN THIS AREA TO ACCOUNT FOR THE UNCERTAINTY. THE FAR EASTERN PLAINS WILL MOST LIKELY REMAIN DRY THROUGH TONIGHT. MODELS IN GOOD AGREEMENT WITH SHOWERS AND THUNDERSTORMS DISSIPATING ACROSS MUCH OF THE AREA AROUND MIDNIGHT. THE EXCEPTION LOOKS TO BE ALONG THE CONTINENTAL DIVIDE WHERE INFLUENCES OF THE UPPER DISTURBANCE OVER UTAH INTO WESTERN COLORADO WILL REMAIN FELT INTO MONDAY MORNING. MOZLEY .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 341 AM MDT SUN AUG 2 2015 ...MONSOON EARLY IN THE WEEK...DRIER FOR A COUPLE DAYS...THEN MONSOON RETURNING BY WEEKS END... ON MONDAY...SOUTHERN COLORADO WILL BE UNDER THE INFLUENCE OF A SUBTROPICAL DISTURBANCE...CARRYING MONSOON MOISTURE THROUGH THE REGION. WATER CONTENT OF THE ATMOSPHERE WILL BE HIGH WITH THUNDERSTORM INITIATION AIDED BY LIFT FROM THE DISTURBANCE. SO...ANOTHER ACTIVE DAY ACROSS THE REGION...WITH PRIMARY THREATS OF LIGHTNING AND HEAVY RAIN...ALONG WITH GUSTY WINDS AND SOME SMALL HAIL. FLASH FLOODING WILL CONTINUE TO BE A CONCERN. TUESDAY IS NOT CURRENTLY LOOKING AS MOIST AS IT ONCE DID. MODELS ARE INDICATING...NOW...THAT DRIER AIR FROM THE WEST WILL ALREADY BE MAKING ITS WAY INTO THE REGION. THERE WILL LIKELY STILL BE ENOUGH MOISTURE AROUND FOR CONVECTION THIS DAY...BUT MUCH LESS SO THAN ON MONDAY. STILL THREATS OF LIGHTNING AND LOCALLY HEAVY RAIN THIS DAY...BUT STARTING TO TREND TOWARD MORE OF A GUSTY WIND THREAT AS DRIER AIR MOVES IN. WEDNESDAY AND THURSDAY LOOK LIKE MOSTLY DRY AND WARM DAYS...AS DRY WESTERLY FLOW PREVAILS OVER THE REGION...AND THE MONSOON GETS SUPPRESSED WELL TO THE SOUTH. MOSTLY ISOLATED STORMS OVER THE HIGHER TERRAIN ON THESE DAYS WITH PRIMARILY A LIGHTNING AND GUSTY WIND THREAT. A LITTLE TRICKY THURSDAY EVENING...THOUGH...AS SOME MODEL RUNS ARE CLIPPING THE FAR EASTERN PLAINS WITH AN MCS MOVING THROUGH THE CENTRAL HIGH PLAINS. ON FRIDAY AND SATURDAY...IT LOOKS LIKE WE WILL TRANSITION BACK INTO THE MONSOON. MODELS INDICATE AN INTENSE LOW PRESSURE SYSTEM WILL MOVE ONSHORE OVER CENTRAL CALIFORNIA LATE FRIDAY AND TRACK INTO THE GREAT BASIN ON SATURDAY. AS THE SYSTEM MOVES INLAND...IT LOOKS LIKE IT WILL PULL ANOTHER STRONG SURGE OF MONSOON MOISTURE NORTH INTO COLORADO. THE MOISTURE STARTS TO SHOW UP ON FRIDAY...BUT REALLY BLANKETS THE REGION ON SATURDAY. WITH THE RETURN OF THE MONSOON MOISTURE PLUME...THE THREAT OF HEAVY RAIN AND FLASH FLOODING WILL RETURN...ALONG WITH CONTINUED THREATS OF LIGHTNING AND GUSTY WINDS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 341 AM MDT SUN AUG 2 2015 KALS...VFR CONDITIONS THIS MORNING. SHOWERS AND THUNDERSTORMS ARE FORECAST TO DEVELOP ACROSS THE MOUNTAINS AND SAN LUIS VALLEY BY LATE MORNING AND CONTINUE THROUGH THE EVENING. THEY WILL MOST LIKELY IMPACT THE TERMINAL...ESPECIALLY AFTER 18Z. REDUCED CIGS AND VIS ARE EXPECTED IN PASSING THUNDERSTORMS. KCOS...VFR CONDITIONS THROUGH EARLY AFTERNOON. SHOWERS AND THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING NEAR THE TERMINAL. IF A THUNDERSTORMS DOES MOVE OVER THE TERMINAL...IT WILL REDUCE THE CIGS AND VIS...OTHERWISE VFR CONDITIONS WILL PREVAIL INTO TONIGHT. KPUB...VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS. THERE IS A LOW PROBABILITY OF SHOWERS AND THUNDERSTORMS IN AND NEAR THE TERMINAL THIS AFTERNOON AND EVENING...BUT CONFIDENCE IN OCCURRENCE IS LOW AT THIS TIME. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THIS EVENING FOR COZ067-068. && $$ UPDATE...ROSE SHORT TERM...MOZLEY LONG TERM...LW AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS PADUCAH KY
244 PM CDT SUN AUG 2 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 244 PM CDT SUN AUG 2 2015 COULD SEE A FEW ISOLATED SHOWERS OR STORMS THIS AFTERNOON OVER SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS. SO FAR IT HAS BEEN A STRUGGLE TO COME UP WITH ENOUGH MOISTURE TO GET SOMETHING GOING...BUT THE HRRR HAS BEEN CONSISTENTLY SHOWING DEVELOPMENT THIS AFTERNOON. IT APPEARS THAT INDIVIDUAL CELLS WILL TRY TO MOVE EAST...AND PROPAGATE SOUTHWARD INTO THE HIGHER THETA-E AIR. FIGURE ANY CONVECTION WILL BE DONE BY SUNSET. HAVE OPTED TO KEEP LATE TONIGHT AND MONDAY MORNING DRY. THE 12Z MODELS CONTINUE TO HINT AT SOME CONVECTION MOVING OFF OF THE APPROACHING COLD FRONT AND FLIRTING WITH SOUTHWEST INDIANA STRADDLING 12Z MONDAY. IN GENERAL THE MODELS HAVE A WEAKENING TREND WITH THIS ACTIVITY AS IT APPROACHES THE AREA...AND NEIGHBORING FORECAST OFFICES PREFER TO KEEP THE FORECAST DRY...SO HAVE FOLLOWED SUIT HERE. THE FRONT MAY PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT MONDAY AFTERNOON AND NIGHT. THE PROBLEMS ARE WHETHER THERE WILL BE ENOUGH CONVERGENCE TO AID IN CONVECTIVE INITIATION...AND WHERE EXACTLY IT WILL BE. THE 12Z MODEL CONSENSUS INDICATES THAT IT SHOULD BE CUTTING ABOUT HALF WAY THROUGH THE AREA BY AFTERNOON...BUT IT IS NOT CLEAR WHETHER IT WILL PUSH THROUGH THE ENTIRE AREA BY EVENING...OR WHETHER IT WILL STALL OUT OVER THE AREA. IF IT DOES FOCUS CONVECTION IT WILL STAND A BETTER CHANCE OF PUSHING THROUGH THE AREA. WILL HAVE SMALL CHANCE POPS MAINLY ACROSS THE NORTHERN HALF OF THE REGION FOR THE AFTERNOON AND THROUGH THE NIGHT. THE BOUNDARY IS EXPECTED TO TAKE ON MORE OF A WARM FRONTAL LOOK TUESDAY AND TUESDAY NIGHT...AS IT SETS UP ALONG/NEAR I-64. CERTAINLY COULD SEE IT PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT...SO WILL CONTINUE WITH THE SMALL CHANCES FOCUSED IN THE NORTH TUESDAY. WILL THEN INCREASE THEM SOME TUESDAY NIGHT AS A MID/UPPER-LEVEL SYSTEM APPROACHES THE REGION. TEMPERATURES ARE RUNNING COOL IN MOST LOCATIONS THIS AFTERNOON...COMPARED TO THE GUIDANCE FROM YESTERDAY...AND THIS HAS BEEN THE TREND FOR AWHILE NOW. THEREFORE...WILL STAY ON THE COOL SIDE OF THE RANGE OF GUIDANCE FOR HIGHS MONDAY AND TUESDAY. LEANED TOWARD THE WARM SIDE OF GUIDANCE FOR LOWS. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 244 PM CDT SUN AUG 2 2015 LATEST MODEL RUNS ARE IN PRETTY GOOD AGREEMENT SHOWING FAIRLY WIDESPREAD QPF ACROSS THE PAH FORECAST AREA WEDNESDAY AND WEDNESDAY NIGHT AS A SURFACE LOW MOVES JUST NORTH OF THE AREA. LATEST ECMWF AND CANADIAN ARE IN FAIRLY CLOSER AGREEMENT IN PLACEMENT AND TIMING, AND THIS OVERALL GIVES A LITTLE MORE CONFIDENCE IN GOING HIGH CHANCE TO LIKELY POPS FOR SHOWERS AND THUNDERSTORMS FOR THESE PERIODS. A GOOD CHANCE OF SHOWERS AND STORMS WILL CONTINUE INTO THURSDAY, DECREASING FROM NORTHWEST TO SOUTHEAST THURSDAY NIGHT AS THE ASSOCIATED COLD FRONT PUSHES THROUGH THE REGION. ECMWF AND GFS IMPLY SOME LINGERING PRECIP CHANCES ON FRIDAY, SO KEPT SOME SLIGHT TO LOW CHANCE POPS GOING FOR NOW. FOR FRIDAY NIGHT AND INTO THE WEEKEND, SURFACE HIGH PRESSURE OVER THE GREAT LAKES REGION WILL KEEP OUR AREA DRY. CONDITIONS WILL REMAIN WARM AND MUGGY WEDNESDAY THROUGH THURSDAY WITH SOUTHERLY FLOW AHEAD OF THE SURFACE PUMPING WARM MOIST AIR NORTHWARD. HIGH TEMPERATURES WILL REACH NEAR NORMAL READINGS IN THE MIDDLE TO UPPER 80S, WITH DEW POINTS GENERALLY IN THE LOWER 70S. WITH THE COLD FRONT MOVING ACROSS THE AREA THURSDAY NIGHT, HIGH TEMPERATURES FRIDAY AND THROUGH THE WEEKEND WILL OVERALL BE IN THE 80 TO 85 DEGREE RANGE, WITH DEW POINTS DROPPING BACK INTO THE LOWER TO MIDDLE 60S. && .AVIATION... ISSUED AT 1230 PM CDT SUN AUG 2 2015 VFR CONDITIONS THROUGHOUT THE TAF PERIOD. THERE IS SOME POTENTIAL OF VCTS AROUND KCGI THIS AFTERNOON BUT CONFIDENCE TOO LOW TO INCLUDE. WILL WATCH TRENDS AND AMEND IF NECESSARY. SCATTERED CU WILL BE PRESENT AT KCGI AND KPAH THIS AFTERNOON. OTHERWISE LIGHT SOUTHERLY WINDS TODAY VEER AROUND TO WESTERLY TMRW AS WEAK FRONT PUSHES THRU. VCTS COULD BE ASSOCIATED WITH THIS FRONT BY THE END OF THE TAF PERIOD AT KEVV AND KOWB BUT PROBABILITY IS LOW AT THIS TIME. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...DRS LONG TERM...RST AVIATION...SP
AREA FORECAST DISCUSSION
NWS JACKSON KY
120 PM EDT SUN AUG 2 2015 .UPDATE... ISSUED AT 1038 AM EDT SUN AUG 2 2015 MUCH OF THE FOG THAT DEVELOPED ACROSS THE RIVER VALLEYS THIS MORNING HAS DISSIPATED. WE ARE LEFT WITH MOSTLY SUNNY TO SUNNY SKIES UNDER SURFACE HIGH PRESSURE. FORECAST IS ON TRACK AT THIS POINT WITH ONLY MINOR ADJUSTMENTS MADE OVERALL TOWARDS LATEST OBS AND TRENDS. UPDATE ISSUED AT 700 AM EDT SUN AUG 2 2015 TOUCHED UP THE GRIDS THIS MORNING BASED ON THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 350 AM EDT SUN AUG 2 2015 07Z SFC ANALYSIS SHOWS HIGH PRESSURE IN PLACE OVER CENTRAL KENTUCKY. THIS IS HELPING TO KEEP THE SKY MOSTLY CLEAR ACROSS THE STATE...BUT A SMATTERING OF MID LEVEL CLOUDS ARE DRIFTING OVER EAST KENTUCKY AND OUT OF THE AREA ATTM. SIMILAR TO THE PAST FEW NIGHTS...AN INVERSION HAS SET UP WHILE GOOD RADIATIONAL COOLING IS UNDERWAY. THIS HAS LED TO ANOTHER NIGHT OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES WITH SOME UPPER 50S FOUND IN THE DEEPER SPOTS WHILE HILLTOPS ARE RUNNING IN THE MID 60S. WINDS REMAIN LIGHT TO CALM ACROSS EAST KENTUCKY WITH NOT MUCH EVIDENCE OF FOG OUT THERE YET. HOWEVER...AGAIN SIMILAR TO THE PAST FEW NIGHTS... EXPECT THE FOG TO FORM IN THE RIVER VALLEYS BEFORE DAWN ALONG WITH LOCALLY DENSE PATCHES. THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT AS A BROAD AREA OF TROUGHING CONTINUES OVER SOUTH CENTRAL CANADA AND DOWN INTO THE OHIO VALLEY ACROSS TO NEW ENGLAND. A WIGGLE AT THE CORE OF THE TROUGH TO THE NORTH WILL SEND A LARGE AMOUNT OF ENERGY INTO THE GREAT LAKES ON MONDAY ALONG WITH A MID LEVEL GRADIENT THAT TIGHTENS...RESULTING IN FASTER FLOW THROUGH THE OHIO VALLEY. GIVEN THE AGREEMENT ALOFT WILL FOLLOW A BLENDED SOLUTION WITH EMPHASIS ON THE HRRR AND NAM12 EARLY ON AND THE BROADER CONSENSUS LATER. SENSIBLE WEATHER WILL FEATURE ANOTHER PLEASANT DAY WITH FAIRLY LOW AND COMFORTABLE HUMIDITY LEVELS AND HIGHS GENERALLY IN THE MID 80S UNDER MOSTLY SUNNY SKIES. THIS WILL LEAD INTO ONE MORE NIGHT OF GOOD RADIATIONAL COOLING AND RIDGE TO VALLEY TEMPERATURE DIFFERENCES INTO MONDAY MORNING...ALONG WITH PATCHY VALLEY FOG TOWARDS DAWN. BY MONDAY...THOUGH...THE SFC PATTERN WILL CHANGE WITH A COLD FRONT PRESSING SOUTH THROUGH THE OHIO VALLEY AND TOWARD EAST KENTUCKY. THIS WILL LIKELY KICK OFF SHOWERS AND THUNDERSTORMS NORTH OF THE STATE THAT SHOULD HELP TO SPAWN ADDITIONAL STORMS TO THE SOUTH WITH TIME THROUGH THE DAY. ANY STORMS THAT MANAGE TO DEVELOP OUT AHEAD OF THE FRONT IN EAST KENTUCKY WILL HAVE THE POTENTIAL TO BECOME STRONG TO SEVERE OWING TO HIGH CAPES AND STRENGTHENING MID LEVEL WINDS. THE BEST CHANCES WILL BE OVER OUR NORTHERN ZONES CLOSER TO THE FRONT AND SPC HAS INDICATED A SLIGHT RISK FOR SEVERE STORMS THERE. WILL HIGHLIGHT THIS CONCERN IN THE FORTHCOMING HWO. STARTED WITH THE SHORTBLEND MODEL FOR THE T/TD/WIND GRIDS THROUGH THE DAY FOLLOWED BY THE SUPERBLEND INTO MONDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENTS TO TEMPERATURES THIS MORNING AND TONIGHT WITH RESPECT TO RIDGE AND VALLEY DIFFERENCES. AS FOR POPS...KEPT THEM LOW AND IN LINE WITH THE DRY GUIDANCE INTO MONDAY MORNING. DID GO A BIT HIGHER THAN THE MET AND MAV NUMBERS FOR MONDAY AFTERNOON TO ACCOUNT FOR THE POTENTIAL INTRUSION OF STORMS... ORGANIZED OR OTHERWISE...FROM THE NORTH BY EVENING. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 340 AM EDT SUN AUG 2 2015 THE EXTENDED FORECAST PERIOD BEGINS ON MONDAY NIGHT WITH THE UPPER LEVEL PATTERN MAINTAINING A RIDGE OVER THE WEST AND THE LONGWAVE TROUGH OVER THE EASTERN CONUS. A CLOSED LOW OVER THE HUDSON BAY AREA WILL GRADUALLY SHIFT OFF TO THE EAST THROUGH THE EXTENDED AS BY THURSDAY...A SERIES OF STRONGER TROUGHS COME ASHORE OVER THE WEST AS THE WESTERN RIDGE BEGINS TO WEAKEN A BIT AND SHIFT EAST. THIS THROUGH THE LAST PORTION OF THE EXTENDED WILL BE THE FORECAST CHALLENGE AS THE BASE OF THE EASTERN TROUGH SETS UP OVER THE MID MS VALLEY AND THROUGH KY. THE GFS AND EURO DOES ALIGN A BIT WITH THIS SOLUTION. CLOSER TO THE SURFACE...THE FRONT THAT HAS PASSED THROUGH ON MONDAY WILL LAG ACROSS NORTHERN KENTUCKY AS A STATIONARY BOUNDARY DEVELOPS. THIS AREA BECOMES A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT AS THE BOUNDARY SLIDES FURTHER SOUTH THROUGH THE DAY ON TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...NORTHWEST FLOW SETS UP OVER THE AREA AS A SERIES OF UPPER LEVEL WAVES TOPPLE OVER THE THE TOP OF THE WESTERN RIDGE AND TRACK SOUTHEAST INTO THE OH VALLEY. THE SUPER BLEND HAS THIS IN IT/S SOLUTION AS WELL WITH THE PATTERN FAVORABLE FOR NOCTURNAL THUNDERSTORMS AS WELL...ESPECIALLY IF THIS PATTERN FOR MCS/S REMAIN...WHICH SEEMS LIKELY BASED UPON THE GFS AND EURO SOLUTIONS . THUS WILL STAY CLOSE TO THE SUPER BLENDS SOLUTION WEDNESDAY THROUGH FRIDAY KEEPING HIGH CHANCE TO LIKELY POPS DURING THIS PERIOD. TOWARDS THE END OF THE EXTENDED ON FRIDAY AND SATURDAY...THE UPPER LEVEL PATTERN LOSES A BIT AMPLITUDE AND BECOMES MORE ACTIVE AS ANOTHER SHORTWAVE TAKES AIM AT THE OH VALLEY. HOWEVER...THE GFS AND EURO DO DIVERGE TOWARDS THE END OF THE EXTENDED. THUS...LACKING CONFIDENCE...WILL GO NEAR OR SLIGHTLY BELOW THE SUPER BLEND ON POPS. THE LINGERING TROUGH OVER THE EAST AND SAGGING SOUTH THROUGH THE EXTENDED WILL KEEP HIGHS AT OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. IN SHORT...THE WEDNESDAY THROUGH FRIDAY PERIOD SEEMS TO BE QUITE ACTIVE AND WET WITH THE END OF THE FORECAST POSSIBLY CONTINUING THIS TREND WITH A COOLING TREND AS WELL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 120 PM EDT SUN AUG 2 2015 HIGH PRESSURE WILL KEEP TAF SITES MOSTLY VFR THROUGH THE TAF PERIOD. THE EXCEPTION TO THE RULE WILL BE MAINLY RIVER VALLEY FOG ACROSS THE REGION OVERNIGHT INTO EARLY MONDAY MORNING. WHILE THIS WILL NOT AFFECT MOST TAF SITES...GIVEN SIMILAR PATTERN HAVE INTRODUCED LOWER MVFR VIS SME...SJS...AND SYM WHICH HAD THE MOST AFFECTS FROM FOG THIS MORNING. THERE IS ALSO AN APPROACHING COLD FRONT AS WE MOVE INTO AFTERNOON HOURS ON MONDAY...BUT STILL UNCERTAINTY ON HOW QUICKLY WE WILL SEE CONVECTION ACROSS NORTHERN TAF SITES. THEREFORE WILL HOLD OFF ON ANY MENTION IN THE TAFS AT THIS TIME GIVEN LOWER CONFIDENCE. WINDS THROUGH THE PERIOD ARE EXPECTED TO REMAIN LIGHT AND VARIABLE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...DJ SHORT TERM...GREIF LONG TERM...SHALLENBERGER AVIATION...DJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
344 PM EDT SUN AUG 2 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 343 PM EDT SUN AUG 2 2015 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV APRCHG THE UPR GREAT LKS IN DEEP CYC NW FLOW ARND CLOSED LO OVER FAR NRN ONTARIO. THERE HAVE BEEN WAVES OF SHOWERS/ELEVATED TS THAT HAVE MOVED THRU UPR MI AS DPVA/DEEP LYR QVECTOR CNVGC AHEAD OF THE SHRTWV HAS LIFTED UNSTABLE ENVIRONMENT SHOWN ON THE 12Z AND 18Z GRB RAOBS /H7-5 LAPSE RATES AOA 8C/KM/. MOST OF THE TS HAVE IMPACTED LOCATIONS NEAR THE WI BORDER WHERE RUC ANALYSIS MUCAPES HAVE BEEN UP TO 1000 J/KG UNDER AXIS OF HIER H85 THETA E. ALTHOUGH SOME OF THE STORMS EARLIER THIS MRNG WERE SEVERE WITH LARGE HAIL...LOTS OF CLD COVER OVER UPR MI HAVE MAINTAINED MORE ELEVATED CORES HAVE LIMITED THE SEVERITY OF THE CONVECTION MOST OF THE DAY DESPITE IMPRESSIVE DEEP LYR SHEAR ON THE ORDER OF 40-50 KTS UNDER RIBBON OF STRONG WNW WINDS ALOFT. THE SHOWERS ARE TENDING TO DIMINISH OVER THE NW CWA WITH ARRIVAL OF NEGATIVE H85 THETA E ADVECTION/MID-LVL DRYING/DEEP LYR QVECTOR DVGC AND MORE MARGINAL LAPSE RATES DEPICTED ON THE 12Z INL RAOB. LATE THIS AFTN...WHILE MORE NMRS SHOWERS/TS MAY IMPACT THE SE CWA...THE ARRIVAL OF MORE MARGINAL LAPSE RATES ACCOMPANYING DEEP LYR QVECTOR CNVGC WL LIMIT THE COVERAGE/INTENSITY OF THIS CONVECTION. TNGT...AFTER ANY LINGERING SHOWERS/TS OVER THE SE CWA END AFTER EARLY EVNG...LARGER SCALE SUBSIDENCE/DRYING IN THE WAKE OF PASSING SHRTWV WL BRING A CLEARING TREND. AS UPR TROF AMPLIFIES INTO THE UPR LKS...LLVL SLGTLY CYC NW FLOW BEHIND COLD FROPA IS FCST TO DROP H85 TEMPS AS LO AS 6 TO 7C BY 12Z MON. WITH THIS THERMAL TROF...EXPECT INCRSG LO CLDS LATE...ESPECIALLY OVER THE HIER TERRAIN OF THE NW CWA. MON...CYC H85 NW FLOW IS PROGGED TO PERSIST AND MAINTAIN THERMAL TROF OVER THE CWA...SO EXPECT A GOOD DEAL OF CLD COVER. COMBINATION OF DATYIME HEATING AND PASSING SHRTWV MAY BRING SOME SCT SHOWERS... MAINLY OVER THE INTERIOR AWAY FM LK SUP MODERATION IN THE AFTN. WITH H85 TEMPS FCST IN THE 8 TO 10C RANGE...EXPECT MAX TEMPS MAINLY IN THE 60S...EXCEPT 70 TO 75 IN THE DOWNSLOPE AREAS OF THE SCENTRAL. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 344 PM EDT SUN AUG 2 2015 SPENT A CONSIDERABLE AMOUNT OF TIME WORKING SHORT FUSE OPERATIONS TODAY GIVEN IMPACTS IN THE SHORT TERM AND LACK OF SIGNIFICANT IMPACTS IN THE LONG TERM. ADDITIONALLY...CONSENSUS GUIDANCE HAS A GOOD HANDLE ON THE LONG TERM SITUATION SO TIME WAS BEST SPENT HELPING IN THE SHORT TERM. BASIC IDEA IS THAT WITH AN UPPER LOW MOVES NE OF THE CWA MON NIGHT INTO TUE...COULD SEE SHOWERS AND MAYBE T-STORMS DUE TO DECREASED MID- UPPER LEVEL TEMPS AND SHORTWAVE ENERGY ROTATING THROUGH. BEST COVERAGE SHOULD BE DURING THE DAY ON TUE WITH GREATEST SFC HEATING. WED LOOKS DRY WITH A SFC RIDGE OVERHEAD. THU THROUGH FRI MAY BE DRY AS WELL...BUT REGIONAL CONDITIONS WILL BE MORE IMPACTED BY AN INCREASE IN SHORTWAVE ACTIVITY AND A RESULTING INCREASE IN UNCERTAINTY. SHOULD SEE BETTER CHANCES FOR PRECIP NEXT WEEKEND...BUT THAT IS QUITE UNCERTAIN AS WELL. OVERALL...LEANED HEAVILY ON CONSENSUS GUIDANCE FOR MOST OF THE LONG TERM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 156 PM EDT SUN AUG 2 2015 SOME SHRA AND PERHAPS A TS IN ADVANCE OF AN APRCHG COLD FNT WL IMPACT MAINLY SAW THRU THIS AFTN. ALTHOUGH SOME LOWER CIGS/VSBYS COULD ACCOMPANY THE HEAVIER SHOWERS...VFR CONDITIONS SHUD PREDOMINATE. FOLLOWING THE COLD FROPA/WSHFT TO THE NW AND ARRIVAL OF DRIER LLVL AIR THIS AFTN...THE SHRA THREAT WL END...AND SKIES WL TURN PCLDY. MORE LOWER CLDS WL ARRIVE AS EARLY AS LATE TNGT OVER THE KEWEENAW AND THEN EXPAND TO IWD/SAW WITH INCRSG LLVL MSTR. ALTHOUGH THERE COULD A -SHRA...VFR CONDITIONS WL BE THE RULE WITH A WELL MIXED/DRY NEAR SFC LYR. BEST CHC FOR A LOWER MVFR CIG WOULD BE AT CMX WITH FVRBL UPSLOPE WIND COMPONENT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 343 PM EDT SUN AUG 2 2015 EXPECT WNW WINDS UP TO 20 KTS INTO MID WEEK AROUND DEEP LO PRES NEAR HUDSON BAY. THE ARRIVAL OF A HI PRES RIDGE LATER IN THE WEEK WILL RESULT IN LIGHT WINDS UNDER 15 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
343 PM EDT SUN AUG 2 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 343 PM EDT SUN AUG 2 2015 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV APRCHG THE UPR GREAT LKS IN DEEP CYC NW FLOW ARND CLOSED LO OVER FAR NRN ONTARIO. THERE HAVE BEEN WAVES OF SHOWERS/ELEVATED TS THAT HAVE MOVED THRU UPR MI AS DPVA/DEEP LYR QVECTOR CNVGC AHEAD OF THE SHRTWV HAS LIFTED UNSTABLE ENVIRONMENT SHOWN ON THE 12Z AND 18Z GRB RAOBS /H7-5 LAPSE RATES AOA 8C/KM/. MOST OF THE TS HAVE IMPACTED LOCATIONS NEAR THE WI BORDER WHERE RUC ANALYSIS MUCAPES HAVE BEEN UP TO 1000 J/KG UNDER AXIS OF HIER H85 THETA E. ALTHOUGH SOME OF THE STORMS EARLIER THIS MRNG WERE SEVERE WITH LARGE HAIL...LOTS OF CLD COVER OVER UPR MI HAVE MAINTAINED MORE ELEVATED CORES HAVE LIMITED THE SEVERITY OF THE CONVECTION MOST OF THE DAY DESPITE IMPRESSIVE DEEP LYR SHEAR ON THE ORDER OF 40-50 KTS UNDER RIBBON OF STRONG WNW WINDS ALOFT. THE SHOWERS ARE TENDING TO DIMINISH OVER THE NW CWA WITH ARRIVAL OF NEGATIVE H85 THETA E ADVECTION/MID-LVL DRYING/DEEP LYR QVECTOR DVGC AND MORE MARGINAL LAPSE RATES DEPICTED ON THE 12Z INL RAOB. LATE THIS AFTN...WHILE MORE NMRS SHOWERS/TS MAY IMPACT THE SE CWA...THE ARRIVAL OF MORE MARGINAL LAPSE RATES ACCOMPANYING DEEP LYR QVECTOR CNVGC WL LIMIT THE COVERAGE/INTENSITY OF THIS CONVECTION. TNGT...AFTER ANY LINGERING SHOWERS/TS OVER THE SE CWA END AFTER EARLY EVNG...LARGER SCALE SUBSIDENCE/DRYING IN THE WAKE OF PASSING SHRTWV WL BRING A CLEARING TREND. AS UPR TROF AMPLIFIES INTO THE UPR LKS...LLVL SLGTLY CYC NW FLOW BEHIND COLD FROPA IS FCST TO DROP H85 TEMPS AS LO AS 6 TO 7C BY 12Z MON. WITH THIS THERMAL TROF...EXPECT INCRSG LO CLDS LATE...ESPECIALLY OVER THE HIER TERRAIN OF THE NW CWA. MON...CYC H85 NW FLOW IS PROGGED TO PERSIST AND MAINTAIN THERMAL TROF OVER THE CWA...SO EXPECT A GOOD DEAL OF CLD COVER. COMBINATION OF DATYIME HEATING AND PASSING SHRTWV MAY BRING SOME SCT SHOWERS... MAINLY OVER THE INTERIOR AWAY FM LK SUP MODERATION IN THE AFTN. WITH H85 TEMPS FCST IN THE 8 TO 10C RANGE...EXPECT MAX TEMPS MAINLY IN THE 60S...EXCEPT 70 TO 75 IN THE DOWNSLOPE AREAS OF THE SCENTRAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 334 AM EDT SUN AUG 2 2015 TEMPS WILL BE BLO NORMAL THIS WEEK AS GREAT LAKES IS WITHIN DIRECT INFLUENCE OF STRONG UPPER TROUGH CENTERED ON ONTARIO AND QUEBEC AND ASSOCIATED SFC LOW SPINNING OVER QUEBEC. BASED ON THE WV LOOP AND IR SATELLITE LOOPS AND 00Z H5 RAOBS...STRONGEST SHORTWAVES AROUND THE UPPER LOW CENTER ARE CURRENTLY WEST OF JAMES BAY...DROPPING OVER NORTHEAST MANITOBA...AND ROTATING NORTHWEST ALONG EAST SHORE OF HUDSON BAY. MODELS IN GENERAL SHOW THE INTENSITY OF INDIVIDUAL WAVES FADING THROUGH TUESDAY...BUT THAT MAY OR MAY NOT OCCUR. ONLY SAY THAT AS MODELS TYPICALLY DOWNPLAY STRENGTH OF SHORTWAVES ROTATING AROUND A LARGE UPPER LOW THE FARTHER OUT IN TIME YOU ARE. SUPPOSE THAT IF ONE OF THESE WAVES SLIDES ACROSS DURING THE PEAK HEATING OF THE DAY MONDAY OR TUESDAY...WITH ALREADY COOL AIR ALOFT/HIGHER H925- H7 RH IN PLACE...THERE WOULD BE AN UPTICK OF COVERAGE AND INTENSITY OF SHOWERS AND AT LEAST SOME POTENTIAL OF TSRA. 00Z SOUNDING FM CYYQ AT CHURCHILL MANITOBA SHOWED MOISTURE FM NEAR SFC THROUGH H7...SO IDEA THAT MODELS ARE SHOWING FOR EARLY THIS WEEK WITH HIGHER RH THROUGH H7 SEEM ON TRACK. WENT AHEAD AND INCREASED POPS TO AT LEAST CHANCE RANGE OVER INTERIOR CNTRL ON MONDAY AFTN AND TUESDAY AFTN. SFC RIDGE BEGINS TO BUILD FM CNTRL CANADA INTO UPPER GREAT LAKES AND OHIO VALLEY TUESDAY NIGHT AND MORE SO INTO WEDNESDAY. LESS IN WAY OF H85-H7 Q-VECTOR CONVERGENCE AND HIGHER RH DURING THIS TIME AS WELL SO SHOULD SEE MINIMAL CHANCES FOR ANY SHRA. A BIT MORE MESSY IN PREDICTABILITY LATER THIS WEEK. 12Z ECMWF SHOWED ANOTHER SHORTWAVE DROPPING OVER THE UPPER GREAT LAKES IN SLOW TO LET GO NW FLOW ALOFT ON EDGE OF UPPER LEVEL TROUGH...WHILE GFS CONTINUES TO TAKE SHORTWAVE CURRENTLY OVER CA/NV AND BRINGS IT ACROSS WESTERN CONUS RIDGE AND OVER NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY WEDNESDAY NIGHT INTO THURSDAY. INTERESTING ENOUGH THE 00Z ECMWF IS SIMILAR TO GFS...JUST NOT AS FAR NORTH WITH THAT SHORTWAVE AND ASSOCIATED QPF. MEANWHILE...GEM-NH BRINGS SHORTWAVE OVER EASTERN PACIFIC OFFSHORE OF CA THIS MORNING AND TAKES IT SLOWLY OVER ROCKIES AND NORTHERN PLAINS...WITH ARRIVAL OVER UPPER MISSISSIPPI RIVER VALLEY THURSDAY INTO FRIDAY. GIVEN ALL THE DIFFERENT SCENARIOS WILL STICK WITH SLIGHT CHANCE POPS OFFERED UP BY A MODEL CONSENSUS...MAINLY FOCUSED ALONG WI BORDER. SEEMS THAT THERE IS BETTER AGREEMENT THAT BY FRIDAY EVENING...SHORTWAVE AND ASSOCIATED WEAK SFC LOW WILL BE SOUTH OF UPR MICHIGAN AS HIGH PRESSURE RIDGE OVER CNTRL CANADA BUILDS ACROSS INTO UPPER GREAT LAKES. SINCE HIGH PRESSURE RIDGE CENTER FOCUSES OVER NORTHERN ONTARIO AND QUEBEC NEXT WEEKEND...MAY SEE POTENTIAL FOR LAKE BREEZES TO HELP FORM SHRA OR TSRA GIVEN ENOUGH DAYTIME HEATING/INSTABILITY. STILL LOOKING LIKE VERY LOW CHANCE THOUGH. OVERALL FOR THIS WEEK THE COOL TEMPERATURES WILL BE THE BIGGER STORY. WILL BE DEALING WITH CHILLY SUMMER AIRMASS FOR SURE AS H85 TEMPS ARE FORECAST TO DROP TO 0-1C OVER NORTHERN ONTARIO BY 12Z MONDAY. COOL AIR MODERATES SOME BUT H85 TEMPS STILL FALL OFF TO AS LOW AS 3-5C OVER UPR MICHIGAN BY TUESDAY AFTN. EXPECT HIGH TEMPS MONDAY TO BE IN THE UPPER 60S TO LOW 70S...COOLEST NEAR LK SUPERIOR. TEMPS ON TUESDAY WILL BE COOL EVERYWHERE. READINGS ALONG LK SUPERIOR MAY STAY BLO 60 DEGREES WITH PERSISTENT NORTHWEST GRADIENT WIND. TEMPS INLAND AND NEAR LK MICHIGAN WILL MOSTLY BE IN THE 60S. ONLY SCNTRL FM IMT TO ESC AND SOUTH TO MNM MAY SEE TEMPS CRACK 70 DEGREES. OVERNIGHT LOWS MONDAY NIGHT AND TUESDAY NIGHT WILL BE REFRESHING WITH 40S AND 50S. SEEMS TO BE ENOUGH NORTHWEST GRADIENT WIND EVEN ON TUESDAY NIGHT TO KEEP LOWS FM DROPPING BLO 40 DEGREES AND KEEPING FROST POTENTIAL TO A MINIMUM. H85 TEMPS BEGIN TO BOUNCE BACK TO 5-8C ON WEDNEDAY AFTN...SUPPORTING HIGHS BACK INTO THE 70S FOR MUCH OF THE CWA...THOUGH PROBABLY WILL BE LOWER 70S FOR MOST WHICH IS STILL BLO NORMAL. TEMPS TO END THE WEEK WILL REMAIN ON THE COOLER SIDE OF NORMAL. DESPITE MOST OF THE RAIN STAYING SOUTH OF CWA THURSDAY INTO FRIDAY...INCREASE IN CLOUDS AND NORTHEAST GRADIENT WIND BTWN HIGH OVER MANITOBA AND NORTHERN ONTARIO AND TROUGHING IN THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY WILL KEEP MAX TEMPS IN THE UPR 60S TO LOW 70S. A BIT OF WARMING AT H85 BY NEXT WEEKEND SHOULD PUSH TEMPS AT LEAST INLAND FM LK SUPERIOR BACK INTO THE MID 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 156 PM EDT SUN AUG 2 2015 SOME SHRA AND PERHAPS A TS IN ADVANCE OF AN APRCHG COLD FNT WL IMPACT MAINLY SAW THRU THIS AFTN. ALTHOUGH SOME LOWER CIGS/VSBYS COULD ACCOMPANY THE HEAVIER SHOWERS...VFR CONDITIONS SHUD PREDOMINATE. FOLLOWING THE COLD FROPA/WSHFT TO THE NW AND ARRIVAL OF DRIER LLVL AIR THIS AFTN...THE SHRA THREAT WL END...AND SKIES WL TURN PCLDY. MORE LOWER CLDS WL ARRIVE AS EARLY AS LATE TNGT OVER THE KEWEENAW AND THEN EXPAND TO IWD/SAW WITH INCRSG LLVL MSTR. ALTHOUGH THERE COULD A -SHRA...VFR CONDITIONS WL BE THE RULE WITH A WELL MIXED/DRY NEAR SFC LYR. BEST CHC FOR A LOWER MVFR CIG WOULD BE AT CMX WITH FVRBL UPSLOPE WIND COMPONENT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 343 PM EDT SUN AUG 2 2015 EXPECT WNW WINDS UP TO 20 KTS INTO MID WEEK AROUND DEEP LO PRES NEAR HUDSON BAY. THE ARRIVAL OF A HI PRES RIDGE LATER IN THE WEEK WILL RESULT IN LIGHT WINDS UNDER 15 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
146 PM EDT SUN AUG 2 2015 .AVIATION... THUNDERSTORMS TO THE NORTH SHOULD CONGEAL AND DROP SOUTH THROUGH AREA THIS EVENING AS A COLD FRONT DROPS SOUTH THROUGH THE CENTRAL GREAT LAKES. EXPECT A DECENT CHANCE OF A POCKETS OF SEVERE WEATHER WITHIN THIS EXPECTED AREA OF THUNDERSTORMS...WHICH WILL MOST LIKELY PROGRESS FROM MBS AT 00Z-01Z TO THE I-94 TERMINALS BY 03Z-05Z AND THEN EXIT SOUTH OF WHOLE AREA AFTER 06-07Z. OTHERWISE THAN PATCHY LATE NIGHT FOG TONIGHT...VFR CONDITIONS SHOULD...ONCE AGAIN...BE THE RULE ONCE THE STORMY WEATHER ENDS TONIGHT. FOR DTW...MOST PROBABLE TIME FOR TSTORMS WILL BE 03-06Z IN ADVANCE OF APPROACHING COLD FRONT. //DTW THRESHOLD PROBABILITIES... * LOW FOR TSTORMS THIS AFTN. MEDIUM AFTER 03Z TONIGHT. && .PREV DISCUSSION...ISSUED 1153 AM EDT SUN AUG 2 2015 UPDATE... FORECAST REMAINS IN GOOD SHAPE AS CONVECTIVE EVOLUTION TO OUR NORTH HAS BEEN FAIRLY PREDICTABLE TO THIS POINT. SEVERAL CLUSTERS OF STORMS CONTINUE TO PEEL EASTWARD ACROSS NORTHERN WISCONSIN ON INTO THE UP AND NORTHERN LOWER MICHIGAN. THUNDERSTORM CHANCES WILL INCREASE OVER THE NORTHERN CWA THIS AFTERNOON AS THE FLOW OF WARM AND MOIST AIR PERSISTS AND A LARGE OUTFLOW BOUNDARY ALONG THE SOUTHERN EDGE OF STORM COMPLEXES TO THE NORTH SETTLES INTO THE FORECAST AREA AND PROVIDES FOCUS FOR THIS INCREASINGLY UNSTABLE AIRMASS. WHILE AN ISOLATED STORM CANNOT BE RULED OUT AS FAR SOUTH AS M 59 LATER THIS AFTERNOON...MOST ACTIVITY WILL REMAIN NORTH OF THE I-69 CORRIDOR. IT LOOKS INCREASINGLY LIKE THE NEXT ROUND OF THUNDERSTORMS WILL ACTUALLY OVERLAP WITH THIS ONGOING ACTIVITY AS OPPOSED TO BEING A MORE DISTINCT EPISODE. A CONTINUED FLOW OF MOIST/UNSTABLE AIR ALONG THE AFOREMENTIONED OUTFLOW BOUNDARY SHOULD MAINTAIN FAIRLY CONSISTENT CONVECTION ALONG/NORTH OF THE CWA INTO EARLY THIS EVENING WITH ADDITIONAL DEVELOPING ACTIVITY ALONG APPROACHING COLD FRONT THEN SPREADING INTO THE AREA FROM NORTHERN LOWER MICHIGAN AND WISCONSON DURING THE COURSE OF THE EVENING...WHICH WILL ACT TO DRAG EXISTING CONVECTION ALONG THE NORTHERN BORDER SOUTHWARD INTO THE AREA. NET RESULT WILL BE THE SAME AS STORM CHANCES INCREASE FROM NORTH TO SOUTH ACROSS THE AREA FROM MID TO LATE EVENING. TIMING FOR LARGEST THREAT OF STORMS FOR METRO DETROIT STILL APPEARS TO BE MAINLY AFTER 10 PM AND PERHAPS CLOSER TO MIDNIGHT FOR MANY LOCALES. WITH ANY LUCK...DECLINING INSTABILITY AT THIS LATER HOUR WILL TAKE SOME PUNCH OUT OF THE LINE OF STORMS THAT EVENTUALLY EVOLVES AND PROGRESSES INTO THE AREA LATER THIS EVENING. THAT SAID...THE THREAT OF SEVERE WEATHER WILL PERSIST GIVEN THE STRONG WIND FIELD AND AT LEAST A MODERATELY UNSTABLE AIRMASS AT THAT POINT. PREV DISCUSSION...ISSUED 526 AM EDT SUN AUG 2 2015 UPDATE... A REFINEMENT OF THOUGHTS AFTER PERUSING FRESH ARRIVING HIGH RESOLUTION GUIDANCE, PARTICULARLY THE RAP, HRRR AND 00Z 3KM EXPERIMENTAL NAM WHICH APPEAR TO BE SHEDDING SOME LIGHT ON THIS AFTERNOON AND EVENING`S SEVERE POTENTIAL. ALTHOUGH OVERALL FORECAST REASONING HAS NOT CHANGED, NEW INFORMATION IS INCREASING CONFIDENCE THAT AFTERNOON CONVECTION WILL REMAIN CONFINED TO NORTHERN AREAS ALONG THE NOSE OF THE DEVELOPING LOW-LEVEL JET WHILE AREAS SOUTH OF M59 REMAIN CAPPED THUS INHIBITING PREMATURE OVERTURNING. IN ADDITION TO THE PRIMARY THREAT OF UPSCALE GROWTH OF CONVECTION INTO AN ORGANIZED MCS, A FEW STORMS COULD ALSO DEVELOP IN ADVANCE OF THIS LINE WITHIN THE CORRIDOR PRECEDING WARM ADVECTION. THIS PREFRONTAL CONVECTION WILL HAVE STEEP LAPSE RATES AND AN APPRECIABLE RESERVOIR OF INSTABILITY WITH WHICH TO WORK. THE OFT CONSERVATIVE 07Z RAP INDICATING 0-1KM MLCAPE APPROACHING 2500 J/KG IN MIDLAND/BAY COUNTY BY 22Z. IN ADDITION, STRENGTHENING SWLY FLOW WILL SUPPORT ELEVATED BULK SHEAR DURING THIS TIME THUS POTENTIALLY SUPPORTING A FEW SUPERCELLS AS UPSTREAM CONVECTION ORGANIZES OVER WISCONSIN, LAKE MICHIGAN, AND NORTHERN LOWER MICHIGAN. GIVEN WELL MIXED/DEEP BOUNDARY LAYER INDICATED ON FORECAST SOUNDINGS, IT APPEARS THAT A POTENTIALLY SIGNIFICANT/70MPH, IF RELATIVELY ISOLATED, WIND THREAT MAY EXIST MAINLY INVOF THE SAGINAW VALLEY IN ADVANCE OF THE MAIN LINE AS EARLY AS 21/22Z. FOR THE SAME REASON, TORNADO THREAT WOULD APPEAR LIMITED DUE TO HIGH LCLS. THOUGH THIS AFTN/EVENING`S CONVECTIVE TRENDS WILL STILL BE CRITICAL, LATEST GUIDANCE DOES SUPPORT THE OFFICIAL FORECAST STRONGLY ENOUGH TO CONSIDER ADVERTISING A THREAT FOR 70 MPH WIND GUSTS CONDITIONAL ON MCS ORGANIZATION. WILL ALLOW TIME FOR UPDATED SPC DAY 1 AND FOR DAY CREW TO EVALUATE LATEST TRENDS AND HIGH RES GUIDANCE BEFORE ELEVATING WORDING IN THE HWO AND OTHER PRODUCTS. FINALLY, AS NOTED IN THE ORIGINAL MORNING FORECAST PACKAGE, A LIMITED SEVERE THREAT WILL EXIST WITH ANY CONVECTION THAT TRAVERSES LAND ACROSS THE NORTH DURING THE AFTERNOON HOURS. IF LATEST RAP RUNS ARE ANY INDICATION, THE THERMODYNAMIC ENVIRONMENT MAY EVOLVE A BIT FASTER THAN PREVIOUSLY FORECAST YIELDING INCREASED CONFIDENCE IN SEVERE WIND POTENTIAL AT LEAST OVER THE THUMB PERHAPS AS EARLY AS 18Z SHOULD UPSTREAM CONVECTION DEVELOP WITHIN FAVORABLE WAA/STEEP LAPSE RATE ENVIRONMENT. PREV DISCUSSION...ISSUED 252 AM EDT SUN AUG 2 2015 SHORT TERM...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER MN AND WI DURING THE PREDAWN HOURS AS A FAST-MOVING LEAD SHORTWAVE PROVIDES FORCING WITHIN THE STEEP LAPSE RATE ENVIRONMENT BEING DRAWN EAST BY BROAD CYCLONIC WNW FLOW. THIS ENVIRONMENT WILL RACE EAST THROUGH THE AFTERNOON FOCUSING A CORRIDOR OF CONVECTION ACROSS PRIMARILY ACROSS LAKE HURON AND NORTHERN LOWER MICHIGAN. SOUTHEASTERN PORTIONS OF THE CWA WILL REMAIN LARGELY CAPPED THROUGH PEAK HEATING AS H85 TEMPERATURES RISE WELL INTO THE UPPER TEENS SUPPORTING HIGHS APPROACHING 90F. HOWEVER, SLIGHTLY WEAKER CAPPING/BETTER FORCING ACROSS THE NORTH WARRANT AT LEAST A HIGH CHC POP FROM THE SAGINAW VALLEY INTO THE THUMB, INCREASING TO LIKELY BY LATE THIS AFTN. THIS ACTIVITY WILL CARRY AT LEAST A LOW END SEVERE RISK 18-00Z NORTH OF THE I-69 CORRIDOR AS IT WILL RESIDE ALONG THE EASTERN PERIPHERY MORE STRONGLY SHEARED SWLY FLOW AND AS SURFACE TDS RISE INTO THE MID AND UPPER 60S SUPPORTING MODERATE DESTABILIZATION. LATEST HRRR RUNS HAVE A DEPICTION SIMILAR TO EXPECTATIONS, PARTICULARLY WRT TO EXPECTED SOUTHWARD EXTENT. MEANWHILE 4KM SPC RUN APPEARS ENTIRELY TOO GENEROUS WITH CONVECTIVE COVERAGE/EVOLUTION WITHIN STRONGLY CAPPED AREAS. SECOND AND POTENTIALLY GREATER SEVERE THREAT MAY EXIST TONIGHT, LARGELY CONDITIONAL ON EXTENT OF PRECEDING AFTERNOON CONVECTION AND QUALITY OF RECOVERY. DEVELOPING STRONG SWLY FLOW IN ADVANCE OF PRIMARY TROUGH AXIS WILL CERTAINLY GIVE THE EXPECTED GENESIS AREA OVER NORTHERN LOWER OR CENTRAL MI A DECENT SHOT AT RECOVERY BY 00Z. BETWEEN 00-06Z, STRONG HEIGHT FALLS WILL SPREAD ACROSS THE GREAT LAKES ELICITING A STRONG LLJ RESPONSE AND IMPRESSIVE MEAN WIND THROUGH THE LOWER ATMOSPHERE. ASSUMING THE ABSENCE OF STABILIZING EFFECTS OF EARLIER ACTIVITY, CONVECTIVE INITIATION ALONG THE INTENSIFYING SURFACE TROUGH WOULD HAVE POTENTIAL TO GROW UPSCALE AND PROPAGATE INTO AN ENVIRONMENT CHARACTERIZED BY 0-1KM BULK SHEAR AROUND 40KTS, H7-H5 LAPSE RATES IN EXCESS OF 7.5C/KM, AND 0-1KM MLCAPE OF 1500 TO 2000 J/KG. THREAT WOULD THEN DIMINISH FROM TOWARD THE FAR SOUTHEAST AS CONVECTION ENCOUNTERS COMBINATION OF INCREASINGLY CAPPED MID-LEVELS AND NOCTURNAL STABILIZATION. LONG TERM... UPPER LEVEL TROUGH AXIS (EXTENDING FROM LARGE UPPER LEVEL LOW CENTERED OVER NORTHERN ONTARIO) WILL BE IN PLACE ON MONDAY OVER THE CENTRAL GREAT LAKES...WITH COLD 500 MB TEMPS AROUND -14 C. THE MAIN SURFACE COLD FRONT SHOULD CLEAR SOUTHERN MICHIGAN SHORTLY AFTER 12Z...AND SOUTHEAST MICHIGAN WILL BEGIN TO DRY OUT WITH SLOWLY FALLING DEW PTS. HOWEVER...THERE STILL COULD BE JUST ENOUGH RESIDUAL LOW LEVEL MOISTURE AROUND TO GENERATE SUFFICIENT INSTABILITY TO POP ISOLATED-SCATTERED SHOWERS AND MAYBE A THUNDERSTORM...AS THERE IS ALSO A SECONDARILY COLD FRONT WHICH LOOKS TO BE DROPPING SOUTH FROM NORTHERN LOWER MICHIGAN...PROVIDING THE BETTER FOCUS. 850 MB TEMPS STILL IN THE LOWER TEENS ON MONDAY...ALLOWING FOR MAXES AROUND 80 DEGREES...WILL FALL INTO THE UPPER SINGLE NUMBERS TO AROUND 10 C BY TUESDAY...WHICH SHOULD RESULT IN MAXES HOLDING IN THE MID/UPPER 70S. A SPOKE OF UPPER LEVEL ENERGY IS FORECASTED TO SWING THROUGH NORTHERN LOWER MICHIGAN DURING TUESDAY..COUPLED WITH THE DAYTIME INSTABILITY COULD TOUCH OF A FEW SHOWERS NORTH OF I-69...OTHERWISE UPPER LEVEL NORTHWEST CONFLUENT FLOW/GENERAL SUBSIDENCE REGIME LOOKS TO PERSIST AT LEAST INTO WEDNESDAY...SUPPORTING SLOWLY STRENGTHENING HIGH PRESSURE OVER LOWER MICHIGAN...PROVIDING FAVORABLE RADIATING NIGHTTIME CONDITIONS ALLOWING MINS TO FALL INTO THE LOW/MID 50S...WITH HIGHS STILL STUCK IN THE 70S FOR WEDNESDAY. MARINE... SOUTHWEST WINDS WILL BE INCREASING TODAY AHEAD OF A COLD FRONT...WITH 25 KNOT GUSTS EXPECTED ACROSS ALL NEARSHORE WATERS...AND SMALL CRAFT ADVISORIES WILL CONTINUE. COLD FRONT ARRIVING TONIGHT LOOKS TO TRIGGER THUNDERSTORMS...WHICH COULD BE SEVERE...PRODUCING WINDS OF 50 KNOTS. WINDS WILL TURN WEST AND THEN NORTHWEST BEHIND THE FRONT DURING MONDAY. WIND SPEEDS MONDAY LOOK TO BE GREATEST OVER NORTHERN LAKE HURON...WHERE THEY WILL REACH BETWEEN 15 TO 25 KNOTS MONDAY NIGHT THROUGH TUESDAY NIGHT AS COOLER AIR SETTLES OVER THE CENTRAL GREAT LAKES REGION. THERE WILL BE A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS OVER LAKE HURON DURING THIS TIME FRAME AS WELL. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ049. LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443. LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LCZ460. MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444. && $$ AVIATION.....DG UPDATE.......DG SHORT TERM...JVC LONG TERM....SF MARINE.......SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
229 PM CDT SUN AUG 2 2015 .SHORT TERM: (THROUGH THIS EVENING) ISSUED AT 226 PM CDT SUN AUG 2 2015 CU FIELD IS GETTING A LITTLE MORE AGITATED ACROSS EASTERN MISSOURI AND SOUTHWEST ILLINOIS AND THE HRRR CONTINUES TO SHOW THE POTENTIAL OF SOME PULSE STORMS...SO HAVE INCLUDED SOME SLIGHT CHANCE/ISOLATED POPS FOR LATE THIS AFTERNOON INTO THIS EVENING FOR THIS AREA. OTHERWISE...ITS HOT OUTSIDE WITH TEMPERATURES IN THE MIDDLE 90S AND HEAT INDICES CLOSING IN ON THE CENTURY MARK IN SOME LOCALS. CVKING .LONG TERM: (MONDAY THROUGH NEXT SUNDAY) ISSUED AT 226 PM CDT SUN AUG 2 2015 COLD FRONT CURRENTLY LOCATED ACROSS THE UPPER MIDWEST WILL DROP SOUTH INTO THE CWA LATE TONIGHT...REACHING THE INTERSTATE 70 CORRIDOR BY DAYBREAK TOMORROW. LITTLE OR NO UPPER LEVEL SUPPORT AND MEAGER SURFACE CONVERGENCE WILL KEEPS POPS IN THE SLIGHT CHANCE CATEGORY OVERNIGHT AND NOT MENTIONABLE TOMORROW MORNING. DAYTIME HEATING TOMORROW AFTERNOON SHOULD RESULT IN AT LEAST ISOLATED CONVECTION NEAR THE STALLED FRONT BUT BETTER CHANCES OF RAIN WILL PROBABLY HOLD OFF UNTIL LATE MONDAY NIGHT AND TUESDAY WHEN MODEL GUIDANCE IS SHOWING MOISTURE CONVERGENCE DEVELOPING NORTH OF THE FRONT FROM NORTH CENTRAL MISSOURI TO SOUTHWEST ILLINOIS. HAVE INCREASED POPS SLIGHTLY FOR THIS TIME PERIOD BUT ANTICIPATE FURTHER ADJUSTMENTS WILL BE NEEDED. THUNDERSTORM CHANCES CONTINUE MUCH OF THE WEEK AS THE QUASI- STATIONARY FRONT WILL INTERACT WITH SEVERAL UPPER LEVEL DISTURBANCES AND THE NOCTURNAL LOW LEVEL JET. TEMPERATURES TO REMAIN BELOW NORMAL WITH CLOUDS AND RAIN CHANCES. HIGH PRESSURE WILL FINALLY MOVE INTO THE AREA FOR THE WEEKEND WITH BELOW NORMAL TEMPERATURES CONTINUING. CVKING && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1240 PM CDT SUN AUG 2 2015 SPECIFICS FOR KUIN, KCOU: WINDS WILL REMAIN SOUTHWESTERLY TO WEST-SOUTHWESTERLY AROUND THE BACK SIDE OF A HIGH PRESSURE CENTER UNTIL AN APPROACHING COLD FRONT GETS CLOSER TO THE TERMINALS. WINDS WILL BECOME WESTERLY JUST AHEAD OF AND ALONG THE FRONT, THEN TURN NORTHERLY AFTER FROPA OCCURS (17-21Z AT KCOU AND 10-14Z AT KUIN). ISOLATED TO SCATTERED SH/TS ARE POSSIBLE THIS AFTERNOON, HOWEVER PCPN CHANCES ARE HIGHER TOMORROW AFTN AT KCOU INVOF THE COLD FRONT. SPECIFICS FOR KSTL, KSUS, KCPS: WINDS WILL REMAIN SOUTHWESTERLY TO WEST-SOUTHWESTERLY AROUND THE BACK SIDE OF A HIGH PRESSURE CENTER UNTIL A COLD FRONT APPROACHES AFTER 03/06Z. WINDS WILL SLOWLY BECOME WESTERLY AS THE FRONT APPROACHES, THEN TURN NORTHWESTERLY TO NORTHERLY AFTER FROPA OCCURS BETWEEN 17-21Z. ISOLATED TO SCATTERED SH/TS ARE POSSIBLE THIS AFTERNOON, HOWEVER PCPN CHANCES ARE HIGHER TOMORROW AFTERNOON INVOF THE COLD FRONT. KANOFSKY && .PRELIMINARY POINT TEMPS/POPS: SAINT LOUIS 77 90 74 87 / 20 20 40 30 QUINCY 68 84 65 82 / 20 10 30 30 COLUMBIA 69 89 70 86 / 10 20 20 40 JEFFERSON CITY 71 91 71 87 / 10 20 20 30 SALEM 71 88 67 85 / 20 20 20 30 FARMINGTON 72 91 72 88 / 20 20 20 30 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1248 PM CDT SUN AUG 2 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 455 AM CDT SUN AUG 2 2015 THUNDERSTORMS HAVE DEVELOPED EARLY THIS MORNING OVER SOUTH CENTRAL IOWA IN AN AREA OF LOW LEVEL MOISTURE CONVERGENCE ON THE NOSE OF A 30KT LOW LEVEL JET. RAP SHOWS THAT THIS LOW LEVEL CONVERGENCE WILL MOVE ACROSS THE NORTHERN PART OF THE CWA THIS MORNING. WILL KEEP ISOLATED THUNDERSTORMS GOING OVER THIS AREA THROUGH AT LEAST THE MORNING HOURS. WENT WITH A BLEND OF THE MOS GUIDANCE FOR HIGHS TODAY WHICH IS SUPPORTED BY MIXING DOWN THE 850MB TEMPERATURES. BRITT .LONG TERM: (TONIGHT THROUGH SATURDAY) ISSUED AT 455 AM CDT SUN AUG 2 2015 (TONIGHT THROUGH TUESDAY) COLD FRONT WILL MOVE DOWN INTO THE AREA TONIGHT AHEAD OF A WEAK SHORTWAVE IN NORTHWESTERLY FLOW ALOFT. STILL EXPECT SCATTERED THUNDERSTORMS TO DEVELOP IN THE WEAK MOISTURE CONVERGENCE ALONG THE COLD FRONT IN AREAS ALONG AND NORTH OF I-70. ISOLATED THUNDERSTORMS WILL CONTINUE INTO MONDAY OVER THE SOUTHERN HALF OF THE CWA AS THE COLD FRONT SHIFTS TO THE SOUTH. CHANCES FOR STORMS WILL INCREASE MONDAY NIGHT INTO TUESDAY NIGHT AS THE FRONT STALLS OVER THE AREA AS STRONGER SHORTWAVE TROUGH MOVES ACROSS THE AREA. (WEDNESDAY THROUGH SATURDAY) THE CHANCE OF THUNDERSTORMS WILL CONTINUE OVER THE AREA THROUGH FRIDAY AS THE FRONT WILL REMAINED STALLED MISSOURI AND ILLINOIS. BOTH THE ECMWF AND GFS ARE SHOWING A SERIES OF SHORTWAVES MOVING OVER THE STALLED FRONT DURING THIS PERIOD. HIGH PRESSURE WILL FINALLY MOVE INTO THE AREA BY SATURDAY PROVIDING A DRY DAY. WENT WITH BELOW TEMPERATURES BECAUSE OF EXPECTED CLOUDS AND RAIN CHANCES. BRITT && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1240 PM CDT SUN AUG 2 2015 SPECIFICS FOR KUIN, KCOU: WINDS WILL REMAIN SOUTHWESTERLY TO WEST-SOUTHWESTERLY AROUND THE BACK SIDE OF A HIGH PRESSURE CENTER UNTIL AN APPROACHING COLD FRONT GETS CLOSER TO THE TERMINALS. WINDS WILL BECOME WESTERLY JUST AHEAD OF AND ALONG THE FRONT, THEN TURN NORTHERLY AFTER FROPA OCCURS (17-21Z AT KCOU AND 10-14Z AT KUIN). ISOLATED TO SCATTERED SH/TS ARE POSSIBLE THIS AFTERNOON, HOWEVER PCPN CHANCES ARE HIGHER TOMORROW AFTN AT KCOU INVOF THE COLD FRONT. SPECIFICS FOR KSTL, KSUS, KCPS: WINDS WILL REMAIN SOUTHWESTERLY TO WEST-SOUTHWESTERLY AROUND THE BACK SIDE OF A HIGH PRESSURE CENTER UNTIL A COLD FRONT APPROACHES AFTER 03/06Z. WINDS WILL SLOWLY BECOME WESTERLY AS THE FRONT APPROACHES, THEN TURN NORTHWESTERLY TO NORTHERLY AFTER FROPA OCCURS BETWEEN 17-21Z. ISOLATED TO SCATTERED SH/TS ARE POSSIBLE THIS AFTERNOON, HOWEVER PCPN CHANCES ARE HIGHER TOMORROW AFTERNOON INVOF THE COLD FRONT. KANOFSKY && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
421 PM CDT SUN AUG 2 2015 .SYNOPSIS... ISSUED AT 419 PM CDT SUN AUG 2 2015 STALLED BOUNDARY STRETCHED EAST WEST ACROSS CENTRAL NEBRASKA THIS AFTERNOON. WARM MOIST ARE SOUTH OF THE BOUNDARY COMBINING WITH SHEAR OF 30 TO 40 KTS AND CAPE OF AROUND 2000 J/KG TO PRODUCE SCATTERED THUNDERSTORMS. UPPER LEVEL RIDGE REMAINS ACROSS SOUTHWEST CONUS WITH NORTHWEST FLOW ACROSS THE HIGH PLAINS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 419 PM CDT SUN AUG 2 2015 ISOLATED TO SCATTERED THUNDERSTORMS CONTINUE TO DEVELOP ALONG AND SOUTH OF A STALLED MID LEVEL FRONT. MOISTURE IS DECENT AND SHEAR IS MARGINAL BUT ENOUGH FOR A FEW STRONG THUNDERSTORMS THIS EVENING. STORMS WILL DRIFT SOUTHEAST AND EXPECT THEM TO DIMINISH AFTER SUNSET. OVERNIGHT A WAVE WILL MOVE ACROSS NORTHERN NEBRASKA AND THE LATEST RAP BRINGS SOME QPF THROUGH THE REGION. THIS ACTIVITY MAY KEEP TEMPS UP...HOWEVER EXPECT SHOWERS TO BE SCT TO ISOLD WITH BREAKS TO ALLOW FOR TEMPS TO COOL DOWN AND WENT WITH GUIDANCE. TOMORROW COOLER CONDITIONS WITH HIGHS IN THE 80S TO LOWER 90S. ANOTHER DISTURBANCE WILL BRING ADDITIONAL CHANCES FOR ISOLATED THUNDERSTORMS. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 419 PM CDT SUN AUG 2 2015 FORECAST CHALLENGES IN THE DAYS 2 AND 3 PERIOD INVOLVE PRECIPITATION CHANCES ASSOCIATED WITH THE WEAK SWD ADVANCING FRONT CURRENTLY WHICH STALLS AND RETREATS SLOWLY NWD THROUGH THIS PERIOD. UPPER PATTERN INFLUENCED BY UPPER LOW OVER HUDSON BAY WITH AN UPPER JET AND ASSOCIATED PV ANOMALIES MOVING ACROSS THE UPPER MIDWEST AND GREAT LAKES AREA. AS THE JET ROUNDS THE BASE OF THE UPPER LOW...UPPER FORCING WANES AND TRANSITIONS EWD AND SFC HIGH SLIDES SEWD. MEANWHILE SIGNIFICANT LEAD PV ANOMALY ASSOCIATED WITH AN UPPER TROUGH OFF THE CA COAST WILL MOVE ACROSS THE CENTRAL ROCKIES CONTINUING ITS NEG TILT. AS THIS OCCURS SFC TROUGHING WILL DEVELOP ALONG THE LEE OF THE ROCKIES ALLOWING A RETURN TO STRONG SRLY LOW LEVEL FLOW WHICH PUSHES THE BOUNDARY NWD THROUGH TUESDAY NIGHT. THIS LEAD PV ANOMALY WILL ENTER THE HIGH PLAINS MONDAY INTO TUES THOUGH THE MODELS DIFF SIGNIFICANTLY ON TIMING AND EVENTUAL LOCATION. THIS WILL OBVIOUSLY HAVE AN IMPACT ON WHERE LOW LEVEL CONVERGENCE CAN MAXIMIZE ALONG THE RETREATING FRONT. SO CONFIDENCE ON TIMING IS ONLY AVERAGE...HOWEVER SERLY FLOW LEVEL FLOW INITIALLY WILL BRING ADDITONIAL MOISTURE BACK INTO THE AREA WITH MUCH BETTER LARGE SCALE FORCING SHOULD SEE BETTER PRECIP CHANCES MONDAY NIGHT INTO TUESDAY THAN OF LATE. FOR THURSDAY THROUGH THE WEEKEND...DEEPENING LOW PRESSURE NEAR THE ALEUTIAN ISLANDS AND DOWNSTREAM TROUGHING ALONG THE PAC NW WILL FLATTEN THE TRANSITORY CENTRAL PLAINS RIDGE LEADING TO QUASI-ZONAL FLOW ACROSS WESTERN AND NORTH CENTRAL NEB. THIS WILL BE ASSOCIATED WITH QUICKER MOVING SUBTLE PV ANOMALIES /SHORT WAVES/ HELPING TO GENERATE THUNDERSTORMS ALONG PRE-EXISTING BOUNDARIES...AND GENERALLY DIURNALLY DRIVEN INTO THE WEEKEND. TEMPERATURES IN THIS TYPE OF PATTERN WILL TYPICALLY BE MODERATE AND GENERALLY AT OR SLIGHTLY BELOW AVERAGE FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 115 PM CDT SUN AUG 2 2015 WEAK ELEVATED FRONTAL BOUNDARY DRIFTING SOUTH ACROSS THE HEART OF THE CWA THIS AFTERNOON. SOME MID LEVEL CU AND EVEN A FEW SHOWERS HAVE DEVELOPED EARLY THIS AFTERNOON. EXPECTED THESE SHOWERS TO CONTINUE TO EXPAND IN COVERAGE AND MOVE SOUTH. ALL THE ACTIVITY WILL REMAIN SOUTH OF KVTN WITH VFR CONDITIONS EXPECTED. FURTHER SOUTH...IMPACTING SOUTHWESTERN NEBRASKA...INCLUDING KLBF...WILL BE ISOLD TO SCT SHOWERS AND THUNDERSTORMS. DIRECT IMPACT AT THE KLBF TERMINAL DIFFICULT TO PIN POINT AND WILL CONTINUE THE VCTS FOR THIS AFTERNOON AND AMEND IF A STORM APPEARS TO MOVE OVER THE TERMINAL. AFTER MIDNIGHT THE STORMS SHOULD BE EXITING/DIMINISHING. GENERALLY VFR CONDITIONS EXPECTED...ALTHOUGH BRIEF MVFR/IFR CONDITIONS IN AND NEAR STRONG THUNDERSTORMS WILL BE POSSIBLE. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MASEK SHORT TERM...MASEK LONG TERM...JWS AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1218 PM CDT SUN AUG 2 2015 .UPDATE... ISSUED AT 1211 PM CDT SUN AUG 2 2015 BUMPED UP DEWPOINTS A COUPLE OF DEGREES ALONG/SOUTH OF I80...ESPECIALLY IN KNOWN AREAS WHERE DEWPOINTS WILL REMAIN ELEVATED. THIS RESULTS IN HEAT INDEX VALUES 100-104 IN SOME SPOTS THIS AFTERNOON ALONG/SOUTH OF I80. HAVE ADDED MENTION TO THE HWO FOR NOW. COLD FRONT IS A LITTLE SLOWER TO MOVE INTO THE REGION. HIRES MODEL SUITES OF HRRR/NMM/ARW CONTINUE TO INDICATE POTENTIAL CONVECTIVE DEVELOPMENT BY 19-21Z...PERHAPS IN THE PLATTE RIVER VALLEY. EXTREME INSTABILITY HAS ALREADY DEVELOPED WITH SPC MESOANALYSIS INDICATING AROUND 4000 J/KG OF CAPE. WIND SHEAR WILL ALSO BE IN THE 30 KNOT RANGE...WHICH SHOULD BE SUPPORTIVE OF SOME LARGE HAIL IF STORMS DEVELOP. BECAUSE OF THE EXTREME INSTABILITY...WILL HAVE TO WATCH FOR MICROBURSTS TOO WITH DOWNDRAFT CAPES PUSHING 1700-1900. WILL MAINTAIN A 20 PERCENT CHANCE FOR NOW UNTIL WE SEE DEVELOPMENT. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 354 AM CDT SUN AUG 2 2015 CHANCE FOR THUNDERSTORMS AND WARM TEMPERATURES TODAY...THEN OFF AND ON STORM CHANCES THROUGH TUESDAY...ARE THE PRIMARY FORECAST CONCERNS. SCATTERED THUNDERSTORMS POPPED UP EARLY THIS MORNING JUST AHEAD OF MID LEVEL WAVE DROPPING SOUTHEAST THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA AS PER WATER VAPOR AND RAP ANALYSIS. THIS WAVE WILL TRACK EAST OF OUR CWA EARLY IN THE DAYLIGHT HOURS...WITH SUBSIDENCE BEHIND WAVE KEEPING MUCH OF THE REST OF THE MORNING DRY. ANOTHER SHORTWAVE IN THE NORTHERN PLAINS INTO THE NORTHERN GREAT LAKES IS FORECAST TO SWEEP SOUTHEAST LATER TODAY...WITH SURFACE REFLECTION IN THE FORM OF A FRONT/WIND SHIFT SETTLING INTO NORTHEAST NEBRASKA THIS AFTERNOON. SURFACE DEW POINTS NEAR OR ABOVE 70F AHEAD OF THIS BOUNDARY ARE EXPECTED TO POOL IN EASTERN NEBRASKA AND WESTERN IOWA DURING PEAK HEATING. CONVERGENCE ALONG BOUNDARY SHOULD BE ENOUGH TO GET AT LEAST ISOLATED THUNDERSTORMS FIRING IN UNSTABLE ATMOSPHERE CHARACTERIZED BY MUCAPES OVER 2500 J/KG. MEANWHILE MODERATE MID LEVEL FLOW WILL HELP GENERATE NEAR 40KT OF BULK SHEAR WITH VECTORS NORMAL TO SURFACE CONVERGENCE...SUGGESTING DISCRETE AND ROTATING STORMS ARE LIKELY...SUPPORTING HAIL AND WIND POTENTIAL. ONLY MARGINAL RISK IN SPC OUTLOOK...AND CAN NOT ARGUE GIVEN EXPECTED SCANT COVERAGE. INITIATION LOOKS TO BE FARTHER NORTH THAN PREVIOUS MODEL RUNS WITH LATER ARRIVAL OF FRONT...MOSTLY LIKELY FIRING NEAR OR SOUTH OF A WAYNE TO ALBION LINE BETWEEN 3 AND 4 PM. EXPECT ISOLATED TO SCATTERED STORMS TO PROGRESS SOUTH THROUGH THE REST OF THE AFTERNOON INTO THE EVENING WITH FRONTAL BOUNDARY BEFORE EXITING SOUTHEAST NEBRASKA AND SOUTHWEST AROUND MIDNIGHT WHEN LAST OF 850 MOISTURE PLUME FINALLY DROPS SOUTH. AHEAD OF FRONT...TEMPERATURES ARE EXPECTED WELL INTO THE 90S ESPECIALLY IF CLOUD COVER FROM MORNING CONVECTION DISSIPATES AS EXPECTED. WILL LIKELY SEE SOME HEAT INDICES TOPPING 100 FOR A COUPLE OF HOURS THIS AFTERNOON. SHOULD SEE A DRY PERIOD AFTER MIDNIGHT TONIGHT...BUT LOWERING PRESSURES IN THE HIGH PLAINS WILL DRAW 850 MOISTURE BACK NORTH RATHER QUICKLY BY LATER MONDAY MORNING AS NORTHWEST MID LEVEL FLOW CONTINUES. WILL KEEP OUR SMALL POPS FOR OUR WESTERN CWA DURING THAT TIME PERIOD...WITH CHANCES/COVERAGE GRADUALLY INCREASING MONDAY AFTERNOON...BUT ESPECIALLY OVERNIGHT AND TUESDAY AS MAGNITUDE OF MOISTURE RETURN INCREASES. WILL MAINTAIN 30 TO 50 PERCENT STORM CHANCES DURING THE DAY TUESDAY. SEVERE THREAT SHOULD BE MINIMAL THEN AS INSTABILITY REMAINS WEAK DUE TO MUCH COOLER SURFACE TEMPERATURES. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 354 AM CDT SUN AUG 2 2015 UNSETTLED WEATHER PATTERN WITH OCCASIONAL RAIN/STORM CHANCES WILL CONTINUE THROUGH MUCH OF THE REST OF THE WEEK. MID LEVEL RIDGE IS FORECAST TO REMAIN FROM TEXAS WEST TO THE SOUTHWESTERN STATES AT LEAST THROUGH THURSDAY...KEEPING STORM TRACK ROLLING FROM THE CENTRAL/NORTHERN ROCKIES ACROSS THE PLAINS. SEVERAL SHORTWAVES COULD TRIGGER CONVECTION AT JUST ABOUT ANY TIME...WITH MORE POTENT WAVES MOVING THROUGH OUR AREA WEDNESDAY DURING THE DAY AND THURSDAY NIGHT AS PER ECMWF/GFS. WE SHOULD REMAIN ON THE COOL SIDE OF SURFACE FRONTAL SYSTEM...SO INSTABILITY PROGS SUGGEST SEVERE CHANCE WILL BE MINIMAL OVERALL WITH TEMPERATURES REMAINING IN THE 70S AND 80S MUCH OF THE WEEK. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1211 PM CDT SUN AUG 2 2015 VFR CONDITIONS THROUGH THE PERIOD AS A COLD FRONT MOVES INTO THE AREA. THERE IS A 20 PERCENT CHANCE THAT STORMS COULD DEVELOP BY 19-21Z. THESE STORMS WOULD LIKELY BE SOUTH OF THE KOFK TAF SITE...BUT COULD AFFECT KLNK/KOMA 23-01Z TIME FRAME. BECAUSE OF LOW CERTAINTY ON DEVELOPMENT...WILL KEEP OUT OF THE TAF FOR NOW...BUT WILL UPDATE FORECAST IF STORMS INDEED DEVELOP AND WOULD AFFECT THOSE TAF SITES. WIND SHIFT WILL ALSO BE AFFECTING KOMA/KLNK FROM SOUTHWEST TO NORTHWEST BY 23-01Z AS WELL. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ UPDATE...DEWALD SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1257 PM EDT SUN AUG 2 2015 .SYNOPSIS... A STATIONARY FRONT LINGERING ALONG THE COAST OF THE SOUTHEAST STATES WILL DISSIPATE MONDAY. THE NEXT FRONT WILL AFFECT THE AREA LATE THIS WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1250 PM SUNDAY...SEA BREEZE SLOWLY WORKING ITS WAY INLAND AND A COUPLE OF SHOWERS HAVE FORMED OVER DOWNEAST CARTERET COUNTY. PER LATEST HRRR AND NCAR ENSEMBLE WRF...THINK PRECIPITATION WILL BE ISOLATED THROUGH THE BALANCE OF THE AFTERNOON AND EVENING AND WILL KEEP ONLY A SLIGHT CHC POP OVER MAINLY THE SOUTHEASTERN HALF OF THE CWA. TEMPERATURES ALREADY INTO THE LOWER 90S IN MANY SPOTS AND CURRENT FORECAST IN GOOD SHAPE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AS OF 3 AM SUN...BOTH MODELS INCREASE MOISTURE FROM THE SOUTH IN RESPONSE TO BROAD UPPER TROF ALONG EASTERN SEABOARD SHARPENING UP. WILL NUDGE POPS A BIT FURTHER NORTH AND INCREASE TO CHANCE SOUTH OF A LINE FROM OREGON INLET TO MOREHEAD CITY. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 3 AM SUN...GFS/ECMWF TRENDING A BIT WETTER COAST MON INTO MON NIGHT AS MOISTURE INCREASES AHEAD OF WEAK LOW LIFTING NE ALONG REMNANT FRONTAL BOUNDARY. FOR NOW KEPT POPS IN CHC RANGE CST BUT IF CURRENT MDL TRENDS CONT THEY MAY NEED TO BE INCREASED IN LATER FCSTS. DEEP INLAND LOOKS MAINLY DRY AS BEST MOISTURE STAYS ALONG THE CST. HIGHS MON LOWER 90S INLAND TO 80S CST WITH 70S AREAS WIDE MON NIGHT. MAIN STORY FOR THE TUE AND WED WILL BE THE HEAT AS TYPICAL SUMMERTIME PATTERN RE-DEVELOPS WITH HIGH PRESSURE OFFSHORE AND STRENGTHENING TROUGH INLAND. HEIGHTS BUILD THROUGH MID WEEK...WITH LOW LEVEL THICKNESS VALUES AND 850MB TEMPS SUPPORTING HIGHS IN THE UPPER 80S/LOW 90S ALONG THE COAST...AND MID 90S/POSSIBLY A FEW UPPER 90S INLAND. FOR NOW FCST DEWPTS KEEP APPARENT TEMPS BELOW 105 BUT WILL BE CLOSE TO HEAT ADVRY. MAINLY SLIGHT CHC POPS TUE AND WED WITH BEST CHC CST EARLY MORN AND INLAND DURING AFTN AND EVENING. CHANCE OF SHRA AND TSRA INCREASE LATE WEEK AS UPR TRF DEVELOPS TO THE W WITH WEAK COLD FRONT APPROACHING FROM THE NW THU AND STALLING NEAR THE AREA FRI INTO SAT. HAVE CHC POPS THRU THE PERIOD. WILL REMAIN MUGGY HOWEVER TEMPS WONT BE QUITE A S HOT WITH MAINLY UPR 80S AND LOWER 90S. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... SHORT TERM /THROUGH 18Z MONDAY/... AS OF 1255 PM SUNDAY...PRETTY MUCH A PERSISTENCE FORECAST FOR AVIATION THIS TAF CYCLE. SHOULD SEE A FEW CUMULUS ONLY THE SEA BREEZE WITH ISOLATED CONVECTION POSSIBLE AT KEWN AND KOAJ. WITH INCREASING DEWPOINTS TONIGHT...WILL AGAIN SEE PATCHY AREAS OF IFR/MVFR FOG IN THE PREDAWN HOURS ON MONDAY. LONG TERM /MON THROUGH THURSDAY/... AS OF 3 AM SUN...DECENT CVRG OF SHRA/TSRA NEAR CST MON INTO MON NIGHT BUT BEST BET FOR REDUCED CIGS/VSBYS WILL BE MAINLY E OF TERMINALS ESPCLY ISO/PGV WITH POSS SOME MVFR OAJ/EWN. MAINLY VFR TUE AND WED WITH LIMITED PRECIP AND LOW LVL SW FLOW LIMITING FOG/ST THREAT. COULD SEE BETTER CVRG OF SHRA AND TSRA THU AHEAD OF NEXT FRONT WITH BRIEF SUB VFR POSS MAINLY IN THE AFTN. && .MARINE... SHORT TERM /THROUGH TONIGHT/ AS OF 1255 PM SUNDAY...WINDS STARTING TO PROCESS OF VEERING AROUND TO THE SE/S AT THE BUOY SITES AND ON THE SOUNDS. WINDS SPEEDS ARE UNIFORMLY 10 KNOTS OR LESS WITH SEAS IN THE 2 TO 3 FOOT RANGE WITH A BIT OF SOME LONG PERIOD SWELL OVER THE NORTHERN WATERS. WINDS BECOME MORE S/SW TONIGHT WITH SOME INCREASE TO 10 TO 15 KNOTS OVER THE SOUTHERN WATERS BY MORNING. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 3 AM SUN...SSW WINDS WILL INCREASE MON AS WEAK LOW LIFTS NE ALONG FRONT/TRF INLAND TIGHTENING GRDNT. WINDS SHLD REACH 15 TO 20 KTS MOST WTRS MON AFTN WITH SEAS BUILDING TO 4 TO 6 FEET HIGHEST OUTER CNTRL AND SRN WTRS. SSW WINDS THEN EXPECTED AT 10 TO 20 KTS REST OF THE FCST PERIOD AS TRF CONTS INLAND WITH HIGH OFFSHORE. THESE WINDS WILL KEEP SEAS ELEVATED ESPCLY OUTER WTRS FROM HAT S WHERE WILL BE MAINLY 5 TO 6 FT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...HSA NEAR TERM...CTC SHORT TERM...HSA LONG TERM...RF AVIATION...RF/CTC MARINE...RF/CTC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1138 AM MDT SUN AUG 2 2015 .UPDATE... ISSUED AT 1128 AM MDT SUN AUG 2 2015 THUNDERSTORMS HAVE DEVELOPED QUICKLY LATE THIS MORNING NEAR THE LARAMIE RANGE...SO INCREASED POP TODAY ALONG AND EAST OF THE LARAMIE RANGE WHERE SCATTERED COVERAGE IS POSSIBLE. THE PROBABILITY OF SEVERE TSTORMS IS LOW TODAY...BUT STORM MOTION AND THE POTENTIAL FOR HEAVY RAINFALL IS THE MAIN CONCERN. STORM MOTION THIS MORNING IS ACTUALLY A SLOW DRIFT TOWARDS THE SOUTHWEST. IT WILL BE INTERESTING TO SEE HOW THIS ACTIVITY EVOLVES THROUGH THE DAY ONCE A FEW PERSISTENT OUTFLOW BOUNDARIES DEVELOP. MAY NEED TO MONITOR THE POTENTIAL FOR FLASH FLOODING THIS AFTERNOON AND INTO THIS EVENING. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 300 AM MDT SUN AUG 2 2015 TODAY...FLOW ALOFT REMAINS NORTHWEST. LOOKS LIKE THE NAM PROJECTS A LOW LEVEL BOUNDARY TO SET UP THIS AFTERNOON ALONG THE WYOMING AND COLORADO STATE LINE WITH A NICE 850/700 MB THETA-E RIDGE AXIS OVER NORTHERN COLORADO. THUS...AS NAM DEPICTS...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP ALONG AND NEAR THE COLORADO STATE LINE...THEN SLOWLY DIMINISH THIS EVENING ALONG THE LARAMIE RANGE. TONIGHT/MONDAY...MODELS CONSISTENT IN SHOWING MORE MONSOONAL MOISTURE BEING TAPPED INTO AND MOVING ACROSS OUR COUNTIES MONDAY AFTERNOON...THOUGH NOW FURTHER WEST THAN PREVIOUS RUNS INDICATED. STILL THOUGH...WITH A SHORTWAVE TROUGH ALOFT MOVING OVERHEAD AND INCREASING LOW AND MID LEVEL MOISTURE...WILL CONTINUE OUR FORECAST WITH ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ALONG AND WEST OF INTERSTATE 25...WITH LESSER ACTIVITY FURTHER EAST. MONDAY NIGHT/TUESDAY/TUESDAY NIGHT...SHORTWAVE TROUGH ALOFT MOVES SLOWLY EASTWARD ACROSS OUR NORTHERN COUNTIES...AND WITH PLENTY OF LOW AND MID LEVEL MOISTURE...WILL SEE SCATTERED SHOWERS AND THUNDERSTORMS ACROSS OUR NORTHERN COUNTIES...LESS ACTIVITY FURTHER SOUTH WITH DRIER AIRMASS AND NEGATIVE THETA-E ADVECTION. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 300 AM MDT SUN AUG 2 2015 MONSOONAL MOISTURE TO REMAIN OVER THE AREA THROUGH AT LEAST THURSDAY. DEPENDING ON WHICH MEDIUM RANGE GUIDANCE USED...IT COULD BE LONGER. FORECAST BASED OFF THE MORE MOIST ECMWF THIS FORECAST CYCLE. STARTING OFF WEDNESDAY...WE ARE LOOKING AT THE SEMI-PERMANENT THATS BEEN IN THE AREA TO LAY ALONG THE NEBRASKA PANHANDLE...MAYBE SLIGHTLY FURTHER EAST. GFS SHOWING THE BOUNDARY FURTHER EAST AND THUS THE ENTIRE CWFA DRY. ECMWF ON THE OTHER HAND HAS THE BOUNDARY REMAINING ALONG THE EAST SLOPES OF THE LARAMIE RANGE...WITH NORTHEAST UPSLOPE FLOW ACROSS THE PANHANDLE. THIS WOULD GIVE MOST LOCATIONS ALONG AND EAST OF THE LARAMIE RANGE WITH AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON. THURSDAY AFTERNOON...A FAIRLY STRONG SHORTWAVE TRACKS ACROSS NORTHERN WYOMING INTO SOUTH DAKOTA. STRONG SOUTH TO SOUTHEASTERLY 850MB WINDS IN THE PANHANDLE AND A 70KT 250MB JET COULD BE SETTING US UP FOR ANOTHER ROUND OF SEVERE THUNDERSTORMS AT LEAST FOR THE SOUTHERN HALF OF THE PANHANDLE AS WELL AS EASTERN LARAMIE COUNTY...UP INTO GOSHEN COUNTY. SHOWERS AND THUNDERSTORMS LOOK TO PERSIST INTO THE LATE EVENING HOURS THURSDAY. AFTER A DRY FRIDAY WITH A TRANSITORY RIDGE MOVING THROUGH THE CWFA...SATURDAY LOOKS TO BE A REPEAT OF THURSDAY AS ANOTHER SHORTWAVE MOVES INTO THE AREA FROM THE SOUTHWEST. SHOULD SEE AT LEAST SLIGHT CHANCE POPS FOR MUCH OF THE AREA WITH BEST CHANCES ALONG THE WYOMING COLORADO STATE LINE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 450 AM MDT SUN AUG 2 2015 LOOKS LIKE A REPEAT IN THE FORECAST FOR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE AIRPORTS AS WAS THE CASE SATURDAY. HRRR USED FOR TIMING OF CONVECTION...MAINLY ALONG THE I-80 CORRIDOR FROM KSNY TO KLAR. TIMING LOOKS TO BE FROM 20Z THROUGH 01Z. && .FIRE WEATHER... ISSUED AT 145 AM MDT SUN AUG 2 2015 HUMIDITIES INCREASING THE NEXT FEW DAYS AS LOW AND MID LEVEL MOISTURE INCREASES ALONG WITH INCREASING CHANCES FOR LATE DAY SHOWERS AND THUNDERSTORMS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...TJT SHORT TERM...RUBIN LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RUBIN