Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/08/15
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
957 PM CDT FRI AUG 7 2015
.UPDATE...
SFC DATA INDC THAT THE QUASI-STATIONARY BNDRY BISECTED THE FA
ALONG THE AR RVR THIS EVENING. SFC DEWPOINTS CONT TO POOL ALONG
AND N OF THE BNDRY...WHERE READINGS ARE HOVERING ARND 80F. AIRMASS
RMNS VERY UNSTABLE IN THIS SECTOR AS WELL...WITH 08/00Z KLZK RAOB
SHOWING SBCAPE APCHG 6K J/KG WITH LTL IN THE WAY OF CINH.
STARTING TO SEE SOME SCTD CONVECTION DVLP OVR FAR ERN AR ATTM. THE
RAPID UPDATE MODEL DATA CONT TO INDC SCTD CONVECTION FORMING
FURTHER NWWD INTO PARTS OF NERN AR LATE THIS EVENING INTO THE
OVERNIGHT HOURS. PLAN TO KEEP SLGT CHC POPS IN PLACE PER GOING
FCST AND WL CONT TO MONITOR RADAR/MODEL TRENDS.
THUS...NO SIG CHGS WERE MADE TO THE CURRENT FCST. JUST UPDATED
HRLY TEMPS TO ACCOUNT FOR LATEST TRENDS. ALL UPDATES OUT. /44/
&&
.PREV DISCUSSION... /ISSUED 647 PM CDT FRI AUG 7 2015/
AVIATION...
HIGH PRESSURE IS CENTERED OVER NORTH TEXAS. THIS IS GIVING
NORTHEAST ARKANSAS A NORTHWEST FLOW WITH QUITE A FEW CUMULUS
CLOUDS AT 4K TO 5K FEET. A FEW THUNDERSTORMS COULD DEVELOP THIS
EVENING IN THE NORTHEAST NEAR A STATIONARY FRONT...BUT SHOULD NOT
AFFECT ANY OF THE TAF SITES. PATCHY FOG IS POSSIBLE IN THE MORNING
WITH MVFR CONDITIONS. OTHERWISE...VFR CONDITIONS ARE EXPECTED
THROUGH THE REST OF THE PERIOD.
PREV DISCUSSION... /ISSUED 239 PM CDT FRI AUG 7 2015/
SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
AN AREA OF SHOWERS AND THUNDERSTORMS MOVED FROM SOUTH CENTRAL
MISSOURI AND TRACKED SOUTHEAST THROUGH PORTIONS OF EASTERN ARKANSAS.
THESE STORMS CONTINUED TO STRENGTHEN DURING THE MID MORNING HOURS
AND LED TO INCREASED CLOUD COVER THROUGH THE EASTERN HALF OF THE
STATE. BY THE EARLY AFTERNOON HOURS...MOSTLY SUNNY SKIES WERE SEEN
AROUND THE STATE WITH TEMPERATURES WARMING INTO THE MID TO UPPER 90S
WITH A FEW LOCATIONS IN WESTERN ARKANSAS ALREADY TOPPING 100
DEGREES. HEAT INDICES AROUND THE STATE HAVE REACHED 112 AT
RUSSELLVILLE WITH A FEW LOCATIONS TOPPING 110.
FOR TONIGHT...KEPT SLIGHT CHANCE POPS ACROSS EASTERN PORTIONS OF THE
AREA WITH BOTH THE HRRR AND WRF SHOWING REDEVELOPMENT ACROSS EASTERN
ARKANSAS.
IN THE COMING DAYS...WILL CONTINUE TO SEE A STRONG RIDGE OF HIGH
PRESSURE BUILD INTO THE REGION WITH TEMPERATURES EXPECTED TO CLIMB
EVEN HOTTER THAN WHAT HAS BEEN SEEN TODAY. FOR NOW...HAVE EXTENDED
AND EXPANDED THE EXCESSIVE HEAT WARNING INTO SATURDAY AND CONTINUED
WITH THE HEAT ADVISORY AT THE REMAINING COUNTIES EXCEPT ACROSS
NORTHEAST ARKANSAS.
HOT TEMPERATURES WILL CONTINUE ON SUNDAY WITH FEWER CLOUDS AND
SLIGHTLY LOWER DEWPOINTS...GENERALLY ACROSS SOUTHWEST AND CENTRAL
ARKANSAS. HOWEVER DEWPOINTS WILL GENERALLY INCREASE ACROSS NORTHEAST
ARKANSAS WHICH WILL LIKELY CAUSE HEAT ADVISORIES/WARNINGS TO BE
EXTENDED AND EXPANDED.
UPPER LEVEL RIDGE WILL BEGIN TO RETREAT ON MONDAY...ALLOWING A COLD
FRONT TO APPROACH THE STATE FROM THE NORTH. AT THIS POINT...IT DOES
NOT APPEAR THAT THERE WILL BE HIGH CHANCE FOR PRECIPITATION WITH
THIS FRONT...BUT SLIGHTLY COOLER TEMPS AND DRIER AIR WILL MOVE INTO
THE STATE FOR THE LONG TERM.
LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
THE UPPER LEVEL RIDGE OF HIGH PRESSURE THAT HAS PERSISTED OVER THE
REGION FOR THE PAST SEVERAL WEEKS WILL RETREAT WESTARD DURING THE
EXTENDED TERM...CHANGING THE UPPER LEVEL FLOW PATTERN TO A
NORTHERLY TO NORTHWESTERLY FLOW. AT THE SURFACE A HIGH PRESSURE
SYSTEM WILL SLOWLY MOVE TO THE EAST ACROSS THE UPPER MIDWEST INTO
THE OHIO VALLEY...KEEPING THE FORECAST AREA ALONG THE SOUTHERN
PERIPHERY OF THE HIGH. THIS WILL RESULT IN A DRY NORTHERLY TO
NORTHEASTERLY SURFACE FLOW.
THIS SETUP WILL ALLOW TEMPERATURES TO REMAIN JUST A BIT COOLER THAN
THEY HAVE BEEN AT PRESENT...MOST NOTABLY ACROSS THE NORTHERN HALF OF
THE AREA. SURFACE DEWPOINTS WILL EVENTUALLY DROP DOWN TO BE ABOUT 10
TO 15 DEGREES LOWER THAN THEY ARE RIGHT NOW...WHICH WILL BE A
WELCOME RELIEF...PUSHING MAXIMUM APPARENT TEMPERATURES DOWN INTO THE
MID 80S ACROSS THE NORTH TO THE MID 90S ACROSS THE SOUTH.
WITH THE NORTH TO NORTHWESTERLY FLOW AT THE UPPER LEVELS...A
SHORTWAVE OR TWO COULD RIPPLE ACROSS THE FORECAST AREA DURING THE
EXTENDED TERM...AND ISOLATED SHOWERS AND THUNDERSTORMS CANNOT BE
RULED OUT. HOWEVER...WITH THE MOISTURE LEVELS REMAINING LOWER...THE
CHANCES FOR PRECIPITATION SHOULD BE RATHER LOW...AND BELOW MENTION
IN MANY AREAS.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 7 AM SATURDAY TO 7 PM CDT SUNDAY FOR BAXTER-
BOONE-INDEPENDENCE-JACKSON-MARION-NEWTON-SEARCY-STONE.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SATURDAY FOR BRADLEY-
CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-
GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-
OUACHITA-PERRY-POPE-PULASKI-SALINE-YELL.
EXCESSIVE HEAT WARNING FROM 7 AM TO 7 PM CDT SATURDAY FOR
ARKANSAS-MONTGOMERY-PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR ARKANSAS-MONTGOMERY-
PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR CLEBURNE-MONROE-VAN
BUREN-WOODRUFF.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
647 PM CDT FRI AUG 7 2015
.AVIATION...
HIGH PRESSURE IS CENTERED OVER NORTH TEXAS. THIS IS GIVING
NORTHEAST ARKANSAS A NORTHWEST FLOW WITH QUITE A FEW CUMULUS
CLOUDS AT 4K TO 5K FEET. A FEW THUNDERSTORMS COULD DEVELOP THIS
EVENING IN THE NORTHEAST NEAR A STATIONARY FRONT...BUT SHOULD NOT
AFFECT ANY OF THE TAF SITES. PATCHY FOG IS POSSIBLE IN THE MORNING
WITH MVFR CONDITIONS. OTHERWISE...VFR CONDITIONS ARE EXPECTED
THROUGH THE REST OF THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 239 PM CDT FRI AUG 7 2015/
SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
AN AREA OF SHOWERS AND THUNDERSTORMS MOVED FROM SOUTH CENTRAL
MISSOURI AND TRACKED SOUTHEAST THROUGH PORTIONS OF EASTERN ARKANSAS.
THESE STORMS CONTINUED TO STRENGTHEN DURING THE MID MORNING HOURS
AND LED TO INCREASED CLOUD COVER THROUGH THE EASTERN HALF OF THE
STATE. BY THE EARLY AFTERNOON HOURS...MOSTLY SUNNY SKIES WERE SEEN
AROUND THE STATE WITH TEMPERATURES WARMING INTO THE MID TO UPPER 90S
WITH A FEW LOCATIONS IN WESTERN ARKANSAS ALREADY TOPPING 100
DEGREES. HEAT INDICES AROUND THE STATE HAVE REACHED 112 AT
RUSSELLVILLE WITH A FEW LOCATIONS TOPPING 110.
FOR TONIGHT...KEPT SLIGHT CHANCE POPS ACROSS EASTERN PORTIONS OF THE
AREA WITH BOTH THE HRRR AND WRF SHOWING REDEVELOPMENT ACROSS EASTERN
ARKANSAS.
IN THE COMING DAYS...WILL CONTINUE TO SEE A STRONG RIDGE OF HIGH
PRESSURE BUILD INTO THE REGION WITH TEMPERATURES EXPECTED TO CLIMB
EVEN HOTTER THAN WHAT HAS BEEN SEEN TODAY. FOR NOW...HAVE EXTENDED
AND EXPANDED THE EXCESSIVE HEAT WARNING INTO SATURDAY AND CONTINUED
WITH THE HEAT ADVISORY AT THE REMAINING COUNTIES EXCEPT ACROSS
NORTHEAST ARKANSAS.
HOT TEMPERATURES WILL CONTINUE ON SUNDAY WITH FEWER CLOUDS AND
SLIGHTLY LOWER DEWPOINTS...GENERALLY ACROSS SOUTHWEST AND CENTRAL
ARKANSAS. HOWEVER DEWPOINTS WILL GENERALLY INCREASE ACROSS NORTHEAST
ARKANSAS WHICH WILL LIKELY CAUSE HEAT ADVISORIES/WARNINGS TO BE
EXTENDED AND EXPANDED.
UPPER LEVEL RIDGE WILL BEGIN TO RETREAT ON MONDAY...ALLOWING A COLD
FRONT TO APPROACH THE STATE FROM THE NORTH. AT THIS POINT...IT DOES
NOT APPEAR THAT THERE WILL BE HIGH CHANCE FOR PRECIPITATION WITH
THIS FRONT...BUT SLIGHTLY COOLER TEMPS AND DRIER AIR WILL MOVE INTO
THE STATE FOR THE LONG TERM.
LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
THE UPPER LEVEL RIDGE OF HIGH PRESSURE THAT HAS PERSISTED OVER THE
REGION FOR THE PAST SEVERAL WEEKS WILL RETREAT WESTARD DURING THE
EXTENDED TERM...CHANGING THE UPPER LEVEL FLOW PATTERN TO A
NORTHERLY TO NORTHWESTERLY FLOW. AT THE SURFACE A HIGH PRESSURE
SYSTEM WILL SLOWLY MOVE TO THE EAST ACROSS THE UPPER MIDWEST INTO
THE OHIO VALLEY...KEEPING THE FORECAST AREA ALONG THE SOUTHERN
PERIPHERY OF THE HIGH. THIS WILL RESULT IN A DRY NORTHERLY TO
NORTHEASTERLY SURFACE FLOW.
THIS SETUP WILL ALLOW TEMPERATURES TO REMAIN JUST A BIT COOLER THAN
THEY HAVE BEEN AT PRESENT...MOST NOTABLY ACROSS THE NORTHERN HALF OF
THE AREA. SURFACE DEWPOINTS WILL EVENTUALLY DROP DOWN TO BE ABOUT 10
TO 15 DEGREES LOWER THAN THEY ARE RIGHT NOW...WHICH WILL BE A
WELCOME RELIEF...PUSHING MAXIMUM APPARENT TEMPERATURES DOWN INTO THE
MID 80S ACROSS THE NORTH TO THE MID 90S ACROSS THE SOUTH.
WITH THE NORTH TO NORTHWESTERLY FLOW AT THE UPPER LEVELS...A
SHORTWAVE OR TWO COULD RIPPLE ACROSS THE FORECAST AREA DURING THE
EXTENDED TERM...AND ISOLATED SHOWERS AND THUNDERSTORMS CANNOT BE
RULED OUT. HOWEVER...WITH THE MOISTURE LEVELS REMAINING LOWER...THE
CHANCES FOR PRECIPITATION SHOULD BE RATHER LOW...AND BELOW MENTION
IN MANY AREAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 74 93 76 100 / 20 10 0 10
CAMDEN AR 80 102 79 103 / 10 10 0 10
HARRISON AR 74 96 74 98 / 20 10 0 10
HOT SPRINGS AR 79 102 78 102 / 10 10 0 10
LITTLE ROCK AR 78 100 79 102 / 20 10 0 10
MONTICELLO AR 79 103 79 104 / 20 10 0 10
MOUNT IDA AR 74 102 74 102 / 10 10 0 10
MOUNTAIN HOME AR 73 95 74 100 / 20 10 0 10
NEWPORT AR 73 94 75 97 / 20 10 0 10
PINE BLUFF AR 77 100 78 101 / 20 10 0 10
RUSSELLVILLE AR 78 101 75 102 / 10 10 0 10
SEARCY AR 76 96 75 100 / 20 10 0 10
STUTTGART AR 76 96 76 99 / 20 10 0 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 7 AM SATURDAY TO 7 PM CDT SUNDAY FOR BAXTER-
BOONE-INDEPENDENCE-JACKSON-MARION-NEWTON-SEARCY-STONE.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SATURDAY FOR BRADLEY-
CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-
GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-
OUACHITA-PERRY-POPE-PULASKI-SALINE-YELL.
EXCESSIVE HEAT WARNING FROM 7 AM TO 7 PM CDT SATURDAY FOR
ARKANSAS-MONTGOMERY-PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR ARKANSAS-MONTGOMERY-
PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR CLEBURNE-MONROE-VAN
BUREN-WOODRUFF.
&&
$$
AVIATION...51
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
258 PM CDT THU AUG 6 2015
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
HOT AND HUMID CONDITIONS HAVE CONTINUED AROUND THE NATURAL STATE
TODAY WITH SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS PORTIONS OF
CENTRAL ARKANSAS DURING THE DAY TODAY AND CONTINUING TO PUSH TO THE
SOUTHEAST THROUGH THE AFTERNOON. THERE ARE SOME SLIGHT CHANCES THAT
ADDITIONAL SHOWERS AND THUNDERSTORMS COULD DEVELOP THIS
AFTERNOON...GENERALLY SOUTH OF THE INTERSTATE 40 CORRIDOR. HRRR AND
WRF...HAVE CONTINUALLY SHOWED CHANCES FOR DEVELOPMENT THIS
AFTERNOON...BUT BASED ON CURRENT SATELLITE TRENDS...COULD NOT
JUSTIFY MORE THAN SLIGHT CHANCE POPS.
TONIGHT...EXPECT SHOWERS AND THUNDERSTORMS TO ONCE AGAIN DEVELOP
ACROSS NORTHWEST ARKANSAS IN RESPONSE TO AN UPPER LEVEL SHORTWAVE
THAT WILL PUSH SOUTHEAST...WITH BEST CHANCES NORTH OF THE INTERSTATE
40 WEST OF LITTLE ROCK TO NORTH OF INTERSTATE 530. THIS WILL ONCE
AGAIN KEEP TEMPERATURES SOMEWHAT LIMITED ACROSS NORTHERN ARKANSAS
AGAIN ON FRIDAY. HOWEVER...TEMPERATURES WILL WARM ALONG THE ARKANSAS
RIVER VALLEY AND TO THE SOUTHWEST ON FRIDAY WITH HEAT INDICES LIKELY
TOPPING 110 DEGREES. AS A RESULT...HAVE GONE AND ISSUED AN EXCESSIVE
HEAT WARNING ALONG THE ARKANSAS RIVER VALLEY.
UPPER LEVEL RIDGE WILL BUILD INTO THE REGION FOR THE WEEKEND AND
BRING EVEN HOTTER TEMPERATURES TO THE NATURAL STATE...WITH NO
PRECIPITATION EXPECTED. AT THIS POINT...FELT CONFIDENT IN EXTENDING
THE HEAT ADVISORY THROUGH SATURDAY...HOWEVER DID NOT EXTEND THE
EXCESSIVE HEAT WARNING. WILL LET FUTURE SHIFTS MONITOR THE THREAT.
&&
.LONG TERM...MONDAY THROUGH THURSDAY
UPPER AIR PATTERNS ACROSS NORTH AMERICA ARE EXPECTED TO UNDERGO
SUBTANTIAL AMPLIFICATION EARLY IN THIS PERIOD. A COLD FRONT WILL
MOVE SOUTH THROUGH THE MID SOUTH EARLY IN THIS PERIOD. AT THIS
TIME...PRECIPITATION AMOUNT SHOULD BE LIGHT. MAIN EFFECT OF THIS
FEATURE WILL BE TO BRING AN AIR MASS WITH NEAR NORMAL TEMPERATURES.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 71 89 74 92 / 50 20 20 10
CAMDEN AR 78 100 79 101 / 20 10 10 10
HARRISON AR 70 92 73 95 / 50 20 20 10
HOT SPRINGS AR 78 100 79 101 / 20 10 10 10
LITTLE ROCK AR 76 98 78 99 / 40 20 20 10
MONTICELLO AR 78 100 78 100 / 20 20 20 10
MOUNT IDA AR 75 100 75 100 / 10 10 10 10
MOUNTAIN HOME AR 70 90 74 94 / 50 20 20 10
NEWPORT AR 71 88 73 92 / 40 20 20 10
PINE BLUFF AR 76 98 76 99 / 30 20 20 10
RUSSELLVILLE AR 76 99 76 101 / 40 20 10 10
SEARCY AR 72 93 76 97 / 50 20 20 10
STUTTGART AR 75 95 76 96 / 40 20 20 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 7 PM CDT SATURDAY FOR BAXTER-BOONE-
INDEPENDENCE-JACKSON-MARION-NEWTON-SEARCY-STONE.
EXCESSIVE HEAT WARNING FROM NOON TO 7 PM CDT FRIDAY FOR BRADLEY-
CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-
GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-
OUACHITA-PERRY-POPE-PULASKI-SALINE-YELL.
HEAT ADVISORY FROM NOON FRIDAY TO 7 PM CDT SATURDAY FOR ARKANSAS-
CLEBURNE-CONWAY-DESHA-FAULKNER-JEFFERSON-JOHNSON-LINCOLN-LOGAN-
LONOKE-MONROE-PERRY-POPE-PRAIRIE-PULASKI-SALINE-VAN BUREN-WHITE-
WOODRUFF-YELL.
HEAT ADVISORY UNTIL 7 PM CDT SATURDAY FOR BRADLEY-CALHOUN-CLARK-
CLEVELAND-DALLAS-DREW-GARLAND-GRANT-HOT SPRING-MONTGOMERY-
OUACHITA-PIKE-POLK-SCOTT.
&&
$$
SHORT TERM...65 / LONG TERM...55
AREA FORECAST DISCUSSION
NWS TUCSON AZ
915 AM MST THU AUG 6 2015
.SYNOPSIS...HIGH PRESSURE WILL BEGIN TO SHIFT EAST OF THE AREA
TODAY...BRINGING MOISTURE AND AN INCREASING THUNDERSTORM TREND BACK
TO THE REGION THROUGH FRIDAY. AS THIS HAPPENS TEMPERATURES WILL FALL
BACK CLOSER TO SEASONAL AVERAGES. WE WILL THEN KEEP ENOUGH MOISTURE
FOR A FEW STORMS OVER THE WEEKEND WITH AN INCREASE EXPECTED AGAIN
EARLY NEXT WEEK.
&&
.DISCUSSION...THE COMPLEX AND OVERNIGHT DEVELOPMENT WE WERE
EXPECTING LINGERED DEEPER INTO MORNING HOURS WITH A MORE ACTIVE
DEBRIS FIELD THAN WE ANTICIPATED. THE REMNANT MCV FROM THE COMPLEX
SOUTH OF THE BORDER CAN BE SEEN SWIRLING ALONG JUST SOUTHWEST OF
TUCSON AT 9 AM. THE PERIPHERY OF THIS FEATURE WILL REMAIN ACTIVE AS
IT CONTINUES NORTHWARD JUST WEST OF THE CITY.
OTHERWISE...THE GULF SURGE AND DEEP CONVECTIVE OUTFLOW WE WERE
EXPECTING IS HERE. THE 12Z KTWC SOUNDING IS VERY CONDUCIVE TO SHOWER
AND THUNDERSTORM DEVELOPMENT WITH MODIFIED ML CAPE OVER 1K J/KG AND
SOLID WIND PROFILE FOR STORM DEVELOPMENT. PRECIPITABLE WATER BACK
OVER 1.5 INCHES. CIRA LPW SHOWS THE INCREASING MOISTURE TREND AT THE
H7 TO H5 LAYER CONTINUED OVERNIGHT PUSHING DEEP INTO SOUTHERN
ARIZONA WITH TOTALS RANGING FROM 1.2 TO 1.6 ACROSS THE AREA.
THE QUESTION IS WILL WE BE ABLE TO TAKE ADVANTAGE OF THIS LATER
TODAY? THE MORNING DEBRIS THROWS A WRENCH IN THE NORMAL DIURNAL
DEVELOPMENT OF STORMS. LATEST HRRR AND UOFA WRF-NAM TRENDS VERY
REASONABLY ARGUE FOR INHIBITED DEVELOPMENT FOR AREAS AFFECTED BY
THIS MORNING`S ACTIVITY (INCLUDING THE TUCSON METRO). WE WILL LOOK
SOUTH AND SOUTHEAST TO AREAS THAT SHOULD SEE BETTER SUNSHINE TODAY.
AFTER STRONG REDEVELOPMENT ACROSS PORTIONS OF SANTA CRUZ AND
SOUTHERN COCHISE COUNTY...WE WILL THEN SEE WHAT WE CAN PUSH NORTH
AND NORTHWEST BACK TOWARD THE REST OF OUR CWA DURING THE LATE
AFTERNOON AND EVENING HOURS.
PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR ADDITIONAL DETAILS.
&&
.AVIATION...VALID THRU 07/18Z.
SCT-BKN CLOUDS AT 8-12K FT AGL AND BKN-OVC CLOUDS AOA 12K FT AGL
WITH SCT SHRA AND ISOLD TSRA FROM TUCSON SOUTH AND WEST THRU 06/19Z.
AFT 06/19Z SHRA/TSRA BECOMING MORE NUMEROUS STILL WITH A FOCUS
ACROSS SOUTHERN AND WESTERN AREAS. BRIEF MVFR CONDITIONS AND
ERRATIC WIND GUSTS TO 40 KTS PSBL IN AND NEAR STRONGER TSRA.
SHRA/TSRA WILL DISSIPATE AFTER 06/05Z. OUTSIDE OF STORM
INFLUENCES...SFC WINDS WILL GENERALLY BE LESS THAN 12 KTS WITH A FEW
HIGHER GUSTS DURING THE AFTERNOON/EARLY EVENING HOURS. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...INCREASING MOISTURE ARRIVING A BIT EARLIER THAN
EXPECTED WILL RESULT IN AN UPSWING IN SHOWER AND THUNDERSTORM
ACTIVITY TODAY AND FRIDAY. THE STRONGEST STORMS WILL BE CAPABLE OF
A SHORT PERIOD OF INTENSE RAIN AND WIND GUSTS IN EXCESS OF 40 MPH.
DECREASING PRECIPITATION CHANCES ARE THEN EXPECTED OVER THE
WEEKEND...WITH MOST OF THE ACTIVITY ALONG THE INTERNATIONAL BORDER
FROM NOGALES EASTWARD...AND ALONG THE NEW MEXICO BORDER. INCREASING
COVERAGE WILL THEN BE ON TAP ACROSS THE FORECAST AREA NEXT WEEK.
OUTSIDE OF THUNDERSTORM WIND GUSTS...20-FT WINDS WILL GENERALLY BE
LESS THAN 15 MPH. HOWEVER...THERE WILL STILL BE SOME AFTERNOON AND
EARLY EVENING BREEZINESS.
&&
.PREV DISCUSSION...WHILE WE`RE CERTAINLY BEGINNING TO SEE A BETTER
MOISTURE SIGNAL TO OUR SOUTH AND WEST...THERE ARE A COUPLE ISSUES TO
CONTEND WITH FOR TODAY`S FORECAST AS THE MID-LEVEL HIGH SWINGS INTO
NM. THE FIRST REVOLVES AROUND THE LEVEL OF CLEARING WE SEE OUT WEST.
WHILE NAM/GFS SOUNDINGS SW OF TUCSON SHOW DECENT MUCAPE...IT`S ALL
LOCKED UP ABOVE A STOUT NOSE OF +25C AIR AROUND 850 MB WHICH WILL
REQUIRE SOLID DIABATIC HEATING TO TAP INTO TODAY. THE SECOND
ISSUE...POSSIBLY A BIT LESS IMPORTANT...IS THE FLOW WHICH IS
GENERALLY LIGHT AND PRETTY ILL-DEFINED BELOW 500 MB. HOWEVER...ALL
NWP SOLUTIONS SHOW SOME KIND OF SUBTLE IMPULSE EMBEDDED IN THE MID-
LEVEL FLOW WHICH MAY AUGMENT THE FLOW A TOUCH TODAY.
BASED ON SATELLITE...RADAR TRENDS...AND HIRES NWP SOLUTIONS...FEEL
WE WILL SEE ENOUGH CLEARING TODAY TO SET THE STAGE FOR GOOD
CONVECTIVE COVERAGE SOUTH AND WEST OF TUCSON. IN ADDITION...OPTED TO
CONTINUE PATCHY BLOWING DUST WORDING OVER PARTS OF CENTRAL/WESTERN
PIMA COUNTY THIS AFTERNOON/EVENING WHERE THE LAND INFORMATION SYSTEM
INDICATES RELATIVE SOIL MOISTURE VALUES DOWN NEAR 30-35 PCT. THESE
VALUES ARE LIKELY TOO `MOIST` FOR WIDESPREAD AREAS OF DUST...BUT LOW
ENOUGH TO CAUSE LOCAL VISIBILITY RESTRICTIONS ESPECIALLY GIVEN
INDICATIONS OF POTENTIALLY STRONG GUSTY OUTFLOWS IN ANY STORMS THAT
DO MANAGE TO FORM.
NO BIG CHANGES FRIDAY AND INTO THE WEEKEND AS OUR POP VALUES ARE
TRENDING VERY NICELY. COVERAGE SHOULD SHIFT EAST A TOUCH TOMORROW
AND AGAIN SATURDAY AS THE MID-LEVEL HIGH MOVES INTO THE ARKLATEX
REGION. AT THIS TIME...THE BEST SHOT AT STORMS FOR THE TUCSON AREA
APPEARS TO BE ON FRIDAY...JUST AS THE MAIN SLUG OF MOISTURE BEGINS
TO MOVE EAST OF AZ. THEN EARLY NEXT WEEK...MOISTURE WILL SLOSH BACK
WEST AGAIN AS THE HIGH AMPLIFIES AND MOVES BACK TOWARDS THE NM/TX
BORDER. BY WEDNESDAY AND THURSDAY...THE HIGH CENTER MAY GET CLOSE
ENOUGH TO BEGIN SHUTTING ACTIVITY DOWN A TOUCH ONCE AGAIN.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
DISCUSSION...MEYER
AVIATION/FIRE WEATHER...CERNIGLIA
PREV DISCUSSION...CARLAW
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS RENO NV
127 PM PDT THU AUG 6 2015
.SYNOPSIS...
NUMEROUS RAIN SHOWERS AND CHANCES FOR THUNDERSTORMS WILL DEVELOP
TONIGHT THROUGH FRIDAY. THERE COULD ALSO BE A FEW LIGHTER SHOWERS
OR THUNDERSTORMS SATURDAY AFTERNOON. DRY WEATHER RETURNS FOR THE
START OF NEXT WEEK WITH AFTERNOON TEMPERATURES SLIGHTLY BELOW
NORMAL.
&&
.SHORT TERM...
SATELLITE IMAGERY SHOWS A LOW-PRESSURE SYSTEM CURRENTLY SPINNING
JUST OFFSHORE OF THE NORTHERN CALIFORNIA COAST. MODEL FORECASTS HAVE
TRENDED A BIT LOWER WITH THE AMOUNT OF MOISTURE THAT REACHES THE
SIERRA/WESTERN NV TONIGHT, BUT SATELLITE ESTIMATES STILL INDICATE
A STREAM OF 1+ INCH ATMOSPHERIC MOISTURE (PW) VALUES ASSOCIATED
WITH THIS SYSTEM. THE MAIN FORECAST CHALLENGE CONTINUES TO BE
INSTABILITY, ESPECIALLY REGARDING THE POTENTIAL FOR THUNDERSTORMS
AND LOCALLY HEAVIER RAIN. FAIRLY STABLE LAPSE RATES ARE EXPECTED
TONIGHT OVERALL, BUT WITH STRONG FORCING OVER THE SIERRA WE CAN`T
RULE OUT THE RISK OF THUNDERSTORMS WITH LITTLE RAIN ESPECIALLY
ALONG THE NORTHERN FRINGE OF DEEPER MOISTURE. AS SUCH, A FIRE
WEATHER WATCH IS IN EFFECT ROUGHLY FOR A REGION ALONG THE SIERRA
FROM MARKLEEVILLE TO TAHOE TO PLUMAS COUNTY. SEE THE FIRE WEATHER
DISCUSSION BELOW FOR DETAILS.
FOR FRIDAY AFTERNOON, THE THREAT FOR STRONG TO SEVERE
THUNDERSTORMS HAS DECREASED COMPARED TO YESTERDAY. THE STRONGEST
FORCING AND VERTICAL WIND SHEAR SHOULD SHIFT EAST OF
MINERAL/PERSHING/CHURCHILL COUNTIES BY AFTERNOON. AS SUCH, THE
MOST LIKELY SCENARIO FOR FRIDAY IS NUMEROUS SHOWERS WITH ISOLATED
EMBEDDED THUNDERSTORMS. THERE IS STILL A GOOD CHANCE FOR MANY
LOCATIONS TO RECEIVE AT LEAST 0.10 INCH RAIN, BUT WITH A FAIRLY
STABLE AIR MASS THE CHANCES FOR RECEIVING GREATER THAN 0.50 INCHES
ARE LIMITED. HOWEVER, THE RISK FOR FLASH FLOODS AND SEVERE STORMS
IS LOW BUT NOT ZERO, ESPECIALLY IF THERE ARE ANY CLOUD BREAKS.
FOR SATURDAY, THERE ARE SLIGHT CHANCES FOR THUNDER NORTH OF
PORTOLA-PYRAMID LAKE-FALLON AS A WEAK UPPER WAVE COULD TRIGGER A
FEW GARDEN VARIETY THUNDERSTORMS. JCM
.LONG TERM...SUNDAY THROUGH THURSDAY...
NO SIGNIFICANT CHANGES TO THE LONG TERM FORECAST TODAY. BY SUNDAY
LOW PRESSURE DROPPING SOUTH OUT OF THE GULF OF ALASKA WILL BE
CENTERED OFF THE COAST OF BRITISH COLUMBIA AS HIGH PRESSURE BUILDS
OVER THE ROCKIES.
GENERALLY EXPECTING NEAR NORMAL TEMPERATURES NEXT WEEK WITH DRY
SOUTHWEST FLOW AND TYPICAL AFTERNOON ZEPHYR WINDS. STRONGER ZEPHYR
WILL BE POSSIBLE STARTING ON TUESDAY, BUT MORE LIKELY ON WEDNESDAY
OR THURSDAY. COMBINED WITH LOW RH, FIRE WEATHER COULD BECOME A
CONCERN LATER IN THE WEEK, ESPECIALLY IF CONSIDERABLE LIGHTNING
STRIKES TONIGHT CREATE THE POSSIBILITY OF HOLD OVER FIRES. CONFIDENCE
IS LOW RIGHT NOW FOR WHICH DAY NEXT WEEK WOULD HAVE THE STRONGEST
WINDS AS MODELS DIVERGE CONSIDERABLY GOING INTO NEXT WEEK ON THE
STRENGTH AND POSITION OF THE LOW PRESSURE. TOLBY
&&
.AVIATION...
VFR CONDITIONS TODAY WITH WSW WINDS GUSTING TO 20KTS AND REDUCED
SLANTWISE VISIBILITY DUE TO SMOKE AND HAZE FROM THE DODGE FIRE IN
THE NORTHERN SIERRA. HAZE IS CURRENTLY EVIDENT FROM THE OREGON
BORDER DOWN TO THE RENO/CARSON CITY AREA AND OUT PAST FALLON. EXPECT
HAZE TO BEGIN MIXING OUT WITH THE AFTERNOON WESTERLIES AFTER 00Z.
THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON ALONG THE SIERRA CREST
IN MONO COUNTY AFTER 00Z. THE THREAT OF THUNDERSTORMS MOVES INTO THE
CENTRAL SIERRA STARTING AROUND 05Z AND INTO CENTRAL WESTERN NEVADA
BY 09Z. HOWEVER, CONFIDENCE IS LOW IN THE AMOUNT OF THUNDERSTORM
ACTIVITY OVERNIGHT. AN ALTERNATE SCENARIO WOULD BE WIDESPREAD
STRATIFORM RAIN SHOWERS WITH ONLY A FEW ISOLATED STORMS EMBEDDED.
TOLBY
&&
.FIRE WEATHER...
THIS REMAINS A LOW-MEDIUM CONFIDENCE SITUATION WITH RESPECT TO
DRY THUNDERSTORM POTENTIAL THIS EVENING AND TONIGHT. CONFLICTING
SIGNALS IN LATEST GFS GUIDANCE (SHEAR/LIFT VS INSTABILITY ALOFT
VS PRECIP WATER), AND HRRR SHOWING MAINLY JUST SHOWERS DEVELOPING
WITH APPROACHING UPPER WAVE. CLOUD COVER IS RATHER THICK,
EXTENDING OFF THE CA COASTLINE, WHICH IS LIMITING HEATING TODAY
AND LAPSE RATES ALOFT.
WE FEEL THERE IS STILL SUFFICIENT RISK OF A FEW DRY STORMS THIS
EVE AND TONIGHT IN THE SIERRA FROM ROUGHLY SONORA PASS TO
SUSANVILLE TO CONTINUE THE FIRE WEATHER WATCH. OUR CONFIDENCE IS
NOWHERE NEAR SUFFICIENT HOWEVER TO UPGRADE TO A RED FLAG WARNING.
STORMS COULD TURN WET QUITE QUICKLY AS UPPER LOW APPROACHES AFTER
MIDNIGHT BUT FREQUENT LIGHTNING CAN RESULT IN NEW FIRE STARTS
OUTSIDE RAIN CORES. A TRANSITION TO WIDESPREAD SHOWERS AND
ISOLATED THUNDER IS ANTICIPATED AREAWIDE AFTER 9-12Z/FRI SO THE
WATCH WILL END THEN.
HEADS UP FOR NEXT WEEK, WHERE PATTERN BECOMES DRY WITH BREEZIER
SW FLOW AS UPPER LOW LOOKS TO PARK OFF THE CA/OR COASTLINE. IF WE
HAVE APPRECIABLE LIGHTNING TONIGHT OR TOMORROW, THESE CONDITIONS
NEXT WEEK COULD PROMOTE THE DEVELOPMENT OF HOLDOVER FIRES. CS
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...CA...FIRE WEATHER WATCH FROM 6 PM PDT THIS EVENING THROUGH LATE
TONIGHT CAZ271>273.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
331 PM EDT THU AUG 6 2015
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL DEVELOP ALONG A STALLED FRONT TO OUR
SOUTH, THEN SLOWLY MOVE THE COAST OF THE NORTH CAROLINA COAST LATE
FRIDAY INTO SATURDAY. THE LOW IS THEN FORECAST TO MOVE NORTHWARD
OVER THE WESTERN ATLANTIC, WHILE HIGH PRESSURE BUILDS IN FOR THE
WEEKEND. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LOW PRESSURE ACROSS KENTUCKY WILL CONTINUE TO MOVE EAST INTO VIRGINIA
TONIGHT ALONG A FRONT. CLOUDS WILL CONTINUE TO INCREASE FROM
SOUTHWEST TO NORTHEAST ACROSS THE REGION. MOISTURE WILL CONTINUE TO
ADVECT NORTH OF THE FRONTAL BOUNDARY AS WELL ALLOWING THE AREA OF
SHOWERS LOCATED IN THE OHIO VALLEY TO MOVE EAST OVERNIGHT. HOWEVER,
HIGH PRESSURE OVER SOUTHEAST CANADA AND NEW ENGLAND HAS FACTORED
INTO THE TRACK OF THE LOW PRESSURE TRENDING FURTHER SOUTH WITH
RECENT MODEL RUNS. THIS PUSHES THE RAIN/ NO RAIN CUTOFF TO ABOUT
PHILADELPHIA, WITH THE HIGHEST COVERAGE OF SHOWERS IN DELMARVA. IN
TERMS OF TIMING, THE HRRR AND RAP MODELS KEEP THE BEST CHANCE AROUND
OR JUST AFTER MIDNIGHT. HOWEVER, A FEW SHOWERS COULD BE AROUND THE
WHOLE NIGHT. STAYED CLOSE TO STAT GUIDANCE TONIGHT. LOWS WILL BE
WARMER WITH THE THICKER CLOUDS IN DELMARVA IN THE LOW 70`S WITH 60`S
AND EVEN SOME 50`S FURTHER NORTHWEST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THE LOW PRESSURE SYSTEM WILL MOVE OFFSHORE ON FRIDAY. CLOUDS AND
SHOWERS ARE STILL LIKELY IN DELMARVA. WITH LITTLE PRECIPITATION FROM
PHILADELPHIA TO THE NORTHWEST. TOTAL QPF HAS ALSO DECREASED WITH THE
SOUTHERN TRENDS ON ALL THE OPERATIONAL MODEL RUNS. WENT WITH THE
DRIER SREF GIVEN THE 12Z MODELS TODAY, WHICH HAS TOP RAINFALL TOTALS
AROUND A HALF INCH IN SOUTHERN DELAWARE. HIGH TEMPERATURES IN SUNNY
AREAS AWAY FROM THE SOUTHERN JERSEY SHORE AND DELMARVA WILL WARM
INTO THE 80`S. FURTHER SOUTHEAST, WHERE CLOUDS AND SHOWERS OCCUR,
THE FORECAST IS LOWER THAN THE MET/MAV GUIDANCE SETS WITH HIGHS IN
THE 70`S. SOME UNCERTAINTY STILL REMAINS OVER THE EXACT RAIN/NO RAIN
LINE TONIGHT AND FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AN AREA OF LOW PRES WILL BE MOVG TO OUR S AT THE START OF THE PD.
LTST MDL RUNS HAVE ALL TRENDED S THIS CYCLE. FOR NRN AREAS, THERE
WILL BE NO PRECIP, CENTRAL AREAS, LITTLE, IF ANY AND FOR SRN
AREAS, QPF HAS DECREASED.
GUIDANCE HAS ALSO SPED THE ENDING OF THE PRECIP UP WITH THE RAIN
BEING OVER MOST EVERYWHERE DURG SAT NIGHT. THE ONLY EXCEPTION IS
ALG THE DELMARVA AND PSBLY EXTREME SERN NJ, WHERE THERE CUD BE
SOME PRECIP LINGERING INTO THE DAY ON SAT.
THE LOW PRES WILL MOV NE WELL OUT TO SEA AS WEAK HIGH PRES BUILDS
IN FOR SUN, BRINGING WHAT SHUD BE A NICE DAY. THEN, BY MON THERE
ARE SOME TIMING DIFFS WRT TO SOME PRECIP IN ADVANCE OF A FRONT
APPROACHING FROM THE W.
THE GFS IS ESSENTIALLY DRY ON MON. THE CMC BRING A CDFNT TO THE
WRN AREAS DURG THE DAY. THE ECMWF KEEPS THE CDFNT TO THE W BUT
BRINGS SOME PREFRONTAL PRECIP DURG THE DAY, SO FOR NOW WILL JUST
GO WITH SOME LOW POPS.
MON NIGHT LOOKS TO BE MAINLY DRY, THEN BOTH THE GFS AND ECMWF
BRING THE CFP ON TUE, WHICH, BASED ON CURRENT TIMING, WOULD BE THE
WETTEST PD...MOST LIKELY TUE AFTN/EVE.
BEHIND THE FRONT, SFC HIGH PRES AND YET ANOTHER H5 RIDGE MOVE OVER
THE REGION.
TEMPS LOOK TO BE RIGHT AROUND TO SLIGHTLY BELOW NRML THRU THE PD,
WITH GENLY PLEASANT HUMIDITY VALUES.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR THROUGHOUT THE WHOLE PERIOD WITH SOME TEMPORARY MVFR CONDITIONS
POSSIBLE FOR KACY, KMIV AND KILG. CLOUDS WILL CONTINUE TO GRADUALLY
THICKEN AND LOWER TONIGHT TO AROUND 5,000 FEET IN MOST SPOTS. SOME
SPOTTY SHOWERS ARE POSSIBLE AT TIMES FROM KILG AND SITES SOUTHEAST.
THE BEST CHANCE FOR ANY BRIEF CEILING OR VISIBILITY RESTRICTION WILL
BE AT KACY WHERE MVFR CONDITIONS ARE FORECASTED FOR A TIME
OVERNIGHT. ON FRIDAY, AWAY FROM KACY CEILINGS SHOULD BEGIN TO LIFT
AND BREAK UP. WINDS ARE EXPECTED TO BE UNDER 10 KNOTS AND VARIABLE
TONIGHT BECOMING STRONGER OUT OF THE EAST-NORTHEAST WITH GUSTS TO
20 KNOTS IN THE AFTERNOON HOURS ON FRIDAY.
OUTLOOK...
FRI NIGHT...MVFR/IFR CONDITIONS PSBL ERLY, ESPECIALLY SE. OTRW,
VFR EXPECTED. IMPROVING CONDS WITH TIME. SOUTHERN AREAS WITH RAIN
POSSIBLE. GENERALLY VFR ACROSS THE NORTH. NE WIND 10 TO 20 KTS
PSBL SERN AREAS. LOW TO MDT CONFIDENCE.
SAT-SUN...VFR. NE WIND 15 TO 25 KTS, ESPECIALLY ALONG THE COAST
DURING THE DAY. MDT CONFIDENCE
MON...VFR. SOME MVFR/IFR PSBL IN MAINLY DIURNAL SHRA/TSRA. NE WIND
10 TO 20 KTS. LOW TO MDT CONFIDENCE.
&&
.MARINE...
AFTER A MAINLY TRANQUIL NIGHT, SEAS WILL INCREASE ON FRIDAY. THEY
WILL LIKELY RISE TO AROUND FOUR FEET LATE IN THE DAY. SOME EAST-
NORTHEAST WIND GUSTS MAY APPROACH 25 KNOTS AS WELL BY SUNSET AS A
DEVELOPING LOW PRESSURE SYSTEM FORMS TO OUR SOUTHEAST.
OUTLOOK...
FRI NIGHT...WINDS AND SEAS WILL INCREASE AND AN SCA WILL BE NEEDED
BY FRI NIGHT, IF NOT SOONER.
SAT-SUN...WINDS AND SEAS EXPECTED TO REMAIN ABOVE SCA CRITERIA.
SUN NIGHT-MON...SEAS ARE EXPECTED TO REMAIN AROUND 5 FT, WHILE
WIND DROPS BELOW ADVISORY CRITERIA ON MONDAY.
&&
.TIDES/COASTAL FLOODING...
THE LATEST MODEL GUIDANCE SUGGESTS THE LOW PRESSURE SYSTEM FROM THE
LOWER OHIO RIVER VALLEY WILL EXHIBIT A SLIGHTLY MORE SOUTHERN
TRACK, WHICH WOULD RESULT IN JUST SPOTTY TO MINOR TIDAL FLOODING.
THIS GUIDANCE ALSO SUGGESTS THE AREAS MOST SUSCEPTIBLE SO SUCH
FLOODING WOULD BE DELAWARE AND SOUTHERN NEW JERSEY DURING THE
SATURDAY AFTERNOON TIDAL CYCLE.
&&
.RIP CURRENTS...
BUILDING SEAS FRIDAY TO AROUND FOUR FEET AND INCREASING WINDS TO
AROUND 20 KNOTS MAY LEAD TO INCREASING RIPS IN THE MODERATE
CATEGORY BY FRIDAY AFTERNOON.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...GAINES
SHORT TERM...GAINES
LONG TERM...NIERENBERG
AVIATION...GAINES/NIERENBERG
MARINE...GAINES/NIERENBERG
TIDES/COASTAL FLOODING...MIKETTA
RIP CURRENTS...GAINES
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
940 AM EDT THU AUG 6 2015
.DISCUSSION...
TODAY...EARLY MORNING BUOY REPORTS AT 41009 AND 41010 SHOWED
SOUTHWEST WINDS WHILE SPGF1 REPORTED A SOUTHEAST WIND. THIS DEPICTS
A NARROW SURFACE RIDGE OVER OUR SOUTHERN SECTIONS. THE RIDGE WILL
NUDGE SOUTH THOUGH AS A FRONTAL TROUGH SAGS INTO THE SOUTHEAST
STATES. THE RESULTANT SOUTHWEST FLOW LOOKS LIGHT ENOUGH FOR A SEA
BREEZE EXCEPT NORTH OF THE CAPE.
MORNING SOUNDINGS INDICATED RATHER AVERAGE LOOKING LAPSE RATES FOR
THIS TIME OF THE YEAR WITH 500 MB TEMPS AROUND MINUS 6 DEGREES
CELSIUS. PRECIPITABLE WATER WAS 1.8 TO 1.9 INCHES ACROSS
CENTRAL FLORIDA BUT MIAMI AND KEY WEST SHOWED A SUBSIDENCE INVERSION
NEAR 850MB WITH DRYING ABOVE. THE LOCAL FORECAST OFFICES THERE HAVE
NOTED THIS DRY LAYER IS DUE TO AN INTRUSION OF SAHARAN AIR.
GPS PRECIPITABLE WATER DATA SUGGESTS THAT SOME OF THIS DRIER AND
MORE STABLE AIR COULD AFFECT OUR SOUTHERN SECTIONS AND THE RAP
FORECAST SOUNDINGS CONFIRM A DRY LAYER FROM ABOUT VRB SOUTHWARD.
WITH THIS IN MIND AND ALSO THAT THE LAKE OKEECHOBEE SHADOW WILL
SHIFT CLOCKWISE TO AFFECT THE TREASURE COAST TODAY...WILL PLAN ON
TWEAKING POPS DOWN A LITTLE OVER THE SOUTH COAST. INTERESTINGLY...
THE 12Z LOCAL WRF AND HRRR MODELS SUGGEST THAT THE NORTH OKEECHOBEE
BOUNDARY WILL PROVIDE INITIAL FOCUS FOR CONVECTION THIS AFTERNOON...
WITH ST LUCIE AND MARTIN COUNTIES MUCH LESS ACTIVE. THE MESOSCALE
MODELS DO NOT GENERATE VERY MUCH CONVECTION ACROSS THE NORTH...BUT
CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME TO MAKE ANY CHANGES TO
THE 40 PERCENT POPS THERE.
&&
.AVIATION...VFR THIS MORNING (WITH A LITTLE HAZE ALOFT NOTED AT
SOUTHERN TERMINALS AROUND KSUA). MAIN CHALLENGE WILL BE COVERAGE
AND TIMING OF AFTERNOON STORMS. THE RIDGE AXIS POSITION SHIFTING
SOUTH OF OKEECHOBEE WILL PLACE MOST OF EAST CENTRAL FLORIDA IN A
MORE FAVORED MOISTURE CONVERGENCE ZONE. BUT PRESENTLY...THE LIMITED
DEEP CONVECTION IN THE GULF AND ATLANTIC...SUGGESTS THAT COVERAGE
WILL BE SCATTERED. THIS LOOKS REASONABLE GIVEN THE RATHER AVERAGE
LOOKING LAPSE RATES (THAT ARE TYPICAL FOR THIS TIME OF THE YEAR) AND
THE FACT THAT MOISTURE...WHILE RUNNING A LITTLE ABOVE CLIMO IN
MOST AREAS...IS NOT "SOUPY" BY ANY MEANS.
&&
.MARINE...
TODAY...SURFACE RIDGE AXIS SHOULD NUDGE INTO SOUTH FLORIDA BUT
PRESSURE GRADIENT LOOKS TO ONLY SUPPORT 10 KNOT SOUTHWEST WINDS...
WHICH WILL BE LIGHT ENOUGH FOR A SEA BREEZE FROM ABOUT THE CAPE
SOUTHWARD. THE MAIN MARINER CONCERN WILL BE SCATTERED AFTERNOON
STORMS OVER THE MAINLAND THAT PUSH ACROSS THE COAST AS STEERING
LEVEL WINDS HAVE INCREASED.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
IMPACT WX....SEDLOCK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
330 AM CDT THU AUG 6 2015
.SHORT TERM...(TODAY)
ISSUED AT 330 AM CDT THU AUG 6 2015
RAIN WILL BE SOUTHEAST OF I-72 THIS MORNING AND CONTINUE TO MOVE
EAST THROUGH THE DAY. MOST OF THE AREA SHOULD BE RAIN-FREE BY
AFTERNOON...THOUGH PCPN COULD LINGER IN THE EXTREME SOUTHEAST EARLY
AFTERNOON. SATELLITE LOOP SHOWS RELATIVELY COLD TOPS OVER PARTS OF
ILLINOIS SO WILL KEEP A CHANCE OF ISOLATED THUNDERSTORMS IN THE
FORECAST FOR TODAY. RIDGING SHOULD MOVE INTO THE AREA FROM THE
NORTHWEST THIS AFTERNOON...WHICH SHOULD REDUCE SOME OF THE CLOUDS IN
THAT AREA. HOWEVER...MOST OF THE AREA SHOULD BE CLOUDY THROUGH THE
DAY. WINDS SHOULD BE NORTHEAST THROUGH THE PERIOD WITH THE STRONGEST
WINDS BEING IN THE EAST AT AROUND 10MPH. HIGH TEMPS WILL BE SIMILAR
TO WEDNESDAY...BUT THE COOLEST TEMPS WILL BE IN THE EAST AND
SOUTHEAST WHERE THE PCPN AND CLOUDS LINGER THE LONGEST. LOOKING FOR
HIGHS IN THE UPPER 70S IN THE EAST AND SOUTHEAST...WITH LOWER 80S IN
THE WEST/NORTHWEST.
&&
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM CDT THU AUG 6 2015
DRY CONDITIONS GENERALLY EXPECTED ACROSS CENTRAL AND SOUTHEAST IL
TONIGHT THROUGH SATURDAY. THE EXCEPTION WILL BE SLIGHT CHANCES FROM
GALESBURG NW FRIDAY MORNING AND NW OF THE IL RIVER SATURDAY. WEAK
SURFACE HIGH PRESSURE RIDGE SETTLES EAST OVER IL TONIGHT BRINGING
MOSTLY CLEAR TO PARTLY CLOUDY SKIES. COULD BE SOME PATCHY SHALLOW
GROUND FOG LATE TONIGHT BUT KEPT OUT OF FORECAST FOR NOW SINCE FEEL
THIS WILL BE FAIRLY ISOLATED IS IT OCCURS. LOWS TONIGHT IN THE LOWER
60S WITH SOME UPPER 50S FROM CHAMPAIGN NE. LOW PRESSURE OVER THE
WESTERN DAKOTAS AND EASTERN MT TO TRACK EASTWARD INTO MN BY 18Z/FRI
AND HAVE SOME SHORT WAVES AHEAD OF IT INTO WI AND NORTHERN HALF OF
IL. THIS COULD BRING ISOLATED CONVECTION TO FAR NORTHERN CWA FRIDAY
MORNING WITH BETTER CHANCES NORTH OF I-80 ON FRIDAY. HIGHS FRIDAY
MOSTLY 82-84F WITH DEWPOINTS IN THE 60S.
00Z MODELS SHOW A STRONGER MCS TO MOVE OUT OF NE/IA INTO
CENTRAL/NORTHERN IL LATE SAT AND MORE LIKELY SAT NIGHT. HAVE SLIGHT
CHANCES OF SHOWERS/THUNDERSTORMS NW OF IL RIVER SAT AND THEN LIKELY
POPS SAT NIGHT NW OF IL RIVER WHILE SLIGHT POPS FAR SE IL LATE SAT
NIGHT. SPC HAS MARGINAL RISK OF SEVERE STORMS LATE SAT AFTERNOON AND
SAT NIGHT OVER CENTRAL IL. HIGHS SAT 83-85 WITH DEWPOINTS IN UPPER
60S TO NEAR 70F. HAVE 40-50% CHANCE OF CONVECTION SUNDAY ESPECIALLY
IN THE MORNING FROM LINGERING MCS ACTIVITY. HIGHS SUNDAY IN THE LOW
TO MID 80S WITH DEWPOINTS 68-73F.
A COLD FRONT TO PUSH SOUTHWARD ACROSS CENTRAL IL MONDAY AFTERNOON
AND INTO SOUTHEAST IL MONDAY NIGHT. GFS IS SLOWER WITH FRONTAL
PASSAGE THAN ECMWF MODEL...BUT BOTH MODELS HAVE TRENDED SLOWER WITH
FRONT FROM THEIR RUNS 24 HOURS AGO. CARRIED CHANCE OF
SHOWERS/THUDNERSTORMS MONDAY AND 20-30% CHANCES MONDAY NIGHT
ESPECIALLY DURING MONDAY EVENING. HIGHS MONDAY IN LOW TO MID 80S
WITH WARMEST READINGS SE OF I-70 WHERE UPPER 80S POSSIBLE.
EXTENDED MODELS SHOW A STRONG UPPER LEVEL LOW OVER NORTHEAST U.S. BY
MIDDLE OF NEXT WEEK WHILE LARGE UPPER LEVEL RIDGE OVER TEXAS INTO
CO. SURFACE RIDGE DRIFTING SE ACROSS MIDWEST TUE-THU AND BRINGING
DRY AND LESS HUMID AIR INTO IL WITH DEWPOINTS IN THE 60S TUE AND
UPPER 50S/LOWER 60S WED/THU. HIGHS GENERALLY IN THE UPPER 70S
AND LOWER 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1105 PM CDT WED AUG 5 2015
FORECAST CONCERN CONTINUES TO REVOLVE AROUND COVERAGE OF SHOWERS
OVERNIGHT AND THE AFFECT ON CIGS. BAND OF RAIN SHOWERS CONTINUES
TO ROTATE NORTH-NORTHWEST AROUND A WEAK SURFACE WAVE ACROSS SE
MISSOURI INTO FAR SOUTHWEST ILLINOIS. MOST SHORT TERM MODELS HAVE
COME AROUND WITH THE IDEA OF THE PRECIP SHIFTING TO OR JUST SOUTH
OF A RUSHVILLE TO BLOOMINGTON LINE LATER TONIGHT INTO THURSDAY
MORNING. HRRR MODEL INDICATING A BAND OF MVFR AND LOCAL IFR CIGS
TO APPROACH A SPI TO CMI LINE AFTER 07Z WITH FORECAST SOUNDINGS
SUGGESTING MUCH MORE MOISTURE BELOW 850 MB THAN WHAT WE SAW
EARLIER THIS EVENING. THE SURFACE WAVE WILL SHIFT OFF TO OUR EAST
BY 18Z TAKING ANY RAIN THREAT AWAY FROM THE TAF SITES. MAY SEE
SOME LOWER VFR CIGS LINGER INTO THE EARLY AFTERNOON ACROSS KDEC
AND KCMI AS THE SYSTEM DEPARTS BUT IT APPEARS WE SHOULD SEE A
DECREASE IN CLOUD COVER FROM NORTHWEST TO SOUTHEAST DURING THE
AFTERNOON IN THE WAKE OF THE WEAK STORM SYSTEM. SURFACE WINDS
WILL BE EAST TO NORTHEAST AT 7 TO 12 KTS TONIGHT AND NORTHEAST
WINDS WILL INCREASE TO BETWEEN 12 AND 17 KTS ON THUR...ESPECIALLY
AT KDEC...KBMI AND KCMI. WE MAY EVEN SEE A FEW GUSTS TO AROUND
22 KTS AT TIMES THRU MID AFTERNOON BEFORE WINDS START TO DIMINISH
TOWARDS SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AUTEN
LONG TERM...07
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1110 PM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 835 PM CDT WED AUG 5 2015
FRONTAL BOUNDARY STRETCHING FROM SOUTHEAST MISSOURI THROUGH
SOUTHERN ILLINOIS CONTINUES TO BE THE FOCUS FOR SHOWERS AND
THUNDERSTORMS THIS EVENING AS AN MCV FROM AFTERNOON CONVECTION
WAS EDGING SLOWLY EAST ACROSS SOUTHEAST MISSOURI. THIS FEATURE
IS EXPECTED TO PUSH OVER SOUTHERN IL LATE TONIGHT INTO THURSDAY
MORNING BRINGING MORE WIDESPREAD RAIN AND THUNDERSTORMS TO ROUGHLY
AREAS ALONG AND SOUTH OF A SPRINGFIELD TO CHAMPAIGN LINE WITH THE
MORE CONCENTRATED QPF/HEAVIER RAINFALL OVER FAR SOUTHEAST IL. THE
SMALL BAND OF SHOWERS AND ISOLATED STORMS THAT MOVED MAINLY ALONG
AND SOUTH OF A JACKSONVILLE TO SPRINGFIELD LINE DUMPED SOME FAIRLY
SIGNIFICANT RAINFALL IN A NARROW BAND FROM WAVERLY WEST TO JUST
SOUTH OF WINCHESTER WHERE 1 TO 2 INCHES WAS ESTIMATED FROM LATE
THIS AFTERNOON INTO EARLY THIS EVENING.
AS THE MCV EDGES SLOWLY INTO SOUTHERN IL WE SHOULD SEE A BETTER
SURFACE REFLECTION DEVELOP LATER TONIGHT WHICH SHOULD ENHANCE THE
LOW LEVEL CONVERGENCE ALONG AND TO THE NORTHEAST OF THE SURFACE
LOW TRACK. THE LAST SEVERAL RUNS OF THE RAPID REFRESH MODEL HAS
BEEN SUGGESTING THE PRECIP SHOULD START TO REORGANIZE FURTHER
SOUTH CLOSER TO THE SURFACE WAVE AND MCV. SPC MESOANALYSIS SHOWING
PRECIPITABLE WATER VALUES OF 2.1 INCHES OVER OUR FAR SOUTH/SE
COUNTIES WITH FORECAST SOUNDINGS IN THESE AREAS SHOWING VERY
LITTLE WIND FLOW ALOFT SO ANY SHOWERS THAT ORGANIZE CLOSE TO
THE SURFACE WAVE AND STALLED FRONTAL BOUNDARY WILL BE VERY
EFFICIENT RAIN PRODUCERS WITH SOME OF THE DETERMINISTIC MODELS
SUGGESTING 1 TO 2 INCHES POSSIBLE OVER PARTS OF SOUTHEAST IL BY
THURSDAY MORNING. WITH SUCH WEAK STEERING WINDS FORECAST INTO
THURSDAY MORNING...IT APPEARS THE SLOWER SOLUTION WITH RESPECT TO
THE SYSTEM EXITING OUR SOUTHEAST COUNTIES IS LOOKING MORE REASONABLE.
HIGHEST POPS WILL BE SOUTH OF I-72 TONIGHT WITH PROGRESSIVELY LOWER
POPS AS YOU HEAD NORTH. HAVE ALREADY SENT OUT AN UPDATED SET OF
ZONE FORECASTS TO BETTER REFLECT THE ONGONG RAIN ACROSS THE WEST
EARLY THIS EVENING AND THE SHOWERS ASSOCIATED WITH THE SLOW
MOVING MCV AND SURFACE WAVE OVER SOUTHEAST ILLINOIS OVERNIGHT. NO
ADDITIONAL UPDATES ARE NEEDED AT THIS TIME...BUT WILL BE WATCHING
FOR THIS SECONDARY DEVELOPMENT OF SHOWERS OVER SOUTHEAST AND SOUTH
CENTRAL ILLINOIS THIS EVENING TO SEE IF WE NEED TO ADJUST OUR POPS
FURTHER NORTH. LATEST IR SATELLITE INDICATES SOME COOLING CLOUD
TOPS STARTING TO DEVELOP JUST AHEAD OF THE MCV BUT AT THE SAME
TIME WE HAVE NOTICED AN INCREASE IN DEEP CONVECTION ALONG AN
OUTFLOW BOUNDARY FROM EARLIER CONVECTION STARTING TO FLARE UP FROM
CENTRAL OKLAHOMA EAST THROUGH NORTHEAST ARKANSAS. IF THAT AREA
BECOMES BETTER ORGANIZED...IT MAY EFFECTIVELY KEEP THE BETTER
MOISTURE TRANSPORT FURTHER SOUTH...RESULTING IN THE HIGHER QPF
VALUES STAYING JUST SOUTH OF OUR AREA.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 255 PM CDT WED AUG 5 2015
RATHER DIFFUSE WEATHER PATTERN OVER MUCH OF THE MIDWEST. HIGH
PRESSURE RIDGE IS OVER THE WESTERN HALF OF THE COUNTRY...WITH AN MCS
MAKING ITS WAY ACROSS THE MID MISSISSIPPI RIVER VALLEY. GENERAL
CONSENSUS OF THE MODELS HAVE BEEN TRENDING PRECIP ALONG A QUASI
BOUNDARY ACROSS THE SOUTHERN TIER OF THE STATE...ALTHOUGH THERE HAS
BEEN SOME QUESTION AS TO WHERE THIS PARTICULAR FEATURE WILL SET UP.
SHORT TERM MODELS HAVE BEEN ENHANCING THAT ACTIVITY AS THE MCV FROM
THE ACTIVITY IN CENTRAL MO MAKES ITS WAY TO THE EAST. WITH THE
MODELS TRENDING FURTHER SOUTH, HAVE SOME CONCERNS AS TO GOING TOO
FAR NORTH WITH THE HIGHER PRECIPITATION CHANCES. WITH PRECIPITATION
ABSENT IN THE NORTHERN HALF OF THE CWA, AND POTENTIALLY FURTHER
SOUTH, THE MODELS HAVE OVERDONE SOME OF THE BOUNDARY LAYER MOISTURE.
HAVE DROPPED THE DEWPOINTS A FEW DEGREES TO COUNTER THIS NORTH OF I-
72.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 255 PM CDT WED AUG 5 2015
SHOWER/STORM CHANCES MAY LINGER TO START THE DAY, MAINLY ACROSS THE
SOUTHERN PORTION OF THE FORECAST AREA, UNTIL A WAVE MOVING OUT OF THE
CENTRAL PLAINS PUSHES EAST OF THE AREA. HOWEVER, AT THIS POINT, THE
BULK OF THE UPSTREAM PRECIPITATION IS TIED TO A MCV MOVING ACROSS
MISSOURI. IF THIS TREND CONTINUES, MOST OF THURSDAY WILL WIND UP
BEING DRY.
BEHIND THIS INITIAL SYSTEM, DRY WEATHER HAD BEEN ANTICIPATED UNTIL
AT LEAST SATURDAY NIGHT/SUNDAY AS UPPER LEVEL RIDGING WAS PROGGED TO
BUILD INTO THE AREA. HOWEVER, MODELS ARE SUGGESTING THAT A STRONGER
WAVE MAY TRACK DOWN THE BACK SIDE OF THE RIDGE THURSDAY NIGHT INTO
FRIDAY NIGHT, POSSIBLY WITH AN ACCOMPANYING RISK OF SHOWERS/STORMS.
THE BEST CHANCES WITH THIS FEATURE APPEAR TO BE THURSDAY NIGHT
UPSTREAM ACROSS THE MIDWEST WITH A DECENT LOW LEVEL JET FOCUSED INTO
THE AREA. THE DIURNAL WEAKENING OF THIS JET, COUPLED WITH THE
SHEARING OUT OF THE WAVE, SHOULD KEEP RAIN CHANCES ON THE LOW SIDE
LOCALLY.
UPSTREAM MCS DEVELOPMENT MAY OCCUR SATURDAY NIGHT, ALTHOUGH GUIDANCE
IS FAR FROM UNANIMOUS IN THE DEVELOPMENT OR WHERE IT MAY TRACK,
POSSIBLY PUSHING ACROSS THE FORECAST AREA LATER SATURDAY NIGHT INTO
SUNDAY. THEN, BEHIND THIS POTENTIAL MCS, THE NEXT MAJOR WAVE/FRONTAL
BOUNDARY AND CHANCE FOR ORGANIZED CONVECTION IS EXPECTED FOR SUNDAY
NIGHT INTO MONDAY. DRY WEATHER IS LIKELY BEHIND THIS SYSTEM TO
FINISH OUT THE FORECAST PERIOD.
NEAR NORMAL TEMPERATURES ARE EXPECTED THROUGH THE PERIOD, WITH HIGHS
IN THE 80S AND LOWS IN THE 60S. THERE WILL BE A GRADUAL INCREASE IN
HUMIDITY AHEAD OF THE SUNDAY NIGHT/MONDAY FRONT, WITH LESS HUMID
CONDITIONS LIKELY IN ITS WAKE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1105 PM CDT WED AUG 5 2015
FORECAST CONCERN CONTINUES TO REVOLVE AROUND COVERAGE OF SHOWERS
OVERNIGHT AND THE AFFECT ON CIGS. BAND OF RAIN SHOWERS CONTINUES
TO ROTATE NORTH-NORTHWEST AROUND A WEAK SURFACE WAVE ACROSS SE
MISSOURI INTO FAR SOUTHWEST ILLINOIS. MOST SHORT TERM MODELS HAVE
COME AROUND WITH THE IDEA OF THE PRECIP SHIFTING TO OR JUST SOUTH
OF A RUSHVILLE TO BLOOMINGTON LINE LATER TONIGHT INTO THURSDAY
MORNING. HRRR MODEL INDICATING A BAND OF MVFR AND LOCAL IFR CIGS
TO APPROACH A SPI TO CMI LINE AFTER 07Z WITH FORECAST SOUNDINGS
SUGGESTING MUCH MORE MOISTURE BELOW 850 MB THAN WHAT WE SAW
EARLIER THIS EVENING. THE SURFACE WAVE WILL SHIFT OFF TO OUR EAST
BY 18Z TAKING ANY RAIN THREAT AWAY FROM THE TAF SITES. MAY SEE
SOME LOWER VFR CIGS LINGER INTO THE EARLY AFTERNOON ACROSS KDEC
AND KCMI AS THE SYSTEM DEPARTS BUT IT APPEARS WE SHOULD SEE A
DECREASE IN CLOUD COVER FROM NORTHWEST TO SOUTHEAST DURING THE
AFTERNOON IN THE WAKE OF THE WEAK STORM SYSTEM. SURFACE WINDS
WILL BE EAST TO NORTHEAST AT 7 TO 12 KTS TONIGHT AND NORTHEAST
WINDS WILL INCREASE TO BETWEEN 12 AND 17 KTS ON THUR...ESPECIALLY
AT KDEC...KBMI AND KCMI. WE MAY EVEN SEE A FEW GUSTS TO AROUND
22 KTS AT TIMES THRU MID AFTERNOON BEFORE WINDS START TO DIMINISH
TOWARDS SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...HJS
LONG TERM...BAK
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
814 PM EDT FRI AUG 7 2015
.SYNOPSIS...
ISSUED AT 814 PM EDT FRI AUG 7 2015
AN UPPER LEVEL DISTURBANCE TRACKING ACROSS THE GREAT LAKES TONIGHT
MAY BRING AN ISOLATED SHOWER TO PARTS OF EXTREME NORTHWEST
INDIANA AND SOUTHWEST LOWER MICHIGAN. LOW TEMPERATURES TONIGHT
WILL RANGE FROM THE UPPER 50S TO LOWER 60S. HIGH TEMPERATURES ON
SATURDAY WILL REACH BACK TO AROUND THE 80 DEGREE MARK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 410 PM EDT FRI AUG 7 2015
A COMPACT UPPER LEVEL SHORT WAVE WILL CONTINUE EASTWARD ACROSS
THE WESTERN GREAT LAKES THIS EVENING...ALTHOUGH LATEST SHORT TERM
TRENDS SEEM TO SUGGEST THIS SHORT WAVE IS BECOMING INCREASINGLY
SHEARED. A LARGE AREA OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
IS ACCOMPANYING THIS VORT. SHORT TERM RAP TRENDS SUGGEST THIS WAVE
WILL BECOMING INCREASINGLY SHEARED WITH A MORE NARROWED CHANNEL OF
DPVA WORKING FROM WEST TO EAST ACROSS THE LOCAL AREA IN THE 22Z-
04Z TIMEFRAME. LOW LEVEL THETAE TROUGH CURRENTLY RESIDING ACROSS
THE AREA IS PROVIDING A FAIRLY SHARP WEST-EAST INSTABILITY
GRADIENT FROM THE MID MS VALLEY TO THE OHIO VALLEY...AND WOULD
EXPECT SOME DIMINISHING TREND IN COVERAGE AS THIS WAVE LOSES SOME
POTENCY AND DUE TO EFFECTS OF INITIALLY DRY AIR MASS ACROSS THE
REGION. HAVE MAINTAINED SOME SLIGHT CHANCE POPS PARTICULARLY
ACROSS THE FAR NORTHWEST/NORTH THIS EVENING FOLLOWING THIS
FORCING...WITH MORE QUESTIONABLE MOISTURE RETURN ACROSS REMAINDER
OF THE AREA ARGUING FOR MAINTENANCE OF DRY FORECAST.
FORCING WITH THIS WAVE WILL WANE LATE EVENING...BUT LAGGING LOW
LEVEL THETAE RIDGE MAY BEGIN TO HAVE SOME INFLUENCE OVERNIGHT INTO
EARLY SATURDAY MORNING. HAVE OPTED TO KEEP SOME SLIGHT CHANCE POPS
GOING OVERNIGHT INTO EARLY SATURDAY MORNING ACROSS THE
NORTH/NORTHWEST DUE TO LINGERING ADVECTIVE FORCING AND APPROACH OF A
VERY WEAK REMNANT SFC TROUGH. SOME EASTWARD PROGRESSION OF DAMPENED
LOW LEVEL THERMAL RIDGING ON SATURDAY SHOULD SOMEWHAT OFFSET
EXPECTED MORE CLOUD COVER ON SATURDAY FOR HIGHS ONCE AGAIN AROUND
80...OR POSSIBLY INTO THE LOWER 80S DEPENDING ON EXTENT OF CLOUD
COVER.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 PM EDT FRI AUG 7 2015
AN UPPER LEVEL SYSTEM OVER THE WESTERN CONUS WILL EJECT AN
UPPER LEVEL TROF OVER THE LARGE UPPER LEVEL SOUTHERN PLAINS RIDGE
AND THEN THE TROF WILL MOVE INTO THE UPPER GREAT LAKES REGION BY
EARLY SUNDAY. NCEP MODELS...THE CANADIAN GEM AND THE ECMWF WERE
SHOWING LARGE DIFFERENCES IN HANDLING THIS SYSTEM. FAVOR A
SOUTHERN TRACK WHICH IS SUPPORTED THE BY ECMWF AND THE CPS
ANALOGS. ALSO...MOST MODELS TRACKED THE SYSTEM EARLIER THIS WEEK
TOO FAR NORTH. SO FOR THIS PACKAGE...KEPT A CHANCE FOR STORMS
SUNDAY. HOWEVER...INCREASED STORM CHANCES A LITTLE OVER SOUTHWEST
AREAS IN DEFERENCE TO THE ECMWF. IF THE SOUTHERN TRACK
VERIFIES...CHANCES FOR SEVERE STORMS SHOULD BE LIMITED MORE TO THE
SOUTH AND SOUTHWEST. OTHERWISE...SOME LINGERING SHOWERS AND STORMS
ARE POSSIBLE MONDAY AND THEN CONDITIONS SHOULD BE DRY WITH
TEMPERATURES A LITTLE BELOW NORMAL AS A LARGE UPPER LEVEL TROF
REMAINS OVER THE AREA NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 814 PM EDT FRI AUG 7 2015
VFR CONDS XPCD THIS PD. LL THETA-E RIDGE SWWD OF SW TROUGH
PIVOTING EWD ACRS LAKE MI SPURNING ISOLD-SCT CONVN INVOF OF THE
MID MISSISSIPPI VALLEY. EWD FOLD OF THIS FTR OVERNIGHT MAY YET
RESULT IN AN ISOLD-SCT SHRA INVOF OF KSBN AFT 06Z YET IN LIGHT OF
MODEL IMPLIED DECAYING VERTICAL MOTION FIELDS AND TIMING WILL
HOLD DRY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...T
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...T
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
546 PM MDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 546 PM MDT FRI AUG 7 2015
VERY MINOR CHANGES WITH THIS CURRENT ESTF UPDATE. HAVE BROUGHT IN
CURRENT DATA FROM LATEST OBS. CWA DOES REMAIN UNDER A SEVERE
THUNDERSTORM WATCH WITH SOME TRW FINALLY SLOWLY MOVING INTO SSW
ZONES AND SHOULD CONTINUE TO PUSH NORTHWARD THRU THE EVENING HRS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM MDT FRI AUG 7 2015
FORECAST PROBLEM WILL BE THUNDERSTORM CHANCES AND ANY HEAVY
RAINFALL THREAT. SATELLITE IS SHOWING AN AMPLIFIED AND MOSTLY
PROGRESSIVE FLOW FROM THE PACIFIC INTO NORTH AMERICA. THIS FLOW
BECOMES MORE OF A SPLIT WITH THE TROUGHS ALONG THE WEST AND EAST
COASTS. A LOT OF PACIFIC AND MONSOONAL MOISTURE IS BEING PULLED UP
INTO THE REGION. CURRENTLY A SYNOPTIC BOUNDARY REMAINS DRAPED TO
OUR SOUTH AND WEST.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...MODELS WERE
NOT TOO FAR APART. THE CANADIAN/UKMET/GFS LED THE PACK WITH OTHERS
NOT FAR BEHIND WITH THE SREF THE WORST. THE NAM/SREF WERE HANDLING
THE SURFACE WIND AND PRESSURE FIELD THE BEST. MODELS TENDED TO BE
A LITTLE COOL ON THE LOW LEVEL THERMAL FIELD WITH THE GFS/CANADIAN
DOING THE BEST.
SATURDAY NIGHT...TO BEGIN THE NIGHT...SURFACE BOUNDARY IS DRAPED
OVER THE FAR SOUTH AND WEST CENTRAL PORTION OF THE AREA. THIS
BOUNDARY GRADUALLY SINKS SOUTH THROUGH THE NIGHT. SHORTWAVE TROUGH
MOVES THROUGH FROM THE SOUTHWEST THROUGH THE NIGHT WITH THE BEST
LIFT BASICALLY OVER THE SOUTHWEST HALF. MAIN JET AXIS/LIFT STAYS NOT
TOO FAR TO OUR NORTH AND WEST THROUGH MOST OF THE PERIOD. LATE IN
THE NIGHT A RIGHT REAR QUADRANT GETS CLOSER TO THE NORTHWEST PORTION.
RIGHT NOW THE HIGHEST POPS LOOK TO BE IN THE SOUTHWEST HALF. PWS
REMAIN NEAR 1.5 INCHES. THAT WITH STORM MOTIONS ONLY 10 TO 15 KNOTS
ALONG THAT FLOW COMING OVER THE TOP OF THE SOUTHERN BOUNDARY WILL
MAKE MODERATE TO LOCALLY HEAVY RAINFALL POSSIBLE. ALSO POSSIBLE LATE
IN THE NIGHT WITH MOIST LOW LEVELS AND LITTLE TO NO WIND THAT PATCHY
FOG COULD DEVELOP WHERE NO PRECIPITATION IS GOING ON.
SUNDAY/SUNDAY NIGHT...IT LOOKS LIKE THERE MAY BE SOME LINGERING
RAINFALL AND PATCHY FOG IN THE MORNING. FOR THE REMAINDER OF THE
PERIOD...BOUNDARY LOOKS TO BE TO THE SOUTH AND WEST OF THE AREA WITH
A WEAK LOW LEVEL UPSLOPE REGIME IN PLACE. HOWEVER...MODELS ARE
HINTING AT A WEAK SECONDARY BOUNDARY MOVING INTO THE NORTHWEST HALF
OF THE AREA DURING THE LATE AFTERNOON INTO THE EVENING. THIS SINKS A
LITTLE FURTHER SOUTHEAST DURING THE LAST HALF OF THE NIGHT.
THE MID LEVEL FORCING THROUGH THE PERIOD REMAINS RATHER WEAK WITH
THE STRONGEST IN THE EVENING. RIGHT REAR QUADRANT OF THE JET REMAINS
NEAR THE NORTHERN AND WESTERN PORTIONS OF THE AREA THROUGH THE DAY
BUT GETS CLOSER/HAS MORE AFFECT ON THOSE LOCATIONS BY THE END OF THE
DAY. THE NORTHERN PORTION OF THE AREA KEEPS GETTING AFFECTED BY THIS
THROUGH THE MIDDLE OF THE NIGHT. WITH A VARIETY OF FORCING IN
DIFFERENT TIMES AND PLACES...WILL BROADBRUSH CHANCE POPS FOR THE
ENTIRE NIGHT.
FOR THE HIGH TEMPERATURES...WILL HAVE LOW LEVEL UPSLOPE IN PLACE
THROUGH THE DAY ALONG WITH LINGERING CLOUD COVER IN THE MORNING AND
DEVELOPING CLOUD COVER IN THE AFTERNOON WITH THE CONVECTION. MODEL
GUIDANCE HAS TENDED TO BE A LITTLE WARM.
MONDAY...JET REMAINS WELL NORTH OF THE AREA THROUGH THE DAY. MID
LEVEL SHORTWAVE RIDGE IS IN PLACE THROUGH THE DAY WITH A LOT OF
DRYING. A SHORTWAVE TROUGH STARTS GETTING CLOSER DURING THE END OF
THE DAY. AREA IS IN A POST FRONTAL AIR MASS. DEPENDING ON WHICH
MODEL YOU USE...THERE COULD BE A WEAK SUBTLE SURFACE BOUNDARY IN THE
FAR SOUTH/SOUTHWEST. SO AT THIS TIME...WILL HAVE SLIGHT TO LOW
CHANCE POPS IN THE FAR SOUTH AND SOUTHWEST PORTION OF THE AREA IN
THE AFTERNOON.
HIGH TEMPERATURES WILL BE COOLER THAN THE PREVIOUS DAY DUE TO LOWER
850 MB TEMPERATURES...UPSLOPE WINDS AND LINGERING MORNING FOG/STRATUS
THAT BEGINS SUNDAY NIGHT.
MONDAY NIGHT THROUGH SATURDAY...CONTINUED AMPLIFIED PATTERN
REMAINS IN PLACE THROUGH THE PERIOD. HOWEVER...THE DETERMINISTIC
AND ENSEMBLE OUTPUT SPREAD GETS WORSE WITH TIME...ALMOST
COMPLETELY OUT OF PHASE AT TIMES. THE DIFFERENCES INVOLVE HOW THE
PERSISTENT SOUTHERN UNITED STATES RIDGE AND WEST TROUGH EVOLVE
WITH TIME. IN GENERAL THE ECMWF REMAINS STRONGER WITH THE RIDGE.
FOR THE WESTERN TROUGH...ALL OUTPUT SUPPORTS A DEEPENING ALONG THE
COAST UPPER TROUGH.
DESPITE THOSE DIFFERENCES...THE CENTER OF THE RIDGE...STILL RATHER
FAR SOUTH...AND THE POSITION OF THE UPPER TROUGH SHOULD CONTINUE TO
ALLOW PACIFIC AND MONSOONAL MOISTURE TO PULLED UP INTO THE REGION
WITH PERIODIC SHORTWAVE TROUGHS EMBEDDED WITHIN THIS FLOW. AT THE
SURFACE...WPC GRAPHICS SHOW A PERSISTENT FRONTAL BOUNDARY STILL
DRAPED NOT TOO FAR TO OUR SOUTH AND WEST OR OVER THE AREA. THIS
KEEPS A CONTINUED UPSLOPE FLOW OVER THE AREA.
GIVEN THE BIG MODEL DIFFERENCES...THE GENERAL PATTERN SUPPORTED
CONTINUED BOUTS OF MOISTURE/LIFT/RAINFALL...AND THE PROXIMITY OF A
BOUNDARY AND UPSLOPE FLOW...SHOULD SEE A CONTINUED THREAT FOR
THUNDERSTORMS AND DO NOT FEEL COMFORTABLE MAKING ANY MAJOR
ADJUSTMENTS TO THE GUIDANCE. THE DETAILS WILL HAVE TO BE REFINED AS
WE GET CLOSER TO EACH EVENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 546 PM MDT FRI AUG 7 2015
BOTH SITES WILL SEE VFR CONDITIONS GIVE WAY TO THUNDERSTORM
DEVELOPMENT FROM 02Z-06Z. AFT 06Z...FOG BEGINS TO DEVELOP AS
WINDS SLACKEN BY 06Z WITH 6SM DROPPING DOWN TO 1SM OR LESS WITH
CEILINGS BLW OVC010 BY 09Z...LASTING THRU 15Z ESPECIALLY FOR KMCK.
AFT THAT...VFR WITH SCATTERED CLOUD COVER. WINDS SE
15-25KTS...BECM LGT/VAR BY 06Z THEN NNE AROUND 10KTS 14Z-15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DLF
LONG TERM...BULLER
AVIATION...JN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
922 AM CDT THU AUG 6 2015
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 920 AM CDT THU AUG 6 2015
WV Imagery and 12Z upper air analysis indicate a weak upper level
ridge of high pressure situated across the Desert Southwest.
Meanwhile, an upper level trough of low pressure is moving
eastward across the Northern Rockies. Near the surface, a near
stationary frontal boundary extends east from the Texas panhandle
into western Oklahoma.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT THU AUG 6 2015
A weak shortwave trough was approaching the northern plains today.
Surface troughing will develop ahead of this feature across the
northern plains. A plume of warm air at 700mb will be shunted
eastward across the plains. Meanwhile, a weak surface low,
partially thermal in nature, will develop over the Oklahoma Panhandle.
A warm front will extend eastward from this low near the
Oklahoma/Kansas border. Low level upslope flow north of this front
will result in very humid conditions today except for the extreme
southwest corner where veered surface winds will allow the lower
levels to dry out. Temperatures will be held down by the moist
upslope flow across most of southwest Kansas, with highs in the
upper 80s to mid 90s. However, temperatures may exceed 100F in
Elkhart. There is a very small chance of an isolated thunderstorm
near a weak wind shift line from Hugoton northward to Scott City
as surface based CAPE values may exceed 4000 j/kg. However, given
the strong capping ahead of the surface trough, any storm that
attempts to develop out in far western Kansas would quickly move
into a strongly capped environment given a 30 mph storm motion to
the southeast. Bottom line is that thunderstorms probably will not
develop. Temperatures may reach close to heat advisory criteria
near the Oklahoma state line this afternoon.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 328 AM CDT THU AUG 6 2015
A minor shortwave trough will pass across the central plains on
Friday as the aforementioned surface front edges northward into
northern Kansas. Thunderstorms are possible across western Kansas
in the late afternoon and evening but could stay north of
Interstate 70. Another minor shortwave trough will approach
western Kansas late Saturday with additional small chances for
thunderstorms in the late afternoon and evening. High temperatures
ought to warm into the mid to upper 90s Friday and Saturday in the
warm sector, particularly from Garden City and Dodge City
southward to the Oklahoma state line Saturday and across
all of western Kansas on Sunday. A shortwave trough traversing
the northern plains on Sunday will push a cold front into western
Kansas late in the day. There is a chance of thunderstorms along
this front. Cooler weather can be expected Monday and Tuesday in
the wake of the front, but there is still a small chance of
thunderstorms on the cool but moist side of the front.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING)
ISSUED AT 603 AM CDT THU AUG 6 2015
Latest satellite and surface observations indicating IFR/LIFR
stratus increasing across western Kansas early this morning. The
latest RAP and HRRR also appears to have a decent handle with this
stratus based on 11z Thursday verification. will therefore follow
the general trend of the HRRR and RAP and begin the 12z tafs with
IFR/LIFR conditions at DDC, GCK, and HYS. This stratus to linger
through 15z and then begin to dissipate. VFR conditions are
expected at all three taf sites by 18z. The winds will be
southeasterly at 10 knots or less.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 92 70 97 72 / 0 0 0 10
GCK 92 68 97 71 / 10 0 0 20
EHA 101 68 100 71 / 0 0 0 20
LBL 100 70 98 73 / 0 0 0 10
HYS 91 68 95 71 / 0 0 0 30
P28 93 73 98 75 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Finch
LONG TERM...Finch
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
604 AM CDT THU AUG 6 2015
...Updated aviation discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT THU AUG 6 2015
A weak shortwave trough was approaching the northern plains today.
Surface troughing will develop ahead of this feature across the
northern plains. A plume of warm air at 700mb will be shunted
eastward across the plains. Meanwhile, a weak surface low,
partially thermal in nature, will develop over the Oklahoma Panhandle.
A warm front will extend eastward from this low near the
Oklahoma/Kansas border. Low level upslope flow north of this front
will result in very humid conditions today except for the extreme
southwest corner where veered surface winds will allow the lower
levels to dry out. Temperatures will be held down by the moist
upslope flow across most of southwest Kansas, with highs in the
upper 80s to mid 90s. However, temperatures may exceed 100F in
Elkhart. There is a very small chance of an isolated thunderstorm
near a weak wind shift line from Hugoton northward to Scott City
as surface based CAPE values may exceed 4000 j/kg. However, given
the strong capping ahead of the surface trough, any storm that
attempts to develop out in far western Kansas would quickly move
into a strongly capped environment given a 30 mph storm motion to
the southeast. Bottom line is that thunderstorms probably will not
develop. Temperatures may reach close to heat advisory criteria
near the Oklahoma state line this afternoon.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 328 AM CDT THU AUG 6 2015
A minor shortwave trough will pass across the central plains on
Friday as the aforementioned surface front edges northward into
northern Kansas. Thunderstorms are possible across western Kansas
in the late afternoon and evening but could stay north of
Interstate 70. Another minor shortwave trough will approach
western Kansas late Saturday with additional small chances for
thunderstorms in the late afternoon and evening. High temperatures
ought to warm into the mid to upper 90s Friday and Saturday in the
warm sector, particularly from Garden City and Dodge City
southward to the Oklahoma state line Saturday and across
all of western Kansas on Sunday. A shortwave trough traversing
the northern plains on Sunday will push a cold front into western
Kansas late in the day. There is a chance of thunderstorms along
this front. Cooler weather can be expected Monday and Tuesday in
the wake of the front, but there is still a small chance of
thunderstorms on the cool but moist side of the front.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING)
ISSUED AT 603 AM CDT THU AUG 6 2015
Latest satellite and surface observations indicating IFR/LIFR
stratus increasing across western Kansas early this morning. The
latest RAP and HRRR also appears to have a decent handle with this
stratus based on 11z Thursday verification. will therefore follow
the general trend of the HRRR and RAP and begin the 12z tafs with
IFR/LIFR conditions at DDC, GCK, and HYS. This stratus to linger
through 15z and then begin to dissipate. VFR conditions are
expected at all three taf sites by 18z. The winds will be
southeasterly at 10 knots or less.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 92 70 96 72 / 0 0 10 10
GCK 92 69 96 71 / 10 10 10 20
EHA 101 69 99 71 / 0 10 20 20
LBL 100 70 97 73 / 0 0 10 10
HYS 91 68 94 71 / 0 10 10 30
P28 93 73 97 75 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Finch
LONG TERM...Finch
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS GOODLAND KS
214 AM MDT THU AUG 6 2015
.UPDATE...
ISSUED AT 1006 PM MDT WED AUG 5 2015
SMALL THREAT FOR OVERNIGHT CONVECTION WILL CONTINUE ALONG H7
THERMAL RIDGE AS PERSISTENT WAA AND WEAK INSTABILITY PRESENT
THROUGH THE EARLY MORNING HOURS. FAIRLY LARGE T-TD SPREADS IN THIS
LAYER KEEP CONFIDENCE IN POTENTIAL INSTABILITY BEING REALIZED LOW.
OTHERWISE WITH DRYLINE HAVING RETREATED TO THE WEST OF THE AREA
HUMID AIRMASS BACK IN PLACE ACROSS THE ENTIRE CWA. STILL A LARGE
DEGREE OF SPREAD WITH POTENTIAL FOG FORECASTS WITH ENSEMBLE
GUIDANCE REMAINING FAIRLY LOW ON POTENTIAL FOR LOW VISIBILITIES.
THAT BEING SAID...WITH CONVERGENCE ALONG SFC-H85 TROUGH SLOWLY
ADVANCING TO THE EAST OVERNIGHT AND AFOREMENTIONED NEARLY
SATURATED LOW LEVEL AIRMASS EXPECT AREA OF STRATUS TO DEVELOP
ACROSS CWA AND SLOWLY ADVANCE TO THE EAST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 238 PM MDT WED AUG 5 2015
FORECAST CONCERNS WILL BE LOW CHANCE OF THUNDERSTORMS IN THE
NORTHWEST CORNER THROUGH THE MIDDLE OF THE NIGHT...THE EXTENT OF THE
FOG LATER TONIGHT INTO TOMORROW MORNING...AND ANOTHER CHANCE OF
THUNDERSTORMS ON THURSDAY. SATELLITE SHOWING
MODELS INITIALLY WELL AT MID AND UPPER LEVELS. THE SREF WAS DOING
A LITTLE BETTER THAN THE GFS AND RAP ON THE SURFACE WIND AND
PRESSURE FIELD. THE GFS AND CANADIAN WERE DOING A LITTLE BETTER
THAN THE SREF AND NAM ON THE LOW LEVEL THERMAL FIELD.
TONIGHT...A SURFACE BOUNDARY HAS SET UP ALONG THE WESTERN END OF
THE AREA WITH SOME CUMULUS DEVELOPMENT. THAT DEVELOPMENT SHOULD
CONTINUE WITH LITTLE TO NO CAP. HOWEVER...THERE IS MUCH AT MID TO
UPPER LEVELS UNTIL THE MID EVENING INTO THE OVERNIGHT. A SHORTWAVE
TROUGH STARTS MOVING THROUGH IN THE LATER HALF OF THE NIGHT AND THERE
ALSO LOOKS TO BE SOME WEAK JET LIFT AFFECTING THE NORTHWEST
CORNER THROUGH THE MIDDLE OF TONIGHT.
INITIALLY THE NAM IS THE MOST AGGRESSIVE IN PRODUCING
THUNDERSTORMS LATER THIS AFTERNOON INTO THE OVERNIGHT HOURS. NOW
THE RAP AND HRRR ARE SUPPORTING SOME ISOLATED DEVELOPMENT IN THE
AREA OF CONVERGENCE THAT IS GOING ON RIGHT NOW. THIS AREA THEN
SHIFTS TO THE NORTH AND EAST THROUGH THE NIGHT. LIFT AND WARM AIR
ADVECTION ALOFT INCREASE A GREAT DEAL IN THE EASTERN PORTION OF
THE AREA DURING THE LAST HALF OF THE NIGHT. MODELS WOULD INDICATE
A STRONG CAP ALOFT BUT MORE THAN ONE PIECE OF GUIDANCE IS
INDICATING SOME LIGHT QPF. AM A LITTLE CONCERNED ABOUT THIS
ACTIVITY. IF THE LIFT BREAKS THE CAP...THE INSTABILITY AND PWS ARE
RATHER IMPRESSIVE. WOULD NOT BE SURPRISED TO HAVE SOME STRONG
STORMS WITH SOME HEAVY RAINFALL.
THURSDAY...THE NAM AND OTHER HIGH RESOLUTION GUIDANCE DEVELOPS
PRECIPITATION OVER THE CENTRAL AND EASTERN PORTION OF THE AREA
EARLY IN THE DAY. THIS MATCHES WELL WITH THE INSTABILITY AND
SHORTWAVE TROUGH MOVING THROUGH SO WILL CONTINUE THE SLIGHT CHANCE
POPS THROUGH THE MORNING. WILL BE POTENTIAL FOR STRONG STORMS AND
HEAVY RAINFALL.
SOME FOG AND ESPECIALLY STRATUS WILL BE AROUND THROUGH
THE MORNING. THIS WILL BE IN ADVANCE OF A BOUNDARY MOVING THROUGH.
MODELS BRING THIS BOUNDARY THROUGH DURING THE LATE MORNING AND
AFTERNOON. MOST OF THE MODEL OUTPUT WOULD INDICATE THAT NOT MUCH
COOLING WILL OCCUR WITH THIS SURFACE TROUGH/WEAK FRONT. THIS DOES
MAKE SENSE CONSIDERING THE WESTERLY FLOW ALOFT AND STRONG RIDGE TO
OUR SOUTH.
SO THE HIGH TEMPERATURE FORECAST WILL BE A LITTLE TRICKY DUE TO
THE VARIABLE NATURE OF THE CLOUD COVER...SOME PRECIPITATION
POSSIBLE...AND THE BOUNDARY TIMING. SO WENT COOLER IN THE EAST
WHERE THE CLOUD COVER LASTS LONGER AND THE 850 MB TEMPERATURES ARE
THE COOLEST. HOTTER TEMPERATURES WILL BE IN THE SOUTH AND WEST IT
DOES APPEAR.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 213 AM MDT THU AUG 6 2015
THE LONG TERM FORECAST PERIOD WILL ONCE AGAIN BE DOMINATED BY AN
UPPER LEVEL RIDGE THAT SETS UP OVER THE SOUTH CENTRAL PORTION OF THE
CONUS STARTING SUNDAY. THE RIDGE WILL RETROGRADE WESTWARD AND
BECOME A HIGH AMPLITUDE MERIDIONAL PATTERN MONDAY AND WILL LAST FOR
THE REST OF THE FORECAST PERIOD. MOST OF THE JET STREAM ACTIVITY
AND VORTICITY AREAS WILL REMAIN WELL OUTSIDE OF THE HIGH PLAINS
REGION.
AT THE SURFACE...ECMWF AND GFS MODELS INDICATE A STATIONARY FRONTAL
BOUNDARY IN PLACE JUST TO THE SOUTH OF THE TRI STATE AREA ON SUNDAY.
BECAUSE OF THE SURFACE BOUNDARY WILL BE IN THE VICINITY OF THE
ENTIRE FORECAST AREA...THERE WILL BE SOME CHANCES FOR RAIN SHOWERS
AND THUNDERSTORMS SUNDAY AND MONDAY. AS OF RIGHT NOW THOUGH...IT
WOULD NOT BE SURPRISING IF MOST OF THE STORM ACTIVITY REMAINED TO
THE SOUTH ALONG THE BEST AREAS OF SURFACE WIND CONVERGENCE. IF THE
BOUNDARY REMAINS TO THE SOUTH...HIGH TEMPERATURES WILL BE SOMEWHAT
COOLER THAN AVERAGE IN THE MID TO UPPER 80S WITH NORTH TO
NORTHEASTERLY WINDS. IF THE BOUNDARY ENDS UP SHIFTING
NORTHWARD...SOUTHERLY WINDS WILL BRING MOIST DEW POINTS IN THE UPPER
50S TO MIDDLE 60S AND BETTER STORM CHANCES. REGARDLESS OF THE
FRONTAL POSITION...ECMWF AND GFS MODEL SOUNDINGS SHOW PLENTY OF
MOISTURE AVAILABLE THROUGHOUT THE PROFILE WITH PRECIPITABLE WATER
VALUES BETWEEN 1 AND 1.5 INCHES...WHICH IS BETWEEN THE 75TH AND 99TH
PERCENTILE FOR AUGUST. WITH CAPE PRESENT IN THE PROFILES BETWEEN
1000 AND 2000 J/KG AND A LACK OF GOOD BULK SHEAR VALUES...EXPECTING
ANY POSSIBILITY OF THUNDERSTORMS TO BE MARGINALLY STRONG TO SEVERE
WITH THE MAIN POTENTIAL BEING HEAVY RAINFALL FOR SUNDAY AND MONDAY.
ONCE THE RIDGE ALOFT AMPLIFIES FOR TUESDAY AND WEDNESDAY...THE UPPER
LEVEL HIGH WILL BE VERY NEARLY POSITIONED RIGHT OVER NORTHWEST
KANSAS. AS A RESULT...NOT EXPECTING MUCH FOR PRECIPITATION OR
CLOUD COVER. CONSENSUS FORECAST WAS INDICATING SOME CHANCES FOR
PRECIPITATION...BUT DECIDED TO REMOVE PRECIPITATION CHANCES DUE TO
THE SYNOPTIC SET UP. TEMPERATURES WILL WARM BACK TO NEAR NORMAL IN
THE UPPER 80S TO LOWER 90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1135 PM MDT WED AUG 5 2015
CONFIDENCE IN A LOW STRATUS SET UP OVER FOG HAS INCREASED WITH 2-5
HOUR PERIOD OF MFVR/IFR CONDITIONS EXPECTED AT GLD AROUND 12Z.
POTENTIAL FOR FOG REMAINS AT MCK...WITH STRATUS EXPECTED LATER IN
THE MORNING AND LIKELY WITH HEIGHTS A BIT HIGHER THAN AT GLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...MK
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1136 PM MDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1006 PM MDT WED AUG 5 2015
SMALL THREAT FOR OVERNIGHT CONVECTION WILL CONTINUE ALONG H7
THERMAL RIDGE AS PERSISTENT WAA AND WEAK INSTABILITY PRESENT
THROUGH THE EARLY MORNING HOURS. FAIRLY LARGE T-TD SPREADS IN THIS
LAYER KEEP CONFIDENCE IN POTENTIAL INSTABILITY BEING REALIZED LOW.
OTHERWISE WITH DRYLINE HAVING RETREATED TO THE WEST OF THE AREA
HUMID AIRMASS BACK IN PLACE ACROSS THE ENTIRE CWA. STILL A LARGE
DEGREE OF SPREAD WITH POTENTIAL FOG FORECASTS WITH ENSEMBLE
GUIDANCE REMAINING FAIRLY LOW ON POTENTIAL FOR LOW VISIBILITIES.
THAT BEING SAID...WITH CONVERGENCE ALONG SFC-H85 TROUGH SLOWLY
ADVANCING TO THE EAST OVERNIGHT AND AFOREMENTIONED NEARLY
SATURATED LOW LEVEL AIRMASS EXPECT AREA OF STRATUS TO DEVELOP
ACROSS CWA AND SLOWLY ADVANCE TO THE EAST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 238 PM MDT WED AUG 5 2015
FORECAST CONCERNS WILL BE LOW CHANCE OF THUNDERSTORMS IN THE
NORTHWEST CORNER THROUGH THE MIDDLE OF THE NIGHT...THE EXTENT OF THE
FOG LATER TONIGHT INTO TOMORROW MORNING...AND ANOTHER CHANCE OF
THUNDERSTORMS ON THURSDAY. SATELLITE SHOWING
MODELS INITIALLY WELL AT MID AND UPPER LEVELS. THE SREF WAS DOING
A LITTLE BETTER THAN THE GFS AND RAP ON THE SURFACE WIND AND
PRESSURE FIELD. THE GFS AND CANADIAN WERE DOING A LITTLE BETTER
THAN THE SREF AND NAM ON THE LOW LEVEL THERMAL FIELD.
TONIGHT...A SURFACE BOUNDARY HAS SET UP ALONG THE WESTERN END OF
THE AREA WITH SOME CUMULUS DEVELOPMENT. THAT DEVELOPMENT SHOULD
CONTINUE WITH LITTLE TO NO CAP. HOWEVER...THERE IS MUCH AT MID TO
UPPER LEVELS UNTIL THE MID EVENING INTO THE OVERNIGHT. A SHORTWAVE
TROUGH STARTS MOVING THROUGH IN THE LATER HALF OF THE NIGHT AND THERE
ALSO LOOKS TO BE SOME WEAK JET LIFT AFFECTING THE NORTHWEST
CORNER THROUGH THE MIDDLE OF TONIGHT.
INITIALLY THE NAM IS THE MOST AGGRESSIVE IN PRODUCING
THUNDERSTORMS LATER THIS AFTERNOON INTO THE OVERNIGHT HOURS. NOW
THE RAP AND HRRR ARE SUPPORTING SOME ISOLATED DEVELOPMENT IN THE
AREA OF CONVERGENCE THAT IS GOING ON RIGHT NOW. THIS AREA THEN
SHIFTS TO THE NORTH AND EAST THROUGH THE NIGHT. LIFT AND WARM AIR
ADVECTION ALOFT INCREASE A GREAT DEAL IN THE EASTERN PORTION OF
THE AREA DURING THE LAST HALF OF THE NIGHT. MODELS WOULD INDICATE
A STRONG CAP ALOFT BUT MORE THAN ONE PIECE OF GUIDANCE IS
INDICATING SOME LIGHT QPF. AM A LITTLE CONCERNED ABOUT THIS
ACTIVITY. IF THE LIFT BREAKS THE CAP...THE INSTABILITY AND PWS ARE
RATHER IMPRESSIVE. WOULD NOT BE SURPRISED TO HAVE SOME STRONG
STORMS WITH SOME HEAVY RAINFALL.
THURSDAY...THE NAM AND OTHER HIGH RESOLUTION GUIDANCE DEVELOPS
PRECIPITATION OVER THE CENTRAL AND EASTERN PORTION OF THE AREA
EARLY IN THE DAY. THIS MATCHES WELL WITH THE INSTABILITY AND
SHORTWAVE TROUGH MOVING THROUGH SO WILL CONTINUE THE SLIGHT CHANCE
POPS THROUGH THE MORNING. WILL BE POTENTIAL FOR STRONG STORMS AND
HEAVY RAINFALL.
SOME FOG AND ESPECIALLY STRATUS WILL BE AROUND THROUGH
THE MORNING. THIS WILL BE IN ADVANCE OF A BOUNDARY MOVING THROUGH.
MODELS BRING THIS BOUNDARY THROUGH DURING THE LATE MORNING AND
AFTERNOON. MOST OF THE MODEL OUTPUT WOULD INDICATE THAT NOT MUCH
COOLING WILL OCCUR WITH THIS SURFACE TROUGH/WEAK FRONT. THIS DOES
MAKE SENSE CONSIDERING THE WESTERLY FLOW ALOFT AND STRONG RIDGE TO
OUR SOUTH.
SO THE HIGH TEMPERATURE FORECAST WILL BE A LITTLE TRICKY DUE TO
THE VARIABLE NATURE OF THE CLOUD COVER...SOME PRECIPITATION
POSSIBLE...AND THE BOUNDARY TIMING. SO WENT COOLER IN THE EAST
WHERE THE CLOUD COVER LASTS LONGER AND THE 850 MB TEMPERATURES ARE
THE COOLEST. HOTTER TEMPERATURES WILL BE IN THE SOUTH AND WEST IT
DOES APPEAR.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 116 PM MDT WED AUG 5 2015
RIDGE AXIS BUILDS OVER THE HIGH PLAINS THURSDAY NIGHT RESULTING IN
DRY CONDITIONS. NEXT SHORTWAVE TROUGH WILL TOP THE RIDGE FRIDAY
AFTERNOON AND EVENING BRINGING A GOOD CHANCE FOR THUNDERSTORMS.
WHILE SHEAR/INSTABILITY PARAMETERS ARE NOT OVERWHELMING...THEY ARE
PROBABLY SUFFICIENT FOR ANOTHER ROUND OF SEVERE WEATHER WITH LARGE
HAIL AND DAMAGING WINDS THE MAIN THREATS. NAM PRECIPITABLE WATER
VALUES INCREASE TO 1-1.5 INCHES BY 00Z/SAT AND STORM MOTIONS WILL
BE NORTHEAST AT AROUND 20KTS...NEITHER PARAMETER REALLY SUGGESTING
WIDESPREAD HEAVY RAINFALL THOUGH THERE WILL CERTAINLY BE SOME
LOCAL DELUGES...ESPECIALLY NEAR RIGHT MOVING SUPERCELLS WHERE
STORM MOTIONS WILL BE MUCH SLOWER.
THE PATTERN DOESN`T CHANGE MUCH ON SATURDAY WITH A BROAD
SOUTHWESTERLY FLOW ALOFT AND EMBEDDED WEAK SHORTWAVE TROUGH
BRINGING ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS...SOME
SEVERE WITH SUFFICIENT SHEAR/INSTABILITY FORECAST ONCE AGAIN.
WILD CARD WILL BE LOCATION OF SURFACE BOUNDARIES WHICH MAY BE
INFLUENCED BY PREVIOUS DAYS CONVECTION AND WILL BE HARD TO PIN
DOWN AT THIS TIME...BUT MAY PROVE TO BE PIVOTAL FOR CONVECTIVE
INITIATION.
SUNDAY THROUGH WEDNESDAY THE RIDGE IS FORECAST TO BUILD SHARPLY
NORTHWARD WITH THE RIDGE AXIS BY WEDNESDAY CENTERED OVER THE HIGH
PLAINS FROM CANADA TO THE TEXAS PANHANDLE. FOR THIS REASON AM
SOMEWHAT SKEPTICAL OF PRECIPITATION CHANCES IN THE GLOBAL MODELS
AND THE DERIVED BLENDS USED TO INITIATE THE EXTENDED THE PERIODS.
NONETHELESS...SURFACE PROGS SHOW A CONSISTENT MOIST SOUTHEASTERLY
FLOW INTO THE REGION WITH RESULTANT INSTABILITY EACH DAY. SO THE
ATMOSPHERE WILL BE PRIMED FOR LIFT AND ANY MINOR DISTURBANCE WHICH
MAY MAKES ITS WAY THROUGH THE RIDGE MAY BE ENOUGH FOR CONVECTION
TO DEVELOP. HOWEVER DEEP LAYER SHEAR WILL BE RATHER LOW UNDER THE
RIDGE SO SEVERE THREAT SHOULD BE LIMITED.
TEMPERATURES WILL BE NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1135 PM MDT WED AUG 5 2015
CONFIDENCE IN A LOW STRATUS SET UP OVER FOG HAS INCREASED WITH 2-5
HOUR PERIOD OF MFVR/IFR CONDITIONS EXPECTED AT GLD AROUND 12Z.
POTENTIAL FOR FOG REMAINS AT MCK...WITH STRATUS EXPECTED LATER IN
THE MORNING AND LIKELY WITH HEIGHTS A BIT HIGHER THAN AT GLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...024
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1026 PM MDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1006 PM MDT WED AUG 5 2015
SMALL THREAT FOR OVERNIGHT CONVECTION WILL CONTINUE ALONG H7
THERMAL RIDGE AS PERSISTENT WAA AND WEAK INSTABILITY PRESENT
THROUGH THE EARLY MORNING HOURS. FAIRLY LARGE T-TD SPREADS IN THIS
LAYER KEEP CONFIDENCE IN POTENTIAL INSTABILITY BEING REALIZED LOW.
OTHERWISE WITH DRYLINE HAVING RETREATED TO THE WEST OF THE AREA
HUMID AIRMASS BACK IN PLACE ACROSS THE ENTIRE CWA. STILL A LARGE
DEGREE OF SPREAD WITH POTENTIAL FOG FORECASTS WITH ENSEMBLE
GUIDANCE REMAINING FAIRLY LOW ON POTENTIAL FOR LOW VISIBILITIES.
THAT BEING SAID...WITH CONVERGENCE ALONG SFC-H85 TROUGH SLOWLY
ADVANCING TO THE EAST OVERNIGHT AND AFOREMENTIONED NEARLY
SATURATED LOW LEVEL AIRMASS EXPECT AREA OF STRATUS TO DEVELOP
ACROSS CWA AND SLOWLY ADVANCE TO THE EAST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 238 PM MDT WED AUG 5 2015
FORECAST CONCERNS WILL BE LOW CHANCE OF THUNDERSTORMS IN THE
NORTHWEST CORNER THROUGH THE MIDDLE OF THE NIGHT...THE EXTENT OF THE
FOG LATER TONIGHT INTO TOMORROW MORNING...AND ANOTHER CHANCE OF
THUNDERSTORMS ON THURSDAY. SATELLITE SHOWING
MODELS INITIALLY WELL AT MID AND UPPER LEVELS. THE SREF WAS DOING
A LITTLE BETTER THAN THE GFS AND RAP ON THE SURFACE WIND AND
PRESSURE FIELD. THE GFS AND CANADIAN WERE DOING A LITTLE BETTER
THAN THE SREF AND NAM ON THE LOW LEVEL THERMAL FIELD.
TONIGHT...A SURFACE BOUNDARY HAS SET UP ALONG THE WESTERN END OF
THE AREA WITH SOME CUMULUS DEVELOPMENT. THAT DEVELOPMENT SHOULD
CONTINUE WITH LITTLE TO NO CAP. HOWEVER...THERE IS MUCH AT MID TO
UPPER LEVELS UNTIL THE MID EVENING INTO THE OVERNIGHT. A SHORTWAVE
TROUGH STARTS MOVING THROUGH IN THE LATER HALF OF THE NIGHT AND THERE
ALSO LOOKS TO BE SOME WEAK JET LIFT AFFECTING THE NORTHWEST
CORNER THROUGH THE MIDDLE OF TONIGHT.
INITIALLY THE NAM IS THE MOST AGGRESSIVE IN PRODUCING
THUNDERSTORMS LATER THIS AFTERNOON INTO THE OVERNIGHT HOURS. NOW
THE RAP AND HRRR ARE SUPPORTING SOME ISOLATED DEVELOPMENT IN THE
AREA OF CONVERGENCE THAT IS GOING ON RIGHT NOW. THIS AREA THEN
SHIFTS TO THE NORTH AND EAST THROUGH THE NIGHT. LIFT AND WARM AIR
ADVECTION ALOFT INCREASE A GREAT DEAL IN THE EASTERN PORTION OF
THE AREA DURING THE LAST HALF OF THE NIGHT. MODELS WOULD INDICATE
A STRONG CAP ALOFT BUT MORE THAN ONE PIECE OF GUIDANCE IS
INDICATING SOME LIGHT QPF. AM A LITTLE CONCERNED ABOUT THIS
ACTIVITY. IF THE LIFT BREAKS THE CAP...THE INSTABILITY AND PWS ARE
RATHER IMPRESSIVE. WOULD NOT BE SURPRISED TO HAVE SOME STRONG
STORMS WITH SOME HEAVY RAINFALL.
THURSDAY...THE NAM AND OTHER HIGH RESOLUTION GUIDANCE DEVELOPS
PRECIPITATION OVER THE CENTRAL AND EASTERN PORTION OF THE AREA
EARLY IN THE DAY. THIS MATCHES WELL WITH THE INSTABILITY AND
SHORTWAVE TROUGH MOVING THROUGH SO WILL CONTINUE THE SLIGHT CHANCE
POPS THROUGH THE MORNING. WILL BE POTENTIAL FOR STRONG STORMS AND
HEAVY RAINFALL.
SOME FOG AND ESPECIALLY STRATUS WILL BE AROUND THROUGH
THE MORNING. THIS WILL BE IN ADVANCE OF A BOUNDARY MOVING THROUGH.
MODELS BRING THIS BOUNDARY THROUGH DURING THE LATE MORNING AND
AFTERNOON. MOST OF THE MODEL OUTPUT WOULD INDICATE THAT NOT MUCH
COOLING WILL OCCUR WITH THIS SURFACE TROUGH/WEAK FRONT. THIS DOES
MAKE SENSE CONSIDERING THE WESTERLY FLOW ALOFT AND STRONG RIDGE TO
OUR SOUTH.
SO THE HIGH TEMPERATURE FORECAST WILL BE A LITTLE TRICKY DUE TO
THE VARIABLE NATURE OF THE CLOUD COVER...SOME PRECIPITATION
POSSIBLE...AND THE BOUNDARY TIMING. SO WENT COOLER IN THE EAST
WHERE THE CLOUD COVER LASTS LONGER AND THE 850 MB TEMPERATURES ARE
THE COOLEST. HOTTER TEMPERATURES WILL BE IN THE SOUTH AND WEST IT
DOES APPEAR.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 116 PM MDT WED AUG 5 2015
RIDGE AXIS BUILDS OVER THE HIGH PLAINS THURSDAY NIGHT RESULTING IN
DRY CONDITIONS. NEXT SHORTWAVE TROUGH WILL TOP THE RIDGE FRIDAY
AFTERNOON AND EVENING BRINGING A GOOD CHANCE FOR THUNDERSTORMS.
WHILE SHEAR/INSTABILITY PARAMETERS ARE NOT OVERWHELMING...THEY ARE
PROBABLY SUFFICIENT FOR ANOTHER ROUND OF SEVERE WEATHER WITH LARGE
HAIL AND DAMAGING WINDS THE MAIN THREATS. NAM PRECIPITABLE WATER
VALUES INCREASE TO 1-1.5 INCHES BY 00Z/SAT AND STORM MOTIONS WILL
BE NORTHEAST AT AROUND 20KTS...NEITHER PARAMETER REALLY SUGGESTING
WIDESPREAD HEAVY RAINFALL THOUGH THERE WILL CERTAINLY BE SOME
LOCAL DELUGES...ESPECIALLY NEAR RIGHT MOVING SUPERCELLS WHERE
STORM MOTIONS WILL BE MUCH SLOWER.
THE PATTERN DOESN`T CHANGE MUCH ON SATURDAY WITH A BROAD
SOUTHWESTERLY FLOW ALOFT AND EMBEDDED WEAK SHORTWAVE TROUGH
BRINGING ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS...SOME
SEVERE WITH SUFFICIENT SHEAR/INSTABILITY FORECAST ONCE AGAIN.
WILD CARD WILL BE LOCATION OF SURFACE BOUNDARIES WHICH MAY BE
INFLUENCED BY PREVIOUS DAYS CONVECTION AND WILL BE HARD TO PIN
DOWN AT THIS TIME...BUT MAY PROVE TO BE PIVOTAL FOR CONVECTIVE
INITIATION.
SUNDAY THROUGH WEDNESDAY THE RIDGE IS FORECAST TO BUILD SHARPLY
NORTHWARD WITH THE RIDGE AXIS BY WEDNESDAY CENTERED OVER THE HIGH
PLAINS FROM CANADA TO THE TEXAS PANHANDLE. FOR THIS REASON AM
SOMEWHAT SKEPTICAL OF PRECIPITATION CHANCES IN THE GLOBAL MODELS
AND THE DERIVED BLENDS USED TO INITIATE THE EXTENDED THE PERIODS.
NONETHELESS...SURFACE PROGS SHOW A CONSISTENT MOIST SOUTHEASTERLY
FLOW INTO THE REGION WITH RESULTANT INSTABILITY EACH DAY. SO THE
ATMOSPHERE WILL BE PRIMED FOR LIFT AND ANY MINOR DISTURBANCE WHICH
MAY MAKES ITS WAY THROUGH THE RIDGE MAY BE ENOUGH FOR CONVECTION
TO DEVELOP. HOWEVER DEEP LAYER SHEAR WILL BE RATHER LOW UNDER THE
RIDGE SO SEVERE THREAT SHOULD BE LIMITED.
TEMPERATURES WILL BE NEAR NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 543 PM MDT WED AUG 5 2015
UPDATED AT 1020 PM MDT...
CONFIDENCE IN A LOW STRATUS SET UP OVER FOG HAS INCREASED WITH 2-5
HOUR PERIOD OF MFVR/IFR CONDITIONS EXPECTED AT GLD AROUND 12Z.
POTENTIAL FOR FOG REMAINS AT MCK...WITH STRATUS EXPECTED LATER IN
THE MORNING AND LIKELY WITH HEIGHTS A BIT HIGHER THAN AT GLD.
PREVIOUS DISCUSSION...
A FEW THUNDERSTORMS ARE POSSIBLE ACROSS NORTHWEST PORTIONS OF THE
AREA BUT DO NOT ANTICIPATE MUCH OF AN IMPACT ON TERMINAL FORECASTS
BUT MAY HAVE A STORM OR TWO NEAR MCK VICINITY LATER TONIGHT. FOG
POTENTIAL AGAIN A CONCERN AND THINK MOST LIKELY AREA WILL BE EAST
OF A TO TRIBUNE LINE WITH HIGHEST CHANCES AT MCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...024
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS JACKSON KY
1208 PM EDT THU AUG 6 2015
.UPDATE...
ISSUED AT 1207 AM EDT THU AUG 6 2015
NEEDED TO MAKE A FEW ADJUSTMENTS TO THE FORECAST FOR THE REST OF
TODAY. CURRENT RADAR TRENDS HAVE BEEN SHOWING A STEADY DECREASE IN
AREAL COVERAGE OF SHOWERS AND STORMS THAT PAST FEW HOURS. IT
APPEARS THAT A COMPLEX OF THUNDERSTORMS CURRENTLY MOVING ACROSS
TENNESSEE MAY BE SAPPING ENERGY FROM THE PRECIPITATION THAT IS
ONGOING ACROSS EASTERN KENTUCKY. UPSTREAM RADAR OBS ALSO SHOWING
THIS SAY DECREASE IN PRECIP. THE HRRR MODEL SEEMS TO HAVE A DECENT
ON THIS SITUATION...ESPECIALLY COMPARED TO THE NAM12 WHICH HAS
PRETTY MUCH 100 PERCENT COVERAGE OF PRECIP ACROSS ALL OF EASTERN
KENTUCKY FOR THE REST OF THE DAY. THE UPDATED FORECAST GRIDS AND
ZONE FORECAST TEXT PRODUCT WERE UPDATED TO REFLECT CURRENT TRENDS.
THE OTHER CHANGE MADE WAS TO CONTINUE TO SHOW AN INCREASE IN
PRECIPCOVERAGE LATE THIS AFTERNOON AND EVENING...AS A SHORT WAVE
ALOFT AND AN AREA OF SURFACE LOW PRESSURE BOTH MOVE ACROSS THE
OHIO AND TENNESSEE VALLEY AREAS. EVEN THOUGH WE ARE EXPERIENCING
A LULL IN THE ACTION...THE MODELS ALL ARE IN GOOD AGREEMENT THAT
AN UPTICK IN SHOWER AND STORM ACTIVITY WILL OCCUR LATER THIS
AFTERNOON. THE OTHER CHANGE MADE WAS TO DECREASE THE COVERAGE OF
THUNDERSTORMS OVERALL...AS INSTABILITY IS A BIT LACKING DUE TO THE
COOLER TEMPERATURES AND LACK OF SUN. THAT ALL BEING SAID...WENT
WITH A GENERAL 80 PERCENT CHANCE OF RAIN THROUGH 0Z THIS
EVENING...AS OPPOSED TO THE PREVIOUS 90 TO 100 POP...TO REFLECT
THE CURRENT DOWNWARD TREND IN PRECIP AND THE LATEST HRRR MODEL
OUTPUT. THEREFORE...THE QPF...POP...POP12...AND WEATHER TYPE GRIDS
WERE ALL UPDATED TO REFLECT THE LATEST THINKING. SOME MINOR
ADJUSTMENTS WERE ALSO MADE TO THE HOURLY
TEMPERATURES...DEWPOINTS...AND HUMIDITY GRIDS...BUT NOTHING THAT
WARRANTED UPDATING IN THE TEXT FORECAST PRODUCT. THE NEW ZONES
HAVE ALREADY BEEN ISSUED.
UPDATE ISSUED AT 813 AM EDT THU AUG 6 2015
PRECIPITATION IS FILLING IN AS SCHEDULED ACROSS THE AREA. SO
FAR...THUNDERSTORMS HAVE BEEN MORE ISOLATED...HOWEVER THESE SHOULD
BECOME MORE NUMEROUS THROUGH THE MIDDLE OF THE DAY AS BETTER
FORCING ARRIVES FROM THE WEST. FRESHENED UP THE HOURLY
TEMPERATURES...DEW POINTS...AND POPS TO ALIGN WITH THE CURRENT
OBSERVATIONS AND RADAR TRENDS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 352 AM EDT THU AUG 6 2015
LATEST SURFACE MAP FEATURES LOW PRESSURE NEAR THE IL/MO
BORDER...WITH A FRONT WARM FRONT DRAPED TO THE EAST ACROSS
KENTUCKY. ALOFT...A SHORT WAVE TROUGH IS ROTATING ACROSS THE OHIO
VALLEY. CONVECTION OVERNIGHT HAS MAINLY BEEN CONFINED TO OUR
WEST...WHERE A MODEST 850 MB LOW JET IS POISED. A LARGER COMPLEX
OF STORMS ALSO DEVELOPED ACROSS ARKANSAS AND PUSHED EAST AND
SOUTHEAST WHILE WEAKENING.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT
TERM...GRADUALLY BRINGING THE SHORT WAVE TROUGH AND REFLECTIVE
SURFACE LOW ACROSS KENTUCKY THROUGH TONIGHT. EXPECT PRECIPITATION
COVERAGE TO INCREASE AND INTENSIFY THROUGH THE DAY. LOWER
INSTABILITY AND HIGHER MOISTURE CONTENT WILL ALLOW FOR EFFICIENT
RAINERS TODAY INTO TONIGHT...AND FLASH FLOODING WILL CONTINUE TO
BE A CONCERN...ESPECIALLY WHERE STORMS CAN TRAIN ACROSS THE SAME
LOCATIONS.
AS LOW PRESSURE PIVOTS AWAY LATER TONIGHT...PRECIPITATION WILL BE
DIMINISHING FROM WEST TO EAST. A FEW SHOWERS MAY LINGER IN THE
EAST ON FRIDAY...WITH UPPER LEVEL RIDGING GRADUALLY WORKING IN
FROM THE SOUTHWEST LATER IN THE DAY.
HIGHS WILL AVERAGE BELOW NORMAL OVER THE NEXT FEW DAYS...WITH MOST
LOCATIONS LIKELY REMAINING IN THE 70S TODAY GIVEN THE PRECIPITATION
AND CLOUD COVER AROUND. ON FRIDAY...READINGS WILL RECOVER A BIT
MORE...WITH MOST PLACES SEEING AROUND THE 80 DEGREE MARK.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT THU AUG 6 2015
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH AN
ACTIVE UPPER LEVEL PATTERN IN PLACE. THIS FEATURES A SET UP WITH A
RIDGE OVER THE WESTERN CONUS WITH THE AXIS MEANDERING JUST WEST OF
THE FRONT RANGE OF THE ROCKIES AND A TROUGH OVER THE EAST. OVERALL
THE MODELS HAVE BEEN IN GOOD AGREEMENT WITH THE BROAD LONGWAVE
PATTERN. THE UPPER LEVEL TROUGH SHIFTS EASTWARDS A BIT AS A
SHORTWAVE SLIDES JUST NORTHEAST OF EASTERN KENTUCKY TO START THE
PERIOD ON SATURDAY BUT AS THE TROUGH BEGINS TO DEEPEN AGAIN
ANOTHER WAVE TAKES A MORE DIRECT TRACK OVER ALL OF KENTUCKY ON
SUNDAY AS IT TRAVELS THE RIDGE AND INTO THE REGION. DURING THE
MONDAY AFTERNOON AND INTO MONDAY NIGHT TIME FRAME...A MUCH MORE
POTENT WAVE TRACKS OVER THE RIDGE AND THE NORTHERN PLAINS AND
EVENTUALLY INTO THE OH VALLEY LATE MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 813 AM EDT THU AUG 6 2015
LIFR OR WORSE FOG WILL MIX OUT AS SHOWERS AND SCATTERED
THUNDERSTORMS MOVE IN FROM THE WEST. MAINLY MVFR CONDITIONS WILL
BE SEEN THROUGH THE MORNING...BEFORE LIKELY DROPPING TO IFR IN THE
AFTERNOON AS MORE SUSTAINED CONVECTION ARRIVES FROM THE WEST OUT
AHEAD OF AN AREA OF LOW PRESSURE MOVES ACROSS THE OHIO VALLEY.
CEILINGS WILL REMAIN LOW END MVFR WITH VISIBILITIES IN THE IFR
RANGE AT TIMES. ONCE CONVECTION BEGINS TO DIMINISH FROM WEST TO
EAST THIS EVENING...IFR STRATUS LOOKS TO FILL IN BEHIND DEPARTING
LOW PRESSURE. IN GENERAL...WINDS WILL REMAIN AT AROUND 5 KTS OR
LESS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...AR
SHORT TERM...GEOGERIAN
LONG TERM...SHALLENBERGER
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1158 PM CDT WED AUG 5 2015
.UPDATE...
ISSUED AT 1158 PM CDT WED AUG 5 2015
UPDATED THE AVIATION DISCUSSION FOR THE 06Z TAF ISSUANCE.
&&
UPDATE ISSUED AT 1030 PM CDT WED AUG 5 2015
MINOR UPDATE TO ADDRESS MOVEMENT OF WEAKENED MCV/OPEN SHORTWAVE
CIRCULATION TO THE NORTH AND THE GRADIENT LIFT ALONG AND SOUTH OF
THE IMPRESSED STATIONARY FRONTAL BOUNDARY ALONG THE SOUTHERN
BORDER OF THE WFO PAH FORECAST AREA.
THE HRRR SUGGESTS THAT THE MEAN LIFT AND ROTATION AROUND THE
CIRCULATION IN SOUTHERN ILLINOIS IS A LITTLE FURTHER SOUTH THAN
ADVERTISED BY THE 12KM NAM-WRF. HOWEVER...AS THE NEXT WAVE ROTATES
INTO SOUTHEAST MISSOURI AFTER MIDNIGHT, ENOUGH FORCING WILL BE IN
PLACE TO LIFT AND CONDENSE MOISTURE NORTHEAST ACROSS THE
STATIONARY BOUNDARY INTO WEST KENTUCKY...WHILE MAINTAINING LIFT
ALONG AND NORTHEAST OF THE MAIN CIRCULATION CENTER IN SOUTHERN
ILLINOIS.
WITH THAT SCENARIO IN PLACE...WILL LEAVE FLASH FLOOD WATCH IN
PLACE FOR THE WFO PAH FORECAST AREA AT THIS TIME. THERE MAY BE AN
OPPORTUNITY AFTER MIDNIGHT TO DROP NORTHERN SECTIONS OF SOUTHEAST
MISSOURI AND SOUTHWEST ILLINOIS BEFORE 7 AM CDT...AS THE EVOLUTION
OF THE LAST MINOR IMPULSE OVER SOUTHEAST MISSOURI TAKES PLACE
ALONG AND SHORTLY AFTER MIDNIGHT.
OTHERWISE...ONLY MINOR ADJUSTMENTS MADE TO REFLECT SHORT TERM
PRECIPITATION AND SENSIBLE WEATHER ELEMENTS VARIATIONS.
UPDATE ISSUED AT 635 PM CDT WED AUG 5 2015
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 312 PM CDT WED AUG 5 2015
LINE OF CONVECTION MOVING INTO SOUTHEAST MISSOURI WILL PUSH
THROUGH MUCH OF SOUTHEAST MISSOURI LATE THIS AFTERNOON AND THEN
LIKELY PIVOT TO MORE OF A NORTHWEST TO SOUTHEAST BAND OVER
SOUTHERN ILLINOIS AND WEST KENTUCKY THIS EVENING. NOTICING NEW
SCATTERED CONVECTION TO THE NORTHEAST AND SOUTHWEST OF KSTL AS THE
PRIMARY CIRCULATION TAKES SHAPE OVER CENTRAL MISSOURI. THIS MAY
BE THE BEGINNING OF A DEFORMATION ZONE ABOUT THE CIRCULATION.
THE DISTURBANCE WILL BE SLOW TO PUSH EAST THROUGH THE REGION
TONIGHT...SO FIGURE THERE WILL STILL BE SIGNIFICANT
RAINFALL...ESPECIALLY EAST OF THE MISSISSIPPI RIVER. SO WILL KEEP
THE FLASH FLOOD WATCH GOING FOR THE ENTIRE ARE AT THIS TIME...BUT
IT MAY BE MORE OF AN AREAL FLOOD EVENT...AND NOT SO MUCH OF A
FLASH FLOOD EVENT. PLAN ON CANCELING AT LEAST THE WESTERN 4
COUNTIES IN MISSOURI ONCE THE LINE HAS PASSED THERE IN AN HOUR OR
TWO.
FIGURE THAT THE PRECIPITATION WILL MOSTLY BE DONE BEFORE 18Z
THURSDAY IN THE EAST...BUT WILL KEEP A CHANCE IN THE SOUTHEAST
THROUGH THE AFTERNOON JUST TO GIVE IT A WIDE BERTH. STILL HAVE A
CHANCE OF CONVECTION MAINLY OVER SOUTHEAST MISSOURI LATE THURSDAY
NIGHT AND FRIDAY...AS ANOTHER DISTURBANCE PUSHES SOUTHEAST THROUGH
THE AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 PM CDT WED AUG 5 2015
UNLIKE MOST LATE SUMMER SITUATION...THE NORMALLY DOMINANT SOUTHEAST
U.S. RIDGE IS NOTICEABLY ABSENT THIS SUMMER. ALTHOUGH CPC SUGGESTS
CURRENT EL NINO REGIME IMPACT IS MINIMAL ACROSS THE U.S. ...WE
CONTINUE TO BE LOCKED INTO A MEAN NORTHWEST FLOW PATTERN WITH THE
MEAN CENTER OF THE BROAD 500 MB HIGH PRESSURE CENTER WAFFLING BETWEEN
TEXAS AND THE FOUR CORNERS AREA OF THE DESERT SOUTHWEST.
MODEL INITIALIZATION...FROM A SATELLITE PERSPECTIVE...GIVES CREDENCE
TO THE DETERMINISTIC AND ENSEMBLE GFS SOLUTIONS FOR THE MEDIUM RANGE
TIME PERIOD. FROM OTHER SENSIBLE WEATHER PERSPECTIVES THE
DETERMINISTIC ECMWF HAS A SLIGHT EDGE OVER ITS GFS COUNTERPART.
STARTING FROM A BLENDED MEDIUM RANGE MODEL INITIALIZATION...UTILIZED
A VARIABLE WEIGHTING OF THE GFS/NAM/GEM/ECMWF...DEPENDING ON THE
WEATHER ELEMENT IN QUESTION.
THE EXTENDED FORECAST PERIOD STARTS (ON SATURDAY) WITH THE MEAN
RIDGE AXIS DOMINATING THE AREA...SUPPRESSING ANY CONVECTION
THROUGH AT LEAST EARLY SUNDAY. LOW PRESSURE CENTERS ROTATING
NORTHEAST FROM THE NORTHWEST PACIFIC COAST INTERACT WITHE
SEMIPERMANENT LOW WOBBLING ALONG ACROSS THE CANADIAN PROVINCES OF
MANITOBA AND ONTARIO. AS THESE LOWS ARE PHASED INTO THE MEAN WEST-
NORTHWEST BAROCLINIC ZONE BETWEEN THE CANADIAN LOW AND THE SOUTHER
U.S. RIDGE SUNDAY NIGHT THROUGH TUESDAY...RAINFALL CHANCES ARE
EXPECTED GENERATE A NORTH TO SOUTH GRADIENT OF POPS/WEATHER
(HIGHEST NORTH NEAR INTERSTATE 64) DURING THIS TIME PERIOD.
CONFIDENCE IS ABOUT 50/50 ON THE RANGE OF POPS/WEATHER...MAINLY DUE
THE UNCERTAINTY ON ANY MESOSCALE PERTURBATIONS IN THE SAME
FLOW...WHICH CAN ENHANCE/DIMINISH POPS FROM ONE PERIOD TO ANOTHER.
THE RIDGE DOES NOT MOVE INTO THE AREA UNTIL WEDNESDAY...WHEN
RELATIVELY DRY WEATHER RETURNS FOR THE END OF THE FORECAST PERIOD.
MAXIMUM TEMPERATURES SHOULD REMAIN IN THE 80S DURING THE
PERIOD...WITH LOWS IN THE UPPER 60S AND LOWER 70S...STILL BELOW
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...
ISSUED AT 1158 PM CDT WED AUG 5 2015
WITH THE APPROACH AND PASSAGE OF A FRONTAL BOUNDARY AND UPPER
LEVEL TROUGH...VFR CONDITIONS WILL BECOME MVFR/IFR EARLY...ESPECIALLY
IN SHRA/TSRA. MAY SEE VFR CONDITIONS AT KCGI/KPAH BY THE END OF
THE PERIOD. SOUTH TO SOUTHWEST WINDS GENERALLY AOB 6 KNOTS WILL
VEER AROUND TO THE NORTHWEST AND INCREASE TO AOB 10 KNOTS WITH
THE FRONTAL PASSAGE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR ILZ076>078-082-
083-086-087-089>094.
FLASH FLOOD WATCH UNTIL 7 AM CDT THURSDAY FOR ILZ075-080-081-084-
085-088.
MO...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR MOZ108>112-114.
FLASH FLOOD WATCH UNTIL 7 AM CDT THURSDAY FOR MOZ076-086-087-100-
107.
IN...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR INZ081-082-
085>088.
KY...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...SMITH
AVIATION...JP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
329 PM EDT THU AUG 6 2015
.SYNOPSIS...
WHILE HIGH PRESSURE REMAINS OVER THE GREAT LAKES...A LOW PRESSURE
SYSTEM IN THE OHIO VALLEY WILL TRAVEL EAST ALONG A STATIONARY
FRONT TO OUR SOUTH TONIGHT AND FRIDAY. THE LOW WILL SLOWLY MOVE
OFF THE CAROLINA COAST SATURDAY. WEAK HIGH PRESSURE WILL BUILD
SOUTHWARD SUNDAY AND MONDAY BEFORE A COLD FRONT MOVES IN FROM THE
NORTHWEST ON TUESDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
SFC LOW AND COMPACT UPPER DISTURBANCE CONTINUE TO TRACK SLOWLY
EASTWARD THROUGH THE MID OHIO VALLEY THIS AFTERNOON. LIGHT TO
MODERATE SHOWERS ARE SPREADING AHEAD OF THIS SYSTEM AND HAVE
SPREAD INTO THE WESTERN CWA. HAVE RELIED ON THE HRRR AND RAP IN
TERMS OF EVOLUTION AS THE SYNOPTIC MODELS DO NOT SEEM TO HAVE A
GOOD HANDLE ON THE NORTHWARD EXTENT OF THIS RAIN.
NEVERTHELESS...THE EVENT AS A WHOLE APPEARS LIGHTER AND MORE
SOUTHWARD IN TERMS OF QPF DISTRIBUTION COMPARED TO PREVIOUS
FORECASTS. INSTBY IS LIMITED TO FAR SOUTHERN MD...AND HEAVIER
SHOWERS MOVING INTO THE LOWER BAY ARE INDICATIVE OF THIS
ENVIRONMENT. OUTSIDE OF THIS AREA...POSSIBLY EXTENDING
SOUTHWESTWARD TO NELSON COUNTY...THUNDER IS NOT EXPECTED.
EXPECT THE SHIELD OF RAIN TO CONTINUE TO MOVE EASTWARD THROUGH THE
EVENING AND OVERNIGHT. MOST AREAS WILL SEE RAIN AT SOME
POINT...ALTHOUGH THE NORTHERN EDGE MAY GRADUALLY ERODE AND LEAVE
LOCATIONS NEAR THE MASON-DIXON LINE DRY AT SOME POINT...ALTHOUGH
THIS IS OF LOWER CONFIDENCE. PWATS WILL BE HIGH ENOUGH (NEAR TWO
INCHES SOUTH OF I-66) TO PRODUCE A SOAKING RAIN...ESPECIALLY FOR
SOUTHERN AREAS. HOWEVER DO NOT THINK THERE WILL BE THE CONVECTIVE
ELEMENTS NEEDED NOR THE STRONG SYNOPTIC FORCING TO PRODUCE SHORT
TERM RUNOFF ISSUES. THERE ARE INDICATIONS LATE TONIGHT AS THE LOW
BEGINS TO STRENGTHEN AND SOME UPPER ENERGY APPROACHES...THAT THERE
COULD BE SOME ENHANCED RAINFALL IN CENTRAL VA. WILL LEAVE A
MENTION OF LOCALIZED FLOODING IN THE HWO. LOWS TONIGHT IN 60S WITH
PERHAPS SOME LOWER 70S.
SPECIFIC DETAILS ARE STILL NOT OF THE HIGHEST CONFIDENCE HEADING
INTO FRIDAY AS MODEL DIFFERENCES REMAIN AS THE LOW REACHES A
PIVOT POINT IN THE EASTERN CAROLINAS. CONFIDENCE HIGHEST IN
RAINFALL...AND PERHAPS AN ISOLATED STORM...SOUTH AND EAST OF DC.
HOWEVER A CHANCE OF SHOWERS COULD EXTEND BACK TOWARD THE SOUTHERN
SHENANDOAH VALLEY. THERE SHOULD BE A GRADUAL DRYING TREND FROM THE
NORTHWEST THROUGH THE DAY THOUGH. HIGH TEMPERATURES WILL BE BELOW
NORMAL...GENERALLY IN THE 70S TO LOWER 80S...BUT WILL LIKELY
DEPEND ON THE DURATION OF RAIN.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
EXPECT MOST PRECIP TO BE MOVING OUT OF CWA BY LATE EVENING
FRIDAY...THE ONLY EXCEPTION WOULD BE FAR SOUTHERN MARYLAND WHERE
SHOWERY ACTIVITY COULD LINGER INTO THE OVERNIGHT FOR A FEW HOURS.
SFC LOW MOVES TO OUR EAST FOR THE WEEKEND...KEEPING US DRY AND
FAIRLY MILD FOR EARLY AUGUST. TEMPS EXPECTED TO REMAIN A FEW DEGREES
BELOW NORMAL...WITH DEWPOINTS IN L60S. OVERALL...IT SHOULD BE A
RATHER BENIGN WEATHER WEEKEND. THE ONLY FLY IN THE OINTMENT WOULD
BE THE LOW CHANCE OF A MOUNTAIN SHOWER OR T-STORM LATE SUNDAY
RESULTING FROM TERRAIN CIRCULATIONS...THOUGH OVERALL COVERAGE
SHOULD BE MINIMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BY MONDAY THE NEXT SYSTEM WILL BEGIN TO APPROACH FROM THE
WEST...WHICH IS DEPICTED BY THE GFS...GGEM...AND ECMWF...BUT MUCH
FASTER ON THE GGEM AND GFS. EXISTING FORECAST HAD WIDESPREAD CHANCE
POPS...WHICH DESPITE THE SLOWER SOLUTION THE ECMWF FAVORS
ANYWAY. BOTTOM LINE...WE MAINTAINED THIS. ON TUESDAY THE ECMWF
ALMOST CATCHES UP WITH THE GFS WITH THE NEXT SYSTEM...WITH THE GFS
SLOWING DOWN WITH IT. GGEM ON THE OTHER HAND KEEPS GOING FAST AND
SENDS THE SYSTEM OFF THE COAST ALREADY. FORECAST ON THIS DAY HAS
MOST CONFIDENCE AT PRESENT GIVEN THE SYSTEM TIMING IS AT LEAST A BIT
CLOSER...BUT GIVEN DISCONTINUITIES EARLIER IN THE PERIOD UNCERTAINTY
IS STILL RATHER LARGE. BY WEDNESDAY THE GFS PUSHES THE SYSTEM OFF THE
COAST...WHILE THE SLOWER ECMWF GENERATES A COASTAL LOW OF RATHER
IMPRESSIVE STRENGTH FOR AUGUST. AGAIN...STAYED FAIRLY CLOSE TO
CONTINUITY WITH A DRYING FORECAST...BUT CONFIDENCE IS QUITE LOW.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
LOW PRESSURE WILL TRACK SOUTH OF THE AREA TONIGHT INTO FRIDAY.
RAIN IS SPREADING INTO THE AREA FROM THE WEST. LIGHT SHOWERS WILL
OVERSPREAD THE TERMINALS THROUGH LATE AFTERNOON...WITH A PERIOD OF
MODERATE RAINFALL POSSIBLE OVERNIGHT. THE DURATION IS SOMEWHAT IN
QUESTION...AS WELL AS HOW FAR NORTH THE HEAVIEST RAIN AND AVIATION
IMPACTS REACH. MVFR CONDITIONS WILL BE POSSIBLE AT ALL
TERMINALS...WITH THE CHANCE OF IFR GENERAL LIMITED TO NEAR OR
SOUTH OF DC. RAIN MAY LINGER INTO THE MORNING AND AT THIS TIME IT
IS UNCERTAIN HOW QUICKLY IT WILL EXIT ON FRIDAY. HOWEVER THERE IS
A PRETTY GOOD CHANCE VFR WILL RETURN BY AFTERNOON. WINDS WILL
REMAIN UNDER 10 KT THROUGH THE TAF PERIOD.
VFR EXPECTED AT ALL TERMINALS BY FRIDAY NIGHT...AS PRECIP
ASSOCIATED WITH LOW PRESSURE MOVES TO OUR EAST. VFR CONDS THEN
EXPECTED THROUGH SUNDAY UNDER HIGH PRESSURE.
NEXT CHANCE FOR SUB-VFR ARRIVES MONDAY AS A COLD FRONT APPROACHES
MONDAY/TUESDAY ALONG WITH INCREASED RISK OF SHRA/TSRA.
&&
.MARINE...
LOW PRESSURE WILL PASS SOUTH OF THE AREA TONIGHT INTO FRIDAY.
WHILE THERE COULD BE A THUNDERSTORM OVER SOUTHERN PORTIONS OF THE
WATERS THIS AFTERNOON OR EVENING...AND AGAIN FRIDAY
AFTERNOON...EXPECT FOR THE MOST PART JUST A GENERAL RAINFALL.
WINDS WILL BE FROM THE NE OR E THROUGH TONIGHT WITH GRADUAL
STRENGTHENING. HAVE CAPPED THE WINDS AT 15 KT THROUGH
TONIGHT...ALTHOUGH THIS WILL NEED TO BE MONITORED FOR POSSIBLE SCA
CONDITIONS. THE SCA NOW GOES INTO EFFECT AT 6 AM FOR THE BAY AND
LOWER POTOMAC AND WILL LAST THROUGH FRIDAY INTO FRIDAY NIGHT WITH
STRONG EASTERLY WINDS.
THE SCA MAY NEED TO BE EXTENDED FURTHER INTO SAT MORNING WITH LOW
PRESSURE REMAINING NEAR OUR AREA. EXPECT WINDS TO SUBSIDE BELOW
SCA BY SAT AFTERNOON AS LOW PULLS AWAY FROM AREA. SUB-SCA WINDS
SUN THROUGH MIDDAY MONDAY UNDER HIGH PRESSURE.
NEXT CHANCE FOR SUB-SCA COMES MONDAY AFTERNOON AND TUESDAY AS NEXT
SYSTEM APPROACHES OUR AREA.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 6 AM EDT SATURDAY FOR
ANZ531>534-537>543.
SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 2 AM EDT SATURDAY FOR
ANZ530.
&&
$$
SYNOPSIS...ADS
NEAR TERM...ADS
SHORT TERM...MSE
LONG TERM...RCM/MSE
AVIATION...ADS/MSE
MARINE...ADS/MSE
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
216 AM EDT THU AUG 6 2015
.SYNOPSIS...
A COLD FRONT LINGERS ACROSS NORTH CAROLINA OVERNIGHT AS HIGH
PRESSURE MOVES EAST FROM THE GREAT LAKES. THE FRONT LIFTS BACK
NORTH AS A WARM FRONT LATE TONIGHT THROUGH THURSDAY WITH LOW
PRESSURE MOVING EAST ALONG IT THURSDAY NIGHT AND FRIDAY. HIGH
PRESSURE SLOWLY RETURNS OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
QUIET WX THIS EVE ACRS FA W/ WK SFC HI PRES INVOF THE RGN.
WATCHING AREA OF CONVECTION SPREADING SLOLY ENE THROUGH SW VA/NW
NC. CURRENT FCST APRS IN GOOD SHAPE ATTM...W/ POPS INCRS TO SLGT
CHC-CHC ACRS MNLY HALF OF THE FA OVRNGT. ADDED ISOLD TSTMS UNTIL
ABT 08-09Z. 23Z/05 RUC GENLY WEAKENS AREA OF CONVECTION AS IT
SPREAD TWD/INTO THE FA. HOLDING ONTO SLGT CHC-CHC POPS LT.
OTRW...PARTLY CLOUDY N...INCRSG CLDNS S...W/ LO TEMPS FM THE
U60S/ARND 70F N TO THE M/U70S FAR SE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
THE WARM FRONT LIFTS N INTO THE AKQ CWA THURSDAY. THE LOW-LEVEL
THETA-E GRADIENT ACTUALLY SHARPENS AS HIGH PRESSURE REMAINS N OF
THE REGION. MODELS HAVE COME INTO BETTER AGREEMENT AMONGST THE 12Z
SOLUTIONS...ALTHOUGH SOME UNCERTAINTY REMAINS DUE TO THE
CONVECTIVE NATURE OF THE ONSET OF THE EVENT. LIKELY POPS HAVE BEEN
MAINTAINED ACROSS WRN/CENTRAL PORTIONS...AND LIKELIES HAVE BEEN
ADDED TO NE NC/SE VA...AS MODELS SUGGEST AFTERNOON CONVECTION
ACROSS THE COASTAL PLAIN OF ERN NC AND SE VA. OVERALL THE PRIMARY
THREAT WILL BE LOCALLY HEAVY RAINFALL. HOWEVER...THERE DOES APPEAR
TO BE A CORRIDOR FROM NE NC INTO SE VA WHERE A BELT OF STRONGER
(30-35KT) 0-6KM BULK SHEAR INTERACTS WITH STRONGER
INSTABILITY...WHICH COULD PRODUCE A LOCALIZED SEVERE THREAT.
FORECAST HIGHS RANGE FROM THE UPPER 70S NE...TO AROUND 90 SE.
LIKELY POPS ARE FORECAST FOR ALL AREAS THURSDAY NIGHT AS LOW
PRESSURE DEEPENS ALONG THE SLOWLY ADVANCING WARM FRONT. THE
COMBINATION OF A SLOW MOVING SYSTEM...AND ANOMALOUSLY HIGH PW
VALUES WILL SUPPORT QPF AMOUNTS OF 1-2 INCHES WITH LOCALLY MUCH
HIGHER AMOUNTS POSSIBLE FROM THURSDAY AFTERNOON THROUGH EARLY
FRIDAY. HEAVY RAIN POTENTIAL WILL BE MAINTAINED IN THE HWO. LOWS
SHOULD BE IN THE UPPER 60S TO LOWS 70S.
MODELS BEGIN TO DIVERGE FRIDAY WITH RESPECT TO HOW FAST THE
SYSTEM PULLS OFFSHORE. THE 12Z GFS SEEMS TO BE A REASONABLE
COMPROMISE OF THE QUICKER NAM AND SLOWER ECMWF. LIKELY POPS WILL
BE MAINTAINED GIVEN THE AMPLIFICATION OF THE OVERALL
PATTERN...ALTHOUGH PCPN COULD TAPER OFF FROM THE W DURING THE
AFTERNOON. CONTINUED LOW-LEVEL NE FLOW SHOULD RESULT IN PERSISTENT
CLOUD COVER AND BELOW NORMAL HIGH TEMPERATURES. THIS WILL KEEP
HIGHS BELOW NORMAL RANGING FROM THE MID 70S NW...TO THE LOW 80S
SE.
HIGH PRESSURE GRADUALLY BUILD IN FROM THE N FRIDAY NIGHT INTO
SATURDAY. BY SATURDAY...THE SKY SHOULD BECOME PARTLY SUNNY W...AND
REMAIN MOSTLY CLOUDY ALONG THE COAST WITH A 20-30% POP. LOWS RANGE
FROM THE MID 60S TO LOW 70S FRIDAY NIGHT...WITH HIGHS IN THE LOW
80S SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
STRENGTHENING SURFACE LOW PRESSURE MOVES OFF THE MID-ATLANTIC COAST
SAT NIGHT...PULLING CLOUDS AND PRECIP OUT TO SEA WITH IT. WEAK HIGH
PRESSURE MOVES OVER THE AREA SUN AND MON WITH INCREASING MID LEVEL
DYNAMIC FORCING ON MONDAY. INCREASING POPS MONDAY THROUGH WED AS
WEAK SURFACE TROUGH ON TUE AHEAD OF AN APPROACHING COLD FRONT
HELPING TO INITIATE SCATTERED PRECIPITATION. FAIRLY GOOD MODEL
AGREEMENT WITH THE TIMING OF THE UPPER WAVE AND SURFACE FRONT MOVING
THROUGH THE AREA ON WEDNESDAY WITH WIDESPREAD PRECIP POSSIBLE.
MODELS DEPICT AN OMEGA LIKE BLOCK FOR THE END OF THE EXTENDED
FORECAST...KEEPING UPPER LEVEL LOW OVER THE AREA WHICH WILL HELP
MAINTAIN CLOUDS AND ISOLATED SHOWERS IN THE FORECAST.
TEMPS UPPER 80S MON AND TUES AHEAD OF THE FRONT WED MODERATING INTO
THE LOW TO MID 80S ON THURS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
LATEST REGIONAL RADAR MOSAIC DEPICTS AN AREA OF
SHOWERS/THUNDERSTORMS LIFTING ALONG A QUASI STATIONARY BOUNDARY
EARLY THIS MORNING. THESE SHOWERS/THUNDERSTORMS WILL CONTINUE TO
LIFT NEWD INTO CENTRAL VA...IMPACTING KRIC DURING THE FIRST FEW
HOURS OF THE 06Z TAF ISSUANCE. BRIEF HEAVY RAINFALL...GUSTY WINDS
AND OCCASIONAL LIGHTNING IS EXPECTED WITH THESE STORMS. ISOLATED
SHOWERS/THUNDERSTORMS ALSO DEVELOPING OVER THE MD ERN SHORE. WILL
MAINTAIN DRY FORECAST FOR KSBY...BUT WILL NEED TO MONITOR. ELSEWHERE...VFR
CONDITIONS PREVAIL THIS MORNING WITH BKN HIGH CLOUDS AOA 20K FT
AGL AND WINDS AOB 10 KT. WARM DEWPOINTS AND ONLY HIGH CLOUDS OVER
NE NC WILL LIKELY PRODUCE SOME PATCHY GROUND FOG THIS MORNING.
HAVE INCLUDED IFR VISIBILITIES FOR KECG EARLY THIS MORNING.
FOR TODAY...LOW PRESSURE PROGGED TO DEVELOP ALONG THE FRONT OVER
ERN NC AS ANOTHER AREA OF LOW PRESSURE APPROACHES FROM THE WEST.
MID-HIGH CLOUDS THIS MORNING WILL LOWER TO BKN-OVC SKIES WITH
DECKS 4-6K FT AGL THIS AFTERNOON. A BRIEF BREAK IN THE PRECIP
EXPECTED THIS MORNING...BEFORE SHOWERS/THUNDERSTORMS SPREAD IN
FROM THE WEST THIS AFTERNOON. WIDESPREAD SHOWERS/THUNDERSTORMS ARE
FORECAST WITH MODERATE TO LOCALLY HEAVY RAINFALL EXPECTED TO
PERSIST INTO THE EVENING...BEYOND THE 06Z TAF ISSUANCE. IFR
CONDITIONS ARE POSSIBLE IN THE STRONGEST STORMS/HEAVIEST SHOWERS.
SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS PERSIST TONIGHT AS LOW
PRESSURE REORGANIZES OVER THE CAROLINAS. UNSETTLED CONDITIONS
CONTINUE INTO THE WEEKEND AS THE LOW SLOWLY PUSHES OFF THE NC
COAST. HIGH PRESSURE BUILDS IN FROM THE WEST THRU THE WEEKEND.
&&
.MARINE...
AN AREA OF LOW PRESSURE PROGGED TO DEVELOP ALONG A STALLED FRONTAL
BOUNDARY THURSDAY AS HIGH PRESSURE BUILDS INTO NEW ENGLAND. THE
RESULT WILL BE ONSHORE FLOW THURS AOB 15 KT. GRADIENT STRENGTHENS
THURS NIGHT AS THE LOW DEEPENS IN THE VICINITY OF EASTERN NC.
MODELS COMING INTO BETTER AGREEMENT WITH RESPECT TO THE LOW
PLACEMENT AND RESULTANT FRONTAL LOCATION. CONFIDENCE CONTINUES TO
INCREASE FOR STRONG SCA CONDITIONS FRIDAY INTO SATURDAY DUE TO
STRENGTH OF THE PRESSURE GRADIENT AND NE FLOW. SEAS
RESPOND...BUILDING TO 4 T0 6+ FT FRI NIGHT THOUGH SAT. LOW PROGGED
TO LIFT AWAY FROM THE COAST SAT NIGHT INTO SUN...ALLOWING THE
GRADIENT TO RELAX AND WINDS/SEAS TO SLOWLY DIMINISH/SUBSIDE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AJZ/ALB/LKB
NEAR TERM...AJZ/ALB
SHORT TERM...AJZ/LKB
LONG TERM...DAP
AVIATION...SAM
MARINE...MAS/DAP
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1157 PM EDT FRI AUG 7 2015
.AVIATION...
LOW PRESSURE MOVING FROM WISCONSIN TOWARD SE MICHIGAN WILL CONTINUE
TO SUPPORT A PATTERN OF LIGHT RAIN BEFORE SUNRISE. MOST LOCATIONS
WILL SEE AT LEAST A SPRINKLE THE LEAST OF WHICH WILL OCCUR AT DTW
WHILE MBS WILL HAVE A STEADIER LIGHT RAIN. EVEN WITH THE RAIN...
CONDITIONS WILL REMAIN VFR ACROSS THE AREA. A SHORT INTERVAL OF MVFR
IS POSSIBLE AT MBS IN ANY HEAVIER SHOWER THAT CAN DEVELOP...BUT
OBSERVATIONAL EVIDENCE DOES NOT SUPPORT THIS ENOUGH TO INCLUDE IN
THE FORECAST. THE LOW PRESSURE SYSTEM WILL WEAKEN ENOUGH TO ALLOW
SURFACE HIGH PRESSURE TO REBUILD OVER THE REGION AFTER SUNRISE WHICH
WILL IMPROVE AVIATION CONDITIONS THROUGH THE DAY INTO SATURDAY NIGHT.
FOR DTW... CLOUDS WILL THICKEN OVER THE TERMINAL AREA DURING THE
EARLY MORNING BUT CEILING WILL REMAIN ABOVE 5000 FEET. A FEW
SPRINKLES OR A PASSING LIGHT RAIN SHOWER WILL BE POSSIBLE FROM THE
HIGH CLOUD BASES. SO FAR...TRENDS INDICATE LOW CONFIDENCE IN ANY
MEANINGFUL RAIN FOR INCLUSION IN THE FORECAST.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR CEILING 5000 FEET OR LESS.
&&
.PREV DISCUSSION...ISSUED 932 PM EDT FRI AUG 7 2015
UPDATE...
A COMPACT AND INTENSE UPPER WAVE CONTINUES TO SHEAR INTO LOWER
MICHIGAN FROM WISCONSIN TONIGHT. STRONG DEFORMATION ASSOCIATED
WITH THE WAVE IS COLOCATED WITH THE MID LEVEL/700 MB THETA-E RIDGE
THAT IS PROVIDING ENOUGH MOISTURE FOR BANDS OF LIGHT RAIN SHOWERS.
RECENT HOURLY UPDATES OF THE RAP AND HRRR ARE TRENDING UPWARD WITH
COVERAGE AND INTENSITY OF SHOWERS OVER THE TRI CITIES AND NORTHERN
THUMB DOWN TO ABOUT THE I-69 CORRIDOR FOR THE OVERNIGHT PERIOD
INTO SATURDAY MORNING. THE 00Z DTX SOUNDING DOES INDICATE STEEPER
LAPSE RATES ALOFT PRIOR TO SATURATION WHICH COULD HELP EXPLAIN
THE NOCTURNAL UPTICK OF INTENSITY IN THE HIGH RES AND CONVECTION-
ALLOWING MODELS. AT THE SAME TIME...THE LARGER SCALE MODELS
ADVERTISE A WEAKENING/FILLING TREND OF THE WAVE. THE CONTRADICTION
SEEMS TO BE SETTLED IN FAVOR OF THE LATTER BY THE RECENT
SATELLITE TREND OF WARMING CLOUD TOPS ON THE SOUTH FLANK OF THE
WAVE DURING MID TO LATE EVENING.
THE EARLIER UPDATE NUDGED POPS INTO THE LIKELY RANGE FOR THE TRI
CITIES AND NORTHERN THUMB AND FARTHER INTO THE CHANCE RANGE DOWN
TO ABOUT THE I-69 CORRIDOR. THIS COVERS THE EXPECTATION OF A
HIGHER POP/LOW QPF SCENARIO OF JUST A FEW 100THS. A MESOSCALE
FLARE-UP CERTAINLY CAN`T BE RULED OUT BUT THE GOING FORECAST SEEMS
TO FIT EXPECTATIONS WELL AT THIS POINT.
PREV DISCUSSION...ISSUED 247 PM EDT FRI AUG 7 2015
SHORT TERM...TONIGHT
ORGANIZING DEFORMATION ASSOCIATED WITH THE LOW AMPLITUDE WAVE
APPROACHING THE WESTERN SHORES OF LAKE MICHIGAN AT PRESS TIME IS
SUPPORTING AN ORGANIZING RAIN SHIELD OVER EASTERN WISCONSIN. MODEL
PROGS REMAIN INSISTENT THAT THIS WAVE WILL BECOME INCREASINGLY
SHEARED THIS EVENING, THE EARLY SIGNS OF WHICH ARE ALREADY BECOMING
EVIDENT ON CURRENT WV IMAGERY. CEILINGS WITHIN THE ACTIVE AREA OF
PRECIP ARE GENERALLY ABOVE 7KFT, A TESTAMENT TO THE AMOUNT OF DRY
AIR IN THE COLUMN. PER 12Z DTX SOUNDING AND LATEST RAP PROGS, EVEN
DRIER AIR RESIDES OVER SOUTHEAST MICHIGAN. TAKEN IN CONSIDERATION
WITH RAPIDLY WEAKENING FORCING OVER THE NEXT SEVERAL HOURS, THIS
CASTS DOUBT ON THE ABILITY OF PRECIP TO SURVIVE ITS TREK INTO
SOUTHEAST MICHIGAN. SOME SEMBLANCE OF THE MID-LEVEL CIRCULATION
MAY PROVIDE JUST ENOUGH ASCENT/DEFORMATION TO RESULT IN A PERIOD
OF LIGHT RAIN FALLING OUT OF HIGH CLOUDS OVER THE SAGINAW VALLEY
WHERE A HIGH CHC POP IS IN PLACE. ELSEWHERE...JUST A CHC LATE
TONIGHT NORTH OF I-69 WITH NO WX MENTION ELSEWHERE. GUIDANCE LOOKS
ON TRACK WITH LOWS IN THE LOW TO MID 60S...A FEW DEGREES WARMER
THAN LAST NIGHT OWING TO INCREASED CLOUD COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
DAMPENING MID LEVEL WAVE AND ATTENDANT 100 KNOT UPPER JET CORE IN
THE PROCESS OF PIVOTING THROUGH LOWER MICHIGAN EARLY SATURDAY. MOST
FAVORABLE UPPER LEVEL FORCING TIED TO THESE FEATURES WILL TEND TO
ALIGN FROM THE TRI-CITIES/THUMB INTO NORTHERN LOWER MICHIGAN THROUGH
THIS TIME. THIS WILL MAINTAIN A WINDOW FOR LIGHT SHOWER PRODUCTION
ACROSS THIS CORRIDOR DURING THE MORNING PERIOD...PERPETUATION OF A
STABLE EASTERLY FLOW SUGGESTING MINIMAL POTENTIAL FOR THUNDERSTORMS.
HI RES MODEL GUIDANCE DOES HINT THAT SOME FORM OF TRAILING PV
FILAMENT AND/OR WEAK SURFACE TROUGH MAY THEN SHIFT ACROSS SE
MICHIGAN DURING PEAK HEATING. THIS IN THE PRESENCE OF SOME LEFT
EXIT REGION JET DYNAMICS MAY PROVE SUFFICIENT IN GENERATING A LOW
END COVERAGE OF SHOWERS /EMBEDDED THUNDER/ DURING THE MID-LATE
AFTERNOON. THE OVERALL SETUP REMAINS SOMEWHAT NEBULOUS AT THIS
STAGE WITH MOISTURE QUALITY AND DEGREE OF DESTABILIZATION AN
ISSUE...AND WILL SIMPLY PROVIDE A SLIGHT CHANCE MENTION. LITTLE
VARIATION IN THE TEMPERATURE PATTERN...WITH AT LEAST PARTIAL SUN
STILL SUPPORTING AFTERNOON HIGHS IN THE VICINITY OF 80 DEGREES.
ATTENTION HEADING INTO THE LATTER HALF OF THE WEEKEND TURNS TO
ANOTHER LOW AMPLITUDE SHORTWAVE EJECTING OVER THE MEAN SOUTHERN
PLAINS RIDGE. HIGH DEGREE OF VARIABILITY YET WITHIN THE MODEL
SOLUTION SPACE IN TERMS OF POTENTIAL STRENGTH...TIMING AND
POSITIONING OF THE ASSOCIATED LOW-MID LEVEL RESPONSE AS THIS SYSTEM
LIFTS EAST OF THE MISSISSIPPI. 12Z NAM TRENDING TOWARD A MUCH MORE
DYNAMIC SOLUTION...NETTING A MORE PRONOUNCED AND PROGRESSIVE
DOWNSTREAM EXPANSION OF LARGE SCALE ASCENT AND MOISTURE TRANSPORT
NORTH OF THE ATTENDANT WARM FRONTAL BOUNDARY AND INTO LOWER MICHIGAN
BY LATE SUNDAY. THIS SOLUTION SUGGESTS AN INCREASING POTENTIAL FOR
SHOWERS AND ELEVATED THUNDERSTORMS SUNDAY AFTERNOON AND EVENING.
HOWEVER 4 KM NAM AND CONSENSUS OF REMAINING GUIDANCE POINTS TOWARD A
MORE TEMPERED/SLOWER EVOLUTION...A GREATER WINDOW FOR PRECIPITATION
DEVELOPMENT HOLDING OFF UNTIL SUNDAY NIGHT/EARLY MONDAY. EVENTUAL
OUTCOME LIKELY CARRIES STRONG DEPENDENCE ON HOW CONVECTIVE TRENDS
EVOLVE UPSTREAM AND SPILL EASTWARD...SE MICHIGAN STILL SEEMINGLY
POSITIONED OUTSIDE OF THE GREATER INSTABILITY AXIS THROUGH THIS
PERIOD. FOR NOW...WILL HOLD TIGHT WITH A DRY FORECAST ON
SUNDAY...CENTERING POPS FOR SUNDAY NIGHT AND MONDAY. ASSUMING AN
EARLIER ONSET OF THICKER CLOUDINESS AND/OR PRECIPITATION NEVER
MATERIALIZES THROUGH PEAK HEATING...PERSISTENCE WILL LEAVE HIGHS
AGAIN WITHIN A COUPLE DEGREE OF 80F.
ZONAL FLOW ACROSS THE CORN BELT MONDAY EXPECTED TO AMPLIFY INTO A
TROUGH AS 80+ KT H25 JET STREAK DEVELOPS. WEAK CYCLOGENESIS ALONG
WITH SOME FORCING FROM FAVORABLE POSITIONING OF POLEWARD JET EXIT
REGION OVER THE LOWER GREAT LAKES ARGUES FOR AT LEAST CHANCE POPS
MONDAY. INSTABILITY LOOKS LIMITED WITH LI ONLY DROPPING TO AROUND
-2...SO HAVE CHC SHOWERS AND SLIGHT CHC T-STORMS. SURFACE CYCLONE
PROGGED TO INTENSIFY OVER THE NORTHEASTERN US WHICH FAVORS MORE
AGRESSIVE COLD/DRY AIR ADVECTION TUESDAY. UPPER TROUGH AMPLIFIES
OVER THE NORTHEASTERN US MIDWEEK WITH LOWER MI IN THE SUBSIDENCE
REGION UPSTREAM OF THE TROUGH. UPSHOT IS MAINLY DRY/COOL FORECAST
MIDWEEK.
MARINE...
MODEST NORTHEAST WINDS THROUGH THE EVENING WILL MAINTAIN SOME
ENHANCED WAVE DEVELOPMENT OVER THE NEARSHORE WATERS. GENERALLY
WEAKER EAST TO SOUTHEAST WINDS WILL THEN HOLD THROUGH THE WEEKEND AS
THE HIGH PRESSURE CENTER REMAINS POSITIONED JUST NORTHEAST OF THE
REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
UPDATE.......BT
SHORT TERM...JVC
LONG TERM....MR/DT
MARINE.......MR
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
932 PM EDT FRI AUG 7 2015
.UPDATE...
A COMPACT AND INTENSE UPPER WAVE CONTINUES TO SHEAR INTO LOWER
MICHIGAN FROM WISCONSIN TONIGHT. STRONG DEFORMATION ASSOCIATED
WITH THE WAVE IS COLOCATED WITH THE MID LEVEL/700 MB THETA-E RIDGE
THAT IS PROVIDING ENOUGH MOISTURE FOR BANDS OF LIGHT RAIN SHOWERS.
RECENT HOURLY UPDATES OF THE RAP AND HRRR ARE TRENDING UPWARD WITH
COVERAGE AND INTENSITY OF SHOWERS OVER THE TRI CITIES AND NORTHERN
THUMB DOWN TO ABOUT THE I-69 CORRIDOR FOR THE OVERNIGHT PERIOD
INTO SATURDAY MORNING. THE 00Z DTX SOUNDING DOES INDICATE STEEPER
LAPSE RATES ALOFT PRIOR TO SATURATION WHICH COULD HELP EXPLAIN
THE NOCTURNAL UPTICK OF INTENSITY IN THE HIGH RES AND CONVECTION-
ALLOWING MODELS. AT THE SAME TIME...THE LARGER SCALE MODELS
ADVERTISE A WEAKENING/FILLING TREND OF THE WAVE. THE CONTRADICTION
SEEMS TO BE SETTLED IN FAVOR OF THE LATTER BY THE RECENT
SATELLITE TREND OF WARMING CLOUD TOPS ON THE SOUTH FLANK OF THE
WAVE DURING MID TO LATE EVENING.
THE EARLIER UPDATE NUDGED POPS INTO THE LIKELY RANGE FOR THE TRI
CITIES AND NORTHERN THUMB AND FARTHER INTO THE CHANCE RANGE DOWN
TO ABOUT THE I-69 CORRIDOR. THIS COVERS THE EXPECTATION OF A
HIGHER POP/LOW QPF SCENARIO OF JUST A FEW 100THS. A MESOSCALE
FLARE-UP CERTAINLY CAN`T BE RULED OUT BUT THE GOING FORECAST SEEMS
TO FIT EXPECTATIONS WELL AT THIS POINT.
&&
.AVIATION...ISSUED 715 PM EDT FRI AUG 7 2015
LOW PRESSURE OVER WISCONSIN WILL MOVE TOWARD SE MICHIGAN WHILE
WEAKENING DURING THE EVENING. IT WILL REMAIN ORGANIZED ENOUGH TO
BRING PATCHES OF SHOWERS TO THE MBS AND FNT AREAS BY MID EVENING
BUT CONFIDENCE IS NOT AS GREAT THAT ANY RAIN WILL REACH PTK AND
POINTS SOUTHWARD. EVEN WITH THE RAIN...CONDITIONS ARE EXPECTED TO
REMAIN VFR ACROSS THE AREA. A SHORT INTERVAL OF MVFR IS POSSIBLE
AT MBS IN ANY HEAVIER SHOWER THAT CAN DEVELOP. THIS TREND WILL BE
MONITORED. THE SYSTEM WILL WEAKEN ENOUGH TO ALLOW SURFACE HIGH
PRESSURE TO REBUILD OVER THE REGION SATURDAY MORNING AND PROVIDE
FAVORABLE AVIATION CONDITIONS THROUGH THE DAY.
FOR DTW... CLOUDS WILL THICKEN OVER THE TERMINAL AREA DURING THE
EVENING BUT CEILING WILL REMAIN ABOVE 5000 FEET. A FEW SPRINKLES OR
A PASSING LIGHT RAIN SHOWER WILL BE POSSIBLE FROM THE HIGH CLOUD
BASES DURING THE EVENING. SO FAR...TRENDS INDICATE LOW CONFIDENCE IN
ANY MEANINGFUL RAIN FOR INCLUSION IN THE FORECAST.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR CEILING 5000 FEET OR LESS.
&&
.PREV DISCUSSION...ISSUED 247 PM EDT FRI AUG 7 2015
SHORT TERM...TONIGHT
ORGANIZING DEFORMATION ASSOCIATED WITH THE LOW AMPLITUDE WAVE
APPROACHING THE WESTERN SHORES OF LAKE MICHIGAN AT PRESS TIME IS
SUPPORTING AN ORGANIZING RAIN SHIELD OVER EASTERN WISCONSIN. MODEL
PROGS REMAIN INSISTENT THAT THIS WAVE WILL BECOME INCREASINGLY
SHEARED THIS EVENING, THE EARLY SIGNS OF WHICH ARE ALREADY BECOMING
EVIDENT ON CURRENT WV IMAGERY. CEILINGS WITHIN THE ACTIVE AREA OF
PRECIP ARE GENERALLY ABOVE 7KFT, A TESTAMENT TO THE AMOUNT OF DRY
AIR IN THE COLUMN. PER 12Z DTX SOUNDING AND LATEST RAP PROGS, EVEN
DRIER AIR RESIDES OVER SOUTHEAST MICHIGAN. TAKEN IN CONSIDERATION
WITH RAPIDLY WEAKENING FORCING OVER THE NEXT SEVERAL HOURS, THIS
CASTS DOUBT ON THE ABILITY OF PRECIP TO SURVIVE ITS TREK INTO
SOUTHEAST MICHIGAN. SOME SEMBLANCE OF THE MID-LEVEL CIRCULATION
MAY PROVIDE JUST ENOUGH ASCENT/DEFORMATION TO RESULT IN A PERIOD
OF LIGHT RAIN FALLING OUT OF HIGH CLOUDS OVER THE SAGINAW VALLEY
WHERE A HIGH CHC POP IS IN PLACE. ELSEWHERE...JUST A CHC LATE
TONIGHT NORTH OF I-69 WITH NO WX MENTION ELSEWHERE. GUIDANCE LOOKS
ON TRACK WITH LOWS IN THE LOW TO MID 60S...A FEW DEGREES WARMER
THAN LAST NIGHT OWING TO INCREASED CLOUD COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
DAMPENING MID LEVEL WAVE AND ATTENDANT 100 KNOT UPPER JET CORE IN
THE PROCESS OF PIVOTING THROUGH LOWER MICHIGAN EARLY SATURDAY. MOST
FAVORABLE UPPER LEVEL FORCING TIED TO THESE FEATURES WILL TEND TO
ALIGN FROM THE TRI-CITIES/THUMB INTO NORTHERN LOWER MICHIGAN THROUGH
THIS TIME. THIS WILL MAINTAIN A WINDOW FOR LIGHT SHOWER PRODUCTION
ACROSS THIS CORRIDOR DURING THE MORNING PERIOD...PERPETUATION OF A
STABLE EASTERLY FLOW SUGGESTING MINIMAL POTENTIAL FOR THUNDERSTORMS.
HI RES MODEL GUIDANCE DOES HINT THAT SOME FORM OF TRAILING PV
FILAMENT AND/OR WEAK SURFACE TROUGH MAY THEN SHIFT ACROSS SE
MICHIGAN DURING PEAK HEATING. THIS IN THE PRESENCE OF SOME LEFT
EXIT REGION JET DYNAMICS MAY PROVE SUFFICIENT IN GENERATING A LOW
END COVERAGE OF SHOWERS /EMBEDDED THUNDER/ DURING THE MID-LATE
AFTERNOON. THE OVERALL SETUP REMAINS SOMEWHAT NEBULOUS AT THIS
STAGE WITH MOISTURE QUALITY AND DEGREE OF DESTABILIZATION AN
ISSUE...AND WILL SIMPLY PROVIDE A SLIGHT CHANCE MENTION. LITTLE
VARIATION IN THE TEMPERATURE PATTERN...WITH AT LEAST PARTIAL SUN
STILL SUPPORTING AFTERNOON HIGHS IN THE VICINITY OF 80 DEGREES.
ATTENTION HEADING INTO THE LATTER HALF OF THE WEEKEND TURNS TO
ANOTHER LOW AMPLITUDE SHORTWAVE EJECTING OVER THE MEAN SOUTHERN
PLAINS RIDGE. HIGH DEGREE OF VARIABILITY YET WITHIN THE MODEL
SOLUTION SPACE IN TERMS OF POTENTIAL STRENGTH...TIMING AND
POSITIONING OF THE ASSOCIATED LOW-MID LEVEL RESPONSE AS THIS SYSTEM
LIFTS EAST OF THE MISSISSIPPI. 12Z NAM TRENDING TOWARD A MUCH MORE
DYNAMIC SOLUTION...NETTING A MORE PRONOUNCED AND PROGRESSIVE
DOWNSTREAM EXPANSION OF LARGE SCALE ASCENT AND MOISTURE TRANSPORT
NORTH OF THE ATTENDANT WARM FRONTAL BOUNDARY AND INTO LOWER MICHIGAN
BY LATE SUNDAY. THIS SOLUTION SUGGESTS AN INCREASING POTENTIAL FOR
SHOWERS AND ELEVATED THUNDERSTORMS SUNDAY AFTERNOON AND EVENING.
HOWEVER 4 KM NAM AND CONSENSUS OF REMAINING GUIDANCE POINTS TOWARD A
MORE TEMPERED/SLOWER EVOLUTION...A GREATER WINDOW FOR PRECIPITATION
DEVELOPMENT HOLDING OFF UNTIL SUNDAY NIGHT/EARLY MONDAY. EVENTUAL
OUTCOME LIKELY CARRIES STRONG DEPENDENCE ON HOW CONVECTIVE TRENDS
EVOLVE UPSTREAM AND SPILL EASTWARD...SE MICHIGAN STILL SEEMINGLY
POSITIONED OUTSIDE OF THE GREATER INSTABILITY AXIS THROUGH THIS
PERIOD. FOR NOW...WILL HOLD TIGHT WITH A DRY FORECAST ON
SUNDAY...CENTERING POPS FOR SUNDAY NIGHT AND MONDAY. ASSUMING AN
EARLIER ONSET OF THICKER CLOUDINESS AND/OR PRECIPITATION NEVER
MATERIALIZES THROUGH PEAK HEATING...PERSISTENCE WILL LEAVE HIGHS
AGAIN WITHIN A COUPLE DEGREE OF 80F.
ZONAL FLOW ACROSS THE CORN BELT MONDAY EXPECTED TO AMPLIFY INTO A
TROUGH AS 80+ KT H25 JET STREAK DEVELOPS. WEAK CYCLOGENESIS ALONG
WITH SOME FORCING FROM FAVORABLE POSITIONING OF POLEWARD JET EXIT
REGION OVER THE LOWER GREAT LAKES ARGUES FOR AT LEAST CHANCE POPS
MONDAY. INSTABILITY LOOKS LIMITED WITH LI ONLY DROPPING TO AROUND
-2...SO HAVE CHC SHOWERS AND SLIGHT CHC T-STORMS. SURFACE CYCLONE
PROGGED TO INTENSIFY OVER THE NORTHEASTERN US WHICH FAVORS MORE
AGRESSIVE COLD/DRY AIR ADVECTION TUESDAY. UPPER TROUGH AMPLIFIES
OVER THE NORTHEASTERN US MIDWEEK WITH LOWER MI IN THE SUBSIDENCE
REGION UPSTREAM OF THE TROUGH. UPSHOT IS MAINLY DRY/COOL FORECAST
MIDWEEK.
MARINE...
MODEST NORTHEAST WINDS THROUGH THE EVENING WILL MAINTAIN SOME
ENHANCED WAVE DEVELOPMENT OVER THE NEARSHORE WATERS. GENERALLY
WEAKER EAST TO SOUTHEAST WINDS WILL THEN HOLD THROUGH THE WEEKEND AS
THE HIGH PRESSURE CENTER REMAINS POSITIONED JUST NORTHEAST OF THE
REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......BT
AVIATION.....BT
SHORT TERM...JVC
LONG TERM....MR/DT
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
928 PM EDT FRI AUG 7 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 330 PM EDT FRI AUG 7 2015
A WEAK AREA OF LOW PRESSURE WILL MOVE INTO THE AREA TONIGHT AND
BRING SCATTERED SHOWERS. MOST OF THESE SHOWERS SHOULD EXIT THE AREA
LATE TONIGHT...GIVING THE REGION A NICE SATURDAY.
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL ARRIVE SUNDAY
AFTERNOON AND LINGER INTO THE EVENING. THIS WILL BE A MORE
WIDESPREAD RAIN...AND THERE MAY BE A FEW STRONG STORMS TOO.
TEMPERATURES THROUGH THE WEEKEND WILL BE MILD WITH DAYTIME HIGHS
MAINLY IN THE UPPER 70S TO AROUND 80.
A FEW SHOWERS MAY LINGER INTO MONDAY...BUT THEN WE SHOULD SEE A DRY
PERIOD FROM MONDAY NIGHT THROUGH THURSDAY. ANOTHER CHANCE OF RAIN
WILL MOVE IN FOR THURSDAY NIGHT AND FRIDAY. HIGHS EACH DAY SHOULD
REMAIN IN THE UPPER 70 TO MID 80S.
&&
.UPDATE...
ISSUED AT 928 PM EDT FRI AUG 7 2015
THE SHORTWAVE CURRENTLY MOVING ACROSS LOWER MICHIGAN CONTINUES TO
PRODUCE MODERATE RAIN OVER OUR NORTHERN COUNTIES. SEVERAL MESONET
SITES HAVE HAD BETWEEN .35 AND .50 INCHES OF RAIN OVER WESTERN
MASON COUNTY SO FAR THIS EVENING. AS A RESULT I HAVE INCREASED THE
POP TO NEAR 100% OVER OUR NORTHERN COUNTIES THROUGH AT LEAST
MIDNIGHT AND I ALSO INCREASED QPF TO NEAR HALF INCH OVER THE NW
SECTIONS OF OUR FORECAST AREA TONIGHT.
SOUTHERN AREAS...DUE TO THE DRY EASTERLY LOW LEVEL INFLOW TO THE
SYSTEM...WILL ONLY SEE SPRINKLES OR POSSIBLY AND A FEW HUNDERTHS
OF AN INCH OF RAIN IN ISOLATED LOCATIONS. FOR THE MOST PART AREAS
NEAR AND SOUTH OF INTERSTATE 96 WILL NOT SEE MUCH IN THE WAY OF
MEASURABLE RAIN TONIGHT.
THIS SYSTEM WILL SLOWLY CONTINUE TO WEAKEN AS IT MOVES ACROSS THE
AREA SO THE RAINFALL RATES WILL DECREASE OVER OUR NORTHERN
COUNTIES BY MIDNIGHT. EVEN SO THERE IS A TRAILING UPPER WAVE THAT
WILL COME ACROSS SOUTHWEST LOWER MICHIGAN JUST PRIOR TO SUNRISE.
THIS WILL RESULT IN ADDITIONAL SHOWERS ACROSS THE AREA. THE
LATEST RAP MODEL AND ASSOCIATED MODEL SOUNDINGS DO NOT SHOW ENOUGH
INSTABILITY FOR THUNDERSTORMS SO I EXPUNGED THE MENTION OF
THUNDERSTORMS FROM OUR OVERNIGHT FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT FRI AUG 7 2015
A GOOD CHANCE OF RAIN TONIGHT...ESPECIALLY EARLY ON. THEN ANOTHER
STRONG CHANCE OF RAIN COMES SUNDAY AFTERNOON INTO THE EVENING.
TOPS WERE SLOWLY WARMING WITH THE SYSTEM THAT WAS MOVING ACROSS LAKE
MICHIGAN THIS AFTERNOON. HOWEVER...AS MENTIONED IN AN EARLIER
UPDATE...THE LOW LEVEL JET FUELING THESE SHOWERS WILL HOLD TOGETHER
THROUGH THIS EVENING...BUT THEN SLOWLY WEAKEN AND MOVE INTO NORTHERN
LOWER LATER TONIGHT. WILL INCREASE POPS TO LIKELY OVER CENTRAL
LOWER...WHILE KEEPING CHANCE POPS ELSEWHERE. SOME WEAK INSTABILITY
ARRIVES LATE TONIGHT WITH THE HIGHER DEW POINTS...SO INCLUDED THE
MENTION OF ISOLATED THUNDER.
OTHER THAN SOME LINGERING MORNING SHOWERS ACROSS THE NE CWA SATURDAY
MORNING...THE REST OF THE CWA SHOULD BE DRY ON SATURDAY AS WE WILL
BE IN BETWEEN SYSTEMS. LOW CLOUDS WILL BE COMMONPLACE FIRST
THING...BUT THESE SHOULD BREAK UP THROUGH THE DAY FOR PARTLY SUNNY
SKIES IN THE AFTERNOON.
THE MODELS ARE IN BETTER AGREEMENT SHOWING LOW PRESSURE EJECTING OUT
OF THE CENTRAL PLAINS ON SATURDAY AND TRACKING IT ACROSS THE LOWER
GREAT LAKES SUNDAY NIGHT. THE SYSTEM CONTINUES TO LOOK MORE
IMPRESSIVE WITH GOOD JET DYNAMICS MOVING ACROSS SW MI STARTING LATE
SATURDAY NIGHT AND CONTINUING INTO SUNDAY EVENING. AGREE WITH SPC
INCLUDING PORTIONS OF THE CWA IN THE MARGINAL RISK OF SEVERE.
HOWEVER SINCE WE WILL BE ON THE COOL SIDE OF THE SYSTEM MOST OF THE
INSTABILITY WILL BE ELEVATED. THIS LEAVES LARGE HAIL AS THE MAIN
SEVERE THREAT. INSTABILITY SHOULD NOT BE OFF THE CHARTS...SO ANY
SEVERE THREAT SHOULD BE LOW END. SEVERE TIME FRAME SHOULD SHOULD BE
LATE AFTERNOON/EARLY EVENING SUNDAY.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EDT FRI AUG 7 2015
NO SIGNIFICANT CHANGE WITH A COLD FRONT EXPECTED TO BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ON MONDAY...AND THEN DRY AND
SEASONABLY COOL THROUGH NEXT WEEK. LOOKING FURTHER...SEASONABLY WARM
CONDITIONS RETURN TOWARDS NEXT WEEKEND WITH CONTINUED DRY CONDITIONS
THROUGH WEEK TWO.
MONDAYS FRONTAL PASSAGE SHOULD BE SUPPORTED BY ROUGHLY 500 J/KG OF
CAPE AND 0-6KM SHEAR OF 30KTS WHICH WOULD BE ENOUGH FOR A FEW
ISOLATED STRONG STORMS. HOWEVER...THE FORCING IS NOT OVERLY
IMPRESSIVE OR ORGANIZED BUT...THEN AGAIN...LATEST NWP IS TRENDING
STRONGER...SO POPS ARE UP A BIT TODAY.
REST OF THE WEEK LOOKS A LOT LIKE THIS WEEK WITH HIGH PRESSURE AND
LIKELY SOME DIURNAL FAIR WEATHER CLOUDINESS THROUGHOUT THE WEEK.
UPPER PATTERN CONTINUES TO FEATURE RIDGE OVER CENTRAL WEST WITH
CLOSED HIGH OVER WEST TEXAS AND A DOWNSTREAM TROUGH OVER THE EAST.
THE PATTERN AMPLIFIES A BIT EARLY NEXT WEEK LEADING TO THE COOLER
AND DRIER AIR OVER MICHIGAN FOR MIDWEEK AND THEN FLATTENS WITH
WARMER AND LIKELY A BIT MORE HUMID AIR FOR NEXT WEEKEND. LOOKING
FURTHER OUT THE PATTERN APPEARS TO MORE OR LESS REPEAT IN WEEK TWO.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 720 PM EDT FRI AUG 7 2015
OVERALL EXPECT VFR CONDITIONS TO CONTINUE THROUGH SATURDAY. THAT
BEING SAID... WE DO HAVE AN AREA OF SHOWERS MOVING ACROSS THE AREA
THIS EVENING. VISIBILITIES ARE VFR UNDER THE SHOWERS AT THIS POINT
(23). THERE IS AN AREA OF MVFR AND EVEN IFR CIGS/VSBY OVER
NORTHERN WISCONSIN AT 23Z BUT IT SEEMS THAT AREA OF LOW CLOUDS
WILL STAY NORTH AND WEST OF THE GRR TAF SITES THROUGH SATURDAY
MORNING EVEN AS THE SYSTEM MOVES THROUGH THE AREA TONIGHT. THE
SHOWERS WILL MOVE ACROSS THE AREA THIS EVENING AND ADDITIONAL
SHOWERS ARE EXPECTED TO REFORM AND MOVE ACROSS THE CENTRAL AND
NORTHERN AREAS INTO THE MID MORNING HOURS OF SATURDAY. IT WOULD
NOT BE OUT OF THE QUESTION WE COULD SEE SOME MVFR VISIBILITIES
TOWARD MORNING WITH THOSE SHOWERS BUT MY CONFIDENCE FOR THAT AT
THIS POINT IS LOW SO I DID NOT INCLUDE IT IN OUR TAFS. EXPECT
CONSIDERABLE CLOUDS SATURDAY BUT NOT MUCH PRECIPITATION.
&&
.MARINE...
ISSUED AT 330 PM EDT FRI AUG 7 2015
WINDS AND WAVES WILL STAY UNDER 3 FEET THROUGH THE SHORT TERM.
THUNDERSTORMS WILL BE THE MAIN THREAT...COMING IN LATE SATURDAY
NIGHT AND LINGERING THROUGH SUNDAY EVENING.
&&
.HYDROLOGY...
ISSUED AT 1241 PM EDT FRI AUG 7 2015
NO FLOODING ISSUES EXPECTED FOR THE NEXT WEEK OR MORE AS A
RELATIVELY DRY PATTERN REMAINS IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...COBB
AVIATION...WDM
HYDROLOGY...MACZKO
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
759 PM EDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 314 PM EDT FRI AUG 7 2015
FCST FOCUS IN THE MEDIUM RANGE PERIOD WL BE ON POPS THE SECOND HALF
OF THIS WEEKEND ASSOCIATED WITH STRONG DISTUBANCE OVER SCENTRAL
CANADA THAT WL BE DROPPING SLOWLY ESEWD THRU NW ONTARIO AND DRAGGING
A COLD FNT ACRS UPR MI ON SUN NGT. TEMPS AHEAD OF THE COLD FROPA WL
BE AOA NORMAL. DURING THE FIRST HALF OF THE NEXT WEEK...EXPECT TEMPS
TO FALL BLO NORMAL WITH NW FLOW ALOFT DEVELOPING BTWN A BLDG UPR RDG
IN THE PLAINS AND DEEPENING TROF DOWNSTREAM IN ERN NAMERICA. CNDN HI
PRES UNDER THIS NW FLOW ALOFT WL BRING GENERALLY DRY WX DURING THE
MON THRU WED PERIOD. LOOKS LIKE TEMPS WL REBOUND AOA NORMAL LATER IN
THE WEEK AS PLAINS RDG BLDS TOWARD THE WRN LKS.
SAT NGT THRU SUN NGT...STRONG SHRTWV OVER FAR NW ONTARIO THAT WL BE
TOPPING UPR RDG IN THE PLAINS IS FCST TO SLIDE SLOWLY ESE THRU NRN
ONTARIO. ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES...MOST OF
THE LATEST GUIDANCE INDICATE A FASTER PRIMARY COLD FROPA ON SUN NGT.
SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE ONTARIO SHRTWV
WL REMAIN TO THE N OF UPR MI...POPS/PCPN AMOUNTS AS EARLY AS SAT NGT
IN ADVANCE OF THIS COLD FNT WL DEPEND ON THE DEGREE TO WHICH MSTR
INFLOW INTO THE UPR LKS WL BE DISRUPTED BY A W-E ORIENTED BNDRY
STRETCHING FM IOWA INTO THE LOWER LKS AND CONVECTION THAT FIRES
ALONG THIS AXIS ACCOMPANYING THE PASSAGE OF ANOTHER SHRTWV OVER THAT
AREA. THE 12Z NAM IS MOST EXTREME SHOWING A NEAR ABSENCE OF PCPN
ACRS THE CWA DURING THIS ENTIRE PERIOD WITH A LACK OF ANY MSTR
INFLOW/DYNAMIC FORCING TO THE N OF STRONG TS COMPLEX/DEEPER SFC LO
TRACKING ALONG THE BNDRY. THE OTHER MODELS SHOW A MORE PRONOUNCED
AXIS OF HIER H85 THETA E AND THUS MORE DEEP LYR MSTR CNVGC/FORCING/
QPF. BEST CHC FOR SOMWHAT HIER POPS WL BE OVER THE W ON SAT EVNG AND
THEN THE CENTRAL ON SUN AFTN/EVNG...WHEN THE 12Z GFS SHOWS MUCAPE AS
HI AS 2500 J/KG...DURING PERIODS OF DAYTIME HEATING. BUT GIVEN
MODEL/TIMING UNCERTAINTIES AND SUPPORT FOR LARGER SCALE FORCING TO
PASS TO THE N AND S OF THE CWA...FCST WL POPS WL BE NO HIER THAN THE
CHC CATEGORY.
MON...SINCE RECENT MEDIUM RANGE GUIDANCE HAS TRENDED TO SPEED UP
PASSAGE OF COLD FROPA ATTENDANT TO SHRTWV SHIFTING ESEWD THRU NW
ONTARIO AND ARRIVAL OF DEEP LYR QVECTOR DVGC/LARGER SCALE
SUBSIDENCE/MID LVL DRYING...PCPN CHCS FOR MON LOOK TO BE
DIMINISHING. WITH MORE SUNSHINE...H85 TEMPS FCST IN IN THE 10 TO 12C
RANGE WL SUPPORT MAX TEMPS IN THE 70S. LOCATIONS NEAR LK SUP WL BE
COOLEST WITH LLVL NNW FLOW IN ADVANCE OF APRCHG CNDN HI PRES.
MON NGT THRU WED...THE UPR RDG IN THE PLAINS IS FCST TO AMPLIFY
EARLY IN THE WEEK...ALLOWING THE TROF IN ERN NAMERICA TO DEEPEN AND
A MORE PRONOUNCED NW FLOW ALOFT BTWN THESE FEATURES TO PREVAIL OVER
THE GREAT LKS. THE ARRIVAL OF CNDN HI PRES/H85 TEMPS AS LO AS 8 TO
10C WL RESULT IN GENERALLY DRY AND COOLER WX FOR MON NGT INTO WED.
ALTHOUGH SOME OF THE MODELS INDICATE A SHRTWV EMBEDDED IN THE NW
FLOW ALOFT COULD CAUSE SOME SHOWERS DURING DAYTIME HEATING ON TUE...
THE COVERAGE/INTENSITY OF THESE SHOWERS WL BE LIMITED BY THE ABSENCE
OF ANY DEEPER MSTR AND GENERAL LARGER SCALE SUBSIDENCE UNDER THE
CONFLUENT NW FLOW ALOFT. RETAINED GOING DRY FCST FOR NOW. WITH
PLENTY OF SUNSHINE...WED AFTN WL TURN WARMER AS H85 TEMPS REBOUND
TOWARD 15C OVER THE W AS THE PLAINS RDG SHIFTS TOWARD THE WRN LKS.
LATE WEEK...A NUMBER OF THE EXTENDED MODELS SHOW ANOTHER SHRTWV
ROUNDING THE TOP OF THE PLAINS RDG WL INFLUENCE THE AREA ON THU AND
BRING THE THREAT OF SOME SHOWERS/TS. AS THE UPR RDG TO THE W BUILDS
BACK TOWARD THE UPR LKS IN THE WAKE OF THIS SHRTWV PASSAGE...FRI
SHOULD BE DRY AND WARMER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 739 PM EDT FRI AUG 7 2015
A LOW CENTERED IN WISCONSIN HAS SHIFTED RAIN SHOWERS OVER MAINLY
THE EAST HALF OF UPPER MICHIGAN THIS EVENING. THE LOW WILL CONTINUE
TO USHER IN INCREASING LOW LEVEL MOISTURE THIS EVENING INTO THE
OVERNIGHT LEADING TO A LOWERING OF CEILINGS AND VSBYS AT KIWD AND
KSAW ESPECIALLY GIVEN THE RECENT RAINFALL. ONCE THE LOW CLOUDS
ARRIVE LATER THIS EVENING INTO THE OVERNIGHT HOURS...WOULD EXPECT
IFR OR LOWER CONDITIONS TO PREVAIL INTO MID-MORNING ON SAT. EXPECT
LOWERING VISIBILITIES IN FOG...ESPECIALLY FOR KSAW WHERE THE
FAVORABLE UPSLOPE SOUTHEASTERLY FLOW WILL BE IN PLACE. DRIER AIR
SHOULD GRADUALLY MOVE INTO THE AREA DURING THE DAY ON SATURDAY AND
BRING IMPROVING CEILINGS AND VISIBILITIES REACHING VFR BY SAT
AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A LOW PRESSURE SYSTEM OVER WESTERN WISCONSIN WILL DISSIPATE TONIGHT
INTO SATURDAY MORNING AS IT MOVES EAST. MEANWHILE...A STRONGER LOW
NEAR LAKE WINNIPEG WILL MOVE TO JAMES BAY BY MONDAY..SWEEPING A
BROAD TROUGH ACROSS THE UPPER GREAT LAKES REGION. HIGH PRESSURE
WILL BUILD IN BEHIND THE TROUGH...AND CONTINUE INTO THE MIDDLE OF
NEXT WEEK. WITH WEAK PRESSURE GRADIENTS EXPECTED...WINDS ARE
EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. FINALLY...WITH
RAIN AND ABUNDANT LOW LEVEL MOISTURE MOVING OVER WESTERN AND
CENTRAL LAKE SUPERIOR...COULD SEE SOME PATCHY FOG OVER THOSE AREAS
TONIGHT INTO SATURDAY MORNING...BUT DON/T EXPECT WIDESPREAD...DENSE
FOG AT THIS TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
715 PM EDT FRI AUG 7 2015
.AVIATION...
LOW PRESSURE OVER WISCONSIN WILL MOVE TOWARD SE MICHIGAN WHILE
WEAKENING DURING THE EVENING. IT WILL REMAIN ORGANIZED ENOUGH TO
BRING PATCHES OF SHOWERS TO THE MBS AND FNT AREAS BY MID EVENING
BUT CONFIDENCE IS NOT AS GREAT THAT ANY RAIN WILL REACH PTK AND
POINTS SOUTHWARD. EVEN WITH THE RAIN...CONDITIONS ARE EXPECTED TO
REMAIN VFR ACROSS THE AREA. A SHORT INTERVAL OF MVFR IS POSSIBLE
AT MBS IN ANY HEAVIER SHOWER THAT CAN DEVELOP. THIS TREND WILL BE
MONITORED. THE SYSTEM WILL WEAKEN ENOUGH TO ALLOW SURFACE HIGH
PRESSURE TO REBUILD OVER THE REGION SATURDAY MORNING AND PROVIDE
FAVORABLE AVIATION CONDITIONS THROUGH THE DAY.
FOR DTW... CLOUDS WILL THICKEN OVER THE TERMINAL AREA DURING THE
EVENING BUT CEILING WILL REMAIN ABOVE 5000 FEET. A FEW SPRINKLES OR
A PASSING LIGHT RAIN SHOWER WILL BE POSSIBLE FROM THE HIGH CLOUD
BASES DURING THE EVENING. SO FAR...TRENDS INDICATE LOW CONFIDENCE IN
ANY MEANINGFUL RAIN FOR INCLUSION IN THE FORECAST.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR CEILING 5000 FEET OR LESS.
&&
.PREV DISCUSSION...ISSUED 247 PM EDT FRI AUG 7 2015
SHORT TERM...TONIGHT
ORGANIZING DEFORMATION ASSOCIATED WITH THE LOW AMPLITUDE WAVE
APPROACHING THE WESTERN SHORES OF LAKE MICHIGAN AT PRESS TIME IS
SUPPORTING AN ORGANIZING RAIN SHIELD OVER EASTERN WISCONSIN. MODEL
PROGS REMAIN INSISTENT THAT THIS WAVE WILL BECOME INCREASINGLY
SHEARED THIS EVENING, THE EARLY SIGNS OF WHICH ARE ALREADY BECOMING
EVIDENT ON CURRENT WV IMAGERY. CEILINGS WITHIN THE ACTIVE AREA OF
PRECIP ARE GENERALLY ABOVE 7KFT, A TESTAMENT TO THE AMOUNT OF DRY
AIR IN THE COLUMN. PER 12Z DTX SOUNDING AND LATEST RAP PROGS, EVEN
DRIER AIR RESIDES OVER SOUTHEAST MICHIGAN. TAKEN IN CONSIDERATION
WITH RAPIDLY WEAKENING FORCING OVER THE NEXT SEVERAL HOURS, THIS
CASTS DOUBT ON THE ABILITY OF PRECIP TO SURVIVE ITS TREK INTO
SOUTHEAST MICHIGAN. SOME SEMBLANCE OF THE MID-LEVEL CIRCULATION
MAY PROVIDE JUST ENOUGH ASCENT/DEFORMATION TO RESULT IN A PERIOD
OF LIGHT RAIN FALLING OUT OF HIGH CLOUDS OVER THE SAGINAW VALLEY
WHERE A HIGH CHC POP IS IN PLACE. ELSEWHERE...JUST A CHC LATE
TONIGHT NORTH OF I-69 WITH NO WX MENTION ELSEWHERE. GUIDANCE LOOKS
ON TRACK WITH LOWS IN THE LOW TO MID 60S...A FEW DEGREES WARMER
THAN LAST NIGHT OWING TO INCREASED CLOUD COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
DAMPENING MID LEVEL WAVE AND ATTENDANT 100 KNOT UPPER JET CORE IN
THE PROCESS OF PIVOTING THROUGH LOWER MICHIGAN EARLY SATURDAY. MOST
FAVORABLE UPPER LEVEL FORCING TIED TO THESE FEATURES WILL TEND TO
ALIGN FROM THE TRI-CITIES/THUMB INTO NORTHERN LOWER MICHIGAN THROUGH
THIS TIME. THIS WILL MAINTAIN A WINDOW FOR LIGHT SHOWER PRODUCTION
ACROSS THIS CORRIDOR DURING THE MORNING PERIOD...PERPETUATION OF A
STABLE EASTERLY FLOW SUGGESTING MINIMAL POTENTIAL FOR THUNDERSTORMS.
HI RES MODEL GUIDANCE DOES HINT THAT SOME FORM OF TRAILING PV
FILAMENT AND/OR WEAK SURFACE TROUGH MAY THEN SHIFT ACROSS SE
MICHIGAN DURING PEAK HEATING. THIS IN THE PRESENCE OF SOME LEFT
EXIT REGION JET DYNAMICS MAY PROVE SUFFICIENT IN GENERATING A LOW
END COVERAGE OF SHOWERS /EMBEDDED THUNDER/ DURING THE MID-LATE
AFTERNOON. THE OVERALL SETUP REMAINS SOMEWHAT NEBULOUS AT THIS
STAGE WITH MOISTURE QUALITY AND DEGREE OF DESTABILIZATION AN
ISSUE...AND WILL SIMPLY PROVIDE A SLIGHT CHANCE MENTION. LITTLE
VARIATION IN THE TEMPERATURE PATTERN...WITH AT LEAST PARTIAL SUN
STILL SUPPORTING AFTERNOON HIGHS IN THE VICINITY OF 80 DEGREES.
ATTENTION HEADING INTO THE LATTER HALF OF THE WEEKEND TURNS TO
ANOTHER LOW AMPLITUDE SHORTWAVE EJECTING OVER THE MEAN SOUTHERN
PLAINS RIDGE. HIGH DEGREE OF VARIABILITY YET WITHIN THE MODEL
SOLUTION SPACE IN TERMS OF POTENTIAL STRENGTH...TIMING AND
POSITIONING OF THE ASSOCIATED LOW-MID LEVEL RESPONSE AS THIS SYSTEM
LIFTS EAST OF THE MISSISSIPPI. 12Z NAM TRENDING TOWARD A MUCH MORE
DYNAMIC SOLUTION...NETTING A MORE PRONOUNCED AND PROGRESSIVE
DOWNSTREAM EXPANSION OF LARGE SCALE ASCENT AND MOISTURE TRANSPORT
NORTH OF THE ATTENDANT WARM FRONTAL BOUNDARY AND INTO LOWER MICHIGAN
BY LATE SUNDAY. THIS SOLUTION SUGGESTS AN INCREASING POTENTIAL FOR
SHOWERS AND ELEVATED THUNDERSTORMS SUNDAY AFTERNOON AND EVENING.
HOWEVER 4 KM NAM AND CONSENSUS OF REMAINING GUIDANCE POINTS TOWARD A
MORE TEMPERED/SLOWER EVOLUTION...A GREATER WINDOW FOR PRECIPITATION
DEVELOPMENT HOLDING OFF UNTIL SUNDAY NIGHT/EARLY MONDAY. EVENTUAL
OUTCOME LIKELY CARRIES STRONG DEPENDENCE ON HOW CONVECTIVE TRENDS
EVOLVE UPSTREAM AND SPILL EASTWARD...SE MICHIGAN STILL SEEMINGLY
POSITIONED OUTSIDE OF THE GREATER INSTABILITY AXIS THROUGH THIS
PERIOD. FOR NOW...WILL HOLD TIGHT WITH A DRY FORECAST ON
SUNDAY...CENTERING POPS FOR SUNDAY NIGHT AND MONDAY. ASSUMING AN
EARLIER ONSET OF THICKER CLOUDINESS AND/OR PRECIPITATION NEVER
MATERIALIZES THROUGH PEAK HEATING...PERSISTENCE WILL LEAVE HIGHS
AGAIN WITHIN A COUPLE DEGREE OF 80F.
ZONAL FLOW ACROSS THE CORN BELT MONDAY EXPECTED TO AMPLIFY INTO A
TROUGH AS 80+ KT H25 JET STREAK DEVELOPS. WEAK CYCLOGENESIS ALONG
WITH SOME FORCING FROM FAVORABLE POSITIONING OF POLEWARD JET EXIT
REGION OVER THE LOWER GREAT LAKES ARGUES FOR AT LEAST CHANCE POPS
MONDAY. INSTABILITY LOOKS LIMITED WITH LI ONLY DROPPING TO AROUND
-2...SO HAVE CHC SHOWERS AND SLIGHT CHC T-STORMS. SURFACE CYCLONE
PROGGED TO INTENSIFY OVER THE NORTHEASTERN US WHICH FAVORS MORE
AGRESSIVE COLD/DRY AIR ADVECTION TUESDAY. UPPER TROUGH AMPLIFIES
OVER THE NORTHEASTERN US MIDWEEK WITH LOWER MI IN THE SUBSIDENCE
REGION UPSTREAM OF THE TROUGH. UPSHOT IS MAINLY DRY/COOL FORECAST
MIDWEEK.
MARINE...
MODEST NORTHEAST WINDS THROUGH THE EVENING WILL MAINTAIN SOME
ENHANCED WAVE DEVELOPMENT OVER THE NEARSHORE WATERS. GENERALLY
WEAKER EAST TO SOUTHEAST WINDS WILL THEN HOLD THROUGH THE WEEKEND AS
THE HIGH PRESSURE CENTER REMAINS POSITIONED JUST NORTHEAST OF THE
REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
SHORT TERM...JVC
LONG TERM....MR/DT
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
335 PM EDT THU AUG 6 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT THU AUG 6 2015
UPPER GREAT LAKES IS WITHIN WESTERLY FLOW ALOFT BETWEEN LARGE UPPER
LOW OVER EASTERN CANADA AND UPPER TROUGH OVER FAR WESTERN CANADA.
COUPLE OF MAIN SHORTWAVES ARE UPSTREAM OF UPPER GREAT LAKES. THE LEAD
WAVE IS OVER SOUTHERN MANITOBA AND IS GENERATING CLUSTER OF SHRA/TSRA
SOUTHERN MANITOBA INTO NORTHWEST MINNESOTA. WARM AIR ADVECTION MAINLY
IN THE MID LEVELS IS SUPPORTING ARC OF LGT SHRA TOWARD ISLE ROYALE
AND NORTHERN LK SUPERIOR. BASED ON HRRR AND RAP AND CURRENT RADAR
TRENDS...COULD SEE ISOLD SHR OR SPRINKLES CLIP TIP OF KEWEENAW
PENINSULA THIS MORNING. OTHERWISE...MAIN EFFECT FM THIS SHORTWAVE
WILL BE A LOT OF MID CLOUDS OVER AT LEAST NORTHERN CWA MOST OF TODAY.
SINCE THERE ARE ALREADY A WIDESPREAD AREA OF 5-10KFT BKN CIGS
UPSTREAM IN MINNESOTA...BUMPED UP CLOUD COVER TODAY. SOUTHERN CWA
SHOULD STAY IN AT LEAST INTERVALS OF SUN AND CLOUDS SO WENT WARMEST
THERE WITH MID 70S NEAR WI BORDER. COOLEST READINGS IN THE UPR 60S TO
NEAR 70 DEGREES WILL BE CLOSER TO LK SUPERIOR WITH MORE CLOUD COVER
AND EAST-SOUTHEAST ONSHORE GRADIENT WINDS.
FOR TONIGHT...ATTN TURNS TO SHORTWAVE CURRENTLY OVER WY AND SD. THIS
SHORTWAVE MOVES ACROSS NORTHERN PLAINS AND ARRIVES OVER CNTRL MN AND
WESTERN WI BY LATE TONIGHT. BULK OF STRONGER Q-VECTOR CONVERGENCE
STAYS OUT AHEAD OF THAT SHORTWAVE...BUT AS ASSOCIATED SFC LOW WITH
THE WAVE MOVES OVER MN...STRONG MOISTURE ADVECTION AT H85 ALONG WITH
ISENTROPIC LIFT 300-305K /H9-H7/ SHOULD SUPPORT INCREASING SHOWERS
INTO WESTERN UPR MICHIGAN AFTER MIDNIGHT. POPS RAMP UP TO HIGHER
CHANCE AT KIWD AFTER MIDNIGHT WITH SLIGHT CHANCES AS FAR EAST AS
ISHPEMING AND IRON MOUNTAIN. MUCAPE IN LOWEST 3KM OR APPROX SFC-H7
STAYS MAINLY SOUTHWEST OF CWA. ISOLD TSRA COULD SNEAK INTO FAR WEST
AS MODEST LOW-LEVEL JET MAY COULD ADVECT SMALL PORTION OF INSTABILITY
INTO CWA...BUT WILL KEEP TSRA OUT OF CWA THROUGH 12Z FRIDAY. MIN
TEMPS MUCH WARMER THAN LAST COUPLE NIGHTS MID 50S TO LOW 60S DUE TO
PLENTY OF CLOUD COVER AND STEADY SOUTH WINDS AHEAD OF THE SFC LOW IN
MN.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 334 PM EDT THU AUG 6 2015
IN THE MEDIUM/EXTENDED RANGE...SLOW MOVING...FAIRLY STRONG SHRTWV
OVER THE NRN ROCKIES/SW CANADA IS FCST TO MOVE SLOWLY TO THE ENE AND
INTO FAR NW ONTARIO THIS WEEKEND WHILE UPR TROF OVER QUEBEC IS FCST
TO WEAKEN AND MOVE ONLY SLOWLY TO THE E. FCST CHALLENGES WL FOCUS ON
TIMING/POPS RELATED TO LARGER SCALE WAA IN ADVANCE OF THE WRN SHRTWV
AND OTHER DISTURBANCES TRACKING AHEAD OF IT NEAR THE CNDN BORDER AS
WELL AS IMPACT OF PERSISTENT HUDSON BAY HI PRES RDG/DRIER AIR HELD
NEARLY IN PLACE UNDER CONFLUENT FLOW ALOFT ON THE WRN FLANK OF SLOW
MOVING QUEBEC TROF. UNFORTUNATELY...SHARP MODEL DIFFERENCES ARE
APRNT AS EARLY AS FRI NGT ON THE MSLP/PCPN EVOLUTION. SO CONFIDENCE
REMAINS LO ON THE FCST THRU THE WEEKEND.
FRI NGT...SHRTWV STREAKING THRU THE UPR MIDWEST WELL IN ADVANCE OF
STRONGER DISTURBANCE MOVING NEAR THE CNDN BORDER IS FCST BY MANY
MODELS...ESPECIALLY THE 12Z GFS...TO SHEAR OUT AND SLIDE SE THRU WI
ON WRN FLANK OF HUDSON BAY HI PRES RDG. ALTHOUGH THE 12Z NAM ALSO
SHOWS THE DIGGING SHRTWV AS WELL...THAT MODEL INDICATES BAND OF
MODEST WAA/ ISENTROPIC ASCENT BEST DEPICTED ON THE 305-310K SFCS
/ABOUT H775-675/ BTWN STRONGER DISTURBANCE AND HUDSON BAY HI PRES
RDG AND SOME UPR DVGC IN LEFT EXIT OF 80-90KT H3 JET MAX WL ALLOW A
BAND OF SHOWERS TO DRIFT E ACROSS UPR MI. WHEREAS THE NAM DROPS 0.50
TO 1.00 INCH OF RA OVER MUCH OF THE NRN CWA...THE GFS QPF IS NEAR
ZERO AS HUDSON BAY HI PRES BUILDS BACK INTO THE CWA ON FRI EVNG.
SINCE THE BULK OF THE OTHER MODELS APPEAR TO SUPPORT THE NAM AND THE
12Z GFS IS VERY DIFFERENT FM THE 06Z RUN /WHICH LOOKED A LOT LIKE
THE 12Z NAM FOR QPF/...WL FOLLOW A FCST CLOSER TO THAT MODEL. AS
BAND OF STRONGEST WAA SHIFTS TO THE E THRU THE NGT AND LARGER SCALE
QVECTOR DVGC/ SUBSIDENCE MOVE IN OVERNGT...EXPECT THE HIER POPS TO
DIMINISH W-E.
SAT...AFTER ANY LINGERING SHOWERS END OVER THE E EARLY IN THE DAY...
RISING HGTS/DEEP LYR QVECTOR DVGC/SUBSIDENCE/MORE LLVL ACYC FLOW
OVER THE UPR LKS WELL TO THE S OF SHRTWV LIFTING SLOWLY TO THE NE
THRU FAR NW ONTARIO SHOULD BRING GENERALLY DRY WX TO THE CWA.
COMBINATION OF AT LEAST PARTIAL SUNSHINE AND H85 TEMPS RISING AS HI
AS 16C OVER THE W LATE IN THE DAY WL SUPPORT MAX TEMPS REACHING AOA
80 ACRS THE W HALF OF THE CWA. MORE LINGERING CLDS AND LOWER H85
TEMPS OVER THE E WL HOLD TEMPS THERE IN THE 70S. SOME OF THE MODELS
INDICATE SOME SHOWERS/TS IN ADVANCE OF COLD FNT ATTENDANT TO ONTARIO
SHRTWV/SFC LO MAY REACH THE W LATE IN THE DAY...BUT WL FCST NO HIER
THAN LO CHC POPS TO ACCOUNT FOR MODEL TIMING DIFFERENCES/DRIER
GUIDANCE WITH MORE PERSISTENT HUDSON BAY HI PRES RDG.
SAT NGT THRU MON...SHRTWV IN FAR NW ONTARIO IS PROGGED TO SLIDE
SLOWLY TO THE ESE THRU NRN ONTARIO TO THE E OF BLDG UPR RDG IN THE
PLAINS. ALTHOUGH THERE IS GENERAL AGREEMENT THE COLD FNT ATTENDANT
TO THIS DISTURBANCE AS WELL AS A TRAILING LO PRES TROF WL DROP SE
THRU THE UPR LKS...TIMING DIFFERENCES ARE APRNT AMONG THE GUIDANCE
AS DISAGREEMENT ON THE PERSISTENCE OF HUDSON BAY HI PRES RDG/AXIS OF
DRIER AIR REMAIN. WITH LO CONFIDENCE...WL THUS HOLD NEAR THE
CONSENSUS FCST. TEMPS IN ADVANCE OF THE COLD FNT WL RUN AOA NORMAL
WITH H85 TEMPS WITHIN A FEW DEGREES OF 14C.
EXTENDED...AS UPR RDG IN THE PLAINS AMPLIFIES NEXT WEEK AND AN UPR
TROF DEEPENS IN SE CANADA/THE ERN CONSU...THE FLOW ALOFT WL TURN TO
THE NNW OVER THE GREAT LKS. CNDN HI PRES SHOULD BRING PREDOMINATELY
DRIER...COOLER WX TO THE CWA FOR TUE INTO THU. A SHRTWV RIDING OVER
THE PLAINS RDG DIGGING SEWD THRU THE NW FLOW ALF TOWARD THE UPR LKS
MAY BRING SOME SHOWERS LATE IN THE DAY NEXT THU...BUT CONFIDENCE
THIS FAR OUT ON THE TIMING OF THIS DISTURBANCE IS TOO LO TO VARY FM
CONSENSUS LO CHC POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 231 PM EDT THU AUG 6 2015
LOW PRESSURE SYSTEM WILL APPROACH FROM THE WEST LATE TONIGHT. COULD
SEE SHOWERS TOWARD DAYBREAK AT KIWD...BUT WEATHER SHOULD STAY
MAINLY DRY AT KCMX AND KSAW UNTIL 14-17Z. CEILING MAY NEAR
MVFR BY 18Z FRIDAY AT IWD. OTHERWISE...WINDS SHOULD REMAIN AROUND
10KTS OR LESS THROUGH THE PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 334 PM EDT THU AUG 6 2015
A COUPLE OF WEAK LO PRES TROFS WILL MOVE ACROSS THE UPPER GREAT
LAKES REGION INTO EARLY NEXT WEEK...BUT RELATIVELY FLAT PRES
GRADIENT WILL MAINTAIN WINDS UNDER 20KTS THRU THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...KF
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
234 PM EDT THU AUG 6 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT THU AUG 6 2015
UPPER GREAT LAKES IS WITHIN WESTERLY FLOW ALOFT BETWEEN LARGE UPPER
LOW OVER EASTERN CANADA AND UPPER TROUGH OVER FAR WESTERN CANADA.
COUPLE OF MAIN SHORTWAVES ARE UPSTREAM OF UPPER GREAT LAKES. THE LEAD
WAVE IS OVER SOUTHERN MANITOBA AND IS GENERATING CLUSTER OF SHRA/TSRA
SOUTHERN MANITOBA INTO NORTHWEST MINNESOTA. WARM AIR ADVECTION MAINLY
IN THE MID LEVELS IS SUPPORTING ARC OF LGT SHRA TOWARD ISLE ROYALE
AND NORTHERN LK SUPERIOR. BASED ON HRRR AND RAP AND CURRENT RADAR
TRENDS...COULD SEE ISOLD SHR OR SPRINKLES CLIP TIP OF KEWEENAW
PENINSULA THIS MORNING. OTHERWISE...MAIN EFFECT FM THIS SHORTWAVE
WILL BE A LOT OF MID CLOUDS OVER AT LEAST NORTHERN CWA MOST OF TODAY.
SINCE THERE ARE ALREADY A WIDESPREAD AREA OF 5-10KFT BKN CIGS
UPSTREAM IN MINNESOTA...BUMPED UP CLOUD COVER TODAY. SOUTHERN CWA
SHOULD STAY IN AT LEAST INTERVALS OF SUN AND CLOUDS SO WENT WARMEST
THERE WITH MID 70S NEAR WI BORDER. COOLEST READINGS IN THE UPR 60S TO
NEAR 70 DEGREES WILL BE CLOSER TO LK SUPERIOR WITH MORE CLOUD COVER
AND EAST-SOUTHEAST ONSHORE GRADIENT WINDS.
FOR TONIGHT...ATTN TURNS TO SHORTWAVE CURRENTLY OVER WY AND SD. THIS
SHORTWAVE MOVES ACROSS NORTHERN PLAINS AND ARRIVES OVER CNTRL MN AND
WESTERN WI BY LATE TONIGHT. BULK OF STRONGER Q-VECTOR CONVERGENCE
STAYS OUT AHEAD OF THAT SHORTWAVE...BUT AS ASSOCIATED SFC LOW WITH
THE WAVE MOVES OVER MN...STRONG MOISTURE ADVECTION AT H85 ALONG WITH
ISENTROPIC LIFT 300-305K /H9-H7/ SHOULD SUPPORT INCREASING SHOWERS
INTO WESTERN UPR MICHIGAN AFTER MIDNIGHT. POPS RAMP UP TO HIGHER
CHANCE AT KIWD AFTER MIDNIGHT WITH SLIGHT CHANCES AS FAR EAST AS
ISHPEMING AND IRON MOUNTAIN. MUCAPE IN LOWEST 3KM OR APPROX SFC-H7
STAYS MAINLY SOUTHWEST OF CWA. ISOLD TSRA COULD SNEAK INTO FAR WEST
AS MODEST LOW-LEVEL JET MAY COULD ADVECT SMALL PORTION OF INSTABILITY
INTO CWA...BUT WILL KEEP TSRA OUT OF CWA THROUGH 12Z FRIDAY. MIN
TEMPS MUCH WARMER THAN LAST COUPLE NIGHTS MID 50S TO LOW 60S DUE TO
PLENTY OF CLOUD COVER AND STEADY SOUTH WINDS AHEAD OF THE SFC LOW IN
MN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 347 AM EDT THU AUG 6 2015
NAM SHOWS A SHORTWAVE OVER THE NORTHERN PLAINS 12Z FRI WITH ANOTHER
ENTERING INTO THE UPPER GREAT LAKES THEN. THIS SHORTWAVE MOVES
THROUGH ON FRI AND THE OTHER SHORTWAVE MOVES SLOWLY EAST AND AFFECTS
THE AREA ON SAT. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE AND
MOISTURE MOVING THROUGH ON FRI AND BOTH MOVE OUT SAT AFTERNOON
BEFORE RETURNING SAT NIGHT.
CONFIDENCE IS LOW WITH THIS FORECAST AS GFS...ECMWF AND NAM ALL HAVE
DIFFERENT IDEAS FOR HOW THIS WEATHER SCENARIO IS GOING TO PLAY OUT.
ECMWF IS DRIER AND FURTHER SOUTH WITH IT PCPN. GFS IS QUICKER MOVING
PCPN THROUGH. WENT WITH A BLEND OF THE SOLUTIONS WHICH SEEMED TO
KEEP SOME CONTINUITY TO THE FORECAST. LOOKS LIKE THERE WILL BE A
BREAK IN PCPN FOR LATE FRI NIGHT INTO SAT MORNING AND THEN ANOTHER
WAVE COMES IN AND TRIED TO REFLECT THIS IN THE FORECAST WITH A BREAK
IN THE PCPN. BEST CHANCE FOR PCPN APPEARS TO BE FRI INTO FRI
EVENING...THEN HAVE LOW CHANCE POPS AND LOW CONFIDENCE FOR SAT AND
SAT NIGHT. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE
SOUTHERN AND CENTRAL PLAINS 12Z SUN WITH A TROUGH ACROSS CENTRAL
CANADA AND A SHORTWAVE IN THE NORTHERN PLAINS. THIS SHORTWAVE HEADS
EAST INTO THE UPPER GREAT LAKES SUN NIGHT INTO MON. THIS SHORTWAVE
HEADS OVER THE TOP OF THE RIDGE ON MON AND PUSHES IT BACK INTO THE
NORTHERN ROCKIES. THE UPPER FLOW BECOMES MORE AMPLIFIED ON TUE WITH
THE RIDGE BUILDING INTO THE CANADIAN ROCKIES AND THE TROUGH DIGGING
INTO THE ERN U.S. THE RIDGE BUILDS INTO THE NORTHERN PLAINS 12Z WED.
SFC RIDGING MOVES INTO THE UPPER GREAT LAKES TUE AND REMAINS INTO
WED. TEMPERATURES WILL CONTINUE TO BE SLIGHTLY BELOW NORMAL FOR THIS
FORECAST PERIOD. AS THE SFC HIGH BUILDS IN FOR MONDAY...WENT DRY FOR
MON NIGHT THROUGH WED AND REMOVED POPS FOR THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 231 PM EDT THU AUG 6 2015
LOW PRESSURE SYSTEM WILL APPROACH FROM THE WEST LATE TONIGHT. COULD
SEE SHOWERS TOWARD DAYBREAK AT KIWD...BUT WEATHER SHOULD STAY
MAINLY DRY AT KCMX AND KSAW UNTIL 14-17Z. CEILING MAY NEAR
MVFR BY 18Z FRIDAY AT IWD. OTHERWISE...WINDS SHOULD REMAIN AROUND
10KTS OR LESS THROUGH THE PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT THU AUG 6 2015
A COUPLE OF WEAK TROUGHS OR LOW PRESSURE SYSTEMS WILL MOVE THROUGH
THE UPPER GREAT LAKES REGION THROUGH THIS WEEKEND...BUT WINDS ARE
EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...KF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
649 AM EDT THU AUG 6 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT THU AUG 6 2015
UPPER GREAT LAKES IS WITHIN WESTERLY FLOW ALOFT BETWEEN LARGE UPPER
LOW OVER EASTERN CANADA AND UPPER TROUGH OVER FAR WESTERN CANADA.
COUPLE OF MAIN SHORTWAVES ARE UPSTREAM OF UPPER GREAT LAKES. THE LEAD
WAVE IS OVER SOUTHERN MANITOBA AND IS GENERATING CLUSTER OF SHRA/TSRA
SOUTHERN MANITOBA INTO NORTHWEST MINNESOTA. WARM AIR ADVECTION MAINLY
IN THE MID LEVELS IS SUPPORTING ARC OF LGT SHRA TOWARD ISLE ROYALE
AND NORTHERN LK SUPERIOR. BASED ON HRRR AND RAP AND CURRENT RADAR
TRENDS...COULD SEE ISOLD SHR OR SPRINKLES CLIP TIP OF KEWEENAW
PENINSULA THIS MORNING. OTHERWISE...MAIN EFFECT FM THIS SHORTWAVE
WILL BE A LOT OF MID CLOUDS OVER AT LEAST NORTHERN CWA MOST OF TODAY.
SINCE THERE ARE ALREADY A WIDESPREAD AREA OF 5-10KFT BKN CIGS
UPSTREAM IN MINNESOTA...BUMPED UP CLOUD COVER TODAY. SOUTHERN CWA
SHOULD STAY IN AT LEAST INTERVALS OF SUN AND CLOUDS SO WENT WARMEST
THERE WITH MID 70S NEAR WI BORDER. COOLEST READINGS IN THE UPR 60S TO
NEAR 70 DEGREES WILL BE CLOSER TO LK SUPERIOR WITH MORE CLOUD COVER
AND EAST-SOUTHEAST ONSHORE GRADIENT WINDS.
FOR TONIGHT...ATTN TURNS TO SHORTWAVE CURRENTLY OVER WY AND SD. THIS
SHORTWAVE MOVES ACROSS NORTHERN PLAINS AND ARRIVES OVER CNTRL MN AND
WESTERN WI BY LATE TONIGHT. BULK OF STRONGER Q-VECTOR CONVERGENCE
STAYS OUT AHEAD OF THAT SHORTWAVE...BUT AS ASSOCIATED SFC LOW WITH
THE WAVE MOVES OVER MN...STRONG MOISTURE ADVECTION AT H85 ALONG WITH
ISENTROPIC LIFT 300-305K /H9-H7/ SHOULD SUPPORT INCREASING SHOWERS
INTO WESTERN UPR MICHIGAN AFTER MIDNIGHT. POPS RAMP UP TO HIGHER
CHANCE AT KIWD AFTER MIDNIGHT WITH SLIGHT CHANCES AS FAR EAST AS
ISHPEMING AND IRON MOUNTAIN. MUCAPE IN LOWEST 3KM OR APPROX SFC-H7
STAYS MAINLY SOUTHWEST OF CWA. ISOLD TSRA COULD SNEAK INTO FAR WEST
AS MODEST LOW-LEVEL JET MAY COULD ADVECT SMALL PORTION OF INSTABILITY
INTO CWA...BUT WILL KEEP TSRA OUT OF CWA THROUGH 12Z FRIDAY. MIN
TEMPS MUCH WARMER THAN LAST COUPLE NIGHTS MID 50S TO LOW 60S DUE TO
PLENTY OF CLOUD COVER AND STEADY SOUTH WINDS AHEAD OF THE SFC LOW IN
MN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 347 AM EDT THU AUG 6 2015
NAM SHOWS A SHORTWAVE OVER THE NORTHERN PLAINS 12Z FRI WITH ANOTHER
ENTERING INTO THE UPPER GREAT LAKES THEN. THIS SHORTWAVE MOVES
THROUGH ON FRI AND THE OTHER SHORTWAVE MOVES SLOWLY EAST AND AFFECTS
THE AREA ON SAT. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE AND
MOISTURE MOVING THROUGH ON FRI AND BOTH MOVE OUT SAT AFTERNOON
BEFORE RETURNING SAT NIGHT.
CONFIDENCE IS LOW WITH THIS FORECAST AS GFS...ECMWF AND NAM ALL HAVE
DIFFERENT IDEAS FOR HOW THIS WEATHER SCENARIO IS GOING TO PLAY OUT.
ECMWF IS DRIER AND FURTHER SOUTH WITH IT PCPN. GFS IS QUICKER MOVING
PCPN THROUGH. WENT WITH A BLEND OF THE SOLUTIONS WHICH SEEMED TO
KEEP SOME CONTINUITY TO THE FORECAST. LOOKS LIKE THERE WILL BE A
BREAK IN PCPN FOR LATE FRI NIGHT INTO SAT MORNING AND THEN ANOTHER
WAVE COMES IN AND TRIED TO REFLECT THIS IN THE FORECAST WITH A BREAK
IN THE PCPN. BEST CHANCE FOR PCPN APPEARS TO BE FRI INTO FRI
EVENING...THEN HAVE LOW CHANCE POPS AND LOW CONFIDENCE FOR SAT AND
SAT NIGHT. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE
SOUTHERN AND CENTRAL PLAINS 12Z SUN WITH A TROUGH ACROSS CENTRAL
CANADA AND A SHORTWAVE IN THE NORTHERN PLAINS. THIS SHORTWAVE HEADS
EAST INTO THE UPPER GREAT LAKES SUN NIGHT INTO MON. THIS SHORTWAVE
HEADS OVER THE TOP OF THE RIDGE ON MON AND PUSHES IT BACK INTO THE
NORTHERN ROCKIES. THE UPPER FLOW BECOMES MORE AMPLIFIED ON TUE WITH
THE RIDGE BUILDING INTO THE CANADIAN ROCKIES AND THE TROUGH DIGGING
INTO THE ERN U.S. THE RIDGE BUILDS INTO THE NORTHERN PLAINS 12Z WED.
SFC RIDGING MOVES INTO THE UPPER GREAT LAKES TUE AND REMAINS INTO
WED. TEMPERATURES WILL CONTINUE TO BE SLIGHTLY BELOW NORMAL FOR THIS
FORECAST PERIOD. AS THE SFC HIGH BUILDS IN FOR MONDAY...WENT DRY FOR
MON NIGHT THROUGH WED AND REMOVED POPS FOR THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 647 AM EDT THU AUG 6 2015
LOW PRESSURE SYSTEM WILL APPROACH FROM THE WEST LATE TONIGHT. COULD
SEE SHOWERS TOWARD DAYBREAK FRIDAY AT KIWD...BUT WEATHER SHOULD STAY
MAINLY DRY AT KCMX AND KSAW. THOUGH A LOT OF MID CLOUDS ARE EXPECTED
INTO TONIGHT...CONDITIONS WILL REMAIN VFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT THU AUG 6 2015
A COUPLE OF WEAK TROUGHS OR LOW PRESSURE SYSTEMS WILL MOVE THROUGH
THE UPPER GREAT LAKES REGION THROUGH THIS WEEKEND...BUT WINDS ARE
EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...JLA
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 AM EDT THU AUG 6 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT THU AUG 6 2015
UPPER GREAT LAKES IS WITHIN WESTERLY FLOW ALOFT BETWEEN LARGE UPPER
LOW OVER EASTERN CANADA AND UPPER TROUGH OVER FAR WESTERN CANADA.
COUPLE OF MAIN SHORTWAVES ARE UPSTREAM OF UPPER GREAT LAKES. THE LEAD
WAVE IS OVER SOUTHERN MANITOBA AND IS GENERATING CLUSTER OF SHRA/TSRA
SOUTHERN MANITOBA INTO NORTHWEST MINNESOTA. WARM AIR ADVECTION MAINLY
IN THE MID LEVELS IS SUPPORTING ARC OF LGT SHRA TOWARD ISLE ROYALE
AND NORTHERN LK SUPERIOR. BASED ON HRRR AND RAP AND CURRENT RADAR
TRENDS...COULD SEE ISOLD SHR OR SPRINKLES CLIP TIP OF KEWEENAW
PENINSULA THIS MORNING. OTHERWISE...MAIN EFFECT FM THIS SHORTWAVE
WILL BE A LOT OF MID CLOUDS OVER AT LEAST NORTHERN CWA MOST OF TODAY.
SINCE THERE ARE ALREADY A WIDESPREAD AREA OF 5-10KFT BKN CIGS
UPSTREAM IN MINNESOTA...BUMPED UP CLOUD COVER TODAY. SOUTHERN CWA
SHOULD STAY IN AT LEAST INTERVALS OF SUN AND CLOUDS SO WENT WARMEST
THERE WITH MID 70S NEAR WI BORDER. COOLEST READINGS IN THE UPR 60S TO
NEAR 70 DEGREES WILL BE CLOSER TO LK SUPERIOR WITH MORE CLOUD COVER
AND EAST-SOUTHEAST ONSHORE GRADIENT WINDS.
FOR TONIGHT...ATTN TURNS TO SHORTWAVE CURRENTLY OVER WY AND SD. THIS
SHORTWAVE MOVES ACROSS NORTHERN PLAINS AND ARRIVES OVER CNTRL MN AND
WESTERN WI BY LATE TONIGHT. BULK OF STRONGER Q-VECTOR CONVERGENCE
STAYS OUT AHEAD OF THAT SHORTWAVE...BUT AS ASSOCIATED SFC LOW WITH
THE WAVE MOVES OVER MN...STRONG MOISTURE ADVECTION AT H85 ALONG WITH
ISENTROPIC LIFT 300-305K /H9-H7/ SHOULD SUPPORT INCREASING SHOWERS
INTO WESTERN UPR MICHIGAN AFTER MIDNIGHT. POPS RAMP UP TO HIGHER
CHANCE AT KIWD AFTER MIDNIGHT WITH SLIGHT CHANCES AS FAR EAST AS
ISHPEMING AND IRON MOUNTAIN. MUCAPE IN LOWEST 3KM OR APPROX SFC-H7
STAYS MAINLY SOUTHWEST OF CWA. ISOLD TSRA COULD SNEAK INTO FAR WEST
AS MODEST LOW-LEVEL JET MAY COULD ADVECT SMALL PORTION OF INSTABILITY
INTO CWA...BUT WILL KEEP TSRA OUT OF CWA THROUGH 12Z FRIDAY. MIN
TEMPS MUCH WARMER THAN LAST COUPLE NIGHTS MID 50S TO LOW 60S DUE TO
PLENTY OF CLOUD COVER AND STEADY SOUTH WINDS AHEAD OF THE SFC LOW IN
MN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 347 AM EDT THU AUG 6 2015
NAM SHOWS A SHORTWAVE OVER THE NORTHERN PLAINS 12Z FRI WITH ANOTHER
ENTERING INTO THE UPPER GREAT LAKES THEN. THIS SHORTWAVE MOVES
THROUGH ON FRI AND THE OTHER SHORTWAVE MOVES SLOWLY EAST AND AFFECTS
THE AREA ON SAT. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE AND
MOISTURE MOVING THROUGH ON FRI AND BOTH MOVE OUT SAT AFTERNOON
BEFORE RETURNING SAT NIGHT.
CONFIDENCE IS LOW WITH THIS FORECAST AS GFS...ECMWF AND NAM ALL HAVE
DIFFERENT IDEAS FOR HOW THIS WEATHER SCENARIO IS GOING TO PLAY OUT.
ECMWF IS DRIER AND FURTHER SOUTH WITH IT PCPN. GFS IS QUICKER MOVING
PCPN THROUGH. WENT WITH A BLEND OF THE SOLUTIONS WHICH SEEMED TO
KEEP SOME CONTINUITY TO THE FORECAST. LOOKS LIKE THERE WILL BE A
BREAK IN PCPN FOR LATE FRI NIGHT INTO SAT MORNING AND THEN ANOTHER
WAVE COMES IN AND TRIED TO REFLECT THIS IN THE FORECAST WITH A BREAK
IN THE PCPN. BEST CHANCE FOR PCPN APPEARS TO BE FRI INTO FRI
EVENING...THEN HAVE LOW CHANCE POPS AND LOW CONFIDENCE FOR SAT AND
SAT NIGHT. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE
SOUTHERN AND CENTRAL PLAINS 12Z SUN WITH A TROUGH ACROSS CENTRAL
CANADA AND A SHORTWAVE IN THE NORTHERN PLAINS. THIS SHORTWAVE HEADS
EAST INTO THE UPPER GREAT LAKES SUN NIGHT INTO MON. THIS SHORTWAVE
HEADS OVER THE TOP OF THE RIDGE ON MON AND PUSHES IT BACK INTO THE
NORTHERN ROCKIES. THE UPPER FLOW BECOMES MORE AMPLIFIED ON TUE WITH
THE RIDGE BUILDING INTO THE CANADIAN ROCKIES AND THE TROUGH DIGGING
INTO THE ERN U.S. THE RIDGE BUILDS INTO THE NORTHERN PLAINS 12Z WED.
SFC RIDGING MOVES INTO THE UPPER GREAT LAKES TUE AND REMAINS INTO
WED. TEMPERATURES WILL CONTINUE TO BE SLIGHTLY BELOW NORMAL FOR THIS
FORECAST PERIOD. AS THE SFC HIGH BUILDS IN FOR MONDAY...WENT DRY FOR
MON NIGHT THROUGH WED AND REMOVED POPS FOR THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 138 AM EDT THU AUG 6 2015
VFR CEILING AND VIS ARE EXPECTED THROUGH THE PERIOD WITH DIURNAL
WINDS AND AFTERNOON LAKE BREEZES OFF LAKE SUPERIOR. THERE IS A SMALL
POTENTIAL FOR EARLY MORNING FOG OVER THE INTERIOR W HALF OF UPPER MI
BUT NOT EXPECTING IT TO IMPACT TAF SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT THU AUG 6 2015
A COUPLE OF WEAK TROUGHS OR LOW PRESSURE SYSTEMS WILL MOVE THROUGH
THE UPPER GREAT LAKES REGION THROUGH THIS WEEKEND...BUT WINDS ARE
EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1250 AM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 1244 AM CDT THU AUG 6 2015
UPDATED 06Z AVIATION DISCUSSION BELOW...
UPDATE ISSUED AT 847 PM CDT WED AUG 5 2015
LATEST HRRR RUNS INDICATE A SLOWER ONSET OF SHOWERS AND STORMS TO
THE WESTERN EDGE OF THE FORECAST AREA UNTIL 12Z. DRY AIR FROM HIGH
PRESSURE OVER LAKE SUPERIOR WILL WIN OUT OVER THE RAIN AND
ADJUSTED ACCORDINGLY.
UPDATE ISSUED AT 657 PM CDT WED AUG 5 2015
LATEST SHORT TERM HIRES MODELS INCLUDING THE NMM/ARW DELAY THE
ONSET OF SHOWERS AND STORMS TO AFTER 09Z. HAVE MADE SOME
ADJUSTMENTS TO ACCOUNT FOR THAT TREND. REFLECTIVITY SHOWING UP ON
KDLH 88D ATTM ARE CLOUDS WITH A MINIMUM 12K FT BASE. REST OF THE
FORECAST ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 313 PM CDT WED AUG 5 2015
A WARM AIR ADVECTION REGIME RETURNS TO THE FORECAST AREA OVERNIGHT
AS WARM FRONT LIFTS NORTH INTO CANADA...AND A VORT MAX/H85 LOW
TRANSLATES EAST ACROSS NORTH DAKOTA/SOUTHERN MANITOBA...REACHING
THE NW CORNER OF MN BY DAYBREAK THURSDAY.
THE VORT MAX THEN DIMINISHES/STALLS OVER NW MINNESOTA MONDAY MORNING
WHILE BECOMING ABSORBED BY ANOTHER FAST APPROACHING WAVE IN THE
DAKOTAS. THIS RAPIDLY DEEPENING WAVE...IN A REGION OF STRONG UPPER
LVL DIVERGENCE...BECOMES A CLOSED LOW AND PUSHES INTO WESTERN
MINNESOTA BY THURSDAY EVENING. THE NORTHLAND WILL BE POSITIONED IN
A SOUTHERLY FLOW WITH INCREASING MOISTURE AND INSTABILITY AHEAD OF
THE LOW THROUGH THE DAY THURSDAY. PWATS INCREASE TO NEAR 2 INCHES
THURSDAY WHILE DEW POINTS SURGE INTO THE 60S OVER NORTH CENTRAL
MN. A FEW STORMS COULD BE STRONG TO LOW-END SEVERE
THURSDAY...MAINLY OVER NORTH-CENTRAL MN WHERE THE LATEST NAM IS
SHOWING AROUND 2000 J/KG OF CAPE DEVELOPING IN THE AFTERNOON.
HOWEVER..THE MAIN THREAT WITH ANY STORMS THURSDAY LOOKS TO BE
PERIOD OF VERY HEAVY RAINFALL AND LOCALIZED FLOODING.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 313 PM CDT WED AUG 5 2015
THE MAIN CONCERN IN THE LONG TERM WILL BE AN APPROACHING LOW
PRESSURE SYSTEM THURSDAY NIGHT WITH ASSOCIATED FRONTAL BOUNDARY.
MODELS ARE IN AGREEMENT AS FAR AS THE OVERALL PATTERN IS CONCERN
FRIDAY AND SATURDAY... INCREASING DEWPOINTS TO THE 60S... SOLID WARM
AIR ADVECTION AND A GENERAL LIKELIHOOD OF SHOWERS AND STORMS. HOWEVER
MODELS DIVERGE ON THE EVENTUAL PATH OF THE LOW AND WHERE THE BULLS-
EYE OF THE QPF WILL BE. 12Z NAM12 HAS THE LOW TAKING A NOSE DIVE TO
SOUTHERN MINNESOTA AND IOWA WITH A LINE OF PRECIP BREAKING APART
ACROSS THE NORTHLAND... THE GFS40 STALLING BUT ALSO MARCHING THROUGH
SOUTHERN MINNESOTA... AND THE ECMWF STICKING TO A MORE NORTHERN
SOLUTION ACROSS CENTRAL PARTS OF THE STATE AND NORTHERN WISCONSIN.
OVERALL DELAYED THE ONSET OF INITIAL FRIDAY PRECIP ALONG THE WARM
FRONT IN COLLABORATION WITH NEIGHBORING OFFICES. EXPECT ANOTHER
CHANCE OF SHOWERS AND STORMS TO MOVE THROUGH SATURDAY WITH THE
SECOND BOUNDARY... BUT QPF WILL LIKELY BE HIGHEST ON FRIDAY.
DEWPOINTS WILL DROP BACK INTO THE MORE COMFORTABLE 50S FOR MOST OF
THE CWA BY MONDAY AS A HIGH PRESSURE RIDGE BUILDS BACK IN ACROSS THE
UPPER MIDWEST... THOUGH EXPECT THE SUMMER WARMTH TO REMAIN... WITH
MID TO UPPER 70 HIGHS IN THE FORECAST NEXT WORK WEEK. AFTER A
SHORTWAVE BRINGS A SHOT OF SHOWERS ACROSS OUR SOUTH MONDAY... THE
REST OF THE WEEK LOOKS MOSTLY DRY AND PARTLY CLOUDY TO SUNNY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1244 AM CDT THU AUG 6 2015
MAINLY VFR CIGS/VSBYS FOR THIS TAF PERIOD...EXCEPT FOR A FEW HOURS
BEFORE SUNRISE WHERE MVFR VSBYS ARE EXPECTED AT HYR/BRD IF SKIES
REMAIN CLEAR. APPROACHING LOW PRESSURE FROM THE PLAINS WILL
RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS LATER TODAY/EARLY
TONIGHT. A FEW STRAY SHOWERS MAY ARRIVE AT BRD EARLIER THAN OTHER
SITES. OPTED FOR VCSH/VCTS FOR PRECIPITATION CHANCES AS CONFIDENCE
IN TIMING PREVAILING CONDITIONS WAS TOO LOW THIS MORNING. WHEN
THUNDERSTORMS MOVE OVER TERMINALS...EXPECT TEMPORARY VSBYS
REDUCTIONS INTO MVFR/IFR CATEGORIES FOR A PERIOD. AGAIN...TIMING
CONCERNS DIDN`T WARRANT INCLUSION AS TEMPO GROUPS FOR LOWER
VIS...WILL LET LATER UPDATES HANDLE TIMING. THUNDERSTORM POTENTIAL
SHOULD DIMINISH QUICKLY TOMORROW EVENING WITH RAIN SHOWERS
LINGERING THROUGH REMAINDER OF TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 61 71 60 78 / 60 50 30 20
INL 59 72 56 78 / 50 40 30 40
BRD 62 77 59 80 / 80 50 10 30
HYR 62 73 57 80 / 60 60 30 20
ASX 60 74 57 78 / 40 60 30 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...GRANING
LONG TERM...MCLOVIN
AVIATION...HUYCK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
636 PM CDT FRI AUG 7 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT FRI AUG 7 2015
THE PRIMARY FORECAST CONCERNS ARE IN REGARDS TO THE POTENTIAL FOR
TSTMS/RAIN LATER TONIGHT AND INTO SATURDAY...PLUS THE CHANCE OF
SEVERE WEATHER SATURDAY.
MAIN FEATURES FROM THE UPPER AIR MAPS THIS MORNING INCLUDED THE
FOLLOWING. AT 300 MB A 75 KT JET STREAK WAS OVER SRN CA PUNCHING TO
THE E/NE. THE 500 MB PATTERN IN GENERAL SHOWED TROUGHING ACROSS THE
W AND E COASTS AND A RIDGE CENTERED OVER TX/OK. CLOSED LOWS WERE
NOTED OVER SRN ALTA AND OVER CNTRL CA. 12 HOUR HEIGHT FALLS WERE
AROUND 50 METERS WITH THE CA SYSTEM...WHICH CONTINUED TO LIFT INTO
NV ACCORDING TO RECENT WATER VAPOR IMAGERY AND RECENT RUC MODEL
INITIALIZATIONS. A THERMAL RIDGE AT 700 MB EXTENDED FROM THE TX
PNHDL UP INTO CO. FAIRLY DECENT MOISTURE WAS NOTED AT 700 MB FROM
AZ INTO SRN NV WITH DEWPOINTS 5-8 DEGREES C. THE KOAX SOUNDING
THIS MORNING HAD ABOUT 0.94 INCHES OF PRECIPITABLE WATER (PW). THIS
WILL BE INCREASING OVER THE AREA TONIGHT. 12Z GFS SHOWED VALUES
APPROACHING 2 INCHES FOR MOST OF OUR AREA BY 12Z SAT AND NEAR 2.25
INCHES BY 00Z SUN. THE 12Z NAM WAS A BIT HIGHER AND MIGHT HAVE
BEEN A BIT OVERDONE.
PREVIOUS FORECAST TREND WAS FOR INCREASING POPS OVERNIGHT AND THAT
STILL SEEMS ON TRACK. WILL KEEP HIGHEST POPS PRIOR TO 12Z SAT OVER
ERN NE...SHIFTING HIGHEST NUMBERS TO NERN NE BY LATE MORNING. MID
LEVEL TEMPS ARE EXPECTED TO WARM SAT MORNING OVER THE SRN HALF OF
THE FCST AREA...SO SHIFTED HIGHEST POPS TO OUR WRN IA ZONES FOR THE
LATE AFTN AND EVENING. CONVECTIVE EVOLUTION AFTER THE MORNING STORMS
IS UNCERTAIN...BUT SHEAR PARAMETERS COULD BE FAVORABLE FOR SOME
SUPERCELLS IN THE AFTN AND EVENING. BEST SHOT FOR HEAVY RAIN WILL
BE ACROSS IOWA SATURDAY NIGHT.
STORM CHANCES SHOULD DIMINISH AFTER MIDNIGHT SATURDAY NIGHT...AND
SUNDAY RAIN CHANCES LOOK FAIRLY LOW. MID LEVEL RIDGE AXIS WILL START
TO BUILD FROM TX UP INTO SASK MONDAY WITH DECENT TROUGHING OVER THE
GREAT LAKES REGION.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 PM CDT FRI AUG 7 2015
A STRONG MID TROPOSPHERIC RIDGE WILL BE BUILDING AT THE START OF
THIS PERIOD OVER MID AMERICA. BY LATE WEEK...THE CENTER OF THE
ANTICYCLONE THAT STARTED OUT OVER TX/OK SHOULD RETROGRADE BACK
INTO NM AND CO. THIS PATTERN GENERALLY PRODUCES WARMER THAN NORMAL
TEMPERATURES (ESPECIALLY HIGHS) AND BELOW NORMAL PCPN. SO...BUMPED
UP HIGHS A BIT COMPARED TO A GFS/ECMWF BLEND.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 632 PM CDT FRI AUG 7 2015
VFR AND RAIN-FREE CONDITIONS THIS EVENING WILL DETERIORATE LATER
TONIGHT AS A BROAD AREA OF SHOWERS AND THUNDERSTORMS MOVES ACROSS
THE AREA. CONFIDENCE REMAINS HIGHEST THAT KOFK WILL BE
AFFECTED...AND HAVE CONTINUED PREVAILING SHOWERS WITH TEMPO
THUNDER THERE...THOUGH DID MOVE UP TIMING BY AN HOUR OR SO. KEPT
TEMPO SHOWER MENTION AT KLNK/KOMA FOR NOW...AS BOTH SITES WILL BE
MORE ON THE EDGE OF SHOWER/THUNDERSTORM POTENTIAL. SHOWERS OR
THUNDERSTORMS COULD AFFECT KOMA/KLNK LATE IN THE TAF CYCLE...BUT
WITH LOW CONFIDENCE ON PLACEMENT/COVERAGE...HAVE KEPT OUT MENTION
FOR NOW. WINDS WILL REMAIN LIGHT AND SOMEWHAT VARIABLE
TONIGHT...WITH AN INCREASE OUT OF THE SOUTHEAST TOMORROW MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1228 PM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 1230 PM CDT THU AUG 6 2015
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUED TO SPREAD
EAST/SOUTHEAST OVER THE AREA EARLY THIS AFTERNOON. BELIEVE THIS
WILL WEAKEN THE NEXT SEVERAL HOURS. RECENT HRRR MODEL RUNS SEEMREASONABLE
IN DEVELOPING NEW CONVECTION ACROSS PARTS OF SERN SD AND NERN NE
IN THE LATE AFTERNOON/EVENING. THERE APPEARS TO BE SOME RISK OVER
SEVERE STORMS IN THOSE AREAS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 357 AM CDT THU AUG 6 2015
AN ANALYSIS OF THE 850MB 00Z CHART DEPICTED A RIDGE OF HIGH
PRESSURE OFF TO OUR EAST...WITH A DEVELOPING AREA OF LOW PRESSURE
OVER WYOMING. RELATIVELY WEAK FLOW WAS IN PLACE HOWEVER PLENTY OF
DEEP LOW LEVEL MOISTURE WAS SURGING INTO THE CENTRAL PLAINS. THE 500
MB CHART ALSO DEPICTED A RIDGE OF HIGH PRESSURE OVER THE NATIONS
MID SECTION...AS WELL AS AN AREA OF HEIGHT FALLS AROUND A
DEEPENING TROUGH NEAR THE PACIFIC NORTHWEST.
A SURFACE COLD FRONT ASSOCIATED WITH THE 850 MB LOW WILL BRING
SHOWERS AND THUNDERSTORMS TO THE AREA LATER TODAY AND INTO TONIGHT.
AROUND 3000 J/KG OF MAX CAPE WILL BE PRESENT ACROSS THE NORTHERN
HALF OF THE CWA WITH LAPSE RATES AROUND 7 C/KM. 40 KTS OF BULK
SHEAR WILL ALSO BE PRESENT AND NORMAL TO THE SURFACE
BOUNDARY...PROVIDING AN OPPORTUNITY FOR DISCRETE SUPERCELL
DEVELOPMENT. THEREFORE THE NORTHERN HALF OF THE CWA HAS BEEN PLACED
IN A SLIGHT RISK FOR SEVERE STORMS...WITH THE REST OF THE AREA IN A
MARGINAL RISK. EXPECT LARGE HAIL AND STRONG WINDS WILL BE THE MAIN
THREATS IF STORMS DEVELOP...HOWEVER THE CHANCE FOR AN ISOLATED
TORNADO OR TWO CANNOT BE ENTIRELY RULED OUT.
DRY CONDITIONS ARE EXPECTED ON FRIDAY BEFORE ANOTHER SHORTWAVE
SWINGS THROUGH THE REGION PRODUCING SHOWERS AND THUNDERSTORMS FRIDAY
NIGHT INTO SATURDAY AS AN MCS PROPAGATES ACROSS THE STATE.
TEMPERATURES TODAY WILL REMAIN FAIRLY PLEASANT IN THE LOW TO MID
80S. ALTHOUGH WARMER AIR WILL ADVECT IN ON FRIDAY WITH HIGHS
CLOSER TO 90 DEGREES.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 357 AM CDT THU AUG 6 2015
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE AS THE RESULT
OF WEAK DISTURBANCES THROUGH THE WEEKEND. HOWEVER HIGH PRESSURE IS
STILL PROGGED TO BUILD INTO THE COUNTRIES MID SECTION EARLY NEXT
WEEK. POTENTIALLY PROVIDING US WITH A PERIOD OF DRIER WEATHER
AND HIGHS IN THE LOW 80S MONDAY THROUGH WEDNESDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1230 PM CDT THU AUG 6 2015
MAINLY VFR CONDITIONS EXPECTED...BUT COULD HAVE MVFR VSBYS AND
POSSIBLY MVFR CIGS WITH PCPN INTO MID AFTERNOON AT KOMA AND KLNK.
STORMS COULD AFFECT KOFK LATER THIS AFTN BUT CONFIDENCE NOT HIGH
ENOUGH TO PUT IN A TEMPO GROUP AT THIS TIME. ACTIVITY WOULD LIKELY
BE ISOLD AND WILL WATCH AND AMEND IF NEEDED.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...KG
LONG TERM...KG
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1130 PM CDT WED AUG 5 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 406 PM CDT WED AUG 5 2015
MAP ANALYSIS INDICATES UPPER TROPOSPHERIC RIDGING OVER THE WESTERN
TWO-THIRDS OF THE CONUS...AND A TROUGH OVER THE EAST. AN UPPER
TROPOSPHERIC SHORT WAVE IS ALSO NOTED MOVING ACROSS PORTIONS OF
THE CENTRAL PLAINS AND MISSOURI RIVER VALLEY. AT THE SURFACE A
WEAK RIDGE OF HIGH BAROMETRIC PRESSURE IS NOTED ACROSS PORTIONS OF
THE CENTRAL PLAINS AND MISSOURI RIVER VALLEY AND AS A RESULT...THE
BOUNDARY-LAYER WIND FIELD ACROSS THE AREA REMAINS FAIRLY WEAK AND
AT TIMES VARIABLE.
GUIDANCE SUGGESTS THE UPPER TROPOSPHERIC SHORT WAVE...CURRENTLY
CLEARING THE AREA...WILL CONTINUE MOVING EAST/SOUTHEAST THROUGH
THE NEXT 24 HOURS...LIKELY CLEARING THE MISSOURI RIVER VALLEY
LATER TONIGHT. QUASI-ZONAL UPPER TROPOSPHERIC FLOW IS THEN
EXPECTED TO OVERTAKE THE AREA THROUGH THURSDAY...ALTHOUGH THERE
ARE INDICATIONS OF ANOTHER UPPER TROPOSPHERIC SHORT WAVE CLEARING
THE AREA THURSDAY INTO THURSDAY EVENING.
AN OVERALL LACK IN OMEGA WOULD OTHERWISE KEEP THE AREA DRY THROUGH
TONIGHT...BUT SOMEWHAT ENHANCED UPPER TROPOSPHERIC LAPSE RATES IN
ASSOCIATION WITH THE PASSING SHORT WAVE TROUGH AXIS COULD BE
ENOUGH TO PROMOTE WEAK SHOWER AND/OR THUNDERSTORM DEVELOPMENT
ACROSS THE SOUTH/SOUTHEASTERN TWO-THIRDS OF THE CWA. THIS IS A
SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM AND OPERATIONAL
GFS...AND TO A LESSER EXTEND THE EC. THIS IS ALSO SUPPORTED BY
SIMULATED REFLECTIVITY FROM THE HRRR AND 4KM WRF-NMM. GIVEN ALL
THIS...OPTED TO GO AHEAD WITH ~20% POPS ACROSS THE
SOUTH/SOUTHEASTERN TWO-THIRDS OF THE CWA UNTIL 00Z. DRY CONDITIONS
ARE THEN FORECAST THROUGH THE OVERNIGHT HOURS AS DIABATIC HEATING
IS LOST.
GUIDANCE THEN SUGGESTS YET ANOTHER CHANCE FOR PRECIPITATION COULD
BE REALIZED THURSDAY INTO THURSDAY EVENING AS THE SECOND UPPER
TROPOSPHERIC SHORT WAVE CLEARS THE AREA. GIVEN THIS...WENT AHEAD
WITH 20-40% POPS ACROSS MUCH OF THE CWA THURSDAY INTO THURSDAY
EVENING.
DESPITE FAIRLY RICH BOUNDARY-LAYER MOISTURE ACROSS THE
REGION...LAPSE RATES REALLY SHOULD NOT BE ANYTHING TO WRITE HOME
ABOUT AND IN FACT...GUIDANCE SUGGESTS NO MORE THAN ~500J/KG OF
POTENTIAL ENERGY WILL BE AVAILABLE FOR UPDRAFT PRODUCTION THROUGH
THIS EVENING. GIVEN THIS...WILL NOT INTRODUCE STRONG/SEVERE
THUNDERSTORM WORDING IN THE HWO. LAPSE RATES ARE SOMEWHAT MORE
RESPECTABLE THURSDAY AFTERNOON AND EVENING AND GUIDANCE RESPONDS
BY PROVIDING POTENTIAL ENERGY VALUES MORE IN THE 1000-2000J/KG
RANGE. IN ADDITION...DEEP-LAYER BULK SHEAR OF ~40KTS IS ALSO
EXPECTED THURSDAY AFTERNOON AND EVENING AND GIVEN ALL THIS...FELT
IT PRUDENT TO AT LEAST GO WITH STRONG THUNDERSTORM WORDING IN THE
HWO.
FINALLY...A CONTINUED WEAK BOUNDARY-LAYER WIND FIELD THROUGH THE
OVERNIGHT HOURS...WORKING IN CONCERT WITH A NEAR-ZERO DEW POINT
DEPRESSIONS...COULD PROMOTE AT LEAST PATCHY FOG DEVELOPMENT ACROSS
MUCH OF THE AREA TONIGHT. GIVEN THIS...WENT AHEAD WITH PATCHY FOG
IN THE GRIDS 06-14Z THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 406 PM CDT WED AUG 5 2015
GUIDANCE SUGGESTS QUASI-ZONAL UPPER TROPOSPHERIC FLOW WILL BE
NOTED ACROSS THE REGION THROUGH MUCH OF THE LONG-TERM FORECAST
PERIOD...WITH THE ONLY EXCEPTION BEING EARLY NEXT WEEK AS AN UPPER
TROPOSPHERIC SHORT WAVE CLEARS THE AREA AND RIDGING STRENGTHENS
OVER THE WESTERN CONUS. MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS
ARE ALSO EXPECTED TO CLEAR THE AREA AND AS A
RESULT...POPS...GENERALLY IN THE 20-40% RANGE...REMAIN INTACT
ACROSS VARIOUS PORTIONS OF THE CWA THROUGH EARLY NEXT WEEK. STRONG
AND/OR SEVERE CONVECTION CERTAINLY CANNOT BE RULED OUT LATE THIS
WEEK INTO EARLY NEXT WEEK...BUT AT THIS TIME IT REMAINS TOO EARLY
TO TRY AND PIN DOWN TIMING OR PLACEMENT OF SUCH ACTIVITY.
LITTLE CHANGE IN THE BOUNDARY-LAYER AIR MASS SHOULD PROVIDE
SIMILAR TEMPERATURE READINGS FROM DAY TO DAY DURING THE LONG-TERM
FORECAST PERIOD...WITH HIGHS GENERALLY IN THE 80S AND LOWS IN THE
60S.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 PM CDT WED AUG 5 2015
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE PERIOD. MVFR VSBY
POSSIBLE FOR A SHORT TIME PRIOR TO AND AFTER SUNRISE...OTHERWISE
HIGH LEVEL CLOUDS WILL PREDOMINATE. SOUTH WINDS INCREASING AFTER
17Z AT KOFK WITH GUSTS TO 25 KTS IN ADVANCE OF APPROACHING SURFACE
TROUGH. WINDS DIMINISH TO LESS THAN 10 KTS AFTER 00Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...BRYANT
LONG TERM...BRYANT
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
205 PM PDT THU AUG 6 2015
.SYNOPSIS...MONSOON MOISTURE CREEPING INTO THE AREA WILL BRING
INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE REGION TODAY.
THUNDERSTORM ACTIVITY WILL DECREASE RAPIDLY FROM WEST TO EAST FRIDAY
AS DRIER AIR PUSHES INTO THE REGION FOR THE WEEKEND. ANOTHER ROUND
OF MOISTURE MAY BE ON TAP FOR THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
CONVECTION THUS FAR THIS AFTERNOON HAS BEEN CONFINED TO MAINLY
WESTERN SAN BERNARDINO COUNTY WHERE SOME MID LEVEL INSTABILITY IS
FUELING FAST MOVING STORMS ALONG THE LEADING EDGE OF A STRONG UPPER
LEVEL JET. SUBCLOUD LAYERS IN THIS AREA ARE QUITE DRY WITH SURFACE
DEWPOINTS MAINLY IN THE 30S...SO GUSTY DOWNBURST WINDS ARE A CONCERN
BUT STORMS WILL STRUGGLE TO PRODUCE ANY MEASURABLE RAINFALL. WHILE
THE STORMS HAVE STRUGGLED TO DEPOSIT RAINFALL....THEY HAVE BEEN VERY
EFFICIENT LIGHTNING PRODUCERS WITH OVER 250 CLOUD TO GROUND
LIGHTNING STRIKES SINCE THE NOON HOUR IN WESTERN SAN BERNARDINO
COUNTY. WITH THIS ACTIVITY MOVING NORTHWARD...A RED FLAG WARNING HAS
BEEN POSTED FOR DRY LIGHTNING FOR MUCH OF SAN BERNARDINO COUNTY AND
THE EASTERN HALF OF INYO COUNTY THROUGH LATE TONIGHT.
STILL EXPECTING ATTENTION TO SHIFT FURTHER EAST THIS AFTERNOON AS
MORE ROBUST CONVECTION DEVELOPS ACROSS THE LOWER COLORADO RIVER
VALLEY. CURRENT MESOANALYSIS SHOWS SURFACE BASED INSTABILITY
BUILDING ACROSS THIS AREA WITH CAPE VALUES EXCEEDING 1000 J/KG WITH
LIMITED CAPPING. SEVERAL CONSECUTIVE HRRR RUNS HAVE INSISTED ON
BREAKING THIS AREA OUT IN THE NEXT FEW HOURS. THE POTENTIAL FOR
STRONG AND POTENTIALLY DAMAGING DOWNBURST WINDS IS QUITE HIGH ALONG
THE COLORADO RIVER ROUGHLY FROM BULLHEAD CITY SOUTHWARD TO LAKE
HAVASU...SO THIS AREA WILL BE WATCHED CLOSELY FOR THE POSSIBILITY OF
SEVERE STORMS.
TONIGHT...ACTIVITY ACROSS MOHAVE AND EASTERN SAN BERNARDINO COUNTIES
WILL DRIFT NORTHWARD INTO SOUTHERN NEVADA WHILE ADDITIONAL ACTIVITY
IS LIKELY TO BREAK OUT ACROSS OUR SOUTHERN GREAT BASIN ZONES. WITH
INCREASING SOUTHWESTERLY SHEAR AS A PACIFIC TROUGH APPROACHES...A
FEW BANDS OF PERSISTENT CONVECTION MAY DEVELOP OVERNIGHT WHICH WILL
BE OUR PRIMARY CONCERN FOR ANY FLASH FLOODING. INDIVIDUAL STORM
MOTION WILL BE RATHER SWIFT...BUT TRAINING STORMS WILL POSE A FLOOD
RISK WITH THE HIGH PRECIPITABLE WATER IN PLACE...SO MAINTAINED THE
FLASH FLOOD WATCH TO ACCOUNT FOR THIS FOR MOHAVE AND LINCOLN
COUNTIES. STRONG AND POTENTIALLY DAMAGING WINDS WILL REMAIN
POSSIBLE OVERNIGHT DUE TO STRENGTHENING DEEP LAYER WIND SHEAR AS
WELL AS THE POSSIBILITY OF HAIL WITH THE STRONGER STORMS.
FRIDAY...PACIFIC TROUGH WILL SWEEP EASTWARD ON FRIDAY DRAGGING THE
DEEPER MOISTURE AND INSTABILITY WITH IT. ANTICIPATE ONGOING
CONVECTION AND CLOUD COVER TO BE CONFINED MAINLY TO SOUTHERN NEVADA
AND NORTHWEST ARIZONA IN THE MORNING WHILE SHIFTING EASTWARD THROUGH
THE DAY. BY 5 PM...ANY REMAINING THUNDERSTORM ACTIVITY WILL BE
PRIMARILY CONFINED TO EASTERN MOHAVE COUNTY AND FAR EASTERN AND
NORTHERN LINCOLN COUNTIES. FLASH FLOODING WILL REMAIN A CONCERN WITH
TRAINING STORMS...BUT THE THREAT WILL BE TRANSLATING EASTWARD
THROUGH THE DAY. WITH STRONG SHEAR IN PLACE...SEVERE STORMS WILL BE
A POSSIBILITY AS WELL DEPENDING ON THE DEGREE OF CLOUD COVER AND HOW
MUCH IT INHIBITS DAYTIME HEATING. BY FRIDAY EVENING MOSTLY DRY AND
CLEAR CONDITIONS WILL OVERSPREAD THE ENTIRE REGION.
.LONG TERM...SATURDAY THROUGH THURSDAY.
A DRY SOUTHWEST FLOW WILL BE OVER THE ENTIRE FORECAST AREA SATURDAY
THROUGH MONDAY. HIGH PRESSURE OVER TEXAS WILL EXPAND WEST TOWARD NEW
MEXICO WHILE A TROUGH OF LOW PRESSURE STRETCHES GENERALLY NORTH-
SOUTH ALONG THE WEST COAST STARTING LATE MONDAY. THIS COMBINATION
WILL ALLOW SOUTHERLY FLOW TO DEVELOP WITH MOISTURE TRACKING
NORTHWARD MAINLY INTO MOHAVE COUNTY. WILL CONTINUE THE SHOWER AND
THUNDERSTORM CHANCES FOR THIS AREA TUESDAY. SOUTHERLY FLOW APPEARS
TO STICK AROUND THROUGH THURSDAY, WITH MOISTURE SLIGHTLY EDGING WEST
WEDNESDAY AND PERHAPS LINGERING INTO THURSDAY. THERE REMAINS
UNCERTAINTY IN JUST HOW MUCH MOISTURE WILL ARRIVE AND HOW FAR WEST
IT MAY TRACK. OTHERWISE NEAR NORMAL TEMPS ARE EXPECTED THROUGHOUT
THE LONG-TERM PERIOD. BREEZY SOUTH TO SOUTHWEST WINDS WILL BE COMMON
EACH AFTERNOON AND EARLY EVENING. &&
.FIRE WEATHER...THUNDERSTORMS HAVE DEVELOPED ACROSS NORTHWESTERN SAN
BERNARDINO AND SOUTHERN INYO COUNTY, HOWEVER, WITH DRY LOW-LEVELS,
VERY LITTLE PRECIPITATION WAS REACHING THE GROUND AND AREA RADARS
SHOWED WEAK TO NO RETURNS ON THE LOWEST ELEVATION SCANS. THUS, THIS
HAS CREATED A SIGNIFICANT POTENTIAL FOR DRY LIGHTNING IN NORTHWEST
SAN BERNARDINO COUNTY AND DEATH VALLEY NATIONAL PARK THIS AFTERNOON
INTO TONIGHT. A RED FLAG WARNING WAS ISSUED FOR DRY LIGHTNING FOR
CALIFORNIA ZONES 227 AND 228 AS A RESULT. WE WILL NEED TO KEEP AN
EYE ON THE REST OF INYO, ESMERALDA, SOUTHERN AND CENTRAL NYE AS WELL
AS WESTERN CLARK AS A SMALL RISK FOR DRY LIGHTNING ALSO EXISTS IN
THESE AREAS THROUGH TONIGHT, HOWEVER, CONFIDENCE IS NOT HIGH ENOUGH
TO ISSUE ANY HEADLINES. HOWEVER, BASED ON THE GENERAL TRENDS THE
THREAT INTO ESMERALDA AND NORTHWESTERN INYO COUNTY LOOKS VERY LOW
AND THAT MOST ACTIVITY THERE SHOULD BE JUST SHOWERS. ACROSS MOHAVE,
LINCOLN AND MOST OF CLARK COUNTIES STORMS ARE EXPECTED TO GENERALLY
BE WET IN NATURE DUE TO THE HIGH MOISTURE CONTENT OF THE ATMOSPHERE.
AS DRIER AIR SWEEPS IN FROM THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY, THIS WILL HELP TO END THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS FROM WEST TO EAST. HOWEVER, THIS WILL ALSO HELP TO
INCREASE WINDS FROM THE SOUTH TO SOUTHWEST. RELATIVE HUMIDITY VALUES
AT OR BELOW 15 PERCENT, WIND GUSTS OF 35 MPH OR GREATER AS WELL AS
FUELS BEING DRIED OUT ENOUGH LOOK TO BE MET IN NEVADA ZONE 462 AND
THE FIRE WEATHER WATCH WAS UPGRADED TO A RED FLAG WARNING HERE.
ELSEWHERE, ONLY ONE OR TWO OF THESE CRITERIA LOOK TO BE MET SO NO
HEADLINES WERE ISSUED.
&&
.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS IN THE 9-12KT
RANGE WITH GUSTS TO 20KTS EXPECTED THROUGH THE EVENING. SHOWERS AND
THUNDERSTORMS EXPECTED TO BREAK OUT SOMETIME BETWEEN 01Z-05Z AND
CONTINUING MUCH OF NIGHT. BIGGEST CONCERN WILL BE GUSTY AND ERRATIC
OUTFLOW WINDS...WHICH COULD EXCEED 35KTS IF ANY ROBUST STORMS
DEVELOP IN THE VALLEY. OTHERWISE...CIGS IN THE 9-12K RANGE WITH
DISRUPTIONS TO APPROACH CORRIDORS LIKELY AT TIMES. SHOWERS AND
THUNDERSTORMS REMAIN POSSIBLE THROUGH 21Z FRIDAY BEFORE IMPROVING
CONDITIONS MOVE IN WITH DECREASING CLOUD COVER. SOUTHWEST WINDS OF
10-15KTS WITH GUSTS TO 25KTS EXPECTED FRIDAY AFTERNOON.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED TO SCATTERED SHRA/TSRA POSSIBLE BEFORE
00Z...PRIMARILY SOUTH OF THE INTERSTATE 15 CORRIDOR. PRECIPITATION
CHANCES WILL SPREAD NORTH INTO THE SOUTHERN GREAT BASIN THIS
EVENING...THEN END RAPIDLY FROM WEST TO EAST THROUGH THE DAY FRIDAY.
STORMS WILL HAVE THE POTENTIAL TO PRODUCE ERRATIC WIND GUSTS IN
EXCESS OF 45 KTS. CIGS ARE GENERALLY EXPECTED TO REMAIN AOA 10K FEET
EXCEPT NEAR SHRA/TSRA WHERE THEY COULD LOWER TO 6-8K FEET. GUSTY
WINDS OF 15-20KTS WITH GUSTS TO 30KTS EXPECTED FRIDAY AFTERNOON
ACROSS THE WESTERN MOJAVE DESERT AND SOUTHERN GREAT BASIN.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...OUTLER
LONG TERM.............PADDOCK
FIRE WEATHER...STACHELSKI
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
850 AM PDT THU AUG 6 2015
.SYNOPSIS...MONSOON MOISTURE WILL PUSH NORTH INTO THE REGION TODAY
AND FRIDAY BRINGING INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS.
THUNDERSTORM ACTIVITY WILL DECREASE RAPIDLY FROM WEST TO EAST FRIDAY
AS DRIER AIR PUSHES INTO THE REGION FOR THE WEEKEND. ANOTHER ROUND
OF MOISTURE MAY BE ON TAP FOR THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...TWEAKED THE GRIDS THIS MORNING TO ACCOUNT FOR CURRENT
CLOUD COVER TRENDS AND NUDGE POPS UPWARDS ALONG THE LOWER COLORADO
RIVER VALLEY WHERE LATEST FEW HRRR RUNS BREAK OUT SUBSTANCIAL
CONVECTION THIS AFTERNOON. FORECAST SOUNDINGS INDICATE A WELL
DEVELOPED INVERTED V PROFILE WHICH WOULD FAVOR LOCALLY STRONG
DOWNBURST WINDS WITH ANY SHOWERS AND THUNDERSTORMS WHICH
DEVELOP...SO THIS WILL BE WATCHED FOR CLOSELY AS STORMS DEVELOP
LATER TODAY. OTHERWISE THE FORECAST IS IN GOOD SHAPE AND NO UPDATES
ARE PLANNED.
-OUTLER-
&&
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
LOTS TO MULL OVER WITH THE SHORT TERM FORECAST THIS MORNING. MODELS
ARE IN RELATIVELY GOOD AGREEMENT ON THE OVERALL PATTERN EVOLUTION
LEADING TO MODERATE-HIGH CONFIDENCE OVERALL. HOWEVER...DIFFERENCES
REMAIN IN PRECIPITATION FIELDS...LEADING TO SLIGHTLY LOWER
CONFIDENCE IN SHOWER/THUNDERSTORM COVERAGE TODAY AND FRIDAY.
TODAY [THROUGH 00Z (5PM)]...TWO MAIN AREAS OF CONCERN EXIST. THE
FIRST OVER THE CENTRAL/SOUTHERN MOHAVE COUNTY...EASTERN SAN
BERNARDINO COUNTY AND EXTREME SOUTHERN CLARK COUNTY WHERE INCREASING
DEEP-LAYER MOISTURE ADVECTION IS EXPECTED TO PERSIST THROUGH THE
DAY. BY 00Z PRECIPITABLE WATER VALUES WILL RANGE FROM 1-1.5 INCHES
ACROSS THIS AREA. WITH A LACK OF SIGNIFICANT FORCING BEFORE 00Z AND
WEAK CAPPING I EXPECT MAINLY TERRAIN-DRIVEN STORMS OVER THIS AREA.
STORM MOTION IS EXPECTED TO BE MODEST AT 10-15 KTS TOWARDS THE NORTH-
NORTHEAST...HOWEVER TRAINING STORMS (ESPECIALLY OVER THE TERRAIN)
ARE A CONCERN WITH CORFIDI VECTORS NEAR ZERO. THE MAIN THREATS WITH
THESE STORMS WILL BE DAMAGING WIND GUSTS AND FLASH FLOODING (WHERE
STORMS TRAIN). THE OTHER AREA OF CONCERN WILL BE ACROSS THE WESTERN
PORTIONS OF SAN BERNARDINO COUNTY WHERE SOME MID-LEVEL MOISTURE AND
WEAK MUCAPE COULD LEAD TO ELEVATED CONVECTION DURING THE LATE
MORNING INTO THE EARLY AFTERNOON. WITH DRY NEAR-SURFACE CONDITIONS I
DON`T EXPECT MUCH RAIN ACCUMULATION...HOWEVER DAMAGING WIND GUSTS
AND DRY LIGHTNING ARE A POSSIBILITY. WIDESPREAD OUTFLOW WINDS COULD
LEAD TO AREAS OF BLOWING DUST AND LOWERED VISIBILITY. SIMILAR
CONDITIONS COULD DEVELOP ACROSS THE HIGHER TERRAIN OF INYO COUNTY
LATER IN THE DAY.
TONIGHT [00Z (5PM) THROUGH 12Z (5AM)]...MOISTURE ADVECTION WILL
CONTINUE...PRIMARILY ACROSS THE EASTERN HALF OF THE FORECAST AREA. A
WEAK VORTICITY LOBE IS EXPECTED TO PUSH NORTH-NORTHEAST UP THE
COLORADO RIVER VALLEY INTO UTAH OVERNIGHT. THIS WILL COMBINE WITH
DIFLUENT FLOW AHEAD OF AN UPPER LEVEL LOW TO TOSS IN SOME ADDITIONAL
DYNAMICS INTO A WEAK-MODERATELY UNSTABLE ATMOSPHERE OVERNIGHT AND
LIKELY KEEP SOME FORM OF CONVECTION GOING THROUGH THE OVERNIGHT
HOURS. PRECIPITABLE WATER VALUES WILL LIKELY REMAIN IN THE 1-1.5
INCH RANGE. STORM MOTION IS EXPECTED TO INCREASE TO 20-25 KTS
TOWARDS THE NORTH-NORTHEAST...AND THUS ANY FLOODING CONCERNS WILL BE
LARGELY CONFINED TO TRAINING STORMS. DAMAGING WINDS WILL REMAIN
POSSIBLE OVERNIGHT...AND HAIL WILL ALSO BECOME A POSSIBILITY...ESPECIALLY
ALONG/NORTH OF THE I-15 CORRIDOR WHERE 0-6KM SHEAR WILL EXCEED
30-35 KTS AND COOLER SUB-CLOUD LAYERS EXIST. ADDITIONALLY...SHOWERS
WILL BE POSSIBLE ACROSS THE SIERRA AND PERHAPS THE LOWER ELEVATIONS
OF INYO AND ESMERALDA COUNTIES ASSOCIATED WITH THE PRIMARY LOW
CIRCULATION...HOWEVER WITH LIMITED MOISTURE IMPACTS SHOULD MAINLY BE
WIND-RELATED IF ANYTHING.
FRIDAY [12Z (5AM) THROUGH 06Z (11PM)]...THE APPROACHING UPPER LEVEL
LOW WILL BRING STIFF SOUTHWESTERLY FLOW TO THE REGION FRIDAY. THIS
WILL ACT TO TIGHTEN THE NORTH-SOUTH MOISTURE GRADIENT ACROSS THE
FORECAST AREA. MODELS ARE IN BETTER AGREEMENT TODAY THAT THIS
BOUNDARY WILL EXTEND ALONG THE WESTERN BORDERS OF LINCOLN AND CLARK
COUNTIES SOUTH THROUGH EASTERN SAN BERNARDINO COUNTY BY 12Z (5AM)
FRIDAY...THEN QUICKLY PUSH EAST TO NEAR THE COLORADO RIVER BY 18Z
(11 AM) AND CENTRAL MOHAVE COUNTY BY 00Z (5PM). SHOWERS AND
THUNDERSTORMS WILL BE A CONCERN MAINLY TO THE EAST OF THIS
FEATURE...MEANING THAT CHANCES IN LAS VEGAS WILL END BEFORE NOON
FRIDAY. STORM MOTION WILL INCREASE ONCE AGAIN TO 25-30 KTS TOWARDS
THE NORTHEAST AND SHEAR VALUES WILL REMAIN ELEVATED. THUS ONCE
AGAIN...THE PRIMARY CONCERN WILL BE DAMAGING WIND GUSTS AND POSSIBLY
SOME HAIL. CHANCES FOR FLASH FLOODING WITH REMAIN POSSIBLE WITH
TRAINING STORMS. BEHIND THIS BOUNDARY BREEZY TO LOCALLY WINDY
CONDITIONS ARE EXPECTED. HOWEVER...THE LATEST HIGH-RES GUIDANCE HAS
BACKED OFF A BIT ON THE MAGNITUDE. AT THIS TIME IT APPEARS THAT
WINDS WILL REMAIN BELOW ADVISORY LEVELS AND BORDERLINE FOR RED FLAG
CONDITIONS. INSTEAD OF REMOVING ANY HIGHLIGHTS THIS MORNING I`VE
OPTED TO KEEP THE PRODUCTS IN PLACE AND LET THE DAY SHIFT TAKE ONE
MORE LOOK AT THEM.
.LONG TERM...SATURDAY THROUGH THURSDAY.
NOT MUCH CHANGE FROM 24 HOURS AGO. A DRY SOUTHWEST FLOW WILL BE OVER
THE ENTIRE FORECAST AREA SATURDAY THROUGH MONDAY. HIGH PRESSURE OVER
TEXAS WILL EXPAND WEST TOWARD NEW MEXICO WHILE A TROUGH OF LOW
PRESSURE STRETCHES GENERALLY NORTH-SOUTH ALONG THE WEST COAST
STARTING LATE MONDAY. THIS COMBINATION WILL ALLOW SOUTHERLY FLOW TO
DEVELOP WITH MOISTURE TRACKING NORTHWARD MAINLY INTO MOHAVE COUNTY.
WILL CONTINUE THE SHOWER AND THUNDERSTORM CHANCES FOR THIS AREA
TUESDAY. SOUTHERLY FLOW APPEARS TO STICK AROUND THROUGH THURSDAY,
WITH MOISTURE SLIGHTLY EDGING WEST WEDNESDAY AND PERHAPS LINGERING
INTO THURSDAY. THERE REMAINS UNCERTAINTY IN JUST HOW MUCH MOISTURE
WILL ARRIVE AND HOW FAR WEST IT MAY TRACK. AS FOR TEMPERATURES,
MONDAY APPEARS TO BE THE WARMEST DAY WITH TEMPS A DEGREE OR TWO
ABOVE NORMAL. OTHERWISE NEAR TO SLIGHTLY BELOW NORMAL TEMPS ARE
EXPECTED THROUGHOUT THE LONG-TERM PERIOD. BREEZY SOUTH TO SOUTHWEST
WINDS WILL BE COMMON EACH AFTERNOON AND EARLY EVENING.
&&
.AVIATION...FOR MCCARRAN...TYPICAL SOUTH-SOUTHWESTERLY WIND THROUGH
MID MORNING BEFORE LIGHT EASTERLY WINDS DEVELOP BETWEEN 15Z AND 20Z.
WINDS WILL RETURN TO A SOUTHWESTERLY DIRECTION AND INCREASE AFTER
20Z. GUSTS DURING THE AFTERNOON OF 15-25 KTS CAN BE EXPECTED. MAINLY
SCT-BKN CLOUDS AOA 10K FEET THROUGH THE PERIOD. THERE IS THE SLIGHT
CHANCE OF SHRA/TSRA AND TEMPORARILY LOWERED CIGS/VIS AND GUSTY WINDS
TO IMPACT THE AIRPORT COMPLEX AS WELL AS THE APPROACH CORRIDORS
BETWEEN ROUGHLY 00Z-18Z FRIDAY. STRONGER WINDS WITH GUSTS 25-30 KTS
WILL BE POSSIBLE BY FRIDAY AFTERNOON.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...BREEZY SOUTH TO SOUTHWEST WINDS ARE EXPECTED AGAIN
TODAY WITH GUSTS GENERALLY 15-25 KTS DURING THE AFTERNOON. ISOLATED
TO SCATTERED SHRA/TSRA POSSIBLE BEFORE 00Z...PRIMARILY SOUTH OF THE
INTERSTATE 15 CORRIDOR. PRECIPITATION CHANCES WILL SPREAD NORTH INTO
THE SOUTHERN GREAT BASIN THIS EVENING...THEN END RAPIDLY FROM WEST
TO EAST THROUGH THE DAY FRIDAY. STORMS WILL HAVE THE POTENTIAL TO
PRODUCE ERRATIC WIND GUSTS IN EXCESS OF 45 KTS. CIGS ARE GENERALLY
EXPECTED TO REMAIN AOA 10K FEET EXCEPT NEAR SHRA/TSRA WHERE THEY
COULD LOWER TO 6-8K FEET.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...WOLCOTT
LONG TERM.............PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1105 AM EDT THU AUG 6 2015
.SYNOPSIS...
TEMPERATURES WILL RUN ABOVE NORMAL TODAY. THUNDERSTORMS WILL
INCREASE IN COVERAGE THIS AFTERNOON AND EVENING AS MORE MOISTURE
IS BROUGHT INTO THE REGION. AN AREA OF LOW PRESSURE AND ITS COLD
FRONT WILL APPROACH FROM THE WEST AND MOVE ACROSS THE AREA LATE
TONIGHT AND FRIDAY...BRINGING A CHANCE OF RAINFALL. A DRYING TREND
IS EXPECTED INTO THE WEEKEND...AS HIGH PRESSURE CROSSES THE AREA
SATURDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 11 AM THURSDAY...ISOLATED MORNING CONVECTION HAS ALL BUT
DIMINISHED BUT AN INCREASE IN ACTIVITY IS EXPECTED THIS AFTERNOON.
INCREASING SOUTHWEST FLOW AHEAD OF SLOW MOVING COLD FRONT WILL
PUMP PLENTY OF GULF MOISTURE OVER THE REGION. DIURNAL HEATING WILL
PUSH MLCAPE VALUES CLOSE TO 3000J/KG BY EARLY AFTERNOON. MID LEVEL
CAPPING IS NOT AS STRONG AS IT WAS YESTERDAY SO EXPECT AN INCREASE
IN COVERAGE FROM WEDNESDAY AFTERNOON. HOWEVER THERE IS MORE
MOISTURE PRESENT...AT NEARLY ALL LEVELS...WHICH HAS LESSENED THE
DOWNDRAFT CAPE SO WHILE COVERAGE OF STORMS MAY INCREASE THE AMOUNT
OF STRONG TO SEVERE STORMS MAY BE SIMILAR TO YESTERDAY. HOWEVER
WET MICROBURSTS WILL REMAIN A CONCERN. LOW LEVEL JET WILL BE
PRESENT...SLOWLY GAINING STRENGTH THROUGH THE AFTERNOON AND
EVENING HOURS...ADDING TO THE DAMAGING WIND POTENTIAL.
CONVECTION WILL BE DELAYED UNTIL PEAK HEATING AS INITIALLY SURFACE
HEATING AND CONVERGENCE ALONG THE SEA BREEZE/PIEDMONT TROUGH WILL
BE THE ONLY SOURCE OF LIFT. LATER TODAY AND OVERNIGHT DYNAMICAL
FORCING WILL START TO PLAY A LARGER ROLE IN MAINTAINING STORMS.
HIGHS REMAIN ON TRACK FOR LOW TO MID 90S WITH HEAT INDEX VALUES
STILL PROGGED TO END UP JUST SHORT OF HEAT ADVISORY CRITERIA.
DISCUSSION FROM 630 AM THURSDAY FOLLOWS:
LOOK FOR INCREASING CHANCES FOR CONVECTION THRUOUT THIS NEAR TERM
PERIOD. THE MAIN CULPRIT AIDING THIS PCPN OUTBREAK COMES FROM A
RATHER POTENT MID- LEVEL S/W TROF THAT MOVES FROM THE MID-
MISSISSIPPI VALLEY EARLY THIS MORNING TO THE CAROLINAS BY DAYBREAK
FRI. THIS SYSTEM WILL HAVE PLENTY OF MOISTURE TO WORK WITH
EVENTHOUGH ITS MOVING WITHIN W TO NW FLOW ALOFT. MOISTURE
ACCOMPANYING THIS S/W TROF AS WELL AS AN INFLUX IN THE LOWER
LEVELS IE...FROM OFF THE ATLANTIC. LOOK FOR POPS IN THE MODEST TO
GOOD CHANCE TODAY...POSSIBLY REACHING LIKELY LATE TODAY THRU
TONIGHT. SEVERE TSTORM PARAMETERS POINT TOWARDS DAMAGING WIND
GUSTS AS THE PRIMARY THREAT...WITH SPC INDICATING WET MICROBURSTS
A POSSIBILITY. THE SPC OUTLINE FOR SVR WX ONLY CLIPS OUR WESTERN
CWA BUT GIVEN THE DYNAMICS ACCOMPANYING THIS SYSTEM AND ITS
INCREASING FORWARD PROGRESSION AFTER CROSSING THE
APPALACHIANS...WILL GO AHEAD AND INDICATE A SEVERE THREAT FOR THE
ENTIRE ILM CWA WITHIN THE HAZARDOUS WX OUTLOOK. TODAYS INSOLATION
MAY AID ANY AFTN RENEGADE CONVECTION TO STRONG OR SEVERE
LIMITS...WELL AHEAD OF THE APPROACHING MID-LEVEL S/W TROF. FOR
MAX/MIN TEMPS...BASICALLY COMPROMISED AMONGST THE AVAILABLE MODEL
MOS GUIDANCE...WITH LOW TO MID 90S FOR HIGHS...AND MID TO UPPER
70S...TO AROUND 80 AT THE COAST...FOR MINS. SFC DEWPOINTS ARE
PROGGED AGAIN TO BE IN THE LOW TO MID 70S WITH A FEW UPPER 70S
ALONG THE IMMEDIATE COAST. THIS WILL BRING HEAT INDEX VALUES JUST
SHY OF HEAT ADVISORY THRESHOLDS OF GREATER THAN OR EQUAL TO 105
DEGREES. A FEW LOCATIONS MAY BRIEFLY TOUCH 105 THIS AFTN...WITH
SFC DEWPOINTS THE DECIDING FACTOR RATHER THAN TEMPS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY... ENERGY ALOFT CONTINUES TO STREAM ACROSS THE
REGION ON FRIDAY WHILE THE COLD FRONT IS STILL SLOW TO MAKE PROGRESS
THROUGH THE AREA...NOW TAKING UNTIL EVENING TO CLEAR. EXPECT AN
ACTIVE DAY OF SHOWERS AND THUNDERSTORMS THOUGH THE CLOUD COVER
TEMPERING OF AFTERNOON HEAT SHOULD MITIGATE SEVERE WEATHER THREAT.
FRIDAY NIGHT INTO SATURDAY THE MID LEVELS WILL DRY OUT QUITE A BIT
BUT UPPER LEVEL PVA REMAINS AS DOES SOME LOW LEVEL MOISTURE. MOST
PLACES WILL STAY RAIN-FREE WITH JUST A FEW ISOLATED SHOWERS
POSSIBLE. THE STEADIER COASTAL RAINFALL DEPICTED IN THE GFS APPEARS
OVERDONE. TEMPERATURES WILL BE FAIRLY CLOSE TO SEASONABLE THROUGH
THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY... UPPER TROUGHINESS FLATTENS OUT SUNDAY AND
MONDAY LEAVING VERY WEAK FLOW ALOFT LOCALLY. SIMILARLY THE FRONT OF
THE SHORT TERM WILL HAVE WASHED OUT LEAVING BEHIND A POORLY DEFINED
GRADIENT. MOISTURE ASSOCIATED WITH THE OLD FRONT MAY STILL LINGER
JUST OFFSHORE BUT UNLESS THE SEA BREEZE MANAGES TO ADVECT ENOUGH OF
IT ONSHORE MOST PLACES WILL STAY RAIN-FREE. THE EXCEPTION IS OVER
INLAND ZONES MONDAY AFTERNOON WHEN SOME MID LEVEL PVA MAY GET
UNDERWAY AHEAD OF THE MAIN TROUGH DEVELOPING OVER THE GREAT LAKES.
THIS NEXT SYSTEM WILL EVENTUALLY TAKE ON AN IMPRESSIVE AMPLITUDE AND
DRIVE A FRONT INT OUR AREA TUESDAY NIGHT OR WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SOME DENSE FOG AT FLO WILL HANG AROUND FOR AN HOUR OR
SO...AND SHOULD MIX OUT BY 14Z. INCREASING CLOUDS LATER TODAY AS
A FRONTAL SYSTEM APPROACHES FROM THE WEST. THE HRRR MODEL HAS
INSTABILITY SHOWERS THIS AFTERNOON...LOOKS REASONABLE. THE MAIN
PRECIP LOAD WILL COME TONIGHT AS THE DEEP MOISTURE INCREASES ALONG WITH
DEEPENING LOW PRESSURE. CONVECTION SHOULD BREAK OUT OVERNIGHT
WITH SOME HEAVY RAIN POSSIBLE.
EXTENDED OUTLOOK...INCREASED CHANCES FOR CONVECTION THROUGH
FRIDAY WITH THE APPROACH OF A COLD FRONT. HIGH PRESSURE WILL NOSE
IN FROM THE NORTH SATURDAY AND SUNDAY. CHANCE FOR STORMS MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 11 AM THURSDAY...SOUTHWEST FLOW OF 10 TO 15 KT THIS MORNING
WILL INCREASE TO 15 TO 20 KT THIS AFTERNOON AND EVENING AS
GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT. SEAS
CURRENTLY 2 TO 4 FT WILL BUILD TO 3 TO 5 FT THIS AFTERNOON AND
EVENING. AT THIS POINT DO NOT PLAN TO RAISE SCEC HEADLINE BUT WILL
CONTINUE TO MONITOR FOR POSSIBLE ISSUANCE WITH THE MIDDAY OR
AFTERNOON UPDATES.
DISCUSSION FROM 630 AM THURSDAY FOLLOWS:
MODELS INDICATE A PINCHED SFC PRESSURE GRADIENT WILL DEVELOP THIS
AFTERNOON AND PERSIST THROUGH TONIGHT. THIS A RESULT OF A RATHER
POTENT MID-LEVEL S/W TROF OVER THE MID- MISSISSIPPI VALLEY THIS
MORNING...THAT MOVES ESE...REACHING THE CAROLINAS OVERNIGHT. A
DOUBLE BARREL SFC LOW WILL DEVELOP/EXIST ACROSS THE VA-NC BORDER
BY LATE TONIGHT. LOOK FOR SSW-WSW WINDS TO INCREASE TO 15 TO 20 KT
BY LATE THIS AFTN AND CONTINUING THRU TONIGHT. SIGNIFICANT SEAS
WILL RESPOND TO THE INCREASING WINDS AND BUILD TO 3 TO 5
FT...POSSIBLY UP TO 6 FT OFF CAPE FEAR. MAY NEED A SCEC OR
POSSIBLY A SHORT TERM SCA FOR LATE IN THIS PERIOD AND SUBSEQUENT
ONES.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY... AUGUST ISN`T REALLY THE TIME OF YEAR FOR
COLD FRONTAL PASSAGES BUT THIS SUMMER HAS LARGELY PROVEN
EXCEPTION. A FAIRLY HEALTHY BOUNDARY WILL BE BEARING DOWN ON THE
REGION ON FRIDAY SLATED FOR A FRIDAY NIGHT PASSAGE. IN THE COOLER
SEASON FRONTS OFTEN RAMP WINDS AND/OR SEAS UP TO ADVISORY REALM
BUT THIS IS OFTEN TOUGHER IN THE WARM SEASON AS THE FLOW ALOFT IS
WEAKER. THIS SHOULD BE THE CASE WITH THIS SETUP AS BOTH REMAIN
BELOW EVEN SCEC THRESHOLDS. VEERING FRIDAY NIGHT INTO SATURDAY
WILL EVENTUALLY BRING ABOUT A NORTHERLY FLOW THAT WILL ABATE IN
SPEED FAIRLY RAPIDLY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY... AS THE FRONT FROM THE SHORT TERM WASHES
OUT FAIRLY RAPIDLY TO OUR SOUTH OVER THE PERIOD THE LOCAL WINDS
AND SEAS WILL BE MINIMAL. THE FLOW WILL VEER TO ONSHORE WHILE
STAYING CAPPED AT 10 KNOTS ON SUNDAY AND THEN PERHAPS ANOTHER
COMPASS POINT MONDAY. SEAS 2 OR PERHAPS 2 TO 3 FT AT MOST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...III
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
635 AM EDT THU AUG 6 2015
.SYNOPSIS...
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH
THURSDAY. THUNDERSTORMS WILL INCREASE IN COVERAGE THURSDAY AS
MORE MOISTURE IS BROUGHT INTO THE REGION. AN AREA OF LOW PRESSURE
AND ITS COLD FRONT WILL APPROACH FROM THE WEST AND MOVE ACROSS THE
AREA FRIDAY AND FRIDAY NIGHT...BRINGING A CHANCE OF RAINFALL. A
DRYING TREND IS EXPECTED INTO THE WEEKEND...AS HIGH PRESSURE
CROSSES THE AREA SATURDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...LOOK FOR INCREASING CHANCES FOR
CONVECTION THRUOUT THIS NEAR TERM PERIOD. THE MAIN CULPRIT AIDING
THIS PCPN OUTBREAK COMES FROM A RATHER POTENT MID-LEVEL S/W TROF
THAT MOVES FROM THE MID-MISSISSIPPI VALLEY EARLY THIS MORNING TO
THE CAROLINAS BY DAYBREAK FRI. THIS SYSTEM WILL HAVE PLENTY OF
MOISTURE TO WORK WITH EVENTHOUGH ITS MOVING WITHIN W TO NW FLOW
ALOFT. MOISTURE ACCOMPANYING THIS S/W TROF AS WELL AS AN INFLUX IN
THE LOWER LEVELS IE...FROM OFF THE ATLANTIC. LOOK FOR POPS IN THE
MODEST TO GOOD CHANCE TODAY...POSSIBLY REACHING LIKELY LATE TODAY
THRU TONIGHT. SEVERE TSTORM PARAMETERS POINT TOWARDS DAMAGING WIND
GUSTS AS THE PRIMARY THREAT...WITH SPC INDICATING WET MICROBURSTS
A POSSIBILITY. THE SPC OUTLINE FOR SVR WX ONLY CLIPS OUR WESTERN
CWA BUT GIVEN THE DYNAMICS ACCOMPANYING THIS SYSTEM AND ITS
INCREASING FORWARD PROGRESSION AFTER CROSSING THE
APPALACHIANS...WILL GO AHEAD AND INDICATE A SEVERE THREAT FOR THE
ENTIRE ILM CWA WITHIN THE HAZARDOUS WX OUTLOOK. TODAYS INSOLATION
MAY AID ANY AFTN RENEGADE CONVECTION TO STRONG OR SEVERE
LIMITS...WELL AHEAD OF THE APPROACHING MID-LEVEL S/W TROF. FOR
MAX/MIN TEMPS...BASICALLY COMPROMISED AMONGST THE AVAILABLE MODEL
MOS GUIDANCE...WITH LOW TO MID 90S FOR HIGHS...AND MID TO UPPER
70S...TO AROUND 80 AT THE COAST...FOR MINS. SFC DEWPOINTS ARE
PROGGED AGAIN TO BE IN THE LOW TO MID 70S WITH A FEW UPPER 70S
ALONG THE IMMEDIATE COAST. THIS WILL BRING HEAT INDEX VALUES JUST
SHY OF HEAT ADVISORY THRESHOLDS OF GREATER THAN OR EQUAL TO 105
DEGREES. A FEW LOCATIONS MAY BRIEFLY TOUCH 105 THIS AFTN...WITH
SFC DEWPOINTS THE DECIDING FACTOR RATHER THAN TEMPS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY... ENERGY ALOFT CONTINUES TO STREAM ACROSS THE
REGION ON FRIDAY WHILE THE COLD FRONT IS STILL SLOW TO MAKE PROGRESS
THROUGH THE AREA...NOW TAKING UNTIL EVENING TO CLEAR. EXPECT AN
ACTIVE DAY OF SHOWERS AND THUNDERSTORMS THOUGH THE CLOUD COVER
TEMPERING OF AFTERNOON HEAT SHOULD MITIGATE SEVERE WEATHER THREAT.
FRIDAY NIGHT INTO SATURDAY THE MID LEVELS WILL DRY OUT QUITE A BIT
BUT UPPER LEVEL PVA REMAINS AS DOES SOME LOW LEVEL MOISTURE. MOST
PLACES WILL STAY RAIN-FREE WITH JUST A FEW ISOLATED SHOWERS
POSSIBLE. THE STEADIER COASTAL RAINFALL DEPICTED IN THE GFS APPEARS
OVERDONE. TEMPERATURES WILL BE FAIRLY CLOSE TO SEASONABLE THROUGH
THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY... UPPER TROUGHINESS FLATTENS OUT SUNDAY AND
MONDAY LEAVING VERY WEAK FLOW ALOFT LOCALLY. SIMILARLY THE FRONT OF
THE SHORT TERM WILL HAVE WASHED OUT LEAVING BEHIND A POORLY DEFINED
GRADIENT. MOISTURE ASSOCIATED WITH THE OLD FRONT MAY STILL LINGER
JUST OFFSHORE BUT UNLESS THE SEA BREEZE MANAGES TO ADVECT ENOUGH OF
IT ONSHORE MOST PLACES WILL STAY RAIN-FREE. THE EXCEPTION IS OVER
INLAND ZONES MONDAY AFTERNOON WHEN SOME MID LEVEL PVA MAY GET
UNDERWAY AHEAD OF THE MAIN TROUGH DEVELOPING OVER THE GREAT LAKES.
THIS NEXT SYSTEM WILL EVENTUALLY TAKE ON AN IMPRESSIVE AMPLITUDE AND
DRIVE A FRONT INT OUR AREA TUESDAY NIGHT OR WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SOME DENSE FOG AT FLO WILL HANG AROUND FOR AN HOUR OR
SO...AND SHOULD MIX OUT BY 14Z. INCREASING CLOUDS LATER TODAY AS
A FRONTAL SYSTEM APPROACHES FROM THE WEST. THE HRRR MODEL HAS
INSTABILITY SHOWERS THIS AFTERNOON...LOOKS REASONABLE. THE MAIN
PRECIP LOAD WILL COME TONIGHT AS THE DEEP MOISTURE INCREASES ALONG WITH
DEEPENING LOW PRESSURE. CONVECTION SHOULD BREAK OUT OVERNIGHT
WITH SOME HEAVY RAIN POSSIBLE.
EXTENDED OUTLOOK...INCREASED CHANCES FOR CONVECTION THROUGH
FRIDAY WITH THE APPROACH OF A COLD FRONT. HIGH PRESSURE WILL NOSE
IN FROM THE NORTH SATURDAY AND SUNDAY. CHANCE FOR STORMS MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...MODELS INDICATE A PINCHED SFC PRESSURE
GRADIENT WILL DEVELOP THIS AFTERNOON AND PERSIST THROUGH TONIGHT.
THIS A RESULT OF A RATHER POTENT MID-LEVEL S/W TROF OVER THE MID-
MISSISSIPPI VALLEY THIS MORNING...THAT MOVES ESE...REACHING THE
CAROLINAS OVERNIGHT. A DOUBLE BARREL SFC LOW WILL DEVELOP/EXIST
ACROSS THE VA-NC BORDER BY LATE TONIGHT. LOOK FOR SSW-WSW WINDS TO
INCREASE TO 15 TO 20 KT BY LATE THIS AFTN AND CONTINUING THRU
TONIGHT. SIGNIFICANT SEAS WILL RESPOND TO THE INCREASING WINDS AND
BUILD TO 3 TO 5 FT...POSSIBLY UP TO 6 FT OFF CAPE FEAR. MAY NEED
A SCEC OR POSSIBLY A SHORT TERM SCA FOR LATE IN THIS PERIOD AND
SUBSEQUENT ONES.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY... AUGUST ISN`T REALLY THE TIME OF YEAR FOR
COLD FRONTAL PASSAGES BUT THIS SUMMER HAS LARGELY PROVEN
EXCEPTION. A FAIRLY HEALTHY BOUNDARY WILL BE BEARING DOWN ON THE
REGION ON FRIDAY SLATED FOR A FRIDAY NIGHT PASSAGE. IN THE COOLER
SEASON FRONTS OFTEN RAMP WINDS AND/OR SEAS UP TO ADVISORY REALM
BUT THIS IS OFTEN TOUGHER IN THE WARM SEASON AS THE FLOW ALOFT IS
WEAKER. THIS SHOULD BE THE CASE WITH THIS SETUP AS BOTH REMAIN
BELOW EVEN SCEC THRESHOLDS. VEERING FRIDAY NIGHT INTO SATURDAY
WILL EVENTUALLY BRING ABOUT A NORTHERLY FLOW THAT WILL ABATE IN
SPEED FAIRLY RAPIDLY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY... AS THE FRONT FROM THE SHORT TERM WASHES
OUT FAIRLY RAPIDLY TO OUR SOUTH OVER THE PERIOD THE LOCAL WINDS
AND SEAS WILL BE MINIMAL. THE FLOW WILL VEER TO ONSHORE WHILE
STAYING CAPPED AT 10 KNOTS ON SUNDAY AND THEN PERHAPS ANOTHER
COMPASS POINT MONDAY. SEAS 2 OR PERHAPS 2 TO 3 FT AT MOST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
623 AM EDT THU AUG 6 2015
.SYNOPSIS...
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH
THURSDAY. THUNDERSTORMS WILL INCREASE IN COVERAGE THURSDAY AS
MORE MOISTURE IS BROUGHT INTO THE REGION. AN AREA OF LOW PRESSURE
AND ITS COLD FRONT WILL APPROACH FROM THE WEST AND MOVE ACROSS THE
AREA FRIDAY AND FRIDAY NIGHT...BRINGING A CHANCE OF RAINFALL. A
DRYING TREND IS EXPECTED INTO THE WEEKEND...AS HIGH PRESSURE
CROSSES THE AREA SATURDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM THURSDAY...LOOK FOR INCREASING CHANCES FOR
CONVECTION THRUOUT THIS NEAR TERM PERIOD. THE MAIN CULPRIT AIDING
THIS PCPN OUTBREAK COMES FROM A RATHER POTENT MID-LEVEL S/W TROF
THAT MOVES FROM THE MID-MISSISSIPPI VALLEY THIS MORNING TO THE
CAROLINAS DURING THE PRE-DAWN FRI HOURS. THIS SYSTEM WILL HAVE
PLENTY OF MOISTURE TO WORK WITH EVENTHOUGH ITS MOVING WITHIN W TO
NW FLOW ALOFT. MOISTURE ACCOMPANYING THIS S/W TROF AS WELL AS AN
INFLUX IN THE LOWER LEVELS IE...FROM OFF THE ATLANTIC. LOOK FOR
POPS IN THE MODEST TO GOOD CHANCE TODAY...POSSIBLY REACHING LIKELY
LATE TODAY THRU TONIGHT. SEVERE TSTORM PARAMETERS POINT TOWARDS
DAMAGING WIND GUSTS AS THE PRIMARY THREAT...WITH SPC INDICATING
WET MICROBURSTS A POSSIBILITY. THE SPC OUTLINE FOR SVR WX ONLY
CLIPS OUR WESTERN CWA BUT GIVEN THE DYNAMICS ACCOMPANYING THIS
SYSTEM AND ITS INCREASING FORWARD PROGRESSION AFTER CROSSING THE
APPALACHIANS...WILL GO AHEAD AND INDICATE A SEVERE THREAT FOR THE
ENTIRE ILM CWA WITHIN THE HAZARDOUS WX OUTLOOK AND INCLUDE THE
TONIGHT PERIOD. TODAYS INSOLATION MAY AID ANY AFTN RENEGADE
CONVECTION TO STRONG OR SEVERE LIMITS...WELL AHEAD OF THE
APPROACHING MID-LEVEL S/W TROF. FOR MAX/MIN TEMPS...BASICALLY
COMPROMISED AMONGST THE AVAILABLE MODEL MOS GUIDANCE...WITH LOW TO
MID 90S FOR HIGHS...AND MID TO UPPER 70S...TO AROUND 80 AT THE
COAST...FOR MINS. SFC DEWPOINTS ARE PROGGED AGAIN TO BE IN THE LOW
TO MID 70S WITH A FEW UPPER 70S ALONG THE IMMEDIATE COAST. THIS
WILL BRING HEAT INDEX VALUES JUST SHY OF HEAT ADVISORY THRESHOLDS
OF GREATER THAN OR EQUAL TO 105 DEGREES. A FEW LOCATIONS MAY
BRIEFLY TOUCH 105 THIS AFTN...WITH SFC DEWPOINTS THE DECIDING
FACTOR RATHER THAN TEMPS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY... ENERGY ALOFT CONTINUES TO STREAM ACROSS THE
REGION ON FRIDAY WHILE THE COLD FRONT IS STILL SLOW TO MAKE PROGRESS
THROUGH THE AREA...NOW TAKING UNTIL EVENING TO CLEAR. EXPECT AN
ACTIVE DAY OF SHOWERS AND THUNDERSTORMS THOUGH THE CLOUD COVER
TEMPERING OF AFTERNOON HEAT SHOULD MITIGATE SEVERE WEATHER THREAT.
FRIDAY NIGHT INTO SATURDAY THE MID LEVELS WILL DRY OUT QUITE A BIT
BUT UPPER LEVEL PVA REMAINS AS DOES SOME LOW LEVEL MOISTURE. MOST
PLACES WILL STAY RAIN-FREE WITH JUST A FEW ISOLATED SHOWERS
POSSIBLE. THE STEADIER COASTAL RAINFALL DEPICTED IN THE GFS APPEARS
OVERDONE. TEMPERATURES WILL BE FAIRLY CLOSE TO SEASONABLE THROUGH
THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY... UPPER TROUGHINESS FLATTENS OUT SUNDAY AND
MONDAY LEAVING VERY WEAK FLOW ALOFT LOCALLY. SIMILARLY THE FRONT OF
THE SHORT TERM WILL HAVE WASHED OUT LEAVING BEHIND A POORLY DEFINED
GRADIENT. MOISTURE ASSOCIATED WITH THE OLD FRONT MAY STILL LINGER
JUST OFFSHORE BUT UNLESS THE SEA BREEZE MANAGES TO ADVECT ENOUGH OF
IT ONSHORE MOST PLACES WILL STAY RAIN-FREE. THE EXCEPTION IS OVER
INLAND ZONES MONDAY AFTERNOON WHEN SOME MID LEVEL PVA MAY GET
UNDERWAY AHEAD OF THE MAIN TROUGH DEVELOPING OVER THE GREAT LAKES.
THIS NEXT SYSTEM WILL EVENTUALLY TAKE ON AN IMPRESSIVE AMPLITUDE AND
DRIVE A FRONT INT OUR AREA TUESDAY NIGHT OR WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SOME DENSE FOG AT FLO WILL HANG AROUND FOR AN HOUR OR
SO...AND SHOULD MIX OUT BY 14Z. INCREASING CLOUDS LATER TODAY AS
A FRONTAL SYSTEM APPROACHES FROM THE WEST. THE HRRR MODEL HAS
INSTABILITY SHOWERS THIS AFTERNOON...LOOKS REASONABLE. THE MAIN
PRECIP LOAD WILL COME TONIGHT AS THE DEEP MOISTURE INCREASES ALONG WITH
DEEPENING LOW PRESSURE. CONVECTION SHOULD BREAK OUT OVERNIGHT
WITH SOME HEAVY RAIN POSSIBLE.
EXTENDED OUTLOOK...INCREASED CHANCES FOR CONVECTION THROUGH
FRIDAY WITH THE APPROACH OF A COLD FRONT. HIGH PRESSURE WILL NOSE
IN FROM THE NORTH SATURDAY AND SUNDAY. CHANCE FOR STORMS MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM THURSDAY...MODELS INDICATE A PINCHED SFC PRESSURE
GRADIENT WILL DEVELOP THIS AFTERNOON AND PERSIST THROUGH TONIGHT.
THIS A RESULT OF A RATHER POTENT MID-LEVEL S/W TROF OVER THE MID-
MISSISSIPPI VALLEY THIS MORNING MOVING ESE...AND REACHING THE
CAROLINAS OVERNIGHT. A DOUBLE BARREL LOW WILL DEVELOP/EXIST
ACROSS THE VA-NC BORDER BY LATE TONIGHT. LOOK FOR SSW-WSW WINDS TO
INCREASE TO 15 TO 20 KT WITH GUSTS UP TO 25 KT BY LATE THIS AFTN
AND CONTINUING THRU TONIGHT. SIGNIFICANT SEAS WILL RESPOND TO THE
INCREASING WINDS AND BUILD TO 3 TO 5 FT...POSSIBLY UP TO 6 FT OFF
CAPE FEAR. WILL LIKELY POST A SCEC OR POSSIBLY A SHORT TERM SCA AT
THE NEXT UPDATE IF THE 06Z MODEL RUNS CONTINUE THIS TREND.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY... AUGUST ISN`T REALLY THE TIME OF YEAR FOR
COLD FRONTAL PASSAGES BUT THIS SUMMER HAS LARGELY PROVEN
EXCEPTION. A FAIRLY HEALTHY BOUNDARY WILL BE BEARING DOWN ON THE
REGION ON FRIDAY SLATED FOR A FRIDAY NIGHT PASSAGE. IN THE COOLER
SEASON FRONTS OFTEN RAMP WINDS AND/OR SEAS UP TO ADVISORY REALM
BUT THIS IS OFTEN TOUGHER IN THE WARM SEASON AS THE FLOW ALOFT IS
WEAKER. THIS SHOULD BE THE CASE WITH THIS SETUP AS BOTH REMAIN
BELOW EVEN SCEC THRESHOLDS. VEERING FRIDAY NIGHT INTO SATURDAY
WILL EVENTUALLY BRING ABOUT A NORTHERLY FLOW THAT WILL ABATE IN
SPEED FAIRLY RAPIDLY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY... AS THE FRONT FROM THE SHORT TERM WASHES
OUT FAIRLY RAPIDLY TO OUR SOUTH OVER THE PERIOD THE LOCAL WINDS
AND SEAS WILL BE MINIMAL. THE FLOW WILL VEER TO ONSHORE WHILE
STAYING CAPPED AT 10 KNOTS ON SUNDAY AND THEN PERHAPS ANOTHER
COMPASS POINT MONDAY. SEAS 2 OR PERHAPS 2 TO 3 FT AT MOST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
MARINE...
AREA FORECAST DISCUSSION
NWS BISMARCK ND
534 PM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 534 PM CDT THU AUG 6 2015
CANCELED THE FLASH FLOOD WATCH FOR ALL BUT THE JAMES RIVER
VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
HEAVY RAINFALL POTENTIAL THROUGH EARLY THIS EVENING SOUTH CENTRAL
AND INTO THE JAMES RIVER VALLEY HIGHLIGHTS THE SHORT TERM
FORECAST.
THE FLASH FLOOD WATCH FOR THE SOUTH CENTRAL AND JAMES RIVER VALLEY
REMAINS IN EFFECT UNTIL 10 PM CDT THIS EVENING. RADAR TRENDS
THROUGH 20 UTC DEPICT NUMEROUS SLOWING MOVING...WARM RAIN PROCESS
DOMINATED STORMS ACROSS THE AFOREMENTIONED AREAS. GIVEN TRENDS IN
THE 17-19 UTC HRRR ITERATIONS WHICH HAVE OVERALL HANDLED THE EVENT
WELL...EXPECT ACTIVITY TO BEGIN TO WANE/PROPAGATE EAST INTO THE
RED RIVER VALLEY BY 23-00 UTC. FURTHER WEST NEAR THE OCCLUDED
FRONTAL BOUNDARY FROM NORTHEAST MONTANA THROUGH LAKE
OAHE...DIURNALLY DRIVEN ISOLATED CONVECTION IS EXPECTED.
HOWEVER...SEVERE WEATHER IS NOT ANTICIPATED.
GIVEN GOOD AGREEMENT ON THE 12 UTC DETERMINISTIC SUITE...A DRY
COLD FRONTAL PASSAGE IS EXPECTED ON FRIDAY...WITH SEASONABLE
TEMPERATURES AND MOSTLY SUNNY SKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
A POTENTIAL WARM UP NEXT WEEK HIGHLIGHTS THE EXTENDED FORECAST.
THE 12 UTC GUIDANCE SUITE IS IN AGREEMENT ON QUASI-ZONAL THIS
WEEKEND AMPLIFYING EARLY NEXT WEEK AS AN INTERMOUNTAIN
WEST/CENTRAL CONUS UPPER LEVEL RIDGE BUILDS. THIS SUPPORTS A
POSSIBLE TRANSITION FROM NEAR NORMAL TEMPERATURES THIS
WEEKEND...WARMING THROUGH NEXT WEEK. GIVEN WEAK WAVES EMBEDDED IN THE
FAST QUASI-ZONAL FLOW THIS WEEKEND...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST SATURDAY AND SUNDAY GENERALLY SOUTH OF
ND HIGHWAY 200. SEVERE THUNDERSTORMS ARE NOT EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 250 PM CDT THU AUG 6 2015
THUNDERSTORMS ARE LIKELY TO IMPACT KJMS THIS AFTERNOON INTO THE
EARLY EVENING WITH IFR CONDITIONS POSSIBLE. VFR CONDITIONS ARE
FORECAST ELSEWHERE WITH ONLY ISOLATED SHOWERS AND THUNDERSTORMS
ACROSS NORTHWEST AND CENTRAL NORTH DAKOTA THAT WILL FADE WITH
SUNSET. VFR CONDITIONS ARE FORECAST FRIDAY AS A DRY COLD FRONT
MOVES THROUGH THE AREA. NORTHWEST WIND GUSTS TO 25 KTS ARE
POSSIBLE AT KISN AND KMOT FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR NDZ025-037-
048-051.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
316 PM CDT THU AUG 6 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
HEAVY RAINFALL POTENTIAL THROUGH EARLY THIS EVENING SOUTH CENTRAL
AND INTO THE JAMES RIVER VALLEY HIGHLIGHTS THE SHORT TERM
FORECAST.
THE FLASH FLOOD WATCH FOR THE SOUTH CENTRAL AND JAMES RIVER VALLEY
REMAINS IN EFFECT UNTIL 10 PM CDT THIS EVENING. RADAR TRENDS
THROUGH 20 UTC DEPICT NUMEROUS SLOWING MOVING...WARM RAIN PROCESS
DOMINATED STORMS ACROSS THE AFOREMENTIONED AREAS. GIVEN TRENDS IN
THE 17-19 UTC HRRR ITERATIONS WHICH HAVE OVERALL HANDLED THE EVENT
WELL...EXPECT ACTIVITY TO BEGIN TO WANE/PROPAGATE EAST INTO THE
RED RIVER VALLEY BY 23-00 UTC. FURTHER WEST NEAR THE OCCLUDED
FRONTAL BOUNDARY FROM NORTHEAST MONTANA THROUGH LAKE
OAHE...DIURNALLY DRIVEN ISOLATED CONVECTION IS EXPECTED.
HOWEVER...SEVERE WEATHER IS NOT ANTICIPATED.
GIVEN GOOD AGREEMENT ON THE 12 UTC DETERMINISTIC SUITE...A DRY
COLD FRONTAL PASSAGE IS EXPECTED ON FRIDAY...WITH SEASONABLE
TEMPERATURES AND MOSTLY SUNNY SKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 250 PM CDT THU AUG 6 2015
A POTENTIAL WARM UP NEXT WEEK HIGHLIGHTS THE EXTENDED FORECAST.
THE 12 UTC GUIDANCE SUITE IS IN AGREEMENT ON QUASI-ZONAL THIS
WEEKEND AMPLIFYING EARLY NEXT WEEK AS AN INTERMOUNTAIN
WEST/CENTRAL CONUS UPPER LEVEL RIDGE BUILDS. THIS SUPPORTS A
POSSIBLE TRANSITION FROM NEAR NORMAL TEMPERATURES THIS
WEEKEND...WARMING THROUGH NEXT WEEK. GIVEN WEAK WAVES EMBEDDED IN THE
FAST QUASI-ZONAL FLOW THIS WEEKEND...DAILY CHANCES FOR
THUNDERSTORMS ARE FORECAST SATURDAY AND SUNDAY GENERALLY SOUTH OF
ND HIGHWAY 200. SEVERE THUNDERSTORMS ARE NOT EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 250 PM CDT THU AUG 6 2015
THUNDERSTORMS ARE LIKELY TO IMPACT KJMS THIS AFTERNOON INTO THE
EARLY EVENING WITH IFR CONDITIONS POSSIBLE. VFR CONDITIONS ARE
FORECAST ELSEWHERE WITH ONLY ISOLATED SHOWERS AND THUNDERSTORMS
ACROSS NORTHWEST AND CENTRAL NORTH DAKOTA THAT WILL FADE WITH
SUNSET. VFR CONDITIONS ARE FORECAST FRIDAY AS A DRY COLD FRONT
MOVES THROUGH THE AREA. NORTHWEST WIND GUSTS TO 25 KTS ARE
POSSIBLE AT KISN AND KMOT FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR NDZ022-023-
025-035>037-046>048-050-051.
&&
$$
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1223 PM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 1219 PM CDT THU AUG 6 2015
QUICK UPDATE TO CANCEL THE FLASH FLOOD WATCH WEST OF THE MISSOURI
RIVER AS MORNING CONVECTION AND TEMPERATURES IN THE 60S HAVE
DIMINISHED THE CHANCES FOR DEEP CONVECTION AND ASSOCIATED
POTENTIAL FLASH FLOODING. OTHERWISE...CONVECTIVE COVERAGE AND
INTENSITY CONTINUES TO SLOWLY INCREASE EAST OF THE MISSOURI RIVER
AND SOUTH OF NORTH DAKOTA HIGHWAY 200...AND THE WATCH REMAINS IN
EFFECT FOR THESE AREAS.
UPDATE ISSUED AT 1059 AM CDT THU AUG 6 2015
NO SIGNIFICANT CHANGES AT THIS TIME TO THE ONGOING FORECAST. THE
QUESTION FOR THE AFTERNOON IS HOW MUCH INSTABILITY AND RESULT
STORM COVERAGE AND INTENSITY CAN BE REALIZED GIVEN CURRENT CLOUD
COVER ACROSS SOUTH CENTRAL NORTH DAKOTA AND INTO THE JAMES RIVER
VALLEY. GIVEN RADAR TRENDS THROUGH 16 UTC...MAY BE ABLE TO TRIM A
FEW COUNTIES OFF OF THE WESTERN PORTION OF THE FLASH FLOOD WATCH
WHERE ONGOING WEAKER CONVECTION WILL PREVENT INSTABILITY BUILD UP
NEEDED FOR DEEPER CONVECTION AND A FLASH FLOOD THREAT. THE 12-14
UTC HRRR ITERATIONS AND 12 UTC GLOBAL SUITE STILL SUGGEST STORM
COVERAGE AND INTENSITY INCREASING THROUGH THE AFTERNOON SOUTH
CENTRAL AND INTO SOUTHEAST NORTH DAKOTA. AS STATED ABOVE...CLOUD
COVER DOES ADD UNCERTAINTY TO THIS SOLUTION...HOWEVER...THE STRONG
SHORTWAVE STILL REMAINS TO THE WEST OF THESE AREAS WHICH MAY
PROVIDE ENOUGH FORCING TO OVERCOME THIS ISSUE.
UPDATE ISSUED AT 832 AM CDT THU AUG 6 2015
SHOWERS/STORMS CONTINUE TO LIFT TO THE NORTHEAST VERY
SLOWLY...WITH SOME AREAS OF PRECIPITATION REMAINING NEARLY
STATIONARY OVER PORTIONS OF THE SOUTHERN JAMES RIVER VALLEY.
LATEST HIGH REST GUIDANCE CONTINUES TO INDICATE SLOW STORM MOTION
THROUGH THE REST OF THE DAY...THEREFORE THE FLOODING THREAT WILL
CONTINUE...PARTICULARLY OVER SOUTH CENTRAL INTO THE JAMES RIVER
VALLEY WHERE CURRENT FLASH FLOOD WATCH REMAINS IN EFFECT.
UPDATE ISSUED AT 636 AM CDT THU AUG 6 2015
TIMING OF PRECIPITATION PROPAGATION NORTHEASTWARD WAS SLOWED BASED
ON THE LATEST RADAR OBSERVATIONS. THE MAIN THREAT CONTINUES TO BE
THE POTENTIAL FOR FLASH FLOODING ACROSS THE SOUTH
CENTRAL/SOUTHEAST COUNTIES WHERE ECHO TRAINING HAS BEEN ONGOING
FOR MUCH OF THE MORNING. INSTANTANEOUS RAIN RATES...SURFACE
REPORTS OF RAINFALL...AND THE PRESENCE OF FREQUENT LIGHTENING
SUGGESTS AN ABSENCE OF WARM RAIN PROCESSES. THUS...HELD OFF ON
ISSUING ANY FLOOD ADVISORIES OR FLASH FLOOD WARNINGS IN DICKEY
COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT THU AUG 6 2015
HIGHLIGHTS OF THE SHORT TERM IS TIMING AND AREAL COVERAGE OF
CONVECTION...AND THREAT OF HEAVY RAINFALL.
CURRENTLY...AN UPPER LEVEL LOW/TROUGH WAS OVER THE ROCKIES...WITH
A SERIES OF STRONG UPSTREAM SHORTWAVE ENERGY IMPULSES MOVING
NORTHEAST FROM THE INTERMOUNTAIN WEST INTO THE NORTHERN PLAINS.
AHEAD OF THE SYSTEM...AN ESTABLISHED SOUTHERLY LOW LEVEL JET OVER
THE EASTERN DAKOTAS WAS ASSOCIATED WITH A SMALL CLUSTER OF
THUNDERSTORMS OVER THE JAMES RIVER BASIN FROM MCINTOSH AND DICKEY
COUNTIES IN NORTH DAKOTA SOUTHWARD TOWARDS ABERDEEN IN SOUTH DAKOTA.
MEANWHILE OUT WEST...THE AFOREMENTIONED UPPER LEVEL TROUGH WAS
ASSOCIATED WITH SCATTERED SHOWERS AND THUNDERSTORMS FROM
SASKATCHEWAN TO EASTERN MONTANA TO THE DAKOTAS.
THE LATEST NAM/HRRR AND HIGH RESOLUTION SHORT TERM MODELS INDICATE
THAT MORE WIDESPREAD CONVECTION FROM EASTERN MONTANA AND WESTERN
SOUTH DAKOTA WILL LIFT NORTHEASTWARD INTO NORTH DAKOTA THIS
MORNING...WITH NUMEROUS SHOWERS AND THUNDERSTORMS OCCURRING FROM
NORTHWEST TO SOUTHEASTERN NORTH DAKOTA THROUGH THE DAY...AS PER THE
ARCING ORIENTATION OF THE UPPER LEVEL IMPULSES LIFTING NORTHEAST
ACROSS THE STATE TODAY. ALONG WITH THUNDERSTORMS ASSOCIATED WITH THE
LOW LEVEL JET PLAGUING THE JAMES RIVER BASIN...MORE CONVECTION IS
EXPECTED LATER TODAY AS THE MAIN UPPER LEVEL IMPULSE SHORTWAVE MOVES
ACROSS THE STATE...REACHING THE JAMES VALLEY THIS AFTERNOON. PWATS
OF 1.50 WITH WARM RAIN PROCESSES IN PLAY WILL KEEP THE THREAT OF
HEAVY RAINFALL OVER THE SOUTH CENTRAL. MAY NEED TO WATCH FOR
FARTHER NORTH AND WEST FOR PERSISTENT RAINS LEADING TO SOME HEAVY
RAINS. CONFIDENCE IS NOT HIGH ENOUGH TO EXPAND THE FLASH FLOOD
WATCH.
THE SYSTEM BEGINS MOVING EASTWARD OUT OF OUR AREA DURING THE
EVENING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 AM CDT THU AUG 6 2015
IN THE WAKE OF THE NORTHWESTERN U.S. TROUGH PROGRESSION INTO
SOUTHEAST CANADA THIS WEEKEND...THE MAIN FORECAST FOCUS SHIFTS TO
THE RETURN TO STRONG RIDGING OVER THE GREAT PLAINS AS A WEST COAST
TROUGH BECOMES REESTABLISHED.
RESULTANT DOWNSTREAM RIDGING ALOFT SHOULD REDUCE PRECIPITATION
CHANCES AT LEAST DURING THE EARLY PART OF NEXT WEEK. BY WEDNESDAY
NIGHT...THOUGH...THERE IS GOOD AGREEMENT AMONG THE 00 UTC
ECMWF/GFS/GEFS THAT MID LEVEL SHORTWAVES WILL BEGIN TO EJECT INTO
MONTANA...AND PERHAPS NORTH DAKOTA. CONSEQUENTLY...PRECIPITATION
CHANCES RETURN WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1219 PM CDT THU AUG 6 2015
WIDESPREAD IFR CONDITIONS IN STRATUS ACROSS CENTRAL AND NORTHWEST
NORTH DAKOTA WILL SLOWLY LIFT INTO THE AFTERNOON. WIDESPREAD
SHOWERS AND THUNDERSTORMS ARE ALSO EXPECTED FOR THESE AREAS
THROUGH THE AFTERNOON...INCLUDING KISN/KMOT/KBIS/KJMS. KDIK LOOKS
TO REMAIN WEST OF PRECIPITATION ACTIVITY FOR THE REMAINDER OF THE
DAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR NDZ022-023-
025-035>037-046>048-050-051.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...SCHECK
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1117 AM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 1059 AM CDT THU AUG 6 2015
NO SIGNIFICANT CHANGES AT THIS TIME TO THE ONGOING FORECAST. THE
QUESTION FOR THE AFTERNOON IS HOW MUCH INSTABILITY AND RESULT
STORM COVERAGE AND INTENSITY CAN BE REALIZED GIVEN CURRENT CLOUD
COVER ACROSS SOUTH CENTRAL NORTH DAKOTA AND INTO THE JAMES RIVER
VALLEY. GIVEN RADAR TRENDS THROUGH 16 UTC...MAY BE ABLE TO TRIM A
FEW COUNTIES OFF OF THE WESTERN PORTION OF THE FLASH FLOOD WATCH
WHERE ONGOING WEAKER CONVECTION WILL PREVENT INSTABILITY BUILD UP
NEEDED FOR DEEPER CONVECTION AND A FLASH FLOOD THREAT. THE 12-14
UTC HRRR ITERATIONS AND 12 UTC GLOBAL SUITE STILL SUGGEST STORM
COVERAGE AND INTENSITY INCREASING THROUGH THE AFTERNOON SOUTH
CENTRAL AND INTO SOUTHEAST NORTH DAKOTA. AS STATED ABOVE...CLOUD
COVER DOES ADD UNCERTAINTY TO THIS SOLUTION...HOWEVER...THE STRONG
SHORTWAVE STILL REMAINS TO THE WEST OF THESE AREAS WHICH MAY
PROVIDE ENOUGH FORCING TO OVERCOME THIS ISSUE.
UPDATE ISSUED AT 832 AM CDT THU AUG 6 2015
SHOWERS/STORMS CONTINUE TO LIFT TO THE NORTHEAST VERY
SLOWLY...WITH SOME AREAS OF PRECIPITATION REMAINING NEARLY
STATIONARY OVER PORTIONS OF THE SOUTHERN JAMES RIVER VALLEY.
LATEST HIGH REST GUIDANCE CONTINUES TO INDICATE SLOW STORM MOTION
THROUGH THE REST OF THE DAY...THEREFORE THE FLOODING THREAT WILL
CONTINUE...PARTICULARLY OVER SOUTH CENTRAL INTO THE JAMES RIVER
VALLEY WHERE CURRENT FLASH FLOOD WATCH REMAINS IN EFFECT.
UPDATE ISSUED AT 636 AM CDT THU AUG 6 2015
TIMING OF PRECIPITATION PROPAGATION NORTHEASTWARD WAS SLOWED BASED
ON THE LATEST RADAR OBSERVATIONS. THE MAIN THREAT CONTINUES TO BE
THE POTENTIAL FOR FLASH FLOODING ACROSS THE SOUTH
CENTRAL/SOUTHEAST COUNTIES WHERE ECHO TRAINING HAS BEEN ONGOING
FOR MUCH OF THE MORNING. INSTANTANEOUS RAIN RATES...SURFACE
REPORTS OF RAINFALL...AND THE PRESENCE OF FREQUENT LIGHTENING
SUGGESTS AN ABSENCE OF WARM RAIN PROCESSES. THUS...HELD OFF ON
ISSUING ANY FLOOD ADVISORIES OR FLASH FLOOD WARNINGS IN DICKEY
COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT THU AUG 6 2015
HIGHLIGHTS OF THE SHORT TERM IS TIMING AND AREAL COVERAGE OF
CONVECTION...AND THREAT OF HEAVY RAINFALL.
CURRENTLY...AN UPPER LEVEL LOW/TROUGH WAS OVER THE ROCKIES...WITH
A SERIES OF STRONG UPSTREAM SHORTWAVE ENERGY IMPULSES MOVING
NORTHEAST FROM THE INTERMOUNTAIN WEST INTO THE NORTHERN PLAINS.
AHEAD OF THE SYSTEM...AN ESTABLISHED SOUTHERLY LOW LEVEL JET OVER
THE EASTERN DAKOTAS WAS ASSOCIATED WITH A SMALL CLUSTER OF
THUNDERSTORMS OVER THE JAMES RIVER BASIN FROM MCINTOSH AND DICKEY
COUNTIES IN NORTH DAKOTA SOUTHWARD TOWARDS ABERDEEN IN SOUTH DAKOTA.
MEANWHILE OUT WEST...THE AFOREMENTIONED UPPER LEVEL TROUGH WAS
ASSOCIATED WITH SCATTERED SHOWERS AND THUNDERSTORMS FROM
SASKATCHEWAN TO EASTERN MONTANA TO THE DAKOTAS.
THE LATEST NAM/HRRR AND HIGH RESOLUTION SHORT TERM MODELS INDICATE
THAT MORE WIDESPREAD CONVECTION FROM EASTERN MONTANA AND WESTERN
SOUTH DAKOTA WILL LIFT NORTHEASTWARD INTO NORTH DAKOTA THIS
MORNING...WITH NUMEROUS SHOWERS AND THUNDERSTORMS OCCURRING FROM
NORTHWEST TO SOUTHEASTERN NORTH DAKOTA THROUGH THE DAY...AS PER THE
ARCING ORIENTATION OF THE UPPER LEVEL IMPULSES LIFTING NORTHEAST
ACROSS THE STATE TODAY. ALONG WITH THUNDERSTORMS ASSOCIATED WITH THE
LOW LEVEL JET PLAGUING THE JAMES RIVER BASIN...MORE CONVECTION IS
EXPECTED LATER TODAY AS THE MAIN UPPER LEVEL IMPULSE SHORTWAVE MOVES
ACROSS THE STATE...REACHING THE JAMES VALLEY THIS AFTERNOON. PWATS
OF 1.50 WITH WARM RAIN PROCESSES IN PLAY WILL KEEP THE THREAT OF
HEAVY RAINFALL OVER THE SOUTH CENTRAL. MAY NEED TO WATCH FOR
FARTHER NORTH AND WEST FOR PERSISTENT RAINS LEADING TO SOME HEAVY
RAINS. CONFIDENCE IS NOT HIGH ENOUGH TO EXPAND THE FLASH FLOOD
WATCH.
THE SYSTEM BEGINS MOVING EASTWARD OUT OF OUR AREA DURING THE
EVENING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 AM CDT THU AUG 6 2015
IN THE WAKE OF THE NORTHWESTERN U.S. TROUGH PROGRESSION INTO
SOUTHEAST CANADA THIS WEEKEND...THE MAIN FORECAST FOCUS SHIFTS TO
THE RETURN TO STRONG RIDGING OVER THE GREAT PLAINS AS A WEST COAST
TROUGH BECOMES REESTABLISHED.
RESULTANT DOWNSTREAM RIDGING ALOFT SHOULD REDUCE PRECIPITATION
CHANCES AT LEAST DURING THE EARLY PART OF NEXT WEEK. BY WEDNESDAY
NIGHT...THOUGH...THERE IS GOOD AGREEMENT AMONG THE 00 UTC
ECMWF/GFS/GEFS THAT MID LEVEL SHORTWAVES WILL BEGIN TO EJECT INTO
MONTANA...AND PERHAPS NORTH DAKOTA. CONSEQUENTLY...PRECIPITATION
CHANCES RETURN WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1059 AM CDT THU AUG 6 2015
WIDESPREAD IFR CONDITIONS IN STRATUS ACROSS CENTRAL AND NORTHWEST
NORTH DAKOTA WILL SLOWLY LIFT INTO THE AFTERNOON. WIDESPREAD
SHOWERS AND THUNDERSTORMS ARE ALSO EXPECTED FOR THESE AREAS
THROUGH THE AFTERNOON...INCLUDING KISN/KMOT/KBIS/KJMS. KDIK LOOKS
TO REMAIN WEST OF PRECIPITATION ACTIVITY FOR THE REMAINDER OF THE
DAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR
NDZ019>023-025-034>037-042-045>048-050-051.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...SCHECK
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1255 AM CDT THU AUG 6 2015
.UPDATE...
ISSUED AT 1255 AM CDT THU AUG 6 2015
A SMALL AREA OF THUNDERSTORMS ALONG THE ND/SD BORDER CONTINUED IN
THE MCINTOSH/DICKEY COUNTY AREA...LIKELY ASSOCIATED WITH LIFT FROM
THE ESTABLISHED LOW LEVEL JET IN PLACE OVER THE EASTERN DAKOTAS.
MEANWHILE THE WESTERN SHORTWAVE AND ASSOCIATED UPPER LEVEL ENERGY
IMPULSES WILL CONTINUE MOVING EAST/NORTHEAST FROM MONTANA/WYOMING
AND MOVING INTO THE DAKOTAS THIS MORNING. ADJUSTED PRECIP CHANCES
ACCORDING TO CURRENT RADAR OBSERVATIONS AND LATEST ITERATIONS OF THE
HRRR MODEL RUN.
OTHERWISE OTHER FORECAST ELEMENTS ON TRACK.
UPDATE ISSUED AT 921 PM CDT WED AUG 5 2015
VERY ISOLATED THUNDERSTORMS CONTINUE EAST OF THE MISSOURI RIVER.
AN AREA OF THUNDERSTORMS WILL BE MOVING INTO THE SOUTHWEST AFTER
10 PM CDT. UPDATED POPS FOR CURRENT TRENDS.
WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH MOVING THROUGH NORTH
CENTRAL WYOMING. THIS WILL LIFT INTO SOUTHWEST NORTH DAKOTA
OVERNIGHT. CURRENT FORECAST TRENDING OK.
UPDATE ISSUED AT 638 PM CDT WED AUG 5 2015
WARM FRONT ACROSS CENTRAL NORTH DAKOTA WILL BE THE FOCUS FOR
SCATTERED TO ISOLATED THUNDERSTORMS ACROSS CENTRAL AND EASTERN
NORTH DAKOTA THIS EVENING. A COLD FRONT ACROSS SOUTHEAST
SASKATCHEWAN WILL MOVE SOUTHEAST AND BE THE FOCUS FOR NUMEROUS
THUNDERSTORMS ACROSS WEST AND CENTRAL NORTH DAKOTA AFTER
MIDNIGHT. HRRR MODEL CONTINUES TO SPREAD THUNDERSTORMS SOUTHWEST
TO NORTHEAST ACROSS THE STATE LATE TONIGHT WITH A MID LEVEL
SHORTWAVE TROUGH CURRENTLY OVER EASTERN IDAHO. THIS STILL LOOKS
REASONABLE. MAIN UPDATES TO FORECAST WERE CURRENT CONDITIONS AND
TIMING OF POPS WEST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 302 PM CDT WED AUG 5 2015
HIGHLIGHTS OF THE SHORT TERM IS CONVECTIVE POTENTIAL THIS
AFTERNOON AND HEAVY RAINFALL ON THURSDAY.
FOR THE REMAINDER OF THE AFTERNOON...EXPECTING ISOLATED TO
SCATTERED SURFACE BASED CONVECTIVE DEVELOPMENT EAST OF THE WARM
FRONT NEAR US HIGHWAY 85. 18 UTC RAP ANALYSIS DEPICTS 1500-2000
J/KG OF ML CAPE AND DEEP LAYER SHEAR OF 30-40 KTS AHEAD OF THE
BOUNDARY. THUS...A FEW STRONG TO POSSIBLY SEVERE STORMS ARE
POSSIBLE...IN LINE WITH THE 18-19 UTC HRRR ITERATIONS AND SPC DAY
1 OUTLOOK.
A STRONG SHORTWAVE IS FORECAST TO PROPAGATE OUT OF THE
INTERMOUNTAIN WEST AND ONTO THE NORTHERN PLAINS LATE THIS EVENING
AND TONIGHT...AND STRENGTHEN THROUGH THE DAY ON THURSDAY.
EXPECTING WIDESPREAD THUNDERSTORMS SOUTH OF US HIGHWAY 2 ENTERING
THE SOUTHWEST TONIGHT...AND FOCUSING CENTRAL THROUGH THURSDAY
AFTERNOON. PWATS OF 1.50 TO 1.75 INCHES WITH TALL...SKINNY CAPE
PROFILES...AND WEAK WINDS THROUGHOUT THE TROPOSPHERE SUPPORTING
SLOW STORM MOTIONS ALL POINT TO A HEAVY RAINFALL THREAT. AREAS
THAT WILL RESIDE IN THIS ENVIRONMENT THE LONGEST IS THE SOUTH
CENTRAL AND JAMES RIVER VALLEY LATE THURSDAY MORNING THROUGH THE
EVENING. THIS IS SUPPORTED BY 00 UTC GEFS QPF MODEL CLIMATE IN
THE MAXIMUM PERCENTILES FOR THESE AREAS THURSDAY AFTERNOON...WHICH
HAS BEEN NOTED AS A FLASH FLOOD SIGNAL IN PREVIOUS EVENTS ACROSS
THE CONUS. THUS...HAVE ISSUED A FLASH FLOOD WATCH FOR THE SOUTH
CENTRAL AND JAMES RIVER VALLEY FOR THURSDAY. ALTHOUGH SOME OF
THESE AREAS HAVE BEEN RELATIVELY DRY OVER THE RECENT
WEEKS...POTENTIAL EXCESSIVE RAINFALL RATES MAY STILL LEAD TO FLASH
FLOODING EVEN WITH DRY SOILS. FLASH FLOODING OF URBAN
AREAS...INCLUDING MANDAN...BISMARCK AND JAMESTOWN ARE ALSO
POSSIBLE WITH THESE SLOW MOVING...HEAVY RAINFALL PRODUCING STORMS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 302 PM CDT WED AUG 5 2015
SHORTWAVE TROUGH WILL BE EXITING THE JAMES RIVER VALLEY THURSDAY
NIGHT/06-12 FRIDAY AS LIKELY POPS DWINDLE AND THE PRECIPITATION COMES
TO AN END. UPPER LOW WILL MOVE ACROSS SOUTHERN CANADA FRIDAY
THROUGH SATURDAY DRAGGING TWO SURFACE COLD FRONTS THROUGH...ONE
FRIDAY NIGHT AND A SECONDARY COLD FRONT SATURDAY. FRIDAY LOOKS DRY
WITH THE INITIAL FRONT. HOWEVER FRIDAY NIGHT AND
SATURDAY...ASSOCIATED WITH THE SECOND FRONT WILL BE THE RIGHT
ENTRANCE REGION OF A 70KT-80KT JET STREAK SLIDING THROUGH CENTRAL
NORTH DAKOTA ATOP OF A SURFACE LOW PRESSURE SCOOTING ACROSS
NORTHERN SOUTH DAKOTA. AN AREA OF PRECIPITATION DEVELOPS OVER OR
NEAR SOUTHERN NORTH DAKOTA SATURDAY IN RESPONSE TO THE LOW LEVEL
CONVERGENCE AND THE UPPER LEVEL DIVERGENCE AREA ASSOCIATED WITH
THE JET. ALTHOUGH WEAK NORTHWEST FLOW ENSUES SATURDAY NIGHT INTO
SUNDAY...THERE IS SOME QUESTION AS TO WHETHER OR NOT THE FRONT
STALLS ALONG/NEAR OR SOUTH OF THE SOUTHERN BORDER SUNDAY FOR
CONTINUED PRECIPITATION CHANCES. AS OF NOW IT APPEARS THAT CHANCES
FOR PRECIPITATION BEGIN ALONG INTERSTATE 94 AND INCREASE SOUTH
TOWARDS THE BORDER SUNDAY. THEREAFTER A CENTRAL CONUS UPPER LEVEL
RIDGE DEVELOPS WITH A TROUGH SETTLING INTO THE WEST FOR DRY AND
WARM CONDITIONS MONDAY AND TUESDAY. THERE MAY BE POTENTIAL
SHORTWAVES TRYING TO BREAK DOWN THE RIDGE BY MID WEEK OR SIGNS OF
THE RIDGE SHIFTING EAST A BIT FOR POSSIBLE SHOWERS AND
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1255 AM CDT THU AUG 6 2015
MAIN HAZARDS TO AVIATION WILL BE THUNDERSTORMS AND POSSIBLE MVFR
TO IFR CONDITIONS IN THE THUNDERSTORM VCNTY. AT MIDNIGHT CDT...A
WARM FRONT EXTENDED ACROSS CENTRAL NORTH DAKOTA IN THE VICINITY OF
HIGHWAY 83. A COLD FRONT EXTENDED ACROSS THE BORDER OF MONTANA AND
SOUTHERN SASKATCHEWAN. THE COLD FRONT WILL MOVE SOUTHEAST AND...WITH
VIGOROUS UPPER LEVEL SHORTWAVE ENERGY...WILL BECOME THE FOCUS FOR
NUMEROUS THUNDERSTORMS ACROSS WEST AND CENTRAL NORTH DAKOTA THIS
MORNING AND THROUGH MUCH OF THE DAY ON THURSDAY. CONDITIONS MAY
BECOME MVFR TO IFR IN THE AREAS OF THUNDERSTORMS KMOT AFT 01Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 10 AM CDT /9 AM MDT/ THIS MORNING THROUGH
THIS EVENING FOR NDZ019>023-025-034>037-042-045>048-050-051.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1033 PM EDT FRI AUG 7 2015
.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS FROM THE NORTH TONIGHT. HOWEVER...MID
LEVEL DISTURBANCES WILL CROSS UNDER NORTHWEST FLOW THROUGH THE WEEKEND.
LOW PRESSURE SYSTEM APPROACHES MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
DECREASED COVERAGE OF THE SLIGHT CHANCE POPS OVERNIGHT.
OTHERWISE...CONVECTIVE ACTIVITY CONTINUES TO BE ON THE WANE.
PREVIOUS DISCUSSION...
WEAK SFC HIGH PRESSURE BUILDS FROM THE NORTH TONIGHT BRINGING
DRIER CONDITIONS. ALTHOUGH MODELS KEEP HIGH LOW LEVEL MOISTURE
ACROSS THE SOUTHERN COAL FIELDS THROUGH AT LEAST 09Z TONIGHT.
MODELS SUGGEST MID LEVEL DISTURBANCES RIDING ACROSS THE AREA
UNDER NORTHWEST FLOW ALOFT. THESE DISTURBANCES COULD BRING CLOUDS
AND SLIGHT CHANCES FOR RAIN SHOWERS INTO THE WEEKEND.
WENT WITH THE SUPER BLEND FOR TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
REAMPLIFICATION OF THE MEAN TROF COMMENCES EARLY NEXT WEEK WHICH
WILL BE MARKED BY A STRONG COLD FRONTAL PASSAGE LATE MONDAY WITH
SHRA/TSRA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
DIFFICULT AVIATION FORECAST TONIGHT WITH A FEW DIFFERENT THINGS
HAPPENING. FIRST...WEAK SOUTHEAST UPSLOPE SHOULD CREATE LOW
STRATUS IN THE IFR RANGE OVER THE MOUNTAINS...AND WILL INCLUDE BKW
IN THIS. SO...EXPECTING LOWERING CEILINGS THERE THROUGH THE
NIGHT...AND SLOW TO MIX OUT WITH HEATING SATURDAY.
SECOND...WATCHING THE SHORT WAVE TROUGH MOVING SOUTHEASTWARD
THROUGH THE GREAT LAKES THAT SHOULD SPREAD A SCATTERED TO BROKEN
LOW TO MID LEVEL CLOUD DECK INTO THE MIDDLE OHIO VALLEY TONIGHT.
THINK THE RAP MODEL IS HANDLING THIS BEST...BUT THIS COULD HAMPER
FOG DEVELOPMENT IN THE VALLEYS. MOS GUIDANCE IS ALL OVER THE PLACE
AND GENERALLY PESSIMISTIC DESPITE THE INCREASED CLOUD COVER...SO
WILL THROW THOSE SOLUTIONS OUT. LAMP IS VERY PESSIMISTIC AS WELL
WITH LIFR FOR THE BULK OF THE OVERNIGHT PERIOD. IN THE END...THINK
THE BEST BET FOR FOG WILL BE ALONG THE OHIO VALLEY
TERMINALS...BRIEFLY...TOWARDS DAWN. WILL CARRY 3SM THERE...BUT NO
LOWER SINCE TEMPOS LIE BEYOND THE ALLOWED TIME PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: TIMING AND COVERAGE OF IFR CONDITIONS
OVERNIGHT MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 08/08/15
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY M M H H H H M M M M M M
HTS CONSISTENCY H M M M M M M M M M M M
BKW CONSISTENCY M M M M M M M M M H M M
EKN CONSISTENCY H H M M M M M M M M M M
PKB CONSISTENCY H H M M M M M M M M M M
CKB CONSISTENCY M M M H M M M M M M M M
AFTER 00Z SUNDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...ARJ/26
SHORT TERM...30
LONG TERM...30
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
722 PM EDT FRI AUG 7 2015
.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS FROM THE NORTH TONIGHT. HOWEVER...MID
LEVEL DISTURBANCES WILL CROSS UNDER NORTHWEST FLOW THROUGH THE WEEKEND.
LOW PRESSURE SYSTEM APPROACHES MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
NO MAJOR CHANGES FOR THE EVENING FORECAST. AWAITING THE DISSOLVING
OF THE SHOWERS AND STORMS OVER THE MOUNTAINS THAT HAVE PRODUCED
LOCALLY HEAVY DOWNPOURS ON THE ORDER OF ONE HALF TO ONE INCH OF
RAIN. THESE HAVE BEEN SLOW TO MOVE TO THE SOUTH.
PREVIOUS DISCUSSION...
WEAK SFC HIGH PRESSURE BUILDS FROM THE NORTH TONIGHT BRINGING
DRIER CONDITIONS. ALTHOUGH MODELS KEEP HIGH LOW LEVEL MOISTURE
ACROSS THE SOUTHERN COAL FIELDS THROUGH AT LEAST 09Z TONIGHT.
MODELS SUGGEST MID LEVEL DISTURBANCES RIDING ACROSS THE AREA
UNDER NORTHWEST FLOW ALOFT. THESE DISTURBANCES COULD BRING CLOUDS
AND SLIGHT CHANCES FOR RAIN SHOWERS INTO THE WEEKEND.
WENT WITH THE SUPER BLEND FOR TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
REAMPLIFICATION OF THE MEAN TROF COMMENCES EARLY NEXT WEEK WHICH
WILL BE MARKED BY A STRONG COLD FRONTAL PASSAGE LATE MONDAY WITH
SHRA/TSRA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
DIFFICULT AVIATION FORECAST TONIGHT WITH A FEW DIFFERENT THINGS
HAPPENING. FIRST...WEAK SOUTHEAST UPSLOPE SHOULD CREATE LOW
STRATUS IN THE IFR RANGE OVER THE MOUNTAINS...AND WILL INCLUDE BKW
IN THIS. SO...EXPECTING LOWERING CEILINGS THERE THROUGH THE
NIGHT...AND SLOW TO MIX OUT WITH HEATING SATURDAY.
SECOND...WATCHING THE SHORT WAVE TROUGH MOVING SOUTHEASTWARD
THROUGH THE GREAT LAKES THAT SHOULD SPREAD A SCATTERED TO BROKEN
LOW TO MID LEVEL CLOUD DECK INTO THE MIDDLE OHIO VALLEY TONIGHT.
THINK THE RAP MODEL IS HANDLING THIS BEST...BUT THIS COULD HAMPER
FOG DEVELOPMENT IN THE VALLEYS. MOS GUIDANCE IS ALL OVER THE PLACE
AND GENERALLY PESSIMISTIC DESPITE THE INCREASED CLOUD COVER...SO
WILL THROW THOSE SOLUTIONS OUT. LAMP IS VERY PESSIMISTIC AS WELL
WITH LIFR FOR THE BULK OF THE OVERNIGHT PERIOD. IN THE END...THINK
THE BEST BET FOR FOG WILL BE ALONG THE OHIO VALLEY
TERMINALS...BRIEFLY...TOWARDS DAWN. WILL CARRY 3SM THERE...BUT NO
LOWER SINCE TEMPOS LIE BEYOND THE ALLOWED TIME PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: TIMING AND COVERAGE OF IFR CONDITIONS
OVERNIGHT MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 21 22 23 00 01 02 03 04 05 06 07 08
EDT 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04
CRW CONSISTENCY M M M M M M M M M M L L
HTS CONSISTENCY H H H H H H H M M M L L
BKW CONSISTENCY M M M M M M M M M M M M
EKN CONSISTENCY H H H M M M M M M M M L
PKB CONSISTENCY H H H H H H H M M M L L
CKB CONSISTENCY H H H H M H H H H H H M
AFTER 00Z SUNDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...ARJ/26
SHORT TERM...30
LONG TERM...30
AVIATION...26
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
735 AM EDT THU AUG 6 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK TO THE SOUTH OF PENNSYLVANIA THROUGH THE
END OF THE WEEK AND MOVE OFFSHORE THIS WEEKEND. HIGH PRESSURE WILL
MOVE INTO THE AREA BEHIND THE DEPARTING LOW. RAIN IS LIKELY NEAR
THE MASON DIXON LINE THIS AFTERNOON INTO TONIGHT BEFORE CONDITIONS
DRY OUT FOR THE MOST PART ON FRIDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
COOL NORTHERN TIER VALLEYS ARE SOCKED IN WITH THICK FOG EARLY THIS
MORNING. EXPECT THIS TO DISSIPATE SHORTLY PAST 12Z. MID TO HIGH
CLOUDS WILL BE INCREASING FROM SW TO NE THROUGH MID DAY IN
ADVANCE OF WELL DEFINED MID/UPPER LEVEL SYSTEM /FOR THIS TIME OF
YEAR/ AND DEVELOPING SFC LOW OVER THE MID MS/LOWER OH VALLEY. SFC
HIGH EXTENDING SEWD FROM THE UPPER GREAT LAKES AND LOW PW AIR WILL
KEEP DRY WX INTACT THIS MORNING.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM FRIDAY/...
SHORT TERM MODELS ARE IN GOOD AGREEMENT IN TAKING THE H5 HEIGHT
FALL CENTER AND SFC REFLECTION TO THE SOUTH OF CENTRAL PA THROUGH
THE PERIOD...FROM KY EWD ACROSS THE CENTRAL APPALACHIANS AND INTO
THE SRN MID ATLC. HOWEVER...THERE CONTINUES TO BE SOME UNCERTAINTY
WITH RESPECT TO THE QPF DISTRIBUTIONS/WARM SEASON OVERRUNNING
SCENARIO TO THE NORTH OF THE SFC WAVE. FOR THIS REASON STAYED
PRETTY CLOSE TO A BLENDED SOLUTION WITH WPC QPF...WHICH LEANED
TOWARD THE HI RES MODELS. THE FINAL NDFD FCST WILL SHOW AN
INCREASE IN POPS OVER THE FAR SRN TIER ZONES FROM THE PA TURNPIKE
SWD TO THE MASON DIXON LINE. THE LATEST HRRR AND 00Z SSEO ARE
STRADDLING THE PA/MD LINE WITH SHOWER ACTIVITY THRU 18-21Z TIME
FRAME. THERE SHOULD BE A FAIRLY SHARP GRADIENT TO THE NRN EDGE OF
THE RAIN AND MODELS MAY BE TOO BULLISH ON WAA/OVERRUNNING
COMPONENT IN LIEU OF CONVECTION FARTHER TO THE SOUTH. LATER SHIFTS
MAY NEED TO MAKE N-S ADJUSTMENTS IN P0PS/QPF AS THE PCPN PATTERN
EVOLVES THROUGH EARLY TONIGHT. POPS WILL TREND LOWER FROM NW TO SE
INTO EARLY FRIDAY WITH M/CLR SKIES/PATCHY FOG OVER THE NW MTNS BY
FRIDAY MORNING.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A FEW LINGERING SHRA MAY AFFECT THE SE COUNTIES INTO PART OF
FRIDAY...AS SFC LOW PUSHES OFF THE COAST NR THE SOUTHERN DELMARVA.
MDL SOUNDINGS IMPLY PERSISTENT CLOUDINESS THRU MUCH OF FRIDAY
ACROSS THE SOUTHERN COUNTIES...WHERE MOIST EASTERLY FLOW WILL
LINGER. ACROSS NORTHERN PA...A MUCH BRIGHTER DAY EXPECTED. GEFS
MEAN 925/850 TEMPS SUPPORT MAX TEMPS BTWN 75-80F.
GENERALLY FAIR AND SEASONABLE WX EXPECTED THIS WEEKEND...AS
CENTRAL PA WILL BE IN REGION OF LG SCALE SUBSIDENCE ON EAST SIDE
OF UPPER RIDGE OVR THE MISS VALLEY. WILL PAINT A SLIGHT CHC OF PM
SHRA/TSRA SUNDAY TO ACCOUNT FOR PASSAGE OF WEAK SHORTWAVE RIDING N
PERIPHERY OF MISS VALLEY UPPER RIDGE. GEFS PLUMES INDICATE A
GRADUAL WARMING TREND INTO THE WEEKEND...WITH READINGS CLOSE TO
AVERAGE FOR EARLY AUGUST.
SOME TIMING DIFFS HAVE ARISEN WITH ANTICIPATED COLD FRONT EARLY
NEXT WEEK. HAVE SIDED WITH THE GEFS/ECENS AND OPER CANADIAN...ALL
OF WHICH INDICATE A FROPA LATE MONDAY/EARLY TUE...AS OPPOSED TO
THE OPER ECMWF...WHICH IS 12-24HRS SLOWER AND IMPLIES A DRY
MONDAY. HAVE INCREASED CHC OF SHRA/TSRA MON PM...AS HGTS FALL
AHEAD OF APPROACHING TROF AND A SURGE OF HIGHER PWATS WORK INTO
THE REGION ON SW FLOW. DEEPENING TROUGH AND SLOWING COLD FRONT
WILL LKLY RESULT IN LINGERING SHRA/TSRA INTO TUESDAY. GEFS AND EC
BOTH CURRENTLY INDICATE THE POSSIBILITY OF HVY RAINFALL ACROSS
EASTERN PA ASSOC WITH THIS SLOWING FRONT. COOLER/DRIER WX IS
LIKELY BY MIDWEEK. HOWEVER...UPPER TROF/COOL MID LVL TEMPS OVR THE
REGION COULD PROMOTE PM SHOWERS...ESP OVR THE MTNS.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
BRIEF VLIFR FOG/ST AT BFD HAS DISSIPATED. LOOK FOR VFR TO PREVAIL
TODAY WITH LGT/VRB WINDS AND EXPANSIVE SHIELD OF LYRD MID AND HIGH
CLOUDS OVERSPREADING THE AIRSPACE FROM SW TO NE THRU THE AFTERNOON.
LOW PRESSURE WILL TRACK EWD FROM THE MID MS/LOWER OH VALLEYS INTO
THE SRN MID ATLC STATES ON FRIDAY AND OFF THE EAST COAST ON SAT.
HIGH PRESSURE/VFR WILL MOVE INTO THE AIRSPACE BEHIND THE
DEPARTING SFC LOW.
THE GREATEST RISK FOR RAIN/SUB-VFR CIGS WILL BE ACROSS THE SRN
1/3 OF THE AIRSPACE TONIGHT INTO EARLY FRIDAY. CONFIDENCE IS LOW
AND THEREFORE KEPT CIGS AOA 050.
OUTLOOK...
SAT-SUN...PATCHY A.M. FOG/VFR.
MON...VFR WITH CHC OF TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DEVOIR/FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
721 AM EDT THU AUG 6 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK TO THE SOUTH OF PENNSYLVANIA THROUGH THE
END OF THE WEEK AND MOVE OFFSHORE THIS WEEKEND. HIGH PRESSURE WILL
MOVE INTO THE AREA BEHIND THE DEPARTING LOW. RAIN IS LIKELY NEAR
THE MASON DIXON LINE THIS AFTERNOON INTO TONIGHT BEFORE CONDITIONS
DRY OUT FOR THE MOST PART ON FRIDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
COOL NORTHERN TIER VALLEYS ARE SOCKED IN WITH THICK FOG EARLY THIS
MORNING. EXPECT THIS TO DISSIPATE SHORTLY PAST 12Z. MID TO HIGH
CLOUDS WILL BE INCREASING FROM SW TO NE THROUGH MID DAY IN
ADVANCE OF WELL DEFINED MID/UPPER LEVEL SYSTEM /FOR THIS TIME OF
YEAR/ AND DEVELOPING SFC LOW OVER THE MID MS/LOWER OH VALLEY. SFC
HIGH EXTENDING SEWD FROM THE UPPER GREAT LAKES AND LOW PW AIR WILL
KEEP DRY WX INTACT THIS MORNING.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM FRIDAY/...
SHORT TERM MODELS ARE IN GOOD AGREEMENT IN TAKING THE H5 HEIGHT
FALL CENTER AND SFC REFLECTION TO THE SOUTH OF CENTRAL PA THROUGH
THE PERIOD...FROM KY EWD ACROSS THE CENTRAL APPALACHIANS AND INTO
THE SRN MID ATLC. HOWEVER...THERE CONTINUES TO BE SOME UNCERTAINTY
WITH RESPECT TO THE QPF DISTRIBUTIONS/WARM SEASON OVERRUNNING
SCENARIO TO THE NORTH OF THE SFC WAVE. FOR THIS REASON STAYED
PRETTY CLOSE TO A BLENDED SOLUTION WITH WPC QPF...WHICH LEANED
TOWARD THE HI RES MODELS. THE FINAL NDFD FCST WILL SHOW AN
INCREASE IN POPS OVER THE FAR SRN TIER ZONES FROM THE PA TURNPIKE
SWD TO THE MASON DIXON LINE. THE LATEST HRRR AND 00Z SSEO ARE
STRADDLING THE PA/MD LINE WITH SHOWER ACTIVITY THRU 18-21Z TIME
FRAME. THERE SHOULD BE A FAIRLY SHARP GRADIENT TO THE NRN EDGE OF
THE RAIN AND MODELS MAY BE TOO BULLISH ON WAA/OVERRUNNING
COMPONENT IN LIEU OF CONVECTION FARTHER TO THE SOUTH. LATER SHIFTS
MAY NEED TO MAKE N-S ADJUSTMENTS IN P0PS/QPF AS THE PCPN PATTERN
EVOLVES THROUGH EARLY TONIGHT. POPS WILL TREND LOWER FROM NW TO SE
INTO EARLY FRIDAY WITH M/CLR SKIES/PATCHY FOG OVER THE NW MTNS BY
FRIDAY MORNING.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A FEW LINGERING SHRA MAY AFFECT THE SE COUNTIES INTO PART OF
FRIDAY...AS SFC LOW PUSHES OFF THE COAST NR THE SOUTHERN DELMARVA.
MDL SOUNDINGS IMPLY PERSISTENT CLOUDINESS THRU MUCH OF FRIDAY
ACROSS THE SOUTHERN COUNTIES...WHERE MOIST EASTERLY FLOW WILL
LINGER. ACROSS NORTHERN PA...A MUCH BRIGHTER DAY EXPECTED. GEFS
MEAN 925/850 TEMPS SUPPORT MAX TEMPS BTWN 75-80F.
GENERALLY FAIR AND SEASONABLE WX EXPECTED THIS WEEKEND...AS
CENTRAL PA WILL BE IN REGION OF LG SCALE SUBSIDENCE ON EAST SIDE
OF UPPER RIDGE OVR THE MISS VALLEY. WILL PAINT A SLIGHT CHC OF PM
SHRA/TSRA SUNDAY TO ACCOUNT FOR PASSAGE OF WEAK SHORTWAVE RIDING N
PERIPHERY OF MISS VALLEY UPPER RIDGE. GEFS PLUMES INDICATE A
GRADUAL WARMING TREND INTO THE WEEKEND...WITH READINGS CLOSE TO
AVERAGE FOR EARLY AUGUST.
SOME TIMING DIFFS HAVE ARISEN WITH ANTICIPATED COLD FRONT EARLY
NEXT WEEK. HAVE SIDED WITH THE GEFS/ECENS AND OPER CANADIAN...ALL
OF WHICH INDICATE A FROPA LATE MONDAY/EARLY TUE...AS OPPOSED TO
THE OPER ECMWF...WHICH IS 12-24HRS SLOWER AND IMPLIES A DRY
MONDAY. HAVE INCREASED CHC OF SHRA/TSRA MON PM...AS HGTS FALL
AHEAD OF APPROACHING TROF AND A SURGE OF HIGHER PWATS WORK INTO
THE REGION ON SW FLOW. DEEPENING TROUGH AND SLOWING COLD FRONT
WILL LKLY RESULT IN LINGERING SHRA/TSRA INTO TUESDAY. GEFS AND EC
BOTH CURRENTLY INDICATE THE POSSIBILITY OF HVY RAINFALL ACROSS
EASTERN PA ASSOC WITH THIS SLOWING FRONT. COOLER/DRIER WX IS
LIKELY BY MIDWEEK. HOWEVER...UPPER TROF/COOL MID LVL TEMPS OVR THE
REGION COULD PROMOTE PM SHOWERS...ESP OVR THE MTNS.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
M/CLR SKIES WITH HIGH CI INCR FROM W TO E. IFR FOG PSBL AT BFD BUT
CONFIDENCE IN SUSTAINED IFR IS LOW THEREFORE CUT BACK TO TEMPO
3SM BR SCT001.
LOW PRESSURE WILL TRACK EWD FROM THE MID MS/LOWER OH VALLEYS INTO
THE SRN MID ATLC STATES ON FRIDAY AND OFF THE EAST COAST ON SAT.
HIGH PRESSURE/VFR WILL MOVE INTO THE AIRSPACE BEHIND THE
DEPARTING SFC LOW. THE GREATEST RISK FOR RAIN/SUB-VFR CIGS WILL BE
ACROSS THE SRN 1/3 OF THE AIRSPACE TONIGHT INTO EARLY FRIDAY.
CONFIDENCE IS LOW AND THEREFORE KEPT CIGS AOA 050.
OUTLOOK...
SAT-SUN...PATCHY A.M. FOG/VFR.
MON...VFR WITH CHC OF TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...STEINBUGL
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
526 AM EDT THU AUG 6 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK TO THE SOUTH OF PENNSYLVANIA THROUGH THE
END OF THE WEEK AND MOVE OFFSHORE THIS WEEKEND. HIGH PRESSURE WILL
MOVE INTO THE AREA BEHIND THE DEPARTING LOW. RAIN IS LIKELY NEAR
THE MASON DIXON LINE THIS AFTERNOON INTO TONIGHT BEFORE CONDITIONS
DRY OUT FOR THE MOST PART ON FRIDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
PATCHY FOG ACROSS THE NORTHERN TIER WILL DISSIPATE AROUND 12Z.
HIGH-TO-MID CLOUDS WILL INCREASE FROM SW TO NE THROUGH MID DAY IN
ADVANCE OF WELL DEFINED MID/UPPER LEVEL SYSTEM /FOR THIS TIME OF
YEAR/ AND DEVELOPING SFC LOW OVER THE MID MS/LOWER OH VALLEY. SFC
HIGH EXTENDING SEWD FROM THE UPPER GREAT LAKES AND LOW PW AIR WILL
KEEP DRY WX INTACT THIS MORNING.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM FRIDAY/...
SHORT TERM MODELS ARE IN GOOD AGREEMENT IN TAKING THE H5 HEIGHT
FALL CENTER AND SFC REFLECTION TO THE SOUTH OF CENTRAL PA THROUGH
THE PERIOD...FROM KY EWD ACROSS THE CENTRAL APPALACHIANS AND INTO
THE SRN MID ATLC. HOWEVER...THERE CONTINUES TO BE SOME UNCERTAINTY
WITH RESPECT TO THE QPF DISTRIBUTIONS/WARM SEASON OVERRUNNING
SCENARIO TO THE NORTH OF THE SFC WAVE. FOR THIS REASON STAYED
PRETTY CLOSE TO A BLENDED SOLUTION WITH WPC QPF...WHICH LEANED
TOWARD THE HI RES MODELS. THE FINAL NDFD FCST WILL SHOW AN
INCREASE IN POPS OVER THE FAR SRN TIER ZONES FROM THE PA TURNPIKE
SWD TO THE MASON DIXON LINE. THE LATEST HRRR AND 00Z SSEO ARE
STRADDLING THE PA/MD LINE WITH SHOWER ACTIVITY THRU 18-21Z TIME
FRAME. THERE SHOULD BE A FAIRLY SHARP GRADIENT TO THE NRN EDGE OF
THE RAIN AND MODELS MAY BE TOO BULLISH ON WAA/OVERRUNNING
COMPONENT IN LIEU OF CONVECTION FARTHER TO THE SOUTH. LATER SHIFTS
MAY NEED TO MAKE N-S ADJUSTMENTS IN P0PS/QPF AS THE PCPN PATTERN
EVOLVES THROUGH EARLY TONIGHT. POPS WILL TREND LOWER FROM NW TO SE
INTO EARLY FRIDAY WITH M/CLR SKIES/PATCHY FOG OVER THE NW MTNS BY
FRIDAY MORNING.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A FEW LINGERING SHRA MAY AFFECT THE SE COUNTIES INTO PART OF
FRIDAY...AS SFC LOW PUSHES OFF THE COAST NR THE SOUTHERN DELMARVA.
MDL SOUNDINGS IMPLY PERSISTENT CLOUDINESS THRU MUCH OF FRIDAY
ACROSS THE SOUTHERN COUNTIES...WHERE MOIST EASTERLY FLOW WILL
LINGER. ACROSS NORTHERN PA...A MUCH BRIGHTER DAY EXPECTED. GEFS
MEAN 925/850 TEMPS SUPPORT MAX TEMPS BTWN 75-80F.
GENERALLY FAIR AND SEASONABLE WX EXPECTED THIS WEEKEND...AS
CENTRAL PA WILL BE IN REGION OF LG SCALE SUBSIDENCE ON EAST SIDE
OF UPPER RIDGE OVR THE MISS VALLEY. WILL PAINT A SLIGHT CHC OF PM
SHRA/TSRA SUNDAY TO ACCOUNT FOR PASSAGE OF WEAK SHORTWAVE RIDING N
PERIPHERY OF MISS VALLEY UPPER RIDGE. GEFS PLUMES INDICATE A
GRADUAL WARMING TREND INTO THE WEEKEND...WITH READINGS CLOSE TO
AVERAGE FOR EARLY AUGUST.
SOME TIMING DIFFS HAVE ARISEN WITH ANTICIPATED COLD FRONT EARLY
NEXT WEEK. HAVE SIDED WITH THE GEFS/ECENS AND OPER CANADIAN...ALL
OF WHICH INDICATE A FROPA LATE MONDAY/EARLY TUE...AS OPPOSED TO
THE OPER ECMWF...WHICH IS 12-24HRS SLOWER AND IMPLIES A DRY
MONDAY. HAVE INCREASED CHC OF SHRA/TSRA MON PM...AS HGTS FALL
AHEAD OF APPROACHING TROF AND A SURGE OF HIGHER PWATS WORK INTO
THE REGION ON SW FLOW. DEEPENING TROUGH AND SLOWING COLD FRONT
WILL LKLY RESULT IN LINGERING SHRA/TSRA INTO TUESDAY. GEFS AND EC
BOTH CURRENTLY INDICATE THE POSSIBILITY OF HVY RAINFALL ACROSS
EASTERN PA ASSOC WITH THIS SLOWING FRONT. COOLER/DRIER WX IS
LIKELY BY MIDWEEK. HOWEVER...UPPER TROF/COOL MID LVL TEMPS OVR THE
REGION COULD PROMOTE PM SHOWERS...ESP OVR THE MTNS.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
M/CLR SKIES WITH HIGH CI INCR FROM W TO E. IFR FOG PSBL AT BFD BUT
CONFIDENCE IN SUSTAINED IFR IS LOW THEREFORE CUT BACK TO TEMPO
3SM BR SCT001.
LOW PRESSURE WILL TRACK EWD FROM THE MID MS/LOWER OH VALLEYS INTO
THE SRN MID ATLC STATES ON FRIDAY AND OFF THE EAST COAST ON SAT.
HIGH PRESSURE/VFR WILL MOVE INTO THE AIRSPACE BEHIND THE
DEPARTING SFC LOW. THE GREATEST RISK FOR RAIN/SUB-VFR CIGS WILL BE
ACROSS THE SRN 1/3 OF THE AIRSPACE TONIGHT INTO EARLY FRIDAY.
CONFIDENCE IS LOW AND THEREFORE KEPT CIGS AOA 050.
OUTLOOK...
SAT-SUN...PATCHY A.M. FOG/VFR.
MON...VFR WITH CHC OF TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
419 AM EDT THU AUG 6 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK TO THE SOUTH OF PENNSYLVANIA THROUGH THE
END OF THE WEEK AND MOVE OFFSHORE THIS WEEKEND. HIGH PRESSURE WILL
MOVE INTO THE AREA BEHIND THE DEPARTING LOW. RAIN IS LIKELY NEAR
THE MASON DIXON LINE THIS AFTERNOON INTO TONIGHT BEFORE CONDITIONS
DRY OUT FOR THE MOST PART ON FRIDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
PATCHY FOG ACROSS THE NORTHERN TIER WILL DISSIPATE AROUND 12Z.
HIGH-TO-MID CLOUDS WILL INCREASE FROM SW TO NE THROUGH MID DAY IN
ADVANCE OF WELL DEFINED MID/UPPER LEVEL SYSTEM /FOR THIS TIME OF
YEAR/ AND DEVELOPING SFC LOW OVER THE MID MS/LOWER OH VALLEY. SFC
HIGH EXTENDING SEWD FROM THE UPPER GREAT LAKES AND LOW PW AIR WILL
KEEP DRY WX INTACT THIS MORNING.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM FRIDAY/...
SHORT TERM MODELS ARE IN GOOD AGREEMENT IN TAKING THE H5 HEIGHT
FALL CENTER AND SFC REFLECTION TO THE SOUTH OF CENTRAL PA THROUGH
THE PERIOD...FROM KY EWD ACROSS THE CENTRAL APPALACHIANS AND INTO
THE SRN MID ATLC. HOWEVER...THERE CONTINUES TO BE SOME UNCERTAINTY
WITH RESPECT TO THE QPF DISTRIBUTIONS/WARM SEASON OVERRUNNING
SCENARIO TO THE NORTH OF THE SFC WAVE. FOR THIS REASON STAYED
PRETTY CLOSE TO A BLENDED SOLUTION WITH WPC QPF...WHICH LEANED
TOWARD THE HI RES MODELS. THE FINAL NDFD FCST WILL SHOW AN
INCREASE IN POPS OVER THE FAR SRN TIER ZONES FROM THE PA TURNPIKE
SWD TO THE MASON DIXON LINE. THE LATEST HRRR AND 00Z SSEO ARE
STRADDLING THE PA/MD LINE WITH SHOWER ACTIVITY THRU 18-21Z TIME
FRAME. THERE SHOULD BE A FAIRLY SHARP GRADIENT TO THE NRN EDGE OF
THE RAIN AND MODELS MAY BE TOO BULLISH ON WAA/OVERRUNNING
COMPONENT IN LIEU OF CONVECTION FARTHER TO THE SOUTH. LATER SHIFTS
MAY NEED TO MAKE N-S ADJUSTMENTS IN P0PS/QPF AS THE PCPN PATTERN
EVOLVES THROUGH EARLY TONIGHT. POPS WILL TREND LOWER FROM NW TO SE
INTO EARLY FRIDAY WITH M/CLR SKIES/PATCHY FOG OVER THE NW MTNS BY
FRIDAY MORNING.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
SEVERAL SUCCESSIVE LOWS MOVING THROUGH CANADA WILL DOMINATE THE
WEATHER PATTERN THROUGH THE MID TO LONG TERM. MINOR DIFFERENCES
REMAIN REGARDING EXACT TRACK OF SFC LOW PASSING SOUTH OF PA
THURSDAY NIGHT INTO EARLY FRIDAY. LOOKS LIKE THE SOUTHERN TIER
COUNTIES WILL BE ON NORTHERN PERIPHERY OF THE PRECIP..SO WILL
MENTION CHC/SCHC OF SHOWERS ACROSS THE SOUTHERN THIRD OF THE STATE
THRU FRIDAY AM. BEHIND THIS SYSTEM...ODDS NOW APPEAR TO FAVOR FAIR
AND SEASONABLE WX THIS WEEKEND...AS CENTRAL PA WILL BE IN REGION
OF LG SCALE SUBSIDENCE ON EAST SIDE OF UPPER RIDGE OVR THE MISS
VALLEY. GEFS TEMP PLUMES INDICATE A GRADUAL WARMING TREND INTO THE
WEEKEND...AS HGTS RISE ACROSS PA.
MED RANGE GUIDANCE EXHIBITING RELATIVELY LITTLE SPREAD WITH MASS
FIELDS INTO NEXT WEEK...LENDING CONFIDENCE IN A COLD FRONTAL
PASSAGE AND ROUND OF SHRA/TSRA ARND NEXT TUESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
M/CLR SKIES WITH HIGH CI INCR FROM W TO E. IFR FOG PSBL AT BFD BUT
CONFIDENCE IN SUSTAINED IFR IS LOW THEREFORE CUT BACK TO TEMPO
3SM BR SCT001.
LOW PRESSURE WILL TRACK EWD FROM THE MID MS/LOWER OH VALLEYS INTO
THE SRN MID ATLC STATES ON FRIDAY AND OFF THE EAST COAST ON SAT.
HIGH PRESSURE/VFR WILL MOVE INTO THE AIRSPACE BEHIND THE
DEPARTING SFC LOW. THE GREATEST RISK FOR RAIN/SUB-VFR CIGS WILL BE
ACROSS THE SRN 1/3 OF THE AIRSPACE TONIGHT INTO EARLY FRIDAY.
CONFIDENCE IS LOW AND THEREFORE KEPT CIGS AOA 050.
OUTLOOK...
SAT-SUN...PATCHY A.M. FOG/VFR.
MON...VFR WITH CHC OF TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...FITZGERALD/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1120 PM MDT WED AUG 5 2015
.UPDATE...
ISSUED AT 821 PM MDT WED AUG 5 2015
00Z KUNR SOUNDING SHOWED DECENT SUPPORT FOR WIND...WHICH DID OCCUR
WITH CONVECTION WEST OF RAPID CITY. WATER VAPOUR SHOWED
RESPONSIBLE SHORTWAVE PLOWING NORTHEAST FROM WY INTO THE DAKOTAS.
SECONDARY WAVE NOTED ACROSS NORTHWEST WY...WHICH THE 00Z GUIDANCE
PICKS UP ON AND MOVES NORTHEAST INTO ND OVERNIGHT. TAIL END OF
WAVE MAY PRODUCE ANOTHER ROUND OF -SHRA/-TSRA ACROSS THE CWA LATER
THIS EVENING BEHIND INITIAL WAVE WHICH IS MOVING ONTO THE SD
PLAINS. STRENGTH OF MUCAPE SLOWLY WANES OVERNIGHT. FORECAST
TWEAKED FOR TIMING...BUT LARGELY IN GOOD SHAPE.
&&
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 218 PM MDT WED AUG 5 2015
UPPER WAVE CONTINUES TO APPROACH THE REGION...AS UPPER LOW
CIRCULATES OVER SOUTHWEST CANADA. WEAK SHOWERS ACROSS NORTHEAST
WYOMING HAVE BEEN DISSIPATING AS THEY MOVE EASTWARD...WITH JUST
SOME CLOUDS PUSHING INTO THE CWA. WITH LIGHT AND VARIABLE
WINDS...TEMPS ARE GENERALLY IN THE 80S.
SHOWERS AND THUNDERSTORMS STILL EXPECTED TO DEVELOP ALONG A LINE OF
FRONTOGENESIS/Q-VECTOR CONVERGENCE ACROSS THE WESTERN CWA AND EXPAND
EASTWARD. MODELS ARE HINTING AT AN INITIAL WAVE WITH BEST FORCING
JUST NORTHWEST OF THE CWA BRINGING A BAND OF STORMS THROUGH THE
NORTHERN HILLS AND NORTHWESTERN SD...WITH A SECONDARY WAVE
IMMEDIATELY FOLLOWING WITH SCATTERED SHOWERS/STORMS. HRRR THIS
MORNING WAS PRETTY CONSISTENT WITH A SQUALL LINE MOVING ACROSS THE
NORTHERN HILLS AND NORTHWEST SD EARLY THIS EVENING...BUT LATER RUNS
ARE SHOWING A MORE SCATTERED FORM. MLCAPE IS UNIMPRESSIVE AROUND
750 J/KG ON THE PLAINS WITH 1500 J/KG OVER THE HILLS...BUT SHEAR
IS 35-45 KTS SO WOULD NOT RULE OUT A STRONG TO SEVERE STORM. MAIN
THREAT WILL BE STRONG WINDS.
SURFACE LOW WILL MOVE ACROSS SD THURSDAY. A TIGHT PRESSURE GRADIENT
BEHIND THE LOW WILL CREATE SOME BREEZY NORTHWEST WINDS ACROSS THE SD
PLAINS AND ALSO BRING IN SOME COOLER AIR TO NORTHWESTERN SD.
SHOWERS/THUNDERSTORMS WILL CONTINUE ACROSS NORTHWESTERN/CENTRAL SD
DURING THE DAY UNTIL THE WAVE FINALLY TRANSITIONS EASTWARD OUT OF
THE REGION. DRY WEATHER IS THEN EXPECTED FOR THURSDAY NIGHT. HIGHS
THURSDAY WILL BE IN THE 80S...70S IN THE BLACK HILLS.
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 218 PM MDT WED AUG 5 2015
PROGRESSIVE FLOW WILL CONTINUE THROUGH THE WEEKEND WITH
A STRONGER UPPER LEVEL TROUGH ON TRACK FOR SAT-SUN. HOWEVER...STRONG
INDICATIONS ARE IN PLACE FOR SIG LONG WAVE RIDGING OVER CENTRAL NOAM
EARLY NEXT WEEK WHICH WOULD SUPPORT A MUCH WARMER PERIOD FOR THE
REGION BY THE MIDDLE OF NEXT WEEK. HIGHEST POPS IN THE PERIOD ARE IN
THE SAT-SUN PERIOD AS THE CURRENT UPPER LOW OFF THE COAST OF CA
EJECTS NE ACROSS THE ROCKIES AND INTO THE REGION. PLENTY OF LL
MOISTURE WILL BE IN PLACE WITH INCREASING LARGE SCALE ASCENT AND
MONSOON MOISTURE TO SUPPORT SCT SHRA/TS IN THIS PERIOD ESP ACROSS
THE NORTHERN ZONES. LINGERING CHANCES FOR PRECIP SUNDAY NIGHT WITH
DRY WEATHER EXPECTED EARLY NEXT WEEK...PERHAPS A SLIGHT CHANCE OF A
TS OVER THE BLACK HILLS TUES WHEN BETTER MOISTURE RETURNS TO THE
AREA AHEAD OF A LEE TROUGH. SOME SEVERE THREAT WILL BE IN PLACE
SAT/SUN WITH INCREASING FLOW SUPPORTING DECENT BULK SHEAR /0-6KM/
NUMBERS ABOVE 35 KNOTS...WITH 1-2 KJ/KG OF CAPE OVER THE SE FA.
HOWEVER...STILL MUCH UNCERTAINTY PER SYSTEM TRACK/SPEED TO ASCERTAIN
A BETTER GRASP ON SEVERE PROBS.
AFTER A SEASONAL DAY FRIDAY...COOLER TEMPS ARE ON TRACK FOR THE
WEEKEND...WITH A MODEST COOL DOWN EXPECTED SUNDAY.. MUCH WARMER
WEATHER ON TRACK FOR TUE AND BEYOND WITH 90S EXPECTED. A FEW 100/S A
CERTAINLY NOT OUT OF THE QUESTION...ESP ON THE SD PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1119 PM MDT WED AUG 5 2015
SCATTERED TSRA WILL MOVE ACROSS THE AREA TONIGHT...CLEARING OUT
FROM WEST TO EAST EARLY THURSDAY MORNING AS A FRONTAL BOUNDARY
MOVES THROUGH. GUSTY WEST/NORTHWEST WINDS EXPECTED ON THE PLAINS
BEHIND THE BOUNDARY TOMORROW. LOCAL IFR CONDITIONS EXPECTED WITH
THE STORMS...BUT VFR CONDITIONS OTHERWISE WILL PREVAIL.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...POJORLIE
LONG TERM...JC
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
939 AM CDT THU AUG 6 2015
.UPDATE...
FOR MORNING UPDATE.
&&
.DISCUSSION...
MORNING UPDATE INCLUDES BACKING OFF POPS JUST A LITTLE BASED ON
CURRENT RADAR TRENDS...ESPECIALLY ACROSS THE WEST. ALSO...REDUCED
THE COVERAGE OF THUNDER. LATEST GUIDANCE SUGGESTS THE POTENTIAL
CONTINUES FOR ADDITIONAL DEVELOPMENT EAST OF I-65 THIS AFTERNOON.
NOT TOO CRAZY ABOUT THIS BUT WILL KEEP SOME POPS IN THROUGH THE
LATE AFTERNOON BEFORE BACKING OFF OVERNIGHT.
CLOUD COVER WILL LIKELY HAMPER HIGHS TODAY. MIGHT BE A LITTLE WARM
WITH CURRENT FORECAST BUT WILL MONITOR AND UPDATE IF NEEDED.
UPDATES ALREADY OUT.
UNGER
&&
.AVIATION...
12Z TAF DISCUSSION.
LEANED HEAVILY ON HRRR MODEL FOR TIMING OF IMPACTS. -SHRA/-TSRA
TO CONTINUE SPREADING ACROSS AREA AIRPORTS THROUGH 16Z AT CKV/BNA
AND 22Z AT CSV. VCSH AFTER THAT TIME AT AIRPORTS WITH MVFR/IFR
CIGS/VIS DEVELOPING THURSDAY EVENING/NIGHT.
SHAMBURGER
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
652 AM CDT THU AUG 6 2015
.UPDATE...
12Z TAF DISCUSSION.
&&
.AVIATION UPDATE...
LEANED HEAVILY ON HRRR MODEL FOR TIMING OF IMPACTS. -SHRA/-TSRA
TO CONTINUE SPREADING ACROSS AREA AIRPORTS THROUGH 16Z AT CKV/BNA
AND 22Z AT CSV. VCSH AFTER THAT TIME AT AIRPORTS WITH MVFR/IFR
CIGS/VIS DEVELOPING THURSDAY EVENING/NIGHT.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 346 AM CDT THU AUG 6 2015/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE ACROSS THE FORECAST
AREA THIS EARLY MORNING WITH THE HEAVIEST RAIN CONCENTRATED OVER
SOUTHERN MIDDLE TENNESSEE AS WELL AS NORTHEAST MISSISSIPPI AND
NORTHWEST ALABAMA. FOR TODAY...IT WILL BE A SOMEWHAT COMPLEX
FORECAST SITUATION AS THE ONGOING STORMS ARE A FEW HOURS EARLY IN
ARRIVAL AND WILL IMPACT WHAT HAPPENS LATER TODAY. SHORT RANGE
MODELS ARE HINTING AT REDEVELOPMENT THIS AFTERNOON ESPECIALLY NEAR
AND EAST OF INTERSTATE 65. IF STORMS CAN GET GOING THIS
AFTERNOON...THESE WOULD HAVE THE POTENTIAL TO BE STRONG TO MAYBE
EVEN SEVERE WITH WIND GUSTS BEING THE MAIN THREATS.
REGARDLESS OF WHETHER STORMS REDEVELOP OR NOT...CLOUD COVER AND
LIGHT SHOWERS WILL GENERALLY REMAIN OVER THE AREA FOR MUCH OF THE
DAY IMPACTING HIGH TEMPERATURES. AS LONG AS THE AREA DOES NOT
BREAK OUT INTO FULL ON SUNSHINE TODAY...LOW TO MID 80S SEEM
REASONABLE WITH ALL MOS GUIDANCE AGREEING WITH THIS SOLUTION TOO.
ONE CONCERN IS ACROSS NORTHWEST MIDDLE TENNESSEE WHERE CONFIDENCE
IS NOT QUITE AS HIGH THAT CONVECTION WILL REMAIN OVER THIS AREA
ALL DAY...SO SOMETHING TO DEFINITELY WATCH WITH THE MORNING
UPDATE.
RAIN WILL QUICKLY END FROM WEST TO EAST THIS EVENING WITH MOST OF
THE RAIN OUT OF THE AREA BY MIDNIGHT. MOSTLY DRY CONDITIONS CAN BE
EXPECTED ON FRIDAY ALTHOUGH SOME RESIDUAL CLOUD COVER WILL REMAIN
KEEPING A LID ON TEMPERATURES FROM REACHING THE 90 DEGREE MARK
WITH LOCATIONS REMAINING IN THE MID TO UPPER 80S. BY THE
WEEKEND...RAIN CHANCES NOW LOOK MINIMAL AT BEST WITH THE UPPER
RIDGE SITUATED OVER TEXAS BUILDING OVER THE AREA. IN FACT...THIS
WILL SPELL A NOTICEABLE INCREASE IN HIGHS WITH LOW TO MID 90S
EXPECTED BOTH DAYS WITH LITTLE RELIEF EXPECTED.
BY SUNDAY NIGHT...THE EASTERN FRINGES OF THIS RIDGE BEGIN TO
BREAK DOWN AND SHOWERS AND THUNDERSTORMS DEVELOP AHEAD OF A COLD
FRONT EXPECTED MONDAY NIGHT INTO TUESDAY. THE GOOD NEWS IS THAT
THIS COLD FRONT IS STILL IN ALL OF THE MEDIUM RANGE MODELS AND
STILL FORECAST TO MOVE ACROSS MIDDLE TENNESSEE WITH VERY PLEASANT
WEATHER FOR EARLY AUGUST EXPECTED AS MUCH DRIER AIR FILTERS INTO
THE REGION. HIGHS TUESDAY THROUGH THURSDAY LOOK TO BE IN THE MID
TO UPPER 80S WITH MARKEDLY LOWER HUMIDITY UNDER SUNNY SKIES...NOT
A BAD SCENARIO AT ALL.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 83 69 86 68 / 100 20 10 10
CLARKSVILLE 84 67 85 67 / 70 20 10 0
CROSSVILLE 79 67 79 65 / 100 60 10 10
COLUMBIA 84 69 86 68 / 100 20 10 10
LAWRENCEBURG 84 69 87 69 / 90 20 10 10
WAVERLY 84 67 85 69 / 80 20 10 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
105 PM CDT THU AUG 6 2015
.AVIATION...
THERE IS A SLIM...ABOUT 10 PERCENT...CHANCE OF A HIGH-BASED
T-STORM IN THE VICINITY OF KPVW BETWEEN 21 UTC AND 02 UTC.
OTHERWISE...VFR CONDITIONS WILL PREVAIL WITH SURFACE WINDS
REMAINING MAINLY SOUTH TO SOUTHWEST AND BECOMING A BIT GUSTY IN
THE AFTERNOON HOURS.
&&
.PREV DISCUSSION... /ISSUED 659 AM CDT THU AUG 6 2015/
AVIATION...
UPPER LEVEL HIGH PRESSURE RIDGE WILL EXPAND FURTHER ACROSS THE
SOUTHERN PLAINS REGION TODAY AND TONIGHT LEADING TO HOT AND MOSTLY
DRY CONDITIONS. LINGERING MID LEVEL MOISTURE AND WEAK CONVERGENCE
WITHIN A SURFACE TROUGH COULD LEAD TO ISOLATED HIGH-BASED
THUNDERSTORMS LATER THIS AFTERNOON UNTIL EARLY THIS EVENING NORTH-
NORTHWEST OF KLBB BUT POSSIBLY NEAR KPVW. COVERAGE EXPECTED TO BE
TOO SPARSE FOR INCLUSION WITHIN THE KPVW TAF FOR NOW. RMCQUEEN
PREV DISCUSSION... /ISSUED 357 AM CDT THU AUG 6 2015/
SHORT TERM...
UPPER LEVEL HIGH PRESSURE WILL CONTINUE TO EXPAND ACROSS THE AREA
TODAY AND TONIGHT. THIS WILL LEAD TO BETTER SURFACE WARMING WITH
HIGHS TODAY A DEGREE OR MAYBE TWO WARMER FOR MOST OF THE AREA...AND
SHOULD BE THE HOTTEST DAY OF SUMMER SO FAR. SURFACE MOISTURE STILL
ELEVATED THOUGH WILL TREND DOWNWARDS DURING THE PEAK MIXING
PERIOD THIS AFTERNOON...SO WILL ALSO LIMIT HEAT INDEX VALUES
SOMEWHAT. WE REMAIN A BIT UNCERTAIN IF MODELS ARE CORRECTLY
FORECASTING SURFACE DEWPOINT VALUES...AND IF UNDERPLAYED BY ONLY 2
OR 3 DEGREES MAY REQUIRE CONSIDERATION OF A HEAT ADVISORY IN THE
SOUTHEAST CORNER OF OUR AREA. BUT FOR NOW WE SIDE WITH THE BULK OF
OUR GUIDANCE WHICH COMES UP JUST SHORT OF HEAT ADVISORY LEVELS.
WHILE THE UPPER RIDGE WILL CONTINUE TO EXPAND...CAPPING STILL LOOKS
MARGINAL AND ACTUALLY FORECAST TO WEAKEN DURING PEAK DEEP MIXING
ACROSS THE NORTHWEST CORNER OF OUR AREA. A SHORT WAVE PASSING BY TO
THE NORTH WILL DRAG ANOTHER BATCH OF LIMITED MID LEVEL MOISTURE
ACROSS THIS AREA THIS AFTERNOON AND EARLY EVENING. A SURFACE TROUGH
ALSO WILL PROVIDE WEAK CONVERGENCE IN OUR NORTHWEST. SHORT RANGE
SOLUTIONS OF RAP AND HRRR HAVE ONCE AGAIN BEEN INSISTENT TONIGHT ON
ISOLATED TO WIDELY SCATTERED COVERAGE OF HIGH-BASED THUNDERSTORMS
LATE THIS AFTERNOON INTO THE EARLY EVENING...ALTHOUGH LESS COVERAGE
THAN EXPERIENCED YESTERDAY. SURFACE BASED CAPES APPEAR MOSTLY UNDER
1000 JOULES PER KILOGRAM LATER TODAY SO STORMS MAY HAVE A LITTLE
LESS OOMPH AS WELL. EVEN SO...WE WILL INCLUDE A SLIGHT CHANCE FOR
THUNDERSTORMS FOR LATER THIS AFTERNOON AND EARLY THIS EVENING IN OUR
NORTHWEST CORNER. ANY STORMS SHOULD QUICKLY DISSIPATE WITH LOSS OF
SURFACE HEATING EARLY THIS EVENING AND ANOTHER QUIET AND MILD NIGHT
WILL FOLLOW. RMCQUEEN
LONG TERM...
FRIDAY AND INTO THE WEEKEND WILL REMAIN HOT...ALTHOUGH A COUPLE OF
DEGREES COOLER THAN TODAY AS THE UPPER HIGH IS NUDGED EAST AHEAD OF
A DISTURBANCE PUSHING ONSHORE CENTRAL CALIFORNIA. HIGH TEMPERATURES
WILL REMAIN MOSTLY IN THE MID 90S TO NEAR THE CENTURY MARK ON THE
CAPROCK WHILE LOCALES IN THE ROLLING PLAINS AND FAR SOUTHEAST
PANHANDLE RESIDE IN THE UPPER 90S TO AROUND 104-105 DEGREES.
LATE SUNDAY CONTINUES TO BEAR WATCHING IN TERMS OF ISOLATED
THUNDERSTORM POTENTIAL NEAR THE FAR SOUTHWEST PANHANDLE INTO THE
NORTHERN SOUTH PLAINS. ENERGY FROM THE PREVIOUSLY MENTIONED
DISTURBANCE...AT THIS TIME ROTATING THROUGH THE NORTHERN PLAINS INTO
THE UPPER MIDWEST...WILL SEND A FRONTAL BOUNDARY SOUTHWARD THROUGH
THE PLAINS. AT THE SAME TIME...A SUBTROPICAL MOISTURE PLUME WILL
ATTEMPT TO BEND EASTWARD ACROSS THE TEXAS/NEW MEXICO BORDER. WHETHER
THIS ENHANCED MID-UPPER MOISTURE MAKES IT INTO THE LONE STAR STATE
WILL DEPEND ON PLACEMENT OF THE UPPER HIGH AS LATER SUNDAY LOOKS TO
BE THE TIME AT WHICH THIS FEATURE BEGINS RETROGRADING WESTWARD.
BELIEVE ENOUGH CONSISTENCY HAS BEEN SHOWN AT THIS TIME TO WARRANT
SLIGHT CHANCE MENTION ACROSS PARMER COUNTY...BUT WILL CONTINUE TO
MONITOR SAID UNCERTAINTIES GOING FORWARD.
HEADING INTO NEXT WEEK...UPPER HIGH STILL LOOKS TO BUILD WEST AND
NORTHWEST WHILE AMPLIFYING...THUS SHIFTING THE H85 THERMAL RIDGE
AXIS IN THE SAME DIRECTION AND KEEPING TEMPERATURES MAINLY IN THE
90S LOCALLY. CYCLONIC FLOW FROM EASTERN CANADA BACK INTO THE OHIO
VALLEY LOOKS TO KEEP SOME SEMBLANCE OF A FRONTAL BOUNDARY IN PLACE
AHEAD OF A SURFACE RIDGE PUSHING SOUTH THROUGH THE MISSISSIPPI
VALLEY. NWP NOW SUGGESTING THAT A PERIOD OF CONTINUED UPSLOPE FLOW
MAY THEREFORE BE IN THE OFFING FOR A PERIOD NEXT WEEK ALONG WITH
CONTINUED ENHANCED MOISTURE TRAPPED UNDERNEATH THE UPPER HIGH.
HAVE KEPT CONDITIONS DRY FOR NOW AFTER SUNDAY EVENING GIVEN THE
UNCERTAINTY IN THE DETAILED SYNOPTIC EVOLUTION AND EXTENT/AMOUNT
OF MOISTURE THAT WILL BE AVAILABLE. THUNDERSTORM CHANCES AND
COOLER TEMPERATURES WOULD BE THE SENSIBLE WEATHER RESULTS IF THIS
SCENARIO DOES INDEED PLAY OUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 69 97 67 97 / 0 0 0 0
TULIA 70 98 69 98 / 10 0 0 0
PLAINVIEW 71 98 70 97 / 10 0 0 0
LEVELLAND 71 99 70 98 / 0 0 0 0
LUBBOCK 74 100 72 98 / 0 0 0 0
DENVER CITY 70 99 70 98 / 0 0 0 0
BROWNFIELD 71 99 71 98 / 0 0 0 0
CHILDRESS 76 104 75 103 / 0 0 0 0
SPUR 75 102 73 101 / 0 0 0 0
ASPERMONT 78 104 77 104 / 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
659 AM CDT THU AUG 6 2015
.AVIATION...
UPPER LEVEL HIGH PRESSURE RIDGE WILL EXPAND FURTHER ACROSS THE
SOUTHERN PLAINS REGION TODAY AND TONIGHT LEADING TO HOT AND MOSTLY
DRY CONDITIONS. LINGERING MID LEVEL MOISTURE AND WEAK CONVERGENCE
WITHIN A SURFACE TROUGH COULD LEAD TO ISOLATED HIGH-BASED
THUNDERSTORMS LATER THIS AFTERNOON UNTIL EARLY THIS EVENING NORTH-
NORTHWEST OF KLBB BUT POSSIBLY NEAR KPVW. COVERAGE EXPECTED TO BE
TOO SPARSE FOR INCLUSION WITHIN THE KPVW TAF FOR NOW. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 357 AM CDT THU AUG 6 2015/
SHORT TERM...
UPPER LEVEL HIGH PRESSURE WILL CONTINUE TO EXPAND ACROSS THE AREA
TODAY AND TONIGHT. THIS WILL LEAD TO BETTER SURFACE WARMING WITH
HIGHS TODAY A DEGREE OR MAYBE TWO WARMER FOR MOST OF THE AREA...AND
SHOULD BE THE HOTTEST DAY OF SUMMER SO FAR. SURFACE MOISTURE STILL
ELEVATED THOUGH WILL TREND DOWNWARDS DURING THE PEAK MIXING
PERIOD THIS AFTERNOON...SO WILL ALSO LIMIT HEAT INDEX VALUES
SOMEWHAT. WE REMAIN A BIT UNCERTAIN IF MODELS ARE CORRECTLY
FORECASTING SURFACE DEWPOINT VALUES...AND IF UNDERPLAYED BY ONLY 2
OR 3 DEGREES MAY REQUIRE CONSIDERATION OF A HEAT ADVISORY IN THE
SOUTHEAST CORNER OF OUR AREA. BUT FOR NOW WE SIDE WITH THE BULK OF
OUR GUIDANCE WHICH COMES UP JUST SHORT OF HEAT ADVISORY LEVELS.
WHILE THE UPPER RIDGE WILL CONTINUE TO EXPAND...CAPPING STILL LOOKS
MARGINAL AND ACTUALLY FORECAST TO WEAKEN DURING PEAK DEEP MIXING
ACROSS THE NORTHWEST CORNER OF OUR AREA. A SHORT WAVE PASSING BY TO
THE NORTH WILL DRAG ANOTHER BATCH OF LIMITED MID LEVEL MOISTURE
ACROSS THIS AREA THIS AFTERNOON AND EARLY EVENING. A SURFACE TROUGH
ALSO WILL PROVIDE WEAK CONVERGENCE IN OUR NORTHWEST. SHORT RANGE
SOLUTIONS OF RAP AND HRRR HAVE ONCE AGAIN BEEN INSISTENT TONIGHT ON
ISOLATED TO WIDELY SCATTERED COVERAGE OF HIGH-BASED THUNDERSTORMS
LATE THIS AFTERNOON INTO THE EARLY EVENING...ALTHOUGH LESS COVERAGE
THAN EXPERIENCED YESTERDAY. SURFACE BASED CAPES APPEAR MOSTLY UNDER
1000 JOULES PER KILOGRAM LATER TODAY SO STORMS MAY HAVE A LITTLE
LESS OOMPH AS WELL. EVEN SO...WE WILL INCLUDE A SLIGHT CHANCE FOR
THUNDERSTORMS FOR LATER THIS AFTERNOON AND EARLY THIS EVENING IN OUR
NORTHWEST CORNER. ANY STORMS SHOULD QUICKLY DISSIPATE WITH LOSS OF
SURFACE HEATING EARLY THIS EVENING AND ANOTHER QUIET AND MILD NIGHT
WILL FOLLOW. RMCQUEEN
LONG TERM...
FRIDAY AND INTO THE WEEKEND WILL REMAIN HOT...ALTHOUGH A COUPLE OF
DEGREES COOLER THAN TODAY AS THE UPPER HIGH IS NUDGED EAST AHEAD OF
A DISTURBANCE PUSHING ONSHORE CENTRAL CALIFORNIA. HIGH TEMPERATURES
WILL REMAIN MOSTLY IN THE MID 90S TO NEAR THE CENTURY MARK ON THE
CAPROCK WHILE LOCALES IN THE ROLLING PLAINS AND FAR SOUTHEAST
PANHANDLE RESIDE IN THE UPPER 90S TO AROUND 104-105 DEGREES.
LATE SUNDAY CONTINUES TO BEAR WATCHING IN TERMS OF ISOLATED
THUNDERSTORM POTENTIAL NEAR THE FAR SOUTHWEST PANHANDLE INTO THE
NORTHERN SOUTH PLAINS. ENERGY FROM THE PREVIOUSLY MENTIONED
DISTURBANCE...AT THIS TIME ROTATING THROUGH THE NORTHERN PLAINS INTO
THE UPPER MIDWEST...WILL SEND A FRONTAL BOUNDARY SOUTHWARD THROUGH
THE PLAINS. AT THE SAME TIME...A SUBTROPICAL MOISTURE PLUME WILL
ATTEMPT TO BEND EASTWARD ACROSS THE TEXAS/NEW MEXICO BORDER. WHETHER
THIS ENHANCED MID-UPPER MOISTURE MAKES IT INTO THE LONE STAR STATE
WILL DEPEND ON PLACEMENT OF THE UPPER HIGH AS LATER SUNDAY LOOKS TO
BE THE TIME AT WHICH THIS FEATURE BEGINS RETROGRADING WESTWARD.
BELIEVE ENOUGH CONSISTENCY HAS BEEN SHOWN AT THIS TIME TO WARRANT
SLIGHT CHANCE MENTION ACROSS PARMER COUNTY...BUT WILL CONTINUE TO
MONITOR SAID UNCERTAINTIES GOING FORWARD.
HEADING INTO NEXT WEEK...UPPER HIGH STILL LOOKS TO BUILD WEST AND
NORTHWEST WHILE AMPLIFYING...THUS SHIFTING THE H85 THERMAL RIDGE
AXIS IN THE SAME DIRECTION AND KEEPING TEMPERATURES MAINLY IN THE
90S LOCALLY. CYCLONIC FLOW FROM EASTERN CANADA BACK INTO THE OHIO
VALLEY LOOKS TO KEEP SOME SEMBLANCE OF A FRONTAL BOUNDARY IN PLACE
AHEAD OF A SURFACE RIDGE PUSHING SOUTH THROUGH THE MISSISSIPPI
VALLEY. NWP NOW SUGGESTING THAT A PERIOD OF CONTINUED UPSLOPE FLOW
MAY THEREFORE BE IN THE OFFING FOR A PERIOD NEXT WEEK ALONG WITH
CONTINUED ENHANCED MOISTURE TRAPPED UNDERNEATH THE UPPER HIGH.
HAVE KEPT CONDITIONS DRY FOR NOW AFTER SUNDAY EVENING GIVEN THE
UNCERTAINTY IN THE DETAILED SYNOPTIC EVOLUTION AND EXTENT/AMOUNT
OF MOISTURE THAT WILL BE AVAILABLE. THUNDERSTORM CHANCES AND
COOLER TEMPERATURES WOULD BE THE SENSIBLE WEATHER RESULTS IF THIS
SCENARIO DOES INDEED PLAY OUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 99 69 97 67 / 10 0 0 0
TULIA 99 70 98 69 / 10 10 0 0
PLAINVIEW 100 71 98 70 / 10 10 0 0
LEVELLAND 101 71 99 70 / 10 0 0 0
LUBBOCK 100 74 100 72 / 0 0 0 0
DENVER CITY 102 70 99 70 / 0 0 0 0
BROWNFIELD 101 71 99 71 / 0 0 0 0
CHILDRESS 104 76 104 75 / 0 0 0 0
SPUR 103 75 102 73 / 0 0 0 0
ASPERMONT 106 78 104 77 / 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
651 AM CDT THU AUG 6 2015
.AVIATION...
INTERMITTENT MVFR CIGS FOR THE I-35 TAF SITES SHOULD LIFT TO
VFR BY 13Z AT AUS AND 14Z AT SAT/SSF. TIMING IS BASED ON THE LAST
FEW DAYS AND THE HRRR WHICH HANDLED THE ONSET OF MVFR CIGS BEST
THIS MORNING DESPITE SIMULATING LOWER IFR CLOUD DECKS. THE MAIN
FORECAST ISSUE PAST THE NEXT FEW HOURS WILL BE GUSTY SOUTHERLY
WINDS UP TO 25 KTS FOR THE I-35 TAF SITES BETWEEN 2-6Z TONIGHT
UNTIL LLJ DECOUPLES FROM THE SURFACE. MODEL GUIDANCE IS TRENDING
TOWARDS MVFR CIGS DEVELOPING AGAIN AT SAT/SSF BRIEFLY TOMORROW
MORNING...BUT LOW LEVEL MOISTURE AND ONSHORE FLOW SHOULD BE LESS
THAN TODAY SO CONFIDENCE WAS TOO LOW TO INCLUDE AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 322 AM CDT THU AUG 6 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
FOCUS FOR THE SHORT TERM...AND LIKELY THE NEXT FEW DAYS IS ON THE
MAX TEMPS AND DEWPOINT TEMPERATURES RESULTING IN APPARENT TEMPS
BRIEFLY REACHING OR EXCEEDING HEAT ADVISORY CRITERIA. THE
COMPLICATION FOR TODAY IS WHILE CONFIDENCE IS FAIRLY HIGH THAT A
FEW OBSERVATIONS WILL REACH THE REQUIRED 108 DEGREE HEAT INDEX
CRITERION...THIS MAY ONLY BE BRIEF AS DEWPOINTS SHOULD DECREASE
THROUGH THE AFTERNOON. THUS CONFIDENCE IN COUNTY WIDE...PERSISTENT
ADVISORY LEVEL INDICES IS LOWER. MODEL VERIFICATION HAS BEEN IN
THE 98-99 PERCENT RANGE ON BOTH MAX T AND MIN RH AND HAVE NOT
DEVIATED WITH THIS PACKAGE.
THE TIME AND SPATIAL EXTENT CONFIDENCE ISSUES...AS WELL AS
INTEROFFICE COLLABORATION...LED TO THE DECISION TO CONTINUE WITH
HANDLING THIS AFTERNOON WITH SPS AND HWO MENTIONS AND INCLUDING
AREA SPECIFICITY. WILL ALSO BRIEF NEXT SHIFT ON THE POSSIBLE
POTENTIAL FOR A SHORT FUSE ADVISORY SHOULD THE FORECAST NOT GO AS
PLANNED.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE SAME FORECAST QUESTIONS WILL COME INTO PLAY FOR THE NEXT FEW
DAYS WITH INCREASING CONFIDENCE IN THE CHANCE FOR ADVISORIES TO BE
ISSUED THIS WEEKEND. AGAIN...AS IN PREVIOUS FORECASTS...THE DAY
THAT APPEARS THE HOTTEST OVER THE NEXT 5 DAYS IS SATURDAY. SOME
SLIGHTLY LOWER SURFACE MOISTURE SUNDAY AND MONDAY MAY RESULT IN A
DEGREE OR TWO OF...FOR LACK OF A BETTER WORD...RELIEF BUT
ADVISORIES MAY STILL BE NEEDED REGARDLESS SINCE MAX TEMPS ALONE
WILL FLIRT WITH CRITERIA.
BY THE MIDDLE OF NEXT WEEK...A VERY SIMILAR SET UP TO LAST WEEKS
BOUNDARY PASSAGE THAT RESULTED IN ISOLATED TO SCATTERED STORM
DEVELOPMENT ACROSS THE CWA WILL DEVELOP. A SOUTHWARD COLD FRONT
GENERATED BY TROUGHING OVER THE MS RIVER VALLEY WILL SPREAD
WESTWARD AND POTENTIALLY IMPACT THE CWA FROM THE NORTHEAST
WEDNESDAY AFTERNOON. WITH FORECAST SOUNDINGS SHOWING DRY ADIABATIC
LAPSE RATES UP TO ABOUT 700 MB AND A VERY DRY LOW LEVEL
ATMOSPHERE...THINK BOUNDARY INDUCED COMPRESSIONAL WARMING MAY
RESULT IN RECORD HIGHS BEING REALIZED WEDNESDAY
AFTERNOON...ESPECIALLY FOR THE AUSTIN AREA. AS FAR AS POPS
GO...PWATS ARE IN THE 1.7-1.8 RANGE EVEN WITH THE VERY DRY LOW
LEVEL ATMOSPHERE. INSTABILITY WILL BE MEAGER WITH THE DRY SURFACE
AIR AND THE ECMWF KEEPS THE AREA DRY...BUT GFS ON THE OTHER HAND
IS QUITE A BIT MORE BULLISH ON QPF DEVELOPMENT. BELIEVE THE BEST
CHANCE FOR POPS WILL BE IF THE BOUNDARY CAN INTERACT WITH THE SEA
BREEZE AND GENERATE ENOUGH LIFT FOR A FEW SHOWERS ACROSS THE
EASTERNMOST ZONES AND COASTAL PLAINS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 101 77 101 77 103 / 0 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 100 75 100 75 102 / 0 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 101 75 101 76 103 / 0 0 0 0 0
BURNET MUNI AIRPORT 100 76 101 75 102 / 0 0 0 0 0
DEL RIO INTL AIRPORT 103 79 103 80 104 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 100 77 101 76 103 / 0 0 0 0 0
HONDO MUNI AIRPORT 100 75 100 75 102 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 100 76 100 76 102 / 0 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 100 77 100 78 102 / 0 0 0 0 0
SAN ANTONIO INTL AIRPORT 100 78 100 77 102 / 0 0 0 0 0
STINSON MUNI AIRPORT 101 77 101 77 103 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...LH
SYNOPTIC/GRIDS...TB3
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
357 AM CDT THU AUG 6 2015
.SHORT TERM...
UPPER LEVEL HIGH PRESSURE WILL CONTINUE TO EXPAND ACROSS THE AREA
TODAY AND TONIGHT. THIS WILL LEAD TO BETTER SURFACE WARMING WITH
HIGHS TODAY A DEGREE OR MAYBE TWO WARMER FOR MOST OF THE AREA...AND
SHOULD BE THE HOTTEST DAY OF SUMMER SO FAR. SURFACE MOISTURE STILL
ELEVATED THOUGH WILL TREND DOWNWARDS DURING THE PEAK MIXING
PERIOD THIS AFTERNOON...SO WILL ALSO LIMIT HEAT INDEX VALUES
SOMEWHAT. WE REMAIN A BIT UNCERTAIN IF MODELS ARE CORRECTLY
FORECASTING SURFACE DEWPOINT VALUES...AND IF UNDERPLAYED BY ONLY 2
OR 3 DEGREES MAY REQUIRE CONSIDERATION OF A HEAT ADVISORY IN THE
SOUTHEAST CORNER OF OUR AREA. BUT FOR NOW WE SIDE WITH THE BULK OF
OUR GUIDANCE WHICH COMES UP JUST SHORT OF HEAT ADVISORY LEVELS.
WHILE THE UPPER RIDGE WILL CONTINUE TO EXPAND...CAPPING STILL LOOKS
MARGINAL AND ACTUALLY FORECAST TO WEAKEN DURING PEAK DEEP MIXING
ACROSS THE NORTHWEST CORNER OF OUR AREA. A SHORT WAVE PASSING BY TO
THE NORTH WILL DRAG ANOTHER BATCH OF LIMITED MID LEVEL MOISTURE
ACROSS THIS AREA THIS AFTERNOON AND EARLY EVENING. A SURFACE TROUGH
ALSO WILL PROVIDE WEAK CONVERGENCE IN OUR NORTHWEST. SHORT RANGE
SOLUTIONS OF RAP AND HRRR HAVE ONCE AGAIN BEEN INSISTENT TONIGHT ON
ISOLATED TO WIDELY SCATTERED COVERAGE OF HIGH-BASED THUNDERSTORMS
LATE THIS AFTERNOON INTO THE EARLY EVENING...ALTHOUGH LESS COVERAGE
THAN EXPERIENCED YESTERDAY. SURFACE BASED CAPES APPEAR MOSTLY UNDER
1000 JOULES PER KILOGRAM LATER TODAY SO STORMS MAY HAVE A LITTLE
LESS OOMPH AS WELL. EVEN SO...WE WILL INCLUDE A SLIGHT CHANCE FOR
THUNDERSTORMS FOR LATER THIS AFTERNOON AND EARLY THIS EVENING IN OUR
NORTHWEST CORNER. ANY STORMS SHOULD QUICKLY DISSIPATE WITH LOSS OF
SURFACE HEATING EARLY THIS EVENING AND ANOTHER QUIET AND MILD NIGHT
WILL FOLLOW. RMCQUEEN
.LONG TERM...
FRIDAY AND INTO THE WEEKEND WILL REMAIN HOT...ALTHOUGH A COUPLE OF
DEGREES COOLER THAN TODAY AS THE UPPER HIGH IS NUDGED EAST AHEAD OF
A DISTURBANCE PUSHING ONSHORE CENTRAL CALIFORNIA. HIGH TEMPERATURES
WILL REMAIN MOSTLY IN THE MID 90S TO NEAR THE CENTURY MARK ON THE
CAPROCK WHILE LOCALES IN THE ROLLING PLAINS AND FAR SOUTHEAST
PANHANDLE RESIDE IN THE UPPER 90S TO AROUND 104-105 DEGREES.
LATE SUNDAY CONTINUES TO BEAR WATCHING IN TERMS OF ISOLATED
THUNDERSTORM POTENTIAL NEAR THE FAR SOUTHWEST PANHANDLE INTO THE
NORTHERN SOUTH PLAINS. ENERGY FROM THE PREVIOUSLY MENTIONED
DISTURBANCE...AT THIS TIME ROTATING THROUGH THE NORTHERN PLAINS INTO
THE UPPER MIDWEST...WILL SEND A FRONTAL BOUNDARY SOUTHWARD THROUGH
THE PLAINS. AT THE SAME TIME...A SUBTROPICAL MOISTURE PLUME WILL
ATTEMPT TO BEND EASTWARD ACROSS THE TEXAS/NEW MEXICO BORDER. WHETHER
THIS ENHANCED MID-UPPER MOISTURE MAKES IT INTO THE LONE STAR STATE
WILL DEPEND ON PLACEMENT OF THE UPPER HIGH AS LATER SUNDAY LOOKS TO
BE THE TIME AT WHICH THIS FEATURE BEGINS RETROGRADING WESTWARD.
BELIEVE ENOUGH CONSISTENCY HAS BEEN SHOWN AT THIS TIME TO WARRANT
SLIGHT CHANCE MENTION ACROSS PARMER COUNTY...BUT WILL CONTINUE TO
MONITOR SAID UNCERTAINTIES GOING FORWARD.
HEADING INTO NEXT WEEK...UPPER HIGH STILL LOOKS TO BUILD WEST AND
NORTHWEST WHILE AMPLIFYING...THUS SHIFTING THE H85 THERMAL RIDGE
AXIS IN THE SAME DIRECTION AND KEEPING TEMPERATURES MAINLY IN THE
90S LOCALLY. CYCLONIC FLOW FROM EASTERN CANADA BACK INTO THE OHIO
VALLEY LOOKS TO KEEP SOME SEMBLANCE OF A FRONTAL BOUNDARY IN PLACE
AHEAD OF A SURFACE RIDGE PUSHING SOUTH THROUGH THE MISSISSIPPI
VALLEY. NWP NOW SUGGESTING THAT A PERIOD OF CONTINUED UPSLOPE FLOW
MAY THEREFORE BE IN THE OFFING FOR A PERIOD NEXT WEEK ALONG WITH
CONTINUED ENHANCED MOISTURE TRAPPED UNDERNEATH THE UPPER HIGH.
HAVE KEPT CONDITIONS DRY FOR NOW AFTER SUNDAY EVENING GIVEN THE
UNCERTAINTY IN THE DETAILED SYNOPTIC EVOLUTION AND EXTENT/AMOUNT
OF MOISTURE THAT WILL BE AVAILABLE. THUNDERSTORM CHANCES AND
COOLER TEMPERATURES WOULD BE THE SENSIBLE WEATHER RESULTS IF THIS
SCENARIO DOES INDEED PLAY OUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 99 69 97 67 / 10 0 0 0
TULIA 99 70 98 69 / 10 10 0 0
PLAINVIEW 100 71 98 70 / 10 10 0 0
LEVELLAND 101 71 99 70 / 10 0 0 0
LUBBOCK 100 74 100 72 / 0 0 0 0
DENVER CITY 102 70 99 70 / 0 0 0 0
BROWNFIELD 101 71 99 71 / 0 0 0 0
CHILDRESS 104 76 104 75 / 0 0 0 0
SPUR 103 75 102 73 / 0 0 0 0
ASPERMONT 106 78 104 77 / 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/31
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
646 PM CDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 312 PM CDT FRI AUG 7 2015
SEVERAL CONCERNS WITH THE FORECAST DURING THIS PERIOD. THE FIRST
COMES TONIGHT AND WHETHER THERE WILL BE ANY VALLEY FOG OR NOT. IN
FAVOR OF THE FOG FORMING IS THE LITTLE BIT OF RAIN THIS MORNING
AND THE CLOUDS THAT HAVE TRAPPED THIS MOISTURE. THE 07.12Z NAM IS
THE MOST AGGRESSIVE WITH SHOWING SATURATION OCCURRING AT THE
SURFACE FOR THE VALLEY LOCATIONS. THE NAM ALSO HAS THE MOST AMOUNT
OF WIND JUST ABOVE THE SURFACE FOR MORE MIXING...WHICH GOES
AGAINST FOG FORMATION. 07.17Z RAP SOUNDINGS WHILE HAVING A DEEPER
LAYER OF LIGHT WINDS...COMES CLOSE TO SATURATING AT THE SURFACE
AND THEN REALLY DRIES OUT JUST ABOVE THE SURFACE. THE 07.12Z GFS
IS EVEN DRIER THAN THE RAP...SO HAVE DOUBTS THAT THERE WILL BE A
LOT OF FOG IN THE VALLEYS TONIGHT. ANOTHER COMPLICATING FACTOR
COULD BE THE INCREASE IN HIGH LEVEL CLOUDS FOR LATE TONIGHT AHEAD
OF AN APPROACHING SHORT WAVE TROUGH. PATCHY VALLEY FOG WAS ALREADY
IN THE FORECAST AND DO NOT PLAN TO MAKE ANY CHANGES TO THIS.
WITH THE APPROACHING SHORT WAVE TROUGH...THE GFS SEEMS TO HAVE THE
MOST SUPPORT FROM THE OTHER MODELS WITH THE 07.12Z ECMWF LOOKING
SIMILAR ALONG WITH THE 07.12Z HI-RES ARW AND NMM. WATER VAPOR
SATELLITE INDICATES THIS WAVE IS COMING OUT OF THE ROCKIES OVER
EASTERN WYOMING AND NORTHERN COLORADO THIS AFTERNOON AND SHOULD
THEN TRACK EAST ACROSS IOWA INTO SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS BY LATE SATURDAY MORNING. THE GFS SUGGESTS THIS WAVE WILL
PRODUCE SOME WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER
ACROSS NORTHEAST IOWA INTO FAR SOUTHERN WISCONSIN LATE TONIGHT
INTO EARLY SATURDAY MORNING. THE BOUNDARY THAT WENT THROUGH TODAY
SHOULD BE HUNG UP OVER CENTRAL IOWA AND IT IS EXPECTED THAT WEAK
TO MODERATE FRONTOGENESIS WILL OCCUR NORTH OF THIS BOUNDARY. THE
BEST ISENTROPIC UP GLIDE ON THE 310K SURFACE IS EXPECTED TO
REMAIN SOUTH OF THE BOUNDARY ACROSS CENTRAL AND SOUTHERN IOWA WITH
POSSIBLY 1 TO 2 UBAR/S OVER NORTHEAST IOWA. THE GENERAL CONSENSUS
AMONG THE MODELS IS THAT A COMPLEX OF SHOWERS AND STORMS SHOULD
FORM OVER NEBRASKA TONIGHT AND MOVE EAST ALONG AND NORTH OF THE
BOUNDARY. THE GFS AND HI-RES ARW AND NMM WOULD SUGGEST THERE IS AT
LEAST A CHANCE THAT THIS COMPLEX SURVIVES LONG ENOUGH TO GET INTO
THE SOUTHERN PARTS OF THE FORECAST AREA WHILE THE 07.12Z ECMWF
STARTS TO DISSIPATE THE COMPLEX AND ONLY BRINGS IN SOME REMAINS
SATURDAY AFTERNOON ACROSS THE SOUTH. WILL BRING IN SOME 20 TO 40
PERCENT CHANCES ACROSS NORTHEAST IOWA SATURDAY MORNING FOR THIS
COMPLEX.
ANOTHER SHORT WAVE TROUGH IS THEN EXPECTED TO COME OUT OF THE
ROCKIES AND TRACK ACROSS THE REGION SATURDAY NIGHT. THE TRACK AND
FORCING LOOK TO BE VERY SIMILAR TO THE WAVE FOR LATE TONIGHT INTO
SATURDAY MORNING WITH THE EXCEPTION THAT THE SURFACE BOUNDARY
SHOULD GET PUSHED FARTHER SOUTH INTO SOUTHERN IOWA OR NORTHERN
MISSOURI. THE COMPLEX OF STORMS WITH THIS NEXT WAVE IS EXPECTED TO
FORM OVER SOUTHWEST IOWA AND THEN TRACK EAST AND SHOULD LARGELY
STAY TO THE SOUTH OF THE FORECAST AREA. THE GFS IS SLIGHTLY
FARTHER NORTH THAN THE ECMWF AND TO HONOR THIS WILL HAVE SOME 20
TO 40 PERCENT CHANCES FROM ABOUT INTERSTATE 90 SOUTH.
BY SUNDAY NIGHT THE MEAN RIDGE WILL BE TRYING TO BUILD OVER THE
ROCKIES WITH AN UPPER LEVEL LOW OVER NORTHERN ONTARIO. THIS WILL
START TO SET UP A NORTHWEST FLOW OVER THE REGION WITH THE
POSSIBILITY OF A WEAK SHORT WAVE TROUGH ROTATING AROUND THE UPPER
LEVEL LOW AND ACROSS THE AREA. THE FORCING WITH THIS WAVE LOOKS TO
BE RATHER WEAK...BUT IT COULD PUSH A WEAK SURFACE BOUNDARY INTO
THE AREA WITH THE POSSIBILITY OF SOME ACTIVITY ALONG IT. WILL
CARRY SOME 30 TO 40 PERCENT CHANCES SUNDAY FOR THIS FEATURE WITH
SOME LINGERING 20 TO 30 PERCENT CHANCES INTO SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 312 PM CDT FRI AUG 7 2015
ONCE THE SHORT WAVE TROUGH FROM SUNDAY NIGHT EXITS THE AREA...A
LARGE AREA OF HIGH PRESSURE WILL BUILD IN OVER THE UPPER MIDWEST.
THIS HIGH LOOKS TO DOMINATE THE REGION FROM MONDAY NIGHT THROUGH
WEDNESDAY NIGHT. THE ECMWF WOULD SUGGESTS IT HOLDS TIGHT OVER THE
REGION THROUGH THE END OF THE WEEK WHILE THE GFS BRINGS A COLD
FRONT ACROSS THE UPPER MIDWEST THURSDAY THROUGH FRIDAY. WILL JUST
CARRY SOME LOW 20 TO 30 PERCENT RAIN CHANCES LATE IN THE PERIOD TO
HONOR THE GFS SOLUTION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 646 PM CDT FRI AUG 7 2015
AS THE SHORT WAVE MOVED INTO MICHIGAN...THE SCATTERED SHOWERS ENDED
ACROSS THE AREA. THE HIGH CLOUDS WILL INCREASE AS THE AREA TONIGHT
AS A SHORT WAVE TROUGH MOVES OUT OF SOUTH DAKOTA. MUCH OF THE
FORCING WITH THIS WAVE WILL STAY SOUTH OF INTERSTATE 90...SO EXPECTING
MAINLY MID CLOUDS FROM THIS SYSTEM.
WILL HAVE TO WATCH FOR THE DEVELOPMENT OF VALLEY FOG TONIGHT. BOTH
THE NAM AND GFS SUGGEST THAT IT WILL DEVELOP TONIGHT. MEANWHILE
THE RAP DOES NOT. WITH CLOUD COVER BEING A CONCERN TONIGHT...OPTED
TO JUST STAY WITH THE 4SM BR AT KLSE FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATE FOR AVIATION
NWS LITTLE ROCK AR
1245 AM CDT SAT 8 2015
.AVIATION...
OVERALL VFR FLIGHT CONDITIONS ARE EXPECTED OVERNIGHT...ALTHOUGH
PATCHY MVFR CEILINGS WILL BE SEEN...ESPECIALLY OVER NORTHERN AR.
SOME FOG WILL ALSO BE POSSIBLE WITH SCATTERED MVFR CONDITIONS. A
WEAK AND STALLED FRONTAL BOUNDARY WILL SPLIT THE STATE...WITH WINDS
NE TO E AT 3 TO 8 MPH OVER NORTHERN TO CENTRAL AR...WHILE S TO SW 3
TO 8 MPH OVER SOUTHERN AR. AN ISOLATED SHOWER OR THUNDERSTORM MAY BE
SEEN...BUT CONFIDENCE IS LOW AND DID NOT INCLUDE IN TAFS. SATURDAY
WILL SEE VFR CONDITIONS WITH OVERALL DRY WEATHER.
&&
.PREV DISCUSSION... /ISSUED 957 PM CDT FRI AUG 7 2015/
.UPDATE...
SFC DATA INDC THAT THE QUASI-STATIONARY BNDRY BISECTED THE FA
ALONG THE AR RVR THIS EVENING. SFC DEWPOINTS CONT TO POOL ALONG
AND N OF THE BNDRY...WHERE READINGS ARE HOVERING ARND 80F. AIRMASS
RMNS VERY UNSTABLE IN THIS SECTOR AS WELL...WITH 08/00Z KLZK RAOB
SHOWING SBCAPE APCHG 6K J/KG WITH LTL IN THE WAY OF CINH.
STARTING TO SEE SOME SCTD CONVECTION DVLP OVR FAR ERN AR ATTM. THE
RAPID UPDATE MODEL DATA CONT TO INDC SCTD CONVECTION FORMING
FURTHER NWWD INTO PARTS OF NERN AR LATE THIS EVENING INTO THE
OVERNIGHT HOURS. PLAN TO KEEP SLGT CHC POPS IN PLACE PER GOING
FCST AND WL CONT TO MONITOR RADAR/MODEL TRENDS.
THUS...NO SIG CHGS WERE MADE TO THE CURRENT FCST. JUST UPDATED
HRLY TEMPS TO ACCOUNT FOR LATEST TRENDS. ALL UPDATES OUT. /44/
&&
PREV DISCUSSION... /ISSUED 239 PM CDT FRI AUG 7 2015/
SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
AN AREA OF SHOWERS AND THUNDERSTORMS MOVED FROM SOUTH CENTRAL
MISSOURI AND TRACKED SOUTHEAST THROUGH PORTIONS OF EASTERN ARKANSAS.
THESE STORMS CONTINUED TO STRENGTHEN DURING THE MID MORNING HOURS
AND LED TO INCREASED CLOUD COVER THROUGH THE EASTERN HALF OF THE
STATE. BY THE EARLY AFTERNOON HOURS...MOSTLY SUNNY SKIES WERE SEEN
AROUND THE STATE WITH TEMPERATURES WARMING INTO THE MID TO UPPER 90S
WITH A FEW LOCATIONS IN WESTERN ARKANSAS ALREADY TOPPING 100
DEGREES. HEAT INDICES AROUND THE STATE HAVE REACHED 112 AT
RUSSELLVILLE WITH A FEW LOCATIONS TOPPING 110.
FOR TONIGHT...KEPT SLIGHT CHANCE POPS ACROSS EASTERN PORTIONS OF THE
AREA WITH BOTH THE HRRR AND WRF SHOWING REDEVELOPMENT ACROSS EASTERN
ARKANSAS.
IN THE COMING DAYS...WILL CONTINUE TO SEE A STRONG RIDGE OF HIGH
PRESSURE BUILD INTO THE REGION WITH TEMPERATURES EXPECTED TO CLIMB
EVEN HOTTER THAN WHAT HAS BEEN SEEN TODAY. FOR NOW...HAVE EXTENDED
AND EXPANDED THE EXCESSIVE HEAT WARNING INTO SATURDAY AND CONTINUED
WITH THE HEAT ADVISORY AT THE REMAINING COUNTIES EXCEPT ACROSS
NORTHEAST ARKANSAS.
HOT TEMPERATURES WILL CONTINUE ON SUNDAY WITH FEWER CLOUDS AND
SLIGHTLY LOWER DEWPOINTS...GENERALLY ACROSS SOUTHWEST AND CENTRAL
ARKANSAS. HOWEVER DEWPOINTS WILL GENERALLY INCREASE ACROSS NORTHEAST
ARKANSAS WHICH WILL LIKELY CAUSE HEAT ADVISORIES/WARNINGS TO BE
EXTENDED AND EXPANDED.
UPPER LEVEL RIDGE WILL BEGIN TO RETREAT ON MONDAY...ALLOWING A COLD
FRONT TO APPROACH THE STATE FROM THE NORTH. AT THIS POINT...IT DOES
NOT APPEAR THAT THERE WILL BE HIGH CHANCE FOR PRECIPITATION WITH
THIS FRONT...BUT SLIGHTLY COOLER TEMPS AND DRIER AIR WILL MOVE INTO
THE STATE FOR THE LONG TERM.
LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
THE UPPER LEVEL RIDGE OF HIGH PRESSURE THAT HAS PERSISTED OVER THE
REGION FOR THE PAST SEVERAL WEEKS WILL RETREAT WESTARD DURING THE
EXTENDED TERM...CHANGING THE UPPER LEVEL FLOW PATTERN TO A
NORTHERLY TO NORTHWESTERLY FLOW. AT THE SURFACE A HIGH PRESSURE
SYSTEM WILL SLOWLY MOVE TO THE EAST ACROSS THE UPPER MIDWEST INTO
THE OHIO VALLEY...KEEPING THE FORECAST AREA ALONG THE SOUTHERN
PERIPHERY OF THE HIGH. THIS WILL RESULT IN A DRY NORTHERLY TO
NORTHEASTERLY SURFACE FLOW.
THIS SETUP WILL ALLOW TEMPERATURES TO REMAIN JUST A BIT COOLER THAN
THEY HAVE BEEN AT PRESENT...MOST NOTABLY ACROSS THE NORTHERN HALF OF
THE AREA. SURFACE DEWPOINTS WILL EVENTUALLY DROP DOWN TO BE ABOUT 10
TO 15 DEGREES LOWER THAN THEY ARE RIGHT NOW...WHICH WILL BE A
WELCOME RELIEF...PUSHING MAXIMUM APPARENT TEMPERATURES DOWN INTO THE
MID 80S ACROSS THE NORTH TO THE MID 90S ACROSS THE SOUTH.
WITH THE NORTH TO NORTHWESTERLY FLOW AT THE UPPER LEVELS...A
SHORTWAVE OR TWO COULD RIPPLE ACROSS THE FORECAST AREA DURING THE
EXTENDED TERM...AND ISOLATED SHOWERS AND THUNDERSTORMS CANNOT BE
RULED OUT. HOWEVER...WITH THE MOISTURE LEVELS REMAINING LOWER...THE
CHANCES FOR PRECIPITATION SHOULD BE RATHER LOW...AND BELOW MENTION
IN MANY AREAS.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 7 AM SATURDAY TO 7 PM CDT SUNDAY FOR BAXTER-
BOONE-INDEPENDENCE-JACKSON-MARION-NEWTON-SEARCY-STONE.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SATURDAY FOR BRADLEY-
CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-
GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-
OUACHITA-PERRY-POPE-PULASKI-SALINE-YELL.
EXCESSIVE HEAT WARNING FROM 7 AM TO 7 PM CDT SATURDAY FOR
ARKANSAS-MONTGOMERY-PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR ARKANSAS-MONTGOMERY-
PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR CLEBURNE-MONROE-VAN
BUREN-WOODRUFF.
&&
$$
AREA FORECAST DISCUSSION
NWS TUCSON AZ
935 PM MST FRI AUG 7 2015
.SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR MAINLY
EAST AND SOUTH OF TUCSON THIS WEEKEND. EXPECT GREATER COVERAGE OF
THUNDERSTORMS BY TUESDAY FOLLOWED BY ANOTHER REDUCTION OF
THUNDERSTORM ACTIVITY LATE NEXT WEEK. ABOVE NORMAL DAYTIME
TEMPERATURES WILL PREVAIL INTO THE UPCOMING WEEK.
&&
.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AT
THIS TIME MOSTLY FROM ERN SANTA CRUZ COUNTY EWD ACROSS SRN COCHISE
COUNTY TO THE NEW MEXICO BORDER. OTHER ISOLATED TO SCATTERED SHOWERS
WERE FROM THE TUCSON METRO AREA NWD INTO SOUTH CENTRAL/SERN PINAL
COUNTY. CLOUD TOPS WERE GENERALLY COOLING DURING THE PAST 1-2 HOURS
ACROSS COCHISE/SANTA CRUZ COUNTIES EAST-TO-SOUTH OF TUCSON.
OTHERWISE...MOSTLY CLOUDY SKIES WERE ACROSS THE AREA EXCEPT ACROSS
WRN PIMA COUNTY WHERE CLEAR SKIES PREVAILED. DEWPOINTS AT LOWER
ELEVATIONS VALID 04Z WERE MAINLY IN THE 60S...AND THESE TEMPS WERE
NEARLY 5-10 DEGS F HIGHER VERSUS 24 HOURS AGO. 08/00Z KTWC SOUNDING
TOTAL PRECIP WATER VALUE WAS 1.67 INCH...WITH MLCAPE OF 412 J/KG.
08/00Z NAM/GFS...08/03Z RAP13 AND 08/03Z HRRR DEPICT ONLY A VERY
GRADUAL REDUCTION IN THE COVERAGE OF SHOWERS/TSTMS THE REST OF
TONIGHT INTO EARLY SAT MORNING. THESE MODELS FAVOR ERN PIMA
COUNTY...ERN SANTA CRUZ COUNTY AND WRN COCHISE COUNTY WITH THE
GREATEST POTENTIAL FOR ADDITIONAL SHOWERS/TSTMS.
THUS...FOR THE REST OF TONIGHT INTO EARLY SAT MORNING...HAVE
CONTINUED WITH ISOLATED TO SCATTERED SHOWERS/TSTMS FROM TUCSON EWD/
SWD TO THE NEW MEXICO/INTERNATIONAL BORDERS. PRECIP-FREE CONDITIONS
SHOULD CONTINUE ACROSS WRN PIMA COUNTY...SOUTH CENTRAL PINAL COUNTY
AND THE TOHONO O`ODHAM NATION. LOCALLY HEAVY RAINFALL SHOULD OCCUR
WITH THE STRONGER SHOWERS/TSTMS.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 09/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA WILL OCCUR FROM KTUS VICINITY EAST
AND SOUTH INTO SATURDAY MORNING. SCATTERED TO PERHAPS NUMEROUS
-TSRA/-SHRA WILL THEN OCCUR MAINLY EAST OF KTUS SATURDAY AFTERNOON
AND EVENING. EXPECT MVFR CONDITIONS AND BRIEF WIND GUSTS OF 35-45
KTS WITH THE STRONGER TSRA. OTHERWISE...CLEAR SKIES OR MOSTLY CLEAR
SKIES WILL PREVAIL ACROSS WESTERN PIMA COUNTY WEST OF KTUS.
ELSEWHERE...CLOUD DECKS WILL GENERALLY RANGE FROM 7-12K FT AGL.
SURFACE WIND WILL MAINLY BE LESS THAN 10 KTS APART FROM TSRA GUSTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MAINLY
EAST AND SOUTH OF TUCSON THROUGH MONDAY. SCATTERED THUNDERSTORMS
WILL THEN OCCUR ACROSS MUCH OF SOUTHEAST ARIZONA TUESDAY INTO
WEDNESDAY. ANOTHER DRYING TREND IS ON TAP DURING THE LATTER PART OF
NEXT WEEK. HOWEVER...THERE WILL BE ENOUGH MOISTURE FOR ISOLATED TO
SCATTERED THUNDERSTORMS FAVORING THE WHITE MOUNTAINS AND LOCATIONS
SOUTH OF TUCSON THURSDAY AND FRIDAY.
&&
.PREV DISCUSSION /206 PM MST/...SYNOPTICALLY SPEAKING...AN UPPER
LEVEL LOW PRESSURE CENTER IS TRACKING ACROSS NORTHERN CALIFORNIA AND
THE GREAT BASIN. THE JET DYNAMICS ASSOCIATED WITH THE LOW ARE
SPREADING ACROSS THE STATE HELPING TO ENHANCE THE CHANCE FOR
CONTINUED STORMS INTO THE EVENING. HEAVY RAINFALL...FREQUENT
LIGHTNING...SMALL HAIL...AND STRONG WIND GUSTS WILL ALL BE THREATS
WITH THE STORMS.
THE AREA OF LOW PRESSURE TO OUR NORTH IS EXPECTED TO TRACK EASTWARD
OVER THE NEXT 48 HOURS. IT IS ANTICIPATED THAT THE LOW WILL ACT TO
SHIFT THE DEEP MOISTURE EAST OF THE AREA FOR MUCH OF THE WEEKEND.
ALTHOUGH THE DEEPEST MOISTURE WILL MOVE EASTWARD OVER NEW MEXICO AND
SW TEXAS...ENOUGH WILL LINGER FOR ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ALONG AND NEAR THE NEW MEXICO BORDER BOTH SATURDAY AND
SUNDAY AFTERNOON. ANOTHER SURGE OF MOISTURE WILL BE POSSIBLE ACROSS
ALL OF SOUTHEAST ARIZONA MONDAY AND TUESDAY AS HIGH PRESSURE
REBOUNDS WESTWARD INTO NM AND CO.
MID RANGE MODELS ARE IN GOOD AGREEMENT THAT THE NEXT MONSOON SURGE
WILL BE FOCUSED ON MONDAY/TUESDAY WITH UPPER LEVEL RIDGING
SUPPRESSING WIDESPREAD CONVECTION BEGINNING EARLY WEDNESDAY AND
LINGERING INTO LATE WEEK. ALONG WITH A REDUCTION IN STORM COVERAGE
DURING THIS PERIOD...TEMPERATURES WILL LIKELY HAVE A CHANCE TO WARM
TO ABOVE NORMAL READINGS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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FRANCIS
PREVIOUS DISCUSSION...CANTIN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
915 PM MST FRI AUG 7 2015
.SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR MAINLY
EAST AND SOUTH OF TUCSON INTO EARLY NEXT WEEK. EXPECT GREATER
COVERAGE OF THUNDERSTORMS TUESDAY INTO WEDNESDAY FOLLOWED BY REDUCED
ACTIVITY LATE NEXT WEEK. ABOVE NORMAL DAYTIME TEMPERATURES WILL
PREVAIL INTO THE UPCOMING WEEK.
&&
.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AT
THIS TIME MOSTLY FROM ERN SANTA CRUZ COUNTY EWD ACROSS SRN COCHISE
COUNTY TO THE NEW MEXICO BORDER. OTHER ISOLATED TO SCATTERED SHOWERS
WERE FROM THE TUCSON METRO AREA NWD INTO SOUTH CENTRAL/SERN PINAL
COUNTY. CLOUD TOPS WERE GENERALLY COOLING DURING THE PAST 1-2 HOURS
ACROSS COCHISE/SANTA CRUZ COUNTIES EAST-TO-SOUTH OF TUCSON.
OTHERWISE...MOSTLY CLOUDY SKIES WERE ACROSS THE AREA EXCEPT ACROSS
WRN PIMA COUNTY WHERE CLEAR SKIES PREVAILED. DEWPOINTS AT LOWER
ELEVATIONS VALID 04Z WERE MAINLY IN THE 60S...AND THESE TEMPS WERE
NEARLY 5-10 DEGS F HIGHER VERSUS 24 HOURS AGO. 08/00Z KTWC SOUNDING
TOTAL PRECIP WATER VALUE WAS 1.67 INCH...WITH MLCAPE OF 412 J/KG.
08/00Z NAM/GFS...08/03Z RAP13 AND 08/03Z HRRR DEPICT ONLY A VERY
GRADUAL REDUCTION IN THE COVERAGE OF SHOWERS/TSTMS THE REST OF
TONIGHT INTO EARLY SAT MORNING. THESE MODELS FAVOR ERN PIMA
COUNTY...ERN SANTA CRUZ COUNTY AND WRN COCHISE COUNTY WITH THE
GREATEST POTENTIAL FOR ADDITIONAL SHOWERS/TSTMS.
THUS...FOR THE REST OF TONIGHT INTO EARLY SAT MORNING...HAVE
CONTINUED WITH ISOLATED TO SCATTERED SHOWERS/TSTMS FROM TUCSON EWD/
SWD TO THE NEW MEXICO/INTERNATIONAL BORDERS. PRECIP-FREE CONDITIONS
SHOULD CONTINUE ACROSS WRN PIMA COUNTY...SOUTH CENTRAL PINAL COUNTY
AND THE TOHONO O`ODHAM NATION. LOCALLY HEAVY RAINFALL SHOULD OCCUR
WITH THE STRONGER SHOWERS/TSTMS.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 09/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA WILL OCCUR FROM KTUS VICINITY EAST
AND SOUTH INTO SATURDAY MORNING. SCATTERED TO PERHAPS NUMEROUS
-TSRA/-SHRA WILL THEN OCCUR MAINLY EAST OF KTUS SATURDAY AFTERNOON
AND EVENING. EXPECT MVFR CONDITIONS AND BRIEF WIND GUSTS OF 35-45
KTS WITH THE STRONGER TSRA. OTHERWISE...CLEAR SKIES OR MOSTLY CLEAR
SKIES WILL PREVAIL ACROSS WESTERN PIMA COUNTY WEST OF KTUS.
ELSEWHERE...CLOUD DECKS WILL GENERALLY RANGE FROM 7-12K FT AGL.
SURFACE WIND WILL MAINLY BE LESS THAN 10 KTS APART FROM TSRA GUSTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MAINLY
EAST AND SOUTH OF TUCSON THROUGH MONDAY. SCATTERED THUNDERSTORMS
WILL THEN OCCUR ACROSS MUCH OF SOUTHEAST ARIZONA TUESDAY INTO
WEDNESDAY. ANOTHER DRYING TREND IS ON TAP DURING THE LATTER PART OF
NEXT WEEK. HOWEVER...THERE WILL BE ENOUGH MOISTURE FOR ISOLATED TO
SCATTERED THUNDERSTORMS FAVORING THE WHITE MOUNTAINS AND LOCATIONS
SOUTH OF TUCSON THURSDAY AND FRIDAY.
&&
.PREV DISCUSSION /206 PM MST/...SYNOPTICALLY SPEAKING...AN UPPER
LEVEL LOW PRESSURE CENTER IS TRACKING ACROSS NORTHERN CALIFORNIA AND
THE GREAT BASIN. THE JET DYNAMICS ASSOCIATED WITH THE LOW ARE
SPREADING ACROSS THE STATE HELPING TO ENHANCE THE CHANCE FOR
CONTINUED STORMS INTO THE EVENING. HEAVY RAINFALL...FREQUENT
LIGHTNING...SMALL HAIL...AND STRONG WIND GUSTS WILL ALL BE THREATS
WITH THE STORMS.
THE AREA OF LOW PRESSURE TO OUR NORTH IS EXPECTED TO TRACK EASTWARD
OVER THE NEXT 48 HOURS. IT IS ANTICIPATED THAT THE LOW WILL ACT TO
SHIFT THE DEEP MOISTURE EAST OF THE AREA FOR MUCH OF THE WEEKEND.
ALTHOUGH THE DEEPEST MOISTURE WILL MOVE EASTWARD OVER NEW MEXICO AND
SW TEXAS...ENOUGH WILL LINGER FOR ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ALONG AND NEAR THE NEW MEXICO BORDER BOTH SATURDAY AND
SUNDAY AFTERNOON. ANOTHER SURGE OF MOISTURE WILL BE POSSIBLE ACROSS
ALL OF SOUTHEAST ARIZONA BY TUESDAY AS HIGH PRESSURE REBOUNDS
WESTWARD INTO NM AND CO.
MID RANGE MODELS ARE IN GOOD AGREEMENT THAT THE NEXT MONSOON SURGE
WILL BE FOCUSED ON TUESDAY AND WEDNESDAY WITH UPPER LEVEL RIDGING
SUPPRESSING WIDESPREAD CONVECTION BEGINNING EARLY THURSDAY AND
LINGERING INTO LATE WEEK. ALONG WITH A REDUCTION IN STORM COVERAGE
DURING THIS PERIOD...TEMPERATURES WILL LIKELY HAVE A CHANCE TO WARM
TO ABOVE NORMAL READINGS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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FRANCIS
PREVIOUS DISCUSSION...CANTIN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
404 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* MVFR CIGS/VIS POSSIBLE THIS MORNING.
* WESTERLY WINDS BECOMING NORTHEAST THIS AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WEAKENING SURFACE LOW CONTINUES TO PUSH THROUGH THE REGION EARLY
THIS MORNING WITH RADAR IMAGERY DEPICTING LIGHT ISOLATED SHOWERY
ACTIVITY EAST/NORTHEAST OF THE TERMINALS. ANY FURTHER PRECIP
DEVELOPMENT WILL REMAIN TO THE EAST OF ALL THE TERMINALS...WITH
DRY CONDITIONS EXPECTED THIS MORNING THROUGH MUCH OF THE DAY.
SHORT TERM GUIDANCE HINTING AT SOME TYPE OF LIGHT PRECIP LATER
THIS AFTERNOON...BUT THINK THIS MAY BE A BIT AGRESSIVE AS FAIRLY
DRY LOW LEVELS WILL REMAIN IN PLACE. IF ANYTHING WERE TO PUSH
ACROSS THE TERMINALS LATER THIS AFTERNOON IT WOULD LIKELY ONLY BE
AN ISOLATED SPRINKLE. VFR CEILINGS EXPECTED THIS MORNING AND
THROUGH THE FORECAST PERIOD...WITH AREAS OF FOG STILL POSSIBLE
EARLY THIS MORNING. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM IN MVFR CIGS/VIS THIS MORNING.
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...CHANCE OF TSRA/MVFR. SOUTH-SOUTHEAST WINDS.
MONDAY...SLGT CHANCE OF AFTN SHRA/TSRA. OTHERWISE VFR. NORTH-
NORTHEAST WINDS.
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. WEST WINDS.
RATZER
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
348 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR VIS POSSIBLE THIS MORNING.
* WESTERLY WINDS BECOMING NORTHEAST THIS AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WEAKENING SURFACE LOW CONTINUES TO PUSH THROUGH THE REGION EARLY
THIS MORNING WITH RADAR IMAGERY DEPICTING LIGHT ISOLATED SHOWERY
ACTIVITY EAST/NORTHEAST OF THE TERMINALS. ANY FURTHER PRECIP
DEVELOPMENT WILL REMAIN TO THE EAST OF ALL THE TERMINALS...WITH
DRY CONDITIONS EXPECTED THIS MORNING THROUGH MUCH OF THE DAY.
SHORT TERM GUIDANCE HINTING AT SOME TYPE OF LIGHT PRECIP LATER
THIS AFTERNOON...BUT THINK THIS MAY BE A BIT AGRESSIVE AS FAIRLY
DRY LOW LEVELS WILL REMAIN IN PLACE. IF ANYTHING WERE TO PUSH
ACROSS THE TERMINALS LATER THIS AFTERNOON IT WOULD LIKELY ONLY BE
AN ISOLATED SPRINKLE. VFR CEILINGS EXPECTED THIS MORNING AND
THROUGH THE FORECAST PERIOD...WITH AREAS OF FOG STILL POSSIBLE
EARLY THIS MORNING. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN MVFR VIS THIS MORNING.
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...CHANCE OF TSRA/MVFR. SOUTH-SOUTHEAST WINDS.
MONDAY...SLGT CHANCE OF AFTN SHRA/TSRA. OTHERWISE VFR. NORTH-
NORTHEAST WINDS.
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. WEST WINDS.
RATZER
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
332 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
259 PM CDT
LATEST MORNING DISCUSSION FORTHCOMING...PREVIOUS DISCUSSION
BELOW...
SATURDAY NIGHT THROUGH FRIDAY...
THE BEST CHANCE FOR PRECIP AND STORMS WILL BE LATE SATURDAY NIGHT
INTO SUNDAY MORNING WITH AN ADDITIONAL SLIGHT CHANCE TO CHANCE OF
PRECIP THROUGH MONDAY AFTERNOON. AS THE UPPER LEVEL LOW SHIFTS EAST
OVER QUEBEC EARLY NEXT WEEK...WE WILL GET UNDER A RIDGING PATTERN
AND A SURFACE HIGH PRESSURE SYSTEM. THIS WILL LEAD TO DRY CONDITIONS
THROUGH MOST OF NEXT WEEK.
FOR SATURDAY NIGHT AND SUNDAY...
EXPECTING A LINGERING MCV TO SUPPORT STORM DEVELOPMENT OVER IOWA
SATURDAY AFTERNOON AND EVENING WITH THE AREA OF STORMS SHIFTING EAST
ACROSS NORTHERN IL AND NW INDIANA EARLY SUNDAY MORNING. HAVE THE
GREATEST CONFIDENCE IN WIDESPREAD RAIN ALONG AND SOUTH OF I-88. NOT
OVERLY EXCITED ABOUT SVR POTENTIAL AS THE STORM COMPLEX MOVES INTO
THE REGION. THE GFS KEEPS THE LLJ NOSE OVER WEST CENTRAL IL WHILE
THE NAM BRINGS IT INTO CENTRAL IL. THE NAM IS TYPICALLY A BIT TOO
AMBITIOUS WITH CAPE VALUES AS WELL SO LEANING TOWARD THE GFS
SOLUTION OF A DECAYING MCS. HOWEVER...IF THE NAM IS CORRECT...THE
MCS COULD PRODUCE SOME STRONG WINDS. EITHER WAY MOST IF NOT ALL OF
THE CWA SHOULD SEE NEEDED ACCUMULATING RAINFALL FROM THE DECAYING
SYSTEM OF STORMS.
KEPT A CHANCE OF AFTERNOON AND EVENING PRECIP AS I AM NOT OVERLY
CONFIDENT THAT WE WILL DESTABILIZE ENOUGH TO SEE A SECOND ROUND OF
STORMS SUNDAY. HAVE LOW CONFIDENCE IN WHEN AND WHERE ADDITIONAL
SHOWERS AND STORMS WILL FORM SUNDAY AFTERNOON AND EVENING.
DEVELOPMENT DEPENDS ON WHERE THE MCV STALLS AND HOW QUICKLY WE
RECOVER FROM THE MORNING/S CONVECTION. GUIDANCE FEATURES NEW
DEVELOPMENT ROUGHLY ALONG AND EAST OF THE I-55 CORRIDOR...BUT ONCE
AGAIN HAVE LOW CONFIDENCE IN TIMING...EXACT LOCATION...AND COVERAGE
OF ANY ADDITIONAL STORMS. IF AFTERNOON STORMS DO DEVELOP...STRAYED
FROM THE OVERLY AMBITIOUS NAM WHICH SEEMS TO HAVE MUCH TOO HIGH CAPE
AND SHEAR VALUES.
KEPT HIGH TEMPS SUNDAY IN THE LOW 80S AND HIGH TEMPS COULD BE EVEN
LOWER IF THE CLOUD SHIELD FROM THE MORNING/S CONVECTION LINGERS
THROUGHOUT THE DAY.
MONDAY THROUGH FRIDAY...
THE UPPER LEVEL TROUGH/S SECONDARY TROUGH AXIS SWINGS THROUGH MONDAY
MORNING WITH SURFACE HIGH PRESSURE BUILDING IN BEHIND IT. HAVE A
SLIGHT CHANCE TO LOW END CHANCE OF SHOWERS AND STORMS OCCURRING AS
THE TROUGH AXIS AND UPPER LEVEL VORT STREAMER SLIDE THROUGH MONDAY
AFTERNOON. NOT EXPECTING WIDESPREAD DEVELOPMENT MONDAY AFTERNOON.
DRY CONDITIONS ARE THEN FORECAST THROUGH THURSDAY AS WE ARE UNDER
THE INFLUENCE OF A SURFACE HIGH. LAKE BREEZES ARE POSSIBLE MONDAY
THROUGH WEDNESDAY LEADING TO LAKE SIDE COOLING. AWAY FROM THE LAKE
EXPECTING HIGH TEMPS AROUND 80. THE HIGH THEN DRIFTS EAST LATE IN
THE WEEK WITH ANOTHER LOW PRESSURE SYSTEM IMPACTING THE MID WEST
THURSDAY NIGHT INTO FRIDAY. GUIDANCE DIFFERS IN THE EXACT PATH OF
THIS LOW SO KEPT PRECIP CHANCES IN THE CHANCE OR LOWER RANGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR VIS POSSIBLE THIS MORNING.
* WESTERLY WINDS BECOMING NORTHEAST THIS AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WEAKENING SURFACE LOW CONTINUES TO PUSH THROUGH THE REGION EARLY
THIS MORNING WITH RADAR IMAGERY DEPICTING LIGHT ISOLATED SHOWERY
ACTIVITY EAST/NORTHEAST OF THE TERMINALS. ANY FURTHER PRECIP
DEVELOPMENT WILL REMAIN TO THE EAST OF ALL THE TERMINALS...WITH
DRY CONDITIONS EXPECTED THIS MORNING THROUGH MUCH OF THE DAY.
SHORT TERM GUIDANCE HINTING AT SOME TYPE OF LIGHT PRECIP LATER
THIS AFTERNOON...BUT THINK THIS MAY BE A BIT AGRESSIVE AS FAIRLY
DRY LOW LEVELS WILL REMAIN IN PLACE. IF ANYTHING WERE TO PUSH
ACROSS THE TERMINALS LATER THIS AFTERNOON IT WOULD LIKELY ONLY BE
AN ISOLATED SPRINKLE. VFR CEILINGS EXPECTED THIS MORNING AND
THROUGH THE FORECAST PERIOD...WITH AREAS OF FOG STILL POSSIBLE
EARLY THIS MORNING. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN MVFR VIS THIS MORNING.
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...CHANCE OF TSRA/MVFR. SOUTH-SOUTHEAST WINDS.
MONDAY...SLGT CHANCE OF AFTN SHRA/TSRA. OTHERWISE VFR. NORTH-
NORTHEAST WINDS.
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. WEST WINDS.
RATZER
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
136 AM EDT SAT AUG 8 2015
.SYNOPSIS...
ISSUED AT 814 PM EDT FRI AUG 7 2015
AN UPPER LEVEL DISTURBANCE TRACKING ACROSS THE GREAT LAKES TONIGHT
MAY BRING AN ISOLATED SHOWER TO PARTS OF EXTREME NORTHWEST
INDIANA AND SOUTHWEST LOWER MICHIGAN. LOW TEMPERATURES TONIGHT
WILL RANGE FROM THE UPPER 50S TO LOWER 60S. HIGH TEMPERATURES ON
SATURDAY WILL REACH BACK TO AROUND THE 80 DEGREE MARK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 410 PM EDT FRI AUG 7 2015
A COMPACT UPPER LEVEL SHORT WAVE WILL CONTINUE EASTWARD ACROSS
THE WESTERN GREAT LAKES THIS EVENING...ALTHOUGH LATEST SHORT TERM
TRENDS SEEM TO SUGGEST THIS SHORT WAVE IS BECOMING INCREASINGLY
SHEARED. A LARGE AREA OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
IS ACCOMPANYING THIS VORT. SHORT TERM RAP TRENDS SUGGEST THIS WAVE
WILL BECOMING INCREASINGLY SHEARED WITH A MORE NARROWED CHANNEL OF
DPVA WORKING FROM WEST TO EAST ACROSS THE LOCAL AREA IN THE 22Z-
04Z TIMEFRAME. LOW LEVEL THETAE TROUGH CURRENTLY RESIDING ACROSS
THE AREA IS PROVIDING A FAIRLY SHARP WEST-EAST INSTABILITY
GRADIENT FROM THE MID MS VALLEY TO THE OHIO VALLEY...AND WOULD
EXPECT SOME DIMINISHING TREND IN COVERAGE AS THIS WAVE LOSES SOME
POTENCY AND DUE TO EFFECTS OF INITIALLY DRY AIR MASS ACROSS THE
REGION. HAVE MAINTAINED SOME SLIGHT CHANCE POPS PARTICULARLY
ACROSS THE FAR NORTHWEST/NORTH THIS EVENING FOLLOWING THIS
FORCING...WITH MORE QUESTIONABLE MOISTURE RETURN ACROSS REMAINDER
OF THE AREA ARGUING FOR MAINTENANCE OF DRY FORECAST.
FORCING WITH THIS WAVE WILL WANE LATE EVENING...BUT LAGGING LOW
LEVEL THETAE RIDGE MAY BEGIN TO HAVE SOME INFLUENCE OVERNIGHT INTO
EARLY SATURDAY MORNING. HAVE OPTED TO KEEP SOME SLIGHT CHANCE POPS
GOING OVERNIGHT INTO EARLY SATURDAY MORNING ACROSS THE
NORTH/NORTHWEST DUE TO LINGERING ADVECTIVE FORCING AND APPROACH OF A
VERY WEAK REMNANT SFC TROUGH. SOME EASTWARD PROGRESSION OF DAMPENED
LOW LEVEL THERMAL RIDGING ON SATURDAY SHOULD SOMEWHAT OFFSET
EXPECTED MORE CLOUD COVER ON SATURDAY FOR HIGHS ONCE AGAIN AROUND
80...OR POSSIBLY INTO THE LOWER 80S DEPENDING ON EXTENT OF CLOUD
COVER.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 PM EDT FRI AUG 7 2015
AN UPPER LEVEL SYSTEM OVER THE WESTERN CONUS WILL EJECT AN
UPPER LEVEL TROF OVER THE LARGE UPPER LEVEL SOUTHERN PLAINS RIDGE
AND THEN THE TROF WILL MOVE INTO THE UPPER GREAT LAKES REGION BY
EARLY SUNDAY. NCEP MODELS...THE CANADIAN GEM AND THE ECMWF WERE
SHOWING LARGE DIFFERENCES IN HANDLING THIS SYSTEM. FAVOR A
SOUTHERN TRACK WHICH IS SUPPORTED THE BY ECMWF AND THE CPS
ANALOGS. ALSO...MOST MODELS TRACKED THE SYSTEM EARLIER THIS WEEK
TOO FAR NORTH. SO FOR THIS PACKAGE...KEPT A CHANCE FOR STORMS
SUNDAY. HOWEVER...INCREASED STORM CHANCES A LITTLE OVER SOUTHWEST
AREAS IN DEFERENCE TO THE ECMWF. IF THE SOUTHERN TRACK
VERIFIES...CHANCES FOR SEVERE STORMS SHOULD BE LIMITED MORE TO THE
SOUTH AND SOUTHWEST. OTHERWISE...SOME LINGERING SHOWERS AND STORMS
ARE POSSIBLE MONDAY AND THEN CONDITIONS SHOULD BE DRY WITH
TEMPERATURES A LITTLE BELOW NORMAL AS A LARGE UPPER LEVEL TROF
REMAINS OVER THE AREA NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 136 AM EDT SAT AUG 8 2015
PRIMARILY VFR CONDITIONS EXPECTED THIS PERIOD. SUBTLE LOW LEVEL
THETA-E RIDGE AND WEAK MIDLEVEL SHORTWAVE MAY TOUCH OFF A FEW
ISOLATED SHOWERS THIS AFTERNOON BUT CHANCES TOO LOW FOR INCLUSION
IN THE TAF AND IMPACTS MINIMAL ANYWAY. DESPITE SLIGHTLY INCREASED
MOISTURE...CEILINGS EXPECTED TO REMAIN ABOVE 3 KFT. WINDS WILL
SLOWLY VEER TO A MORE WESTERLY DIRECTION BY THIS
AFTERNOON...BECOMING LIGHT AND VARIABLE BY THE END OF THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...T
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...AGD
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
223 AM MDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 1018 PM MDT FRI AUG 7 2015
UPDATE SENT TO CANCEL SEVERE THUNDERSTORM WATCH FOR THE ENTIRE
AREA. SEVERE THREAT HAS SHIFTED EAST OF THE CWA...BUT DO EXPECT
SCATTERED RW/TRW TO PERSIST BUT TAPER AS THE OVERNIGHT HRS
PROGRESS. FLASH FLOOD WARNING REMAINS IN EFFECT FOR HITCHCOCK
COUNTY IN NEBRASKA. CONCERN IS FOR HEAVY RAINFALL THAT OCCURRED
JUST TO THE NORTH EARLIER THIS EVENING IN CHASE/HAYS COUNTIES...
WILL FILTER SOUTH VIA THE FRENCHMEN CREEK AND AFFECT AREAS LIKE
STRATTON...CULBERTSON.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 222 AM MDT SAT AUG 8 2015
AN UPPER LEVEL RIDGE WILL BE IN PLACE OVER THE TRI STATE AREA TO
START OFF THE LONG TERM PERIOD TUESDAY. THE CENTRAL AREA OF HIGH
PRESSURE WILL CONTINUE TO RETROGRADE AND INCREASE IN AMPLITUDE OVER
THE ROCKY MOUNTAIN RANGE AND THE NORTHERN PLAINS WEDNESDAY. WITH
THE PRESENCE OF THE UPPER RIDGE...JET AREAS AND POCKETS OF VORTICITY
WILL REMAIN WELL AWAY FROM THE TRI STATE AREA...WHICH WILL BRING
UPPER STABILITY FOR THE REST OF THE FORECAST PERIOD.
AT THE SURFACE...A COOLER AIR MASS WITH A SURFACE HIGH PRESSURE
FILTERING INTO THE PLAINS BEHIND A COLD FRONTAL PASSAGE WILL BRING
COOLER HIGH TEMPERATURES IN THE MID TO UPPER 80S ON TUESDAY. ON THE
FRONT SIDE OF THE HIGH PRESSURE SYSTEM...EASTERLY UPSLOPE FLOW WILL
BRING MOISTURE INTO THE HIGH PLAINS DURING THE MORNING HOURS BEFORE
SURFACE WINDS SHIFT TO THE SOUTH/SOUTHEAST. GFS/ECMWF HINT AT A
SURFACE DRY LINE POSITIONED MORE ALONG THE SOUTHWESTERN PORTION OF
THE FORECAST AREA...SO THUNDERSTORMS LOOK MORE LIKELY TO FORM ALONG
THE VICINITY OF THE FORECAST AREA ALONG THIS BOUNDARY. A DEVELOPING
SURFACE TROUGH IN EASTERN COLORADO MAY ALLOW STORMS TO DEVELOP
ELSEWHERE WITH CAPE AND MOISTURE PROFILES SUFFICIENT ENOUGH FOR
DEVELOPMENT.
THE UPPER LEVEL HIGH WILL THEN MOVE AND BECOME POSITIONED DIRECTLY
OVER THE TRI STATE AREA FOR THE END OF THE COMING WEEK...WHICH WILL
DRY OUT CONDITIONS WITH A LACK OF UPPER OR SURFACE FORCING.
EXPECTING TEMPERATURES IN THE LOW TO MID 90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1114 PM MDT FRI AUG 7 2015
SCATTERED SHOWERS AND 6SM IN FOG WILL GIVE WAY TO 1SM OR LESS IN
FOG BY 10Z SATURDAY THRU 14Z-15Z...WITH CEILINGS OVC010 OR LESS.
FROM 14Z-15Z ONWARD...VFR CONDITIONS WITH SCT050-150. WINDS WILL
HAVE VARYING DIRECTION THRU FORECAST PERIOD WITH 5-15KTS RANGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DLF
LONG TERM...MK
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1114 PM MDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 1018 PM MDT FRI AUG 7 2015
UPDATE SENT TO CANCEL SEVERE THUNDERSTORM WATCH FOR THE ENTIRE
AREA. SEVERE THREAT HAS SHIFTED EAST OF THE CWA...BUT DO EXPECT
SCATTERED RW/TRW TO PERSIST BUT TAPER AS THE OVERNIGHT HRS
PROGRESS. FLASH FLOOD WARNING REMAINS IN EFFECT FOR HITCHCOCK
COUNTY IN NEBRASKA. CONCERN IS FOR HEAVY RAINFALL THAT OCCURRED
JUST TO THE NORTH EARLIER THIS EVENING IN CHASE/HAYS COUNTIES...
WILL FILTER SOUTH VIA THE FRENCHMEN CREEK AND AFFECT AREAS LIKE
STRATTON...CULBERTSON.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM MDT FRI AUG 7 2015
FORECAST PROBLEM WILL BE THUNDERSTORM CHANCES AND ANY HEAVY
RAINFALL THREAT. SATELLITE IS SHOWING AN AMPLIFIED AND MOSTLY
PROGRESSIVE FLOW FROM THE PACIFIC INTO NORTH AMERICA. THIS FLOW
BECOMES MORE OF A SPLIT WITH THE TROUGHS ALONG THE WEST AND EAST
COASTS. A LOT OF PACIFIC AND MONSOONAL MOISTURE IS BEING PULLED UP
INTO THE REGION. CURRENTLY A SYNOPTIC BOUNDARY REMAINS DRAPED TO
OUR SOUTH AND WEST.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...MODELS WERE
NOT TOO FAR APART. THE CANADIAN/UKMET/GFS LED THE PACK WITH OTHERS
NOT FAR BEHIND WITH THE SREF THE WORST. THE NAM/SREF WERE HANDLING
THE SURFACE WIND AND PRESSURE FIELD THE BEST. MODELS TENDED TO BE
A LITTLE COOL ON THE LOW LEVEL THERMAL FIELD WITH THE GFS/CANADIAN
DOING THE BEST.
SATURDAY NIGHT...TO BEGIN THE NIGHT...SURFACE BOUNDARY IS DRAPED
OVER THE FAR SOUTH AND WEST CENTRAL PORTION OF THE AREA. THIS
BOUNDARY GRADUALLY SINKS SOUTH THROUGH THE NIGHT. SHORTWAVE TROUGH
MOVES THROUGH FROM THE SOUTHWEST THROUGH THE NIGHT WITH THE BEST
LIFT BASICALLY OVER THE SOUTHWEST HALF. MAIN JET AXIS/LIFT STAYS NOT
TOO FAR TO OUR NORTH AND WEST THROUGH MOST OF THE PERIOD. LATE IN
THE NIGHT A RIGHT REAR QUADRANT GETS CLOSER TO THE NORTHWEST PORTION.
RIGHT NOW THE HIGHEST POPS LOOK TO BE IN THE SOUTHWEST HALF. PWS
REMAIN NEAR 1.5 INCHES. THAT WITH STORM MOTIONS ONLY 10 TO 15 KNOTS
ALONG THAT FLOW COMING OVER THE TOP OF THE SOUTHERN BOUNDARY WILL
MAKE MODERATE TO LOCALLY HEAVY RAINFALL POSSIBLE. ALSO POSSIBLE LATE
IN THE NIGHT WITH MOIST LOW LEVELS AND LITTLE TO NO WIND THAT PATCHY
FOG COULD DEVELOP WHERE NO PRECIPITATION IS GOING ON.
SUNDAY/SUNDAY NIGHT...IT LOOKS LIKE THERE MAY BE SOME LINGERING
RAINFALL AND PATCHY FOG IN THE MORNING. FOR THE REMAINDER OF THE
PERIOD...BOUNDARY LOOKS TO BE TO THE SOUTH AND WEST OF THE AREA WITH
A WEAK LOW LEVEL UPSLOPE REGIME IN PLACE. HOWEVER...MODELS ARE
HINTING AT A WEAK SECONDARY BOUNDARY MOVING INTO THE NORTHWEST HALF
OF THE AREA DURING THE LATE AFTERNOON INTO THE EVENING. THIS SINKS A
LITTLE FURTHER SOUTHEAST DURING THE LAST HALF OF THE NIGHT.
THE MID LEVEL FORCING THROUGH THE PERIOD REMAINS RATHER WEAK WITH
THE STRONGEST IN THE EVENING. RIGHT REAR QUADRANT OF THE JET REMAINS
NEAR THE NORTHERN AND WESTERN PORTIONS OF THE AREA THROUGH THE DAY
BUT GETS CLOSER/HAS MORE AFFECT ON THOSE LOCATIONS BY THE END OF THE
DAY. THE NORTHERN PORTION OF THE AREA KEEPS GETTING AFFECTED BY THIS
THROUGH THE MIDDLE OF THE NIGHT. WITH A VARIETY OF FORCING IN
DIFFERENT TIMES AND PLACES...WILL BROADBRUSH CHANCE POPS FOR THE
ENTIRE NIGHT.
FOR THE HIGH TEMPERATURES...WILL HAVE LOW LEVEL UPSLOPE IN PLACE
THROUGH THE DAY ALONG WITH LINGERING CLOUD COVER IN THE MORNING AND
DEVELOPING CLOUD COVER IN THE AFTERNOON WITH THE CONVECTION. MODEL
GUIDANCE HAS TENDED TO BE A LITTLE WARM.
MONDAY...JET REMAINS WELL NORTH OF THE AREA THROUGH THE DAY. MID
LEVEL SHORTWAVE RIDGE IS IN PLACE THROUGH THE DAY WITH A LOT OF
DRYING. A SHORTWAVE TROUGH STARTS GETTING CLOSER DURING THE END OF
THE DAY. AREA IS IN A POST FRONTAL AIR MASS. DEPENDING ON WHICH
MODEL YOU USE...THERE COULD BE A WEAK SUBTLE SURFACE BOUNDARY IN THE
FAR SOUTH/SOUTHWEST. SO AT THIS TIME...WILL HAVE SLIGHT TO LOW
CHANCE POPS IN THE FAR SOUTH AND SOUTHWEST PORTION OF THE AREA IN
THE AFTERNOON.
HIGH TEMPERATURES WILL BE COOLER THAN THE PREVIOUS DAY DUE TO LOWER
850 MB TEMPERATURES...UPSLOPE WINDS AND LINGERING MORNING FOG/STRATUS
THAT BEGINS SUNDAY NIGHT.
MONDAY NIGHT THROUGH SATURDAY...CONTINUED AMPLIFIED PATTERN
REMAINS IN PLACE THROUGH THE PERIOD. HOWEVER...THE DETERMINISTIC
AND ENSEMBLE OUTPUT SPREAD GETS WORSE WITH TIME...ALMOST
COMPLETELY OUT OF PHASE AT TIMES. THE DIFFERENCES INVOLVE HOW THE
PERSISTENT SOUTHERN UNITED STATES RIDGE AND WEST TROUGH EVOLVE
WITH TIME. IN GENERAL THE ECMWF REMAINS STRONGER WITH THE RIDGE.
FOR THE WESTERN TROUGH...ALL OUTPUT SUPPORTS A DEEPENING ALONG THE
COAST UPPER TROUGH.
DESPITE THOSE DIFFERENCES...THE CENTER OF THE RIDGE...STILL RATHER
FAR SOUTH...AND THE POSITION OF THE UPPER TROUGH SHOULD CONTINUE TO
ALLOW PACIFIC AND MONSOONAL MOISTURE TO PULLED UP INTO THE REGION
WITH PERIODIC SHORTWAVE TROUGHS EMBEDDED WITHIN THIS FLOW. AT THE
SURFACE...WPC GRAPHICS SHOW A PERSISTENT FRONTAL BOUNDARY STILL
DRAPED NOT TOO FAR TO OUR SOUTH AND WEST OR OVER THE AREA. THIS
KEEPS A CONTINUED UPSLOPE FLOW OVER THE AREA.
GIVEN THE BIG MODEL DIFFERENCES...THE GENERAL PATTERN SUPPORTED
CONTINUED BOUTS OF MOISTURE/LIFT/RAINFALL...AND THE PROXIMITY OF A
BOUNDARY AND UPSLOPE FLOW...SHOULD SEE A CONTINUED THREAT FOR
THUNDERSTORMS AND DO NOT FEEL COMFORTABLE MAKING ANY MAJOR
ADJUSTMENTS TO THE GUIDANCE. THE DETAILS WILL HAVE TO BE REFINED AS
WE GET CLOSER TO EACH EVENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1114 PM MDT FRI AUG 7 2015
SCATTERED SHOWERS AND 6SM IN FOG WILL GIVE WAY TO 1SM OR LESS IN
FOG BY 10Z SATURDAY THRU 14Z-15Z...WITH CEILINGS OVC010 OR LESS.
FROM 14Z-15Z ONWARD...VFR CONDITIONS WITH SCT050-150. WINDS WILL
HAVE VARYING DIRECTION THRU FORECAST PERIOD WITH 5-15KTS RANGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DLF
LONG TERM...BULLER
AVIATION...JN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1135 PM CDT FRI AUG 7 2015
...AVIATION UPDATE...
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 336 PM CDT FRI AUG 7 2015
ONGOING BAND OF ELEVATED SHOWERS AND THUNDERSTORMS OVER NORTH
CENTRAL KANSAS CONTINUE TO BE ROOTED AROUND 10-12 THOUSAND FEET AS
CEILINGS ARE NOT EVEN BEING MEASURED AT ASOS SITES. PARCELS LIFTED
FROM THIS LEVEL ARE LIKELY REALIZING ON THE ORDER OF 400-800 J/KG OF
CAPE AND RADAR TRENDS SUPPORT THIS AS WELL. THE BAND OF ELEVATED
FORCING/CONVERGENCE/WARM ADVECTION APPEARS LIKELY TO CONTINUE FOR A
WHILE ALTHOUGH INSTABILITY OF THESE ELEVATED PARCELS MAY WANE WITH
TIME. BOTTOM LINE IS THAT THE SCATTERED SHOWERS AND A FEW STORMS
WILL CONTINUE FOR A FEW HOURS BUT LIKELY DECREASE IN COVERAGE DURING
THE EVENING.
FARTHER WEST, A DEEP TROUGH OVER NEVADA WAS SPINNING AMPLE MOISTURE
AND ENERGY NORTHEAST ACROSS THE CENTRAL ROCKIES AND INTO THE PLAINS.
WIDESPREAD PRESSURE FALLS AND A VERY MOIST BOUNDARY LAYER OVER THE
HIGH PLAINS OF COLORADO INTO NORTH TEXAS WILL LIKELY RESULT IN
WIDESPREAD THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING.
THESE STORMS APPEAR LIKELY TO CONGEAL INTO ONE OR MORE CONVECTIVE
CLUSTERS AND MOVE TO THE EAST AND NORTHEAST. THE MOST LIKELY CLUSTER
SEEMS AIMED TO MOVE ACROSS NEBRASKA TONIGHT, BUT MORE RECENT MODEL
RUNS AND OBSERVATIONAL DATA SUGGEST THE POTENTIAL FOR ANOTHER WELL
ORGANIZED CLUSTER TO DEVELOP IN SOUTHWEST KANSAS AND MOVE TOWARD THE
NORTHEAST...LIKELY IMPACTING A GOOD PART OF THE LOCAL FORECAST AREA.
WHILE THUNDERSTORMS ARE LIKELY TO DEVELOP, THEIR EVOLUTION HAS LESS
CONFIDENCE AS THEY WILL INTERACT WITH THE UPPER RIDGE, DRY AIR JUST
ABOVE THE BOUNDARY LAYER, AND A STOUT INVERSION/CAP JUST OFF THE
SURFACE. SO, HAVE LOWER POPS WITH SOUTHERN EXTENT GIVEN THE GREATER
UNCERTAINTY, BUT THE POTENTIAL DOES EXIST FOR WIDESPREAD STORMS
ESPECIALLY OVER THE NORTHERN HALF OF THE FORECAST AREA TONIGHT...
MAINLY AFTER MIDNIGHT. MODERATE INSTABILITY SHOULD BE AVAILABLE FOR
ANY STORMS THAT DO DEVELOP, BUT THE EXTENT OF COLD POOL
ORGANIZATION, ESPECIALLY GIVEN THE STRONG CAP, IS IN QUESTION. WOULD
NOT BE SURPRISED TO SEE AN ORGANIZED COLD POOL SUPPORT DAMAGING WIND
GUSTS INTO PART OF THE AREA...ESPECIALLY NORTH CENTRAL KANSAS...BUT
IT SEEMS UNLIKELY AT THE SAME TIME.
THUNDERSTORMS WILL SHIFT NORTHEAST OF THE AREA ON SATURDAY MORNING
WITH A VERY MOIST BOUNDARY LAYER REMAINING IN PLACE. THE SUN WILL
COME OUT IN FULL FORCE AND EXPECT A VERY HOT DAY WITH HIGHS WELL
INTO THE 90S AND LOWER 100S IN SOME AREAS. WHILE SOME GUIDANCE (GFS
IN PARTICULAR) MIXES VERY DEEP, IT DOES NOT APPEAR REALISTIC AND
HAVE FORECAST CLOSER TO HOW PAST EVENTS HAVE BEHAVED...MAINTAINING A
SHALLOW LAYER OF VERY HIGH NEAR-SURFACE DEWPOINTS AND HIGH HEAT
INDICES THROUGH THE AFTERNOON. WILL NEED TO CLOSELY MONITOR THE
FORECAST, ESPECIALLY FOR DEWPOINTS AND THE BEHAVIOR OF ANY REMNANT
OUTFLOW, AS PARTS OF THE AREA MAY APPROACH THE 110 HEAT INDEX
CRITERIA FOR AN EXCESSIVE HEAT WARNING.
BY LATE IN THE AFTERNOON, EXPECT EXTREME CAPE TO DEVELOP ACROSS
NORTHERN AND EASTERN KANSAS WHILE A REMNANT OUTFLOW BOUNDARY
AND/OR WEAK SYNOPTIC FRONT SETS UP ACROSS PARTS OF THE LOCAL AREA
AND INTO SOUTHEAST NEBRASKA. A BAND OF SEASONALLY STRONG MID LEVEL
FLOW OVER THE TOP OF STRENGTHENING LOW LEVEL FLOW WILL SUPPORT
LARGE LOOPING HODOGRAPHS ACROSS NORTHERN KANSAS AND ANY STORMS
THAT DEVELOP APPEAR LIKELY TO DEVELOP SUPERCELL STRUCTURES. ANY
STORMS IN THE LATE AFTERNOON AND EARLY EVENING WILL POSE A THREAT
FOR RATHER LARGE HAIL, DAMAGING WINDS, AND A NON-ZERO TORNADO
POTENTIAL. THE MAIN QUESTION IS WHERE THOSE STORMS WILL DEVELOP
AND CURRENT SUGGESTIONS POINT TO AREAS NEAR AND NORTH OF THE NE/KS
BORDER.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 336 PM CDT FRI AUG 7 2015
ONGOING CONVECTION MAY LINGER THROUGH THE LATE EVENING HOURS MAINLY
FOR AREAS NORTH OF I-70. DURING THIS TIME FRAME A COLD FRONT
POSSIBLY REINFORCED BY AN OUTFLOW BOUNDARY SHOULD EXTEND FROM FAR
NORTHEAST KS TO CENTRAL KS AND GRADUALLY SLIDE SOUTHWARD OVERNIGHT.
INSTABILITY BEHIND THE FRONT APPEARS TO STILL POSE THE RISK FOR
ELEVATED STORMS, WHILE DEEP LAYER SHEAR IS FORECAST TO DECREASE
OVERALL. THE LOW TEMPERATURES SUNDAY MORNING WILL BE QUITE WARM IN
THE MID TO UPPER 70S WITH THE EXCEPTION OF FAR NORTHERN KS WHERE
PRECIP MAY COOL THINGS OFF A TOUCH. AS THAT FRONT SLIDES SOUTHWARD
THE MODELS ARE HINTING AT WEAK SHORTWAVES TRACKING OVER KS DURING
THE DAY SUNDAY. AS FOR NOW THE COVERAGE APPEARS TO BE SCATTERED DUE
TO THE WEAK LARGE SCALE FORCING. WITH POSSIBLE PRECIP AND CLOUDS
AROUND THE AREA HIGH TEMPERATURES ARE SOMEWHAT UNCERTAIN. BY SUNDAY
EVENING THE FRONT SHOULD REACH THE OK/KS STATE LINE. ALTHOUGH
ELEVATED SHOWERS AND STORMS WILL STILL BE POSSIBLE OVERNIGHT SUNDAY
ESPECIALLY SINCE THE MID/UPPER LEVEL FLOW BECOMES MORE WESTERLY
OPENING THE DOOR FOR MORE WEAK SHORTWAVES TO TRACK OVER THE REGION
WITH THE BETTER CHANCES SOUTH OF I-70. COOLER AIR WILL PUSH
SOUTHWARD ON MONDAY GIVING US HIGHS IN THE MID TO UPPER 80S. MOST OF
THE DAYTIME HOURS SHOULD BE DRY ON MONDAY ALTHOUGH A SHORTWAVE WILL
DIG ACROSS THE UPPER MIDWEST LATE MONDAY BRINGING A SECONDARY
BOUNDARY SOUTHWARD THROUGH NE. STORMS DEVELOPING ON THIS BOUNDARY
COULD GET CLOSE TO FAR NORTHERN KS.
MID WEEK TIME FRAME LOOKS TO BE QUIET WEATHER WISE AT THIS POINT.
BOTH GFS AND ECMWF ARE IN GOOD AGREEMENT EARLY IN THE PERIOD WITH
A LARGE SCALE TROUGH OVER THE WEST AND EAST COAST OF THE CONUS. IN
THE MIDDLE GROUND IS A HIGHLY AMPLIFIED RIDGE OVER THE CENTRAL
CONUS. THE DIFFERENCE COMES LATER IN THE PERIOD WHERE THE GFS DOES
SUGGEST THAT THE RIDGE AXIS WILL BECOME MORE NARROW OVER THE
CENTRAL CONUS BY LATE WEDNESDAY AS A CUT-OFF LOW MAY SET UP ALONG
THE CENTRAL CALIFORNIA COAST. THE MAIN WESTERLIES ARE FORCED
AROUND THE NORTHERN PERIPHERY OF THIS UPPER LOW WHICH COULD ALLOW
FOR A TROUGH TO DIG INTO THE NORTHERN ROCKIES WITH AN ASSOCIATED
DEEPENING LOW MOVING ALONG THE US/CANADIAN BORDER. WITHIN A
LEESIDE TROUGH SETTING UP AND THIS MID TO UPPER LEVEL TROUGH
FEATURE TO THE NORTH, A SURFACE WARM FRONT COULD EXTEND INTO THE
CENTRAL PLAINS AND CAUSE SOME SMALL CHANCES FOR PRECIP BY AROUND
FRIDAY MORNING TIME FRAME. THIS CHANCE LOOKS TO BE MINIMAL AT THIS
POINT, SO OPTED TO KEEP SLIGHT POP CHANCES IN THE FORECAST AT THIS
TIME. TEMPS ARE EXPECTED TO BE IN CHECK DURING THE UPCOMING WEEK WITH
A CANADIAN HIGH PRESSURE RIDGE INFLUENCING THE REGION, SO HIGHS
SHOULD REMAIN IN THE UPPER 80S WITH LOWS IN THE MID TO UPPER 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1135 PM CDT FRI AUG 7 2015
THERE IS QUITE A BIT OF UNCERTAINTY IN WHERE THE MCS WILL GO
DURING THE EARLY MORNING HOURS. THE HRRR HAS BEEN CONSISTENTLY
BRINGING THE ELEVATED STORMS THROUGH EASTERN KS, ALTHOUGH IT SEEMS
TO BE DELAYING THE PROGRESS TO MORE MID MORNING. MEANWHILE THE
OPERATIONAL MODELS CONTINUE TO FOCUS THE MOST LIKELY TRACK OF THE
STORMS ACROSS SOUTHERN NEB AND FAR NORTHERN KS. WITH PROFILER DATA
SHOWING THE DECENT LOW LEVEL JET VEERING TO THE SOUTH AND
SOUTHWEST, THINK THERE IS A CHANCE FOR ELEVATED STORMS TO MOVE
INTO THE TERMINALS SO WILL INCLUDE A VCTS WITH VFR CONDITIONS AND
MONITOR TRENDS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 9 PM CDT SATURDAY FOR KSZ010>012-
021>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM...DRAKE/SANDERS
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1018 PM MDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 1018 PM MDT FRI AUG 7 2015
UPDATE SENT TO CANCEL SEVERE THUNDERSTORM WATCH FOR THE ENTIRE
AREA. SEVERE THREAT HAS SHIFTED EAST OF THE CWA...BUT DO EXPECT
SCATTERED RW/TRW TO PERSIST BUT TAPER AS THE OVERNIGHT HRS
PROGRESS. FLASH FLOOD WARNING REMAINS IN EFFECT FOR HITCHCOCK
COUNTY IN NEBRASKA. CONCERN IS FOR HEAVY RAINFALL THAT OCCURRED
JUST TO THE NORTH EARLIER THIS EVENING IN CHASE/HAYS COUNTIES...
WILL FILTER SOUTH VIA THE FRENCHMEN CREEK AND AFFECT AREAS LIKE
STRATTON...CULBERTSON.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM MDT FRI AUG 7 2015
FORECAST PROBLEM WILL BE THUNDERSTORM CHANCES AND ANY HEAVY
RAINFALL THREAT. SATELLITE IS SHOWING AN AMPLIFIED AND MOSTLY
PROGRESSIVE FLOW FROM THE PACIFIC INTO NORTH AMERICA. THIS FLOW
BECOMES MORE OF A SPLIT WITH THE TROUGHS ALONG THE WEST AND EAST
COASTS. A LOT OF PACIFIC AND MONSOONAL MOISTURE IS BEING PULLED UP
INTO THE REGION. CURRENTLY A SYNOPTIC BOUNDARY REMAINS DRAPED TO
OUR SOUTH AND WEST.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...MODELS WERE
NOT TOO FAR APART. THE CANADIAN/UKMET/GFS LED THE PACK WITH OTHERS
NOT FAR BEHIND WITH THE SREF THE WORST. THE NAM/SREF WERE HANDLING
THE SURFACE WIND AND PRESSURE FIELD THE BEST. MODELS TENDED TO BE
A LITTLE COOL ON THE LOW LEVEL THERMAL FIELD WITH THE GFS/CANADIAN
DOING THE BEST.
SATURDAY NIGHT...TO BEGIN THE NIGHT...SURFACE BOUNDARY IS DRAPED
OVER THE FAR SOUTH AND WEST CENTRAL PORTION OF THE AREA. THIS
BOUNDARY GRADUALLY SINKS SOUTH THROUGH THE NIGHT. SHORTWAVE TROUGH
MOVES THROUGH FROM THE SOUTHWEST THROUGH THE NIGHT WITH THE BEST
LIFT BASICALLY OVER THE SOUTHWEST HALF. MAIN JET AXIS/LIFT STAYS NOT
TOO FAR TO OUR NORTH AND WEST THROUGH MOST OF THE PERIOD. LATE IN
THE NIGHT A RIGHT REAR QUADRANT GETS CLOSER TO THE NORTHWEST PORTION.
RIGHT NOW THE HIGHEST POPS LOOK TO BE IN THE SOUTHWEST HALF. PWS
REMAIN NEAR 1.5 INCHES. THAT WITH STORM MOTIONS ONLY 10 TO 15 KNOTS
ALONG THAT FLOW COMING OVER THE TOP OF THE SOUTHERN BOUNDARY WILL
MAKE MODERATE TO LOCALLY HEAVY RAINFALL POSSIBLE. ALSO POSSIBLE LATE
IN THE NIGHT WITH MOIST LOW LEVELS AND LITTLE TO NO WIND THAT PATCHY
FOG COULD DEVELOP WHERE NO PRECIPITATION IS GOING ON.
SUNDAY/SUNDAY NIGHT...IT LOOKS LIKE THERE MAY BE SOME LINGERING
RAINFALL AND PATCHY FOG IN THE MORNING. FOR THE REMAINDER OF THE
PERIOD...BOUNDARY LOOKS TO BE TO THE SOUTH AND WEST OF THE AREA WITH
A WEAK LOW LEVEL UPSLOPE REGIME IN PLACE. HOWEVER...MODELS ARE
HINTING AT A WEAK SECONDARY BOUNDARY MOVING INTO THE NORTHWEST HALF
OF THE AREA DURING THE LATE AFTERNOON INTO THE EVENING. THIS SINKS A
LITTLE FURTHER SOUTHEAST DURING THE LAST HALF OF THE NIGHT.
THE MID LEVEL FORCING THROUGH THE PERIOD REMAINS RATHER WEAK WITH
THE STRONGEST IN THE EVENING. RIGHT REAR QUADRANT OF THE JET REMAINS
NEAR THE NORTHERN AND WESTERN PORTIONS OF THE AREA THROUGH THE DAY
BUT GETS CLOSER/HAS MORE AFFECT ON THOSE LOCATIONS BY THE END OF THE
DAY. THE NORTHERN PORTION OF THE AREA KEEPS GETTING AFFECTED BY THIS
THROUGH THE MIDDLE OF THE NIGHT. WITH A VARIETY OF FORCING IN
DIFFERENT TIMES AND PLACES...WILL BROADBRUSH CHANCE POPS FOR THE
ENTIRE NIGHT.
FOR THE HIGH TEMPERATURES...WILL HAVE LOW LEVEL UPSLOPE IN PLACE
THROUGH THE DAY ALONG WITH LINGERING CLOUD COVER IN THE MORNING AND
DEVELOPING CLOUD COVER IN THE AFTERNOON WITH THE CONVECTION. MODEL
GUIDANCE HAS TENDED TO BE A LITTLE WARM.
MONDAY...JET REMAINS WELL NORTH OF THE AREA THROUGH THE DAY. MID
LEVEL SHORTWAVE RIDGE IS IN PLACE THROUGH THE DAY WITH A LOT OF
DRYING. A SHORTWAVE TROUGH STARTS GETTING CLOSER DURING THE END OF
THE DAY. AREA IS IN A POST FRONTAL AIR MASS. DEPENDING ON WHICH
MODEL YOU USE...THERE COULD BE A WEAK SUBTLE SURFACE BOUNDARY IN THE
FAR SOUTH/SOUTHWEST. SO AT THIS TIME...WILL HAVE SLIGHT TO LOW
CHANCE POPS IN THE FAR SOUTH AND SOUTHWEST PORTION OF THE AREA IN
THE AFTERNOON.
HIGH TEMPERATURES WILL BE COOLER THAN THE PREVIOUS DAY DUE TO LOWER
850 MB TEMPERATURES...UPSLOPE WINDS AND LINGERING MORNING FOG/STRATUS
THAT BEGINS SUNDAY NIGHT.
MONDAY NIGHT THROUGH SATURDAY...CONTINUED AMPLIFIED PATTERN
REMAINS IN PLACE THROUGH THE PERIOD. HOWEVER...THE DETERMINISTIC
AND ENSEMBLE OUTPUT SPREAD GETS WORSE WITH TIME...ALMOST
COMPLETELY OUT OF PHASE AT TIMES. THE DIFFERENCES INVOLVE HOW THE
PERSISTENT SOUTHERN UNITED STATES RIDGE AND WEST TROUGH EVOLVE
WITH TIME. IN GENERAL THE ECMWF REMAINS STRONGER WITH THE RIDGE.
FOR THE WESTERN TROUGH...ALL OUTPUT SUPPORTS A DEEPENING ALONG THE
COAST UPPER TROUGH.
DESPITE THOSE DIFFERENCES...THE CENTER OF THE RIDGE...STILL RATHER
FAR SOUTH...AND THE POSITION OF THE UPPER TROUGH SHOULD CONTINUE TO
ALLOW PACIFIC AND MONSOONAL MOISTURE TO PULLED UP INTO THE REGION
WITH PERIODIC SHORTWAVE TROUGHS EMBEDDED WITHIN THIS FLOW. AT THE
SURFACE...WPC GRAPHICS SHOW A PERSISTENT FRONTAL BOUNDARY STILL
DRAPED NOT TOO FAR TO OUR SOUTH AND WEST OR OVER THE AREA. THIS
KEEPS A CONTINUED UPSLOPE FLOW OVER THE AREA.
GIVEN THE BIG MODEL DIFFERENCES...THE GENERAL PATTERN SUPPORTED
CONTINUED BOUTS OF MOISTURE/LIFT/RAINFALL...AND THE PROXIMITY OF A
BOUNDARY AND UPSLOPE FLOW...SHOULD SEE A CONTINUED THREAT FOR
THUNDERSTORMS AND DO NOT FEEL COMFORTABLE MAKING ANY MAJOR
ADJUSTMENTS TO THE GUIDANCE. THE DETAILS WILL HAVE TO BE REFINED AS
WE GET CLOSER TO EACH EVENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 546 PM MDT FRI AUG 7 2015
BOTH SITES WILL SEE VFR CONDITIONS GIVE WAY TO THUNDERSTORM
DEVELOPMENT FROM 02Z-06Z. AFT 06Z...FOG BEGINS TO DEVELOP AS
WINDS SLACKEN BY 06Z WITH 6SM DROPPING DOWN TO 1SM OR LESS WITH
CEILINGS BLW OVC010 BY 09Z...LASTING THRU 15Z ESPECIALLY FOR KMCK.
AFT THAT...VFR WITH SCATTERED CLOUD COVER. WINDS SE
15-25KTS...BECM LGT/VAR BY 06Z THEN NNE AROUND 10KTS 14Z-15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DLF
LONG TERM...BULLER
AVIATION...JN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 AM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 506 AM EDT SAT AUG 8 2015
DURING THE LONG TERM...MID LEVEL LOW CURRENTLY OVER SRN MANITOBA IS
FCST TO MOVE SLOWLY E INTO NRN ONTARIO BY SUN MORNING. AS THIS
FEATURE CONTINUES TO SHIFT SLOWLY E...A BUILDING RIDGE TO THE LEE OF
THE ROCKIES WILL FORCE A DEEPENING TROF INTO ERN NAMERICA DURING THE
FIRST HALF OF NEXT WEEK. THIS TROF WILL LIKELY LINGER THRU THE REST
OF THE WEEK. PRIOR TO THE DEEPENING TROF...A SERIES OF SHORTWAVES
TRACKING ACROSS THE PLAINS TO THE GREAT LAKES WILL PROVIDE SOME
OPPORTUNITY FOR SHRA/TSTMS. DEEPENING ERN TROF AND RESULTING NW FLOW
INTO THE GREAT LAKES DURING THE FIRST HALF OF NEXT WEEK WILL THEN
BRING DRY WEATHER. HOWEVER...TYPICAL FOR SUMMERTIME NW FLOW...ANY
SUBTLE SHORTWAVE DROPPING THRU THE AREA COULD SPARK ISOLD AFTN
CONVECTION. PCPN CHANCES WILL RETURN LATE IN THE WEEK AS THERE ARE
INDICATIONS OF A DECENT SHORTWAVE ROUNDING THE WRN PLAINS RIDGE AND
THEN DROPPING INTO THE ERN TROF. THIS WOULD RESULT IN POSSIBLE
CONVECTION WITH LOW-LEVEL JET/WAA REGIME AHEAD OF WAVE AND ALSO WITH
COLD FRONT THAT WOULD DROP S INTO THE GREAT LAKES. AS FOR TEMPS...
AFTER READINGS NOT TOO FAR FROM NORMAL (ON THE WARM SIDE OF NORMAL
FOR MOST LOCATIONS)...DEVELOPING NW FLOW EARLY NEXT WEEK WILL DROP
TEMPS TO BLO NORMAL...BUT NOT SIGNIFICANTLY AS THERE WON`T BE A TAP
OF CHILLY AIR FROM NORTHERN CANADA. ABOVE NORMAL TEMPS WILL RETURN
BY THU AHEAD OF THE AFOREMENTIONED SHORTWAVE ROUNDING THE RIDGE.
SOME COOLING SHOULD THEN FOLLOW BY THE WEEKEND...DEPENDING ON HOW
SHARPLY THE SHORTWAVE DROPS INTO THE ERN TROF.
BEGINNING SUN/SUN NIGHT...MID LEVEL LOW CURRENTLY OVER SRN MANITOBA
WILL HAVE OPENED UP AND WILL BE DRIFTING ACROSS NRN ONTARIO. TO THE
S OF THIS FEATURE...THERE REMAINS UNCERTAINTY IN THE WEAKER
SHORTWAVE ENERGY TRACKING ACROSS THE PLAINS TO THE GREAT LAKES...
PARTICULARLY WITH RESPECT TO WHERE CONVECTION WILL BE FIRING WITH
THESE MORE SUBTLE FEATURES. HOWEVER...THERE HAS BEEN A FAIRLY
CONSISTENT SIGNAL IN THE MODELS FOR A SUBTLE SFC WAVE AND MORE
SUBSTANTIAL CONVECTIVE ACTIVITY TRACKING EASTWARD FROM VCNTY OF IA
EARLY SUN ON THE NRN EDGE OF STRONG INSTABILITY IN THAT AREA. THIS
WILL HELP KEEP STRONG INSTABILITY FROM BUILDING N ALONG COLD FRONT
THAT WILL BE MOVING INTO THE UPPER LAKES SUN/SUN NIGHT IN
ASSOCIATION WITH THE NRN ONTARIO SHORTWAVE. AHEAD OF APPROACHING
COLD FRONT...NAM/GFS SHOW MLCAPE INCREASING TO ROUGHLY 500 TO
1500J/KG OVER THE W HALF OF UPPER MI SUN (NAM AS HIGH AS 2000J/KG).
WHILE THERE MAY BE A FEW SHRA IN THE MORNING...APPROACHING COLD
FRONT AND WEAK DEEP LAYER QVECTOR CONVERGENCE SHOULD SPARK SCT
CONVECTION IN THE AFTN WHICH WILL THEN SPREAD E INTO SUN NIGHT
ALONG/AHEAD OF PASSING COLD FRONT. WITH DEEP LAYER SHEAR NO GREATER
THAN AROUND 25KT...NOT ANTICIPATING ANY SVR STORMS. HOWEVER...IF
INSTABILITY ENDS UP AT OR ABOVE THE HIGH END OF THE CURRENTLY
EXPECTED RANGE...COULDN`T RULE OUT A BRIEF ISOLD SVR STORM. LATEST
SPC OUTLOOKS DO NOT HIGHLIGHT UPPER MI FOR A SVR RISK SUN/SUN
NIGHT...AND THAT LOOKS RIGHT ON TRACK.
ON MON...COLD FRONT SHOULD BE JUST E OF THE FCST AREA AT 12Z...
ENDING THE RISK OF MORE ORGANIZED PCPN. THE NAM STILL MANAGES TO
BUILD MLCAPE UPWARDS OF 1500J/KG OVER THE SCNTRL AND E...BUT THE GFS
SHOWS LESS THAN 50J/KG. SINCE OTHER MODELS SUPPORT THE GFS WITH A
STRONGER PRES GRADIENT BTWN HIGH PRES BUILDING INTO THE NRN PLAINS
AND LOW PRES/COLD FRONT TO THE E...WILL FAVOR THE THE DRIER/LACK OF
INSTABILITY GFS SOLUTION. WILL LINGER SCHC POPS FOR SHRA OVER THE E
EARLY. OTHERWISE...PLAN TO CARRY A DRY FCST ON MON. EXPECT HIGHS IN
THE 70S...BUT IT WILL BE COOLER NEAR LAKE SUPERIOR...ESPECIALLY OVER
THE E UNDER NNW WINDS THERE.
MON NIGHT THRU WED...BUILDING UPPER RIDGE WITH AXIS ROUGHLY OVER THE
WRN HIGH PLAINS WILL FORCE A DEEPENING ERN NAMERICA TROF AND NW FLOW
OVER THE GREAT LAKES...RESULTING IN COOLER WEATHER...BUT ONLY A
LITTLE BLO NORMAL FOR EARLY/MID AUG. IN THE INTERIOR...NIGHTTIME MIN
TEMPS WILL PROBABLY BE IN THE 40S IN THE USUAL COOL SPOTS. THERE
CONTINUES TO BE SOME INDICATION OF A WEAK SHORTWAVE DROPPING THRU
THE UPPER LAKES ON TUE WHICH COULD GENERATE A FEW ISOLD SHRA WITH
DAYTIME HEATING. AT THIS POINT...THE POTENTIAL IS STILL LOW ENOUGH
TO PRECLUDE A MENTION OF PCPN IN THE FCST FOR TUE. WITH UPPER TROF
SHIFTING A BIT FARTHER E ON WED AND SFC HIGH PRES MORE FIRMLY OVER
THE AREA...DRY WEATHER IS EXPECTED TO CONTINUE. MAX TEMPS WILL BE A
LITTLE HIGHER ON WED.
THU/FRI...TRENDS IN MEDIUM RANGE GUIDANCE ARE FOR A STRONGER
SHORTWAVE TO CUT THRU THE NRN PORTION OF THE WRN RIDGE AND THEN DROP
MORE SHARPLY TO THE SE INTO THE ERN NAMERICA TROF LATE NEXT WEEK. IF
THIS TREND CONTINUES WITH THE NEXT SET OF MEDIUM RANGE GUIDANCE...
THEN SHRA/TSTM CHANCES WILL NEED TO BE INCREASED FOR THU...WITH PCPN
POSSIBLE AS EARLY AS WED DEPENDING ON WHERE WAA IS FOCUSED AHEAD OF
THE SHORTWAVE. THE 00Z ECWMF/GFS INDICATE COLD FRONT WILL BE S OF
THE AREA BY FRI...LEADING TO A DRY DAY AND SOME COOLING. WILL WAIT
TO SEE IF THESE TRENDS FOR THU/FRI HOLD UP IN THE NEXT ROUND OF
GUIDANCE BEFORE SHIFTING FCST MORE STRONGLY TOWARD THIS SOLUTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY MORNING)
ISSUED AT 1210 AM EDT SAT AUG 8 2015
A LOW CENTERED IN SOUTHERN WISCONSIN WILL MOVE SLOWLY EAST THIS
MORNING ALLOWING ISOLATED SHOWERS TO SLOWLY DISSIPATE. LINGERING LOW-
LEVEL MOISTURE WILL ALLOW FOR LIFR TO POSSIBLY VLIFR CONDITIONS TO
PERSIST AT ALL TAF SITES OVERNIGHT IN A LIGHT E-SE WIND FLOW. DRIER
AIR SHOULD GRADUALLY MOVE INTO THE AREA LATER THIS MORNING INTO THE
AFTERNOON BRINGING AN IMPROVEMENT TO CEILINGS AND VISIBILITIES WITH
VFR CONDITIONS EXPECTED BY AFTERNOON. A FRONTAL SYSTEM APPROACHING
FROM THE WEST TOWARD EVENING COULD BRING A CHANCE FOR SHOWERS LATE
IN THE TAF PERIOD AT BOTH KIWD AND KCMX. MEANWHILE...KSAW COULD SEE
A REDEVELOPMENT OF STRATUS AND MVFR CIGS BY LATE EVENING IN A
CONTINUED UPSLOPE SSE FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT AUG 8 2015
WILL CONTINUE TO TRACK BOAT OBSERVATIONS THIS MORNING TO GET A
BETTER HANDLE ON ANY FOG THAT MAY BET SET UP ACROSS LAKE SUPERIOR.
HOWEVER AT THIS TIME...IT LOOKS LIKE PATCHY TO AREAS OF FOG WILL BE
ABOUT THE EXTENT OF IT THIS MORNING...BEFORE DISSIPATING THIS
AFTERNOON.
EXPECT A WEAKENING LOW OVER E WI/S LAKE MI THIS MORNING. A SECONDARY
LOW LAKE WINNIPEG WILL SLOWLY MOVE E OVER THE NEXT FEW DAYS AND
REACH S JAMES BAY BY MONDAY. THAT LOW WILL SWEEP A TROUGH ACROSS THE
UPPER GREAT LAKES REGION ON SUNDAY. A HIGH PRESSURE RIDGE STRETCHING
FROM MANITOBA TO THE N PLAINS MONDAY WILL SLIDE OVER THE GREAT LAKES
TUESDAY AND WEDNESDAY. EXPECT WIND GUSTS LESS THAN 25KTS THROUGH THE
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 AM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 314 PM EDT FRI AUG 7 2015
FCST FOCUS IN THE MEDIUM RANGE PERIOD WL BE ON POPS THE SECOND HALF
OF THIS WEEKEND ASSOCIATED WITH STRONG DISTUBANCE OVER SCENTRAL
CANADA THAT WL BE DROPPING SLOWLY ESEWD THRU NW ONTARIO AND DRAGGING
A COLD FNT ACRS UPR MI ON SUN NGT. TEMPS AHEAD OF THE COLD FROPA WL
BE AOA NORMAL. DURING THE FIRST HALF OF THE NEXT WEEK...EXPECT TEMPS
TO FALL BLO NORMAL WITH NW FLOW ALOFT DEVELOPING BTWN A BLDG UPR RDG
IN THE PLAINS AND DEEPENING TROF DOWNSTREAM IN ERN NAMERICA. CNDN HI
PRES UNDER THIS NW FLOW ALOFT WL BRING GENERALLY DRY WX DURING THE
MON THRU WED PERIOD. LOOKS LIKE TEMPS WL REBOUND AOA NORMAL LATER IN
THE WEEK AS PLAINS RDG BLDS TOWARD THE WRN LKS.
SAT NGT THRU SUN NGT...STRONG SHRTWV OVER FAR NW ONTARIO THAT WL BE
TOPPING UPR RDG IN THE PLAINS IS FCST TO SLIDE SLOWLY ESE THRU NRN
ONTARIO. ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES...MOST OF
THE LATEST GUIDANCE INDICATE A FASTER PRIMARY COLD FROPA ON SUN NGT.
SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE ONTARIO SHRTWV
WL REMAIN TO THE N OF UPR MI...POPS/PCPN AMOUNTS AS EARLY AS SAT NGT
IN ADVANCE OF THIS COLD FNT WL DEPEND ON THE DEGREE TO WHICH MSTR
INFLOW INTO THE UPR LKS WL BE DISRUPTED BY A W-E ORIENTED BNDRY
STRETCHING FM IOWA INTO THE LOWER LKS AND CONVECTION THAT FIRES
ALONG THIS AXIS ACCOMPANYING THE PASSAGE OF ANOTHER SHRTWV OVER THAT
AREA. THE 12Z NAM IS MOST EXTREME SHOWING A NEAR ABSENCE OF PCPN
ACRS THE CWA DURING THIS ENTIRE PERIOD WITH A LACK OF ANY MSTR
INFLOW/DYNAMIC FORCING TO THE N OF STRONG TS COMPLEX/DEEPER SFC LO
TRACKING ALONG THE BNDRY. THE OTHER MODELS SHOW A MORE PRONOUNCED
AXIS OF HIER H85 THETA E AND THUS MORE DEEP LYR MSTR CNVGC/FORCING/
QPF. BEST CHC FOR SOMWHAT HIER POPS WL BE OVER THE W ON SAT EVNG AND
THEN THE CENTRAL ON SUN AFTN/EVNG...WHEN THE 12Z GFS SHOWS MUCAPE AS
HI AS 2500 J/KG...DURING PERIODS OF DAYTIME HEATING. BUT GIVEN
MODEL/TIMING UNCERTAINTIES AND SUPPORT FOR LARGER SCALE FORCING TO
PASS TO THE N AND S OF THE CWA...FCST WL POPS WL BE NO HIER THAN THE
CHC CATEGORY.
MON...SINCE RECENT MEDIUM RANGE GUIDANCE HAS TRENDED TO SPEED UP
PASSAGE OF COLD FROPA ATTENDANT TO SHRTWV SHIFTING ESEWD THRU NW
ONTARIO AND ARRIVAL OF DEEP LYR QVECTOR DVGC/LARGER SCALE
SUBSIDENCE/MID LVL DRYING...PCPN CHCS FOR MON LOOK TO BE
DIMINISHING. WITH MORE SUNSHINE...H85 TEMPS FCST IN IN THE 10 TO 12C
RANGE WL SUPPORT MAX TEMPS IN THE 70S. LOCATIONS NEAR LK SUP WL BE
COOLEST WITH LLVL NNW FLOW IN ADVANCE OF APRCHG CNDN HI PRES.
MON NGT THRU WED...THE UPR RDG IN THE PLAINS IS FCST TO AMPLIFY
EARLY IN THE WEEK...ALLOWING THE TROF IN ERN NAMERICA TO DEEPEN AND
A MORE PRONOUNCED NW FLOW ALOFT BTWN THESE FEATURES TO PREVAIL OVER
THE GREAT LKS. THE ARRIVAL OF CNDN HI PRES/H85 TEMPS AS LO AS 8 TO
10C WL RESULT IN GENERALLY DRY AND COOLER WX FOR MON NGT INTO WED.
ALTHOUGH SOME OF THE MODELS INDICATE A SHRTWV EMBEDDED IN THE NW
FLOW ALOFT COULD CAUSE SOME SHOWERS DURING DAYTIME HEATING ON TUE...
THE COVERAGE/INTENSITY OF THESE SHOWERS WL BE LIMITED BY THE ABSENCE
OF ANY DEEPER MSTR AND GENERAL LARGER SCALE SUBSIDENCE UNDER THE
CONFLUENT NW FLOW ALOFT. RETAINED GOING DRY FCST FOR NOW. WITH
PLENTY OF SUNSHINE...WED AFTN WL TURN WARMER AS H85 TEMPS REBOUND
TOWARD 15C OVER THE W AS THE PLAINS RDG SHIFTS TOWARD THE WRN LKS.
LATE WEEK...A NUMBER OF THE EXTENDED MODELS SHOW ANOTHER SHRTWV
ROUNDING THE TOP OF THE PLAINS RDG WL INFLUENCE THE AREA ON THU AND
BRING THE THREAT OF SOME SHOWERS/TS. AS THE UPR RDG TO THE W BUILDS
BACK TOWARD THE UPR LKS IN THE WAKE OF THIS SHRTWV PASSAGE...FRI
SHOULD BE DRY AND WARMER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY MORNING)
ISSUED AT 1210 AM EDT SAT AUG 8 2015
A LOW CENTERED IN SOUTHERN WISCONSIN WILL MOVE SLOWLY EAST THIS
MORNING ALLOWING ISOLATED SHOWERS TO SLOWLY DISSIPATE. LINGERING LOW-
LEVEL MOISTURE WILL ALLOW FOR LIFR TO POSSIBLY VLIFR CONDITIONS TO
PERSIST AT ALL TAF SITES OVERNIGHT IN A LIGHT E-SE WIND FLOW. DRIER
AIR SHOULD GRADUALLY MOVE INTO THE AREA LATER THIS MORNING INTO THE
AFTERNOON BRINGING AN IMPROVEMENT TO CEILINGS AND VISIBILITIES WITH
VFR CONDITIONS EXPECTED BY AFTERNOON. A FRONTAL SYSTEM APPROACHING
FROM THE WEST TOWARD EVENING COULD BRING A CHANCE FOR SHOWERS LATE
IN THE TAF PERIOD AT BOTH KIWD AND KCMX. MEANWHILE...KSAW COULD SEE
A REDEVELOPMENT OF STRATUS AND MVFR CIGS BY LATE EVENING IN A
CONTINUED UPSLOPE SSE FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT AUG 8 2015
WILL CONTINUE TO TRACK BOAT OBSERVATIONS THIS MORNING TO GET A
BETTER HANDLE ON ANY FOG THAT MAY BET SET UP ACROSS LAKE SUPERIOR.
HOWEVER AT THIS TIME...IT LOOKS LIKE PATCHY TO AREAS OF FOG WILL BE
ABOUT THE EXTENT OF IT THIS MORNING...BEFORE DISSIPATING THIS
AFTERNOON.
EXPECT A WEAKENING LOW OVER E WI/S LAKE MI THIS MORNING. A SECONDARY
LOW LAKE WINNIPEG WILL SLOWLY MOVE E OVER THE NEXT FEW DAYS AND
REACH S JAMES BAY BY MONDAY. THAT LOW WILL SWEEP A TROUGH ACROSS THE
UPPER GREAT LAKES REGION ON SUNDAY. A HIGH PRESSURE RIDGE STRETCHING
FROM MANITOBA TO THE N PLAINS MONDAY WILL SLIDE OVER THE GREAT LAKES
TUESDAY AND WEDNESDAY. EXPECT WIND GUSTS LESS THAN 25KTS THROUGH THE
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
124 AM EDT SAT AUG 8 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EDT FRI AUG 7 2015
A WEAK AREA OF LOW PRESSURE WILL MOVE INTO THE AREA TONIGHT AND
BRING SCATTERED SHOWERS. MOST OF THESE SHOWERS SHOULD EXIT THE AREA
LATE TONIGHT...GIVING THE REGION A NICE SATURDAY.
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL ARRIVE SUNDAY
AFTERNOON AND LINGER INTO THE EVENING. THIS WILL BE A MORE
WIDESPREAD RAIN...AND THERE MAY BE A FEW STRONG STORMS TOO.
TEMPERATURES THROUGH THE WEEKEND WILL BE MILD WITH DAYTIME HIGHS
MAINLY IN THE UPPER 70S TO AROUND 80.
A FEW SHOWERS MAY LINGER INTO MONDAY...BUT THEN WE SHOULD SEE A DRY
PERIOD FROM MONDAY NIGHT THROUGH THURSDAY. ANOTHER CHANCE OF RAIN
WILL MOVE IN FOR THURSDAY NIGHT AND FRIDAY. HIGHS EACH DAY SHOULD
REMAIN IN THE UPPER 70 TO MID 80S.
&&
.UPDATE...
ISSUED AT 928 PM EDT FRI AUG 7 2015
THE SHORTWAVE CURRENTLY MOVING ACROSS LOWER MICHIGAN CONTINUES TO
PRODUCE MODERATE RAIN OVER OUR NORTHERN COUNTIES. SEVERAL MESONET
SITES HAVE HAD BETWEEN .35 AND .50 INCHES OF RAIN OVER WESTERN
MASON COUNTY SO FAR THIS EVENING. AS A RESULT I HAVE INCREASED THE
POP TO NEAR 100% OVER OUR NORTHERN COUNTIES THROUGH AT LEAST
MIDNIGHT AND I ALSO INCREASED QPF TO NEAR HALF INCH OVER THE NW
SECTIONS OF OUR FORECAST AREA TONIGHT.
SOUTHERN AREAS...DUE TO THE DRY EASTERLY LOW LEVEL INFLOW TO THE
SYSTEM...WILL ONLY SEE SPRINKLES OR POSSIBLY AND A FEW HUNDERTHS
OF AN INCH OF RAIN IN ISOLATED LOCATIONS. FOR THE MOST PART AREAS
NEAR AND SOUTH OF INTERSTATE 96 WILL NOT SEE MUCH IN THE WAY OF
MEASURABLE RAIN TONIGHT.
THIS SYSTEM WILL SLOWLY CONTINUE TO WEAKEN AS IT MOVES ACROSS THE
AREA SO THE RAINFALL RATES WILL DECREASE OVER OUR NORTHERN
COUNTIES BY MIDNIGHT. EVEN SO THERE IS A TRAILING UPPER WAVE THAT
WILL COME ACROSS SOUTHWEST LOWER MICHIGAN JUST PRIOR TO SUNRISE.
THIS WILL RESULT IN ADDITIONAL SHOWERS ACROSS THE AREA. THE
LATEST RAP MODEL AND ASSOCIATED MODEL SOUNDINGS DO NOT SHOW ENOUGH
INSTABILITY FOR THUNDERSTORMS SO I EXPUNGED THE MENTION OF
THUNDERSTORMS FROM OUR OVERNIGHT FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT FRI AUG 7 2015
A GOOD CHANCE OF RAIN TONIGHT...ESPECIALLY EARLY ON. THEN ANOTHER
STRONG CHANCE OF RAIN COMES SUNDAY AFTERNOON INTO THE EVENING.
TOPS WERE SLOWLY WARMING WITH THE SYSTEM THAT WAS MOVING ACROSS LAKE
MICHIGAN THIS AFTERNOON. HOWEVER...AS MENTIONED IN AN EARLIER
UPDATE...THE LOW LEVEL JET FUELING THESE SHOWERS WILL HOLD TOGETHER
THROUGH THIS EVENING...BUT THEN SLOWLY WEAKEN AND MOVE INTO NORTHERN
LOWER LATER TONIGHT. WILL INCREASE POPS TO LIKELY OVER CENTRAL
LOWER...WHILE KEEPING CHANCE POPS ELSEWHERE. SOME WEAK INSTABILITY
ARRIVES LATE TONIGHT WITH THE HIGHER DEW POINTS...SO INCLUDED THE
MENTION OF ISOLATED THUNDER.
OTHER THAN SOME LINGERING MORNING SHOWERS ACROSS THE NE CWA SATURDAY
MORNING...THE REST OF THE CWA SHOULD BE DRY ON SATURDAY AS WE WILL
BE IN BETWEEN SYSTEMS. LOW CLOUDS WILL BE COMMONPLACE FIRST
THING...BUT THESE SHOULD BREAK UP THROUGH THE DAY FOR PARTLY SUNNY
SKIES IN THE AFTERNOON.
THE MODELS ARE IN BETTER AGREEMENT SHOWING LOW PRESSURE EJECTING OUT
OF THE CENTRAL PLAINS ON SATURDAY AND TRACKING IT ACROSS THE LOWER
GREAT LAKES SUNDAY NIGHT. THE SYSTEM CONTINUES TO LOOK MORE
IMPRESSIVE WITH GOOD JET DYNAMICS MOVING ACROSS SW MI STARTING LATE
SATURDAY NIGHT AND CONTINUING INTO SUNDAY EVENING. AGREE WITH SPC
INCLUDING PORTIONS OF THE CWA IN THE MARGINAL RISK OF SEVERE.
HOWEVER SINCE WE WILL BE ON THE COOL SIDE OF THE SYSTEM MOST OF THE
INSTABILITY WILL BE ELEVATED. THIS LEAVES LARGE HAIL AS THE MAIN
SEVERE THREAT. INSTABILITY SHOULD NOT BE OFF THE CHARTS...SO ANY
SEVERE THREAT SHOULD BE LOW END. SEVERE TIME FRAME SHOULD SHOULD BE
LATE AFTERNOON/EARLY EVENING SUNDAY.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EDT FRI AUG 7 2015
NO SIGNIFICANT CHANGE WITH A COLD FRONT EXPECTED TO BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ON MONDAY...AND THEN DRY AND
SEASONABLY COOL THROUGH NEXT WEEK. LOOKING FURTHER...SEASONABLY WARM
CONDITIONS RETURN TOWARDS NEXT WEEKEND WITH CONTINUED DRY CONDITIONS
THROUGH WEEK TWO.
MONDAYS FRONTAL PASSAGE SHOULD BE SUPPORTED BY ROUGHLY 500 J/KG OF
CAPE AND 0-6KM SHEAR OF 30KTS WHICH WOULD BE ENOUGH FOR A FEW
ISOLATED STRONG STORMS. HOWEVER...THE FORCING IS NOT OVERLY
IMPRESSIVE OR ORGANIZED BUT...THEN AGAIN...LATEST NWP IS TRENDING
STRONGER...SO POPS ARE UP A BIT TODAY.
REST OF THE WEEK LOOKS A LOT LIKE THIS WEEK WITH HIGH PRESSURE AND
LIKELY SOME DIURNAL FAIR WEATHER CLOUDINESS THROUGHOUT THE WEEK.
UPPER PATTERN CONTINUES TO FEATURE RIDGE OVER CENTRAL WEST WITH
CLOSED HIGH OVER WEST TEXAS AND A DOWNSTREAM TROUGH OVER THE EAST.
THE PATTERN AMPLIFIES A BIT EARLY NEXT WEEK LEADING TO THE COOLER
AND DRIER AIR OVER MICHIGAN FOR MIDWEEK AND THEN FLATTENS WITH
WARMER AND LIKELY A BIT MORE HUMID AIR FOR NEXT WEEKEND. LOOKING
FURTHER OUT THE PATTERN APPEARS TO MORE OR LESS REPEAT IN WEEK TWO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 123 AM EDT SAT AUG 8 2015
LIGHT RAIN SHOWERS CONTINUE TO MOVE ACROSS CENTRAL LOWER MI. A FEW
SHOWERS MAY CLIP THE NRN TAF SITES OVERNIGHT BUT NO RESTRICTIONS
TO VSBY. VFR EXPECTED THROUGH THE PERIOD.
&&
.MARINE...
ISSUED AT 330 PM EDT FRI AUG 7 2015
WINDS AND WAVES WILL STAY UNDER 3 FEET THROUGH THE SHORT TERM.
THUNDERSTORMS WILL BE THE MAIN THREAT...COMING IN LATE SATURDAY
NIGHT AND LINGERING THROUGH SUNDAY EVENING.
&&
.HYDROLOGY...
ISSUED AT 1241 PM EDT FRI AUG 7 2015
NO FLOODING ISSUES EXPECTED FOR THE NEXT WEEK OR MORE AS A
RELATIVELY DRY PATTERN REMAINS IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...COBB
AVIATION...04
HYDROLOGY...MACZKO
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1210 AM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 314 PM EDT FRI AUG 7 2015
FCST FOCUS IN THE MEDIUM RANGE PERIOD WL BE ON POPS THE SECOND HALF
OF THIS WEEKEND ASSOCIATED WITH STRONG DISTUBANCE OVER SCENTRAL
CANADA THAT WL BE DROPPING SLOWLY ESEWD THRU NW ONTARIO AND DRAGGING
A COLD FNT ACRS UPR MI ON SUN NGT. TEMPS AHEAD OF THE COLD FROPA WL
BE AOA NORMAL. DURING THE FIRST HALF OF THE NEXT WEEK...EXPECT TEMPS
TO FALL BLO NORMAL WITH NW FLOW ALOFT DEVELOPING BTWN A BLDG UPR RDG
IN THE PLAINS AND DEEPENING TROF DOWNSTREAM IN ERN NAMERICA. CNDN HI
PRES UNDER THIS NW FLOW ALOFT WL BRING GENERALLY DRY WX DURING THE
MON THRU WED PERIOD. LOOKS LIKE TEMPS WL REBOUND AOA NORMAL LATER IN
THE WEEK AS PLAINS RDG BLDS TOWARD THE WRN LKS.
SAT NGT THRU SUN NGT...STRONG SHRTWV OVER FAR NW ONTARIO THAT WL BE
TOPPING UPR RDG IN THE PLAINS IS FCST TO SLIDE SLOWLY ESE THRU NRN
ONTARIO. ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES...MOST OF
THE LATEST GUIDANCE INDICATE A FASTER PRIMARY COLD FROPA ON SUN NGT.
SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE ONTARIO SHRTWV
WL REMAIN TO THE N OF UPR MI...POPS/PCPN AMOUNTS AS EARLY AS SAT NGT
IN ADVANCE OF THIS COLD FNT WL DEPEND ON THE DEGREE TO WHICH MSTR
INFLOW INTO THE UPR LKS WL BE DISRUPTED BY A W-E ORIENTED BNDRY
STRETCHING FM IOWA INTO THE LOWER LKS AND CONVECTION THAT FIRES
ALONG THIS AXIS ACCOMPANYING THE PASSAGE OF ANOTHER SHRTWV OVER THAT
AREA. THE 12Z NAM IS MOST EXTREME SHOWING A NEAR ABSENCE OF PCPN
ACRS THE CWA DURING THIS ENTIRE PERIOD WITH A LACK OF ANY MSTR
INFLOW/DYNAMIC FORCING TO THE N OF STRONG TS COMPLEX/DEEPER SFC LO
TRACKING ALONG THE BNDRY. THE OTHER MODELS SHOW A MORE PRONOUNCED
AXIS OF HIER H85 THETA E AND THUS MORE DEEP LYR MSTR CNVGC/FORCING/
QPF. BEST CHC FOR SOMWHAT HIER POPS WL BE OVER THE W ON SAT EVNG AND
THEN THE CENTRAL ON SUN AFTN/EVNG...WHEN THE 12Z GFS SHOWS MUCAPE AS
HI AS 2500 J/KG...DURING PERIODS OF DAYTIME HEATING. BUT GIVEN
MODEL/TIMING UNCERTAINTIES AND SUPPORT FOR LARGER SCALE FORCING TO
PASS TO THE N AND S OF THE CWA...FCST WL POPS WL BE NO HIER THAN THE
CHC CATEGORY.
MON...SINCE RECENT MEDIUM RANGE GUIDANCE HAS TRENDED TO SPEED UP
PASSAGE OF COLD FROPA ATTENDANT TO SHRTWV SHIFTING ESEWD THRU NW
ONTARIO AND ARRIVAL OF DEEP LYR QVECTOR DVGC/LARGER SCALE
SUBSIDENCE/MID LVL DRYING...PCPN CHCS FOR MON LOOK TO BE
DIMINISHING. WITH MORE SUNSHINE...H85 TEMPS FCST IN IN THE 10 TO 12C
RANGE WL SUPPORT MAX TEMPS IN THE 70S. LOCATIONS NEAR LK SUP WL BE
COOLEST WITH LLVL NNW FLOW IN ADVANCE OF APRCHG CNDN HI PRES.
MON NGT THRU WED...THE UPR RDG IN THE PLAINS IS FCST TO AMPLIFY
EARLY IN THE WEEK...ALLOWING THE TROF IN ERN NAMERICA TO DEEPEN AND
A MORE PRONOUNCED NW FLOW ALOFT BTWN THESE FEATURES TO PREVAIL OVER
THE GREAT LKS. THE ARRIVAL OF CNDN HI PRES/H85 TEMPS AS LO AS 8 TO
10C WL RESULT IN GENERALLY DRY AND COOLER WX FOR MON NGT INTO WED.
ALTHOUGH SOME OF THE MODELS INDICATE A SHRTWV EMBEDDED IN THE NW
FLOW ALOFT COULD CAUSE SOME SHOWERS DURING DAYTIME HEATING ON TUE...
THE COVERAGE/INTENSITY OF THESE SHOWERS WL BE LIMITED BY THE ABSENCE
OF ANY DEEPER MSTR AND GENERAL LARGER SCALE SUBSIDENCE UNDER THE
CONFLUENT NW FLOW ALOFT. RETAINED GOING DRY FCST FOR NOW. WITH
PLENTY OF SUNSHINE...WED AFTN WL TURN WARMER AS H85 TEMPS REBOUND
TOWARD 15C OVER THE W AS THE PLAINS RDG SHIFTS TOWARD THE WRN LKS.
LATE WEEK...A NUMBER OF THE EXTENDED MODELS SHOW ANOTHER SHRTWV
ROUNDING THE TOP OF THE PLAINS RDG WL INFLUENCE THE AREA ON THU AND
BRING THE THREAT OF SOME SHOWERS/TS. AS THE UPR RDG TO THE W BUILDS
BACK TOWARD THE UPR LKS IN THE WAKE OF THIS SHRTWV PASSAGE...FRI
SHOULD BE DRY AND WARMER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY MORNING)
ISSUED AT 1210 AM EDT SAT AUG 8 2015
A LOW CENTERED IN SOUTHERN WISCONSIN WILL MOVE SLOWLY EAST THIS
MORNING ALLOWING ISOLATED SHOWERS TO SLOWLY DISSIPATE. LINGERING LOW-
LEVEL MOISTURE WILL ALLOW FOR LIFR TO POSSIBLY VLIFR CONDITIONS TO
PERSIST AT ALL TAF SITES OVERNIGHT IN A LIGHT E-SE WIND FLOW. DRIER
AIR SHOULD GRADUALLY MOVE INTO THE AREA LATER THIS MORNING INTO THE
AFTERNOON BRINGING AN IMPROVEMENT TO CEILINGS AND VISIBILITIES WITH
VFR CONDITIONS EXPECTED BY AFTERNOON. A FRONTAL SYSTEM APPROACHING
FROM THE WEST TOWARD EVENING COULD BRING A CHANCE FOR SHOWERS LATE
IN THE TAF PERIOD AT BOTH KIWD AND KCMX. MEANWHILE...KSAW COULD SEE
A REDEVELOPMENT OF STRATUS AND MVFR CIGS BY LATE EVENING IN A
CONTINUED UPSLOPE SSE FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A LOW PRESSURE SYSTEM OVER WESTERN WISCONSIN WILL DISSIPATE TONIGHT
INTO SATURDAY MORNING AS IT MOVES EAST. MEANWHILE...A STRONGER LOW
NEAR LAKE WINNIPEG WILL MOVE TO JAMES BAY BY MONDAY..SWEEPING A
BROAD TROUGH ACROSS THE UPPER GREAT LAKES REGION. HIGH PRESSURE
WILL BUILD IN BEHIND THE TROUGH...AND CONTINUE INTO THE MIDDLE OF
NEXT WEEK. WITH WEAK PRESSURE GRADIENTS EXPECTED...WINDS ARE
EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. FINALLY...WITH
RAIN AND ABUNDANT LOW LEVEL MOISTURE MOVING OVER WESTERN AND
CENTRAL LAKE SUPERIOR...COULD SEE SOME PATCHY FOG OVER THOSE AREAS
TONIGHT INTO SATURDAY MORNING...BUT DON/T EXPECT WIDESPREAD...DENSE
FOG AT THIS TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS DULUTH MN
335 AM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 331 AM CDT SAT AUG 8 2015
UPDATED TO EXPAND FOG ADVISORY TO ST. CROIX RIVER VALLEY OF PINE
AND BURNETT COUNTY...WHERE VISIBILITIES ARE CURRENTLY A HALF
MILE...AND SHOULD ONLY GET WORSE IN THE NEXT FEW HOURS. EXPIRATION
TIME REMAINS THE SAME.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 320 AM CDT SAT AUG 8 2015
COMPLICATED WEATHER SCENE OUT THERE THIS MORNING WITH A STRONG
SURFACE LOW OVER MANITOBA...AND A WEAK FRON DRAPED SOUTH ACROSS
THE EASTERN DAKOTAS. LAST EVENING THUNDERSTORMS DEVELOPED ALONG
THIS FRONT...AND HAVE PUSHED EAST INTO THE FOREAST AREA EARLY THIS
MORNING. THEY HAVE BEEN MAINTAINING STRENGTH ACROSS THE WESTERN
CWA...BUT ONCE THEY GET INTO THE CENTRAL PORTIONS OF THE CWA THEY
HAVE BEEN DIMINISHING RAPIDLY DUE TO THE LACK OF INSTABILITY
FARTHER EAST. ALSO OF CONCERN THIS MORNING IS THE FOG. LAST NIGHTS
RAINFALL CREATED EXCELLENT PRECONDITIONS FOR FOG...AND WITH OUR
TEMPERATURES AND DEWPOINTS IN THE MIDDLE-UPPER 50S HERE WE ARE
WITH FOG OVER MUCH OF THE FORECAST AREA. IT IS WORST AROUND LAKE
SUPERIOR FROM ASHLAND...THROUGH THE TWIN PORTS AND UP THE NORTH
SHORE WHERE A QUARTER MILE VISIBILITY IS PRETTY COMMON. ANY STORMS
THAT GET FAR ENOUGH EAST TO MOVE ACROSS THE FOG IS LIKELY TO BRING
THE VISIBILITY UP TEMPORARILY...BUT IT SHOULD GO RIGHT BACK DOWN.
FOG SHOULD DISSIPATE WITH THE INCREASING TEMPERATURES IN THE
MORNING SO HAVE PUT OUT A DENSE FOG ADVISORY FOR THE WORST
AFFECTED AREAS UNTIL 10 AM.
TODAY THE EARLY MORNING CONVECTION IS LIKELY TO DISSIPATE IN THE
NEXT 3-6 HOURS...ESPECIALLY AS IT IS ALREADY SHOWING SIGNS OF
WEAKENING WITH WEAKER STORMS AND MORE STRATIFORM APPEARANCE ON
RADAR. IN COMBINATION WITH THE WEAKENING TREND AS STORMS MOVE
EAST...EXPECT US TO BE DOWN TO JUST SHOWERS BY SUNRISE OR SHORTLY
AFTER. HOWEVER...THIS IS UNLIKELY TO LAST AS INSTABILITY WILL BUILD
ONCE AGAIN AHEAD OF THE COLD FRONT AS IT SLOWLY MOVES INTO THE
WESTERN CWA THIS AFTERNOON. BETWEEN THAT AND THE RESPECTABLE SHEAR
THAT WILL BE OVER THE AREA THIS AFTERNOON WE SHOULD HAVE SOME STRONG
TO EVEN A FEW SEVERE STORMS THIS AFTERNOON AND EVENING AS THE FRONT
SAGS SLOWLY ACROSS NORTHERN MINNESOTA. THE FRONT SHOULD CONTINUE TO
SAG SOUTHEAST OVERNIGHT TONIGHT...AND CONTINUE ON INTO NORTHWEST
WISCONSIN FOR SUNDAY. HOWEVER...ON SUNDAY THE CONVERGENCE ALONG THE
BOUNDARY IS MUCH WEAKER...THE SHEAR IS MUCH WEAKER AS IS THE
INSTABILITY...SO DO NOT EXPECT AS MUCH INTENSITY OR COVERAGE FROM
THE STORMS AND HAVE GONE WITH LOWER POPS. OTHERWISE...TEMPERATURES
TO REMAIN SEASONABLE...WITH COOLER TEMPS NEAR THE LAKE AS USUAL.
EXPECT FOG AGAIN ACROSS THE AREA TONIGHT WITH THE RECENT RAINFALL
AND LIGHT WINDS...AND HAVE PUT IN AREAS OF FOG FOR A LARGE PORTION
OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT AUG 8 2015
A WEAKENING UPPER LEVEL TROF IS FORECAST TO MOVE OUT OF THE AREA
SUNDAY EVENING...BUT NOT BEFORE DROPPING SOME RAIN ALONG THE
SOUTHERN EDGE OF THE REGION. THIS ACTIVITY WILL QUICKLY DEPART BY
06Z AND HAVE REMOVED THE POPS THEREAFTER AS HIGH PRESSURE IS
BUILDING IN. ON MONDAY...EVEN THOUGH HIGH PRESSURE COVERS THE
AREA...AN UPPER LEVEL TROF WILL SWING THROUGH THE ARROWHEAD AND HAVE
POPS TO REFLECT THIS. THE TROF MOVES EAST OF THE AREA MONDAY NIGHT
LEAVING THE SFC HIGH IN CHARGE. UPPER LEVEL RIDGING EDGES BACK
ACROSS THE REGION TUESDAY WHILE THE SFC HIGH REMAINS NEARBY. THE
RIDGING PREVAILS THROUGH WEDNESDAY. WEDNESDAY NIGHT FINDS A MID
LEVEL TROF MOVING ACROSS THE ARROWHEAD. THE GFS IS SUFFERING FROM
CONVECTIVE/GRIDSCALE FEEDBACK AND PUSHES A LARGE COLD FRONT INTO NE
MN. MEANWHILE...THE ECMWF HAS A WEAK SFC TROF ALONG THE CANADIAN
BORDER WITH SOME LIGHT QPF WITH THE GEM FURTHER TO THE WEST WITH THE
TROF AND NO RAIN. USED A BLEND OF THE GEM/ECMWF FOR POPS. MODEL
DIFFERENCES BECOME QUITE LARGE THURSDAY AND FRIDAY WITH THE HANDLING
OF AN UPPER TROF AND ASSOCIATED FRONTAL BOUNDARY. KEPT WITH THE
BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 106 AM CDT SAT AUG 8 2015
A FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY MOVE INTO THE NORTHLAND
DURING THE FORECAST PERIOD. THIS HAS GENERATED SHOWERS AND STORMS
OVER WESTERN AND NORTH CENTRAL MINNESOTA. CURRENTLY STORMS ARE
MOVING THROUGH KINL. EXPECTING THIS ACTIVITY TO SPREAD EASTWARDS
AND AFFECT ALL OTHER TERMINALS...EXCEPT FOR KHYR BETWEEN 07Z AND
12Z. THIS MATCHES WELL WITH THE CURRENT RADAR TRENDS ALONG WITH
THE LAST SEVERAL HRRR RUNS.
EXPECTING ALL TERMINALS TO SEE EITHER IFR OR LIFR CONDITIONS AT
SOME POINT AS THE NIGHT PROGRESSES INTO THE EARLY MORNING HOURS.
MOST CONFIDENT OF LIFR CIGS AND VISBYS FOR KDLH AND KHYR UNTIL 14Z
TO 17Z.
WILL SEE ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT
DUE TO DAY TIME HEATING IN COMBINATION WITH THE FRONT MOVING
THROUGH MINNESOTA SATURDAY AFTERNOON. THINK THAT KINL AND KBRD MAY
BE ON THE BACKSIDE OF THE FRONT BY THE TIME THIS OCCURS...SO LEFT
IN AS VCSH...AND EVENTUALLY BROUGHT KINL AND KBRD TO VFR
CONDITIONS BETWEEN 21Z AND 02Z. EXPECTING ALL OTHER TERMINALS TO
SEE SHOWERS AND STORMS DURING THE AFTERNOON...HOWEVER UNSURE ON
THE EXACT LOCATION OF SPECIFIC STORMS...SO LEFT AS VCTS. SOME OF
THESE STORMS MAY BE STRONG DURING THE AFTERNOON AND HEADING INTO
THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 72 60 78 58 / 40 50 10 10
INL 78 54 74 55 / 40 10 0 10
BRD 79 60 80 58 / 50 40 20 10
HYR 76 60 78 57 / 20 30 20 20
ASX 74 60 78 58 / 30 40 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001>003-
006.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037-038.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...LE
LONG TERM...GSF
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
322 AM CDT SAT AUG 8 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 320 AM CDT SAT AUG 8 2015
COMPLICATED WEATHER SCENE OUT THERE THIS MORNING WITH A STRONG
SURFACE LOW OVER MANITOBA...AND A WEAK FRON DRAPED SOUTH ACROSS
THE EASTERN DAKOTAS. LAST EVENING THUNDERSTORMS DEVELOPED ALONG
THIS FRONT...AND HAVE PUSHED EAST INTO THE FOREAST AREA EARLY THIS
MORNING. THEY HAVE BEEN MAINTAINING STRENGTH ACROSS THE WESTERN
CWA...BUT ONCE THEY GET INTO THE CENTRAL PORTIONS OF THE CWA THEY
HAVE BEEN DIMINISHING RAPIDLY DUE TO THE LACK OF INSTABILITY
FARTHER EAST. ALSO OF CONCERN THIS MORNING IS THE FOG. LAST NIGHTS
RAINFALL CREATED EXCELLENT PRECONDITIONS FOR FOG...AND WITH OUR
TEMPERATURES AND DEWPOINTS IN THE MIDDLE-UPPER 50S HERE WE ARE
WITH FOG OVER MUCH OF THE FORECAST AREA. IT IS WORST AROUND LAKE
SUPERIOR FROM ASHLAND...THROUGH THE TWIN PORTS AND UP THE NORTH
SHORE WHERE A QUARTER MILE VISIBILITY IS PRETTY COMMON. ANY STORMS
THAT GET FAR ENOUGH EAST TO MOVE ACROSS THE FOG IS LIKELY TO BRING
THE VISIBILITY UP TEMPORARILY...BUT IT SHOULD GO RIGHT BACK DOWN.
FOG SHOULD DISSIPATE WITH THE INCREASING TEMPERATURES IN THE
MORNING SO HAVE PUT OUT A DENSE FOG ADVISORY FOR THE WORST
AFFECTED AREAS UNTIL 10 AM.
TODAY THE EARLY MORNING CONVECTION IS LIKELY TO DISSIPATE IN THE
NEXT 3-6 HOURS...ESPECIALLY AS IT IS ALREADY SHOWING SIGNS OF
WEAKENING WITH WEAKER STORMS AND MORE STRATIFORM APPEARANCE ON
RADAR. IN COMBINATION WITH THE WEAKENING TREND AS STORMS MOVE
EAST...EXPECT US TO BE DOWN TO JUST SHOWERS BY SUNRISE OR SHORTLY
AFTER. HOWEVER...THIS IS UNLIKELY TO LAST AS INSTABILITY WILL BUILD
ONCE AGAIN AHEAD OF THE COLD FRONT AS IT SLOWLY MOVES INTO THE
WESTERN CWA THIS AFTERNOON. BETWEEN THAT AND THE RESPECTABLE SHEAR
THAT WILL BE OVER THE AREA THIS AFTERNOON WE SHOULD HAVE SOME STRONG
TO EVEN A FEW SEVERE STORMS THIS AFTERNOON AND EVENING AS THE FRONT
SAGS SLOWLY ACROSS NORTHERN MINNESOTA. THE FRONT SHOULD CONTINUE TO
SAG SOUTHEAST OVERNIGHT TONIGHT...AND CONTINUE ON INTO NORTHWEST
WISCONSIN FOR SUNDAY. HOWEVER...ON SUNDAY THE CONVERGENCE ALONG THE
BOUNDARY IS MUCH WEAKER...THE SHEAR IS MUCH WEAKER AS IS THE
INSTABILITY...SO DO NOT EXPECT AS MUCH INTENSITY OR COVERAGE FROM
THE STORMS AND HAVE GONE WITH LOWER POPS. OTHERWISE...TEMPERATURES
TO REMAIN SEASONABLE...WITH COOLER TEMPS NEAR THE LAKE AS USUAL.
EXPECT FOG AGAIN ACROSS THE AREA TONIGHT WITH THE RECENT RAINFALL
AND LIGHT WINDS...AND HAVE PUT IN AREAS OF FOG FOR A LARGE PORTION
OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT AUG 8 2015
A WEAKENING UPPER LEVEL TROF IS FORECAST TO MOVE OUT OF THE AREA
SUNDAY EVENING...BUT NOT BEFORE DROPPING SOME RAIN ALONG THE
SOUTHERN EDGE OF THE REGION. THIS ACTIVITY WILL QUICKLY DEPART BY
06Z AND HAVE REMOVED THE POPS THEREAFTER AS HIGH PRESSURE IS
BUILDING IN. ON MONDAY...EVEN THOUGH HIGH PRESSURE COVERS THE
AREA...AN UPPER LEVEL TROF WILL SWING THROUGH THE ARROWHEAD AND HAVE
POPS TO REFLECT THIS. THE TROF MOVES EAST OF THE AREA MONDAY NIGHT
LEAVING THE SFC HIGH IN CHARGE. UPPER LEVEL RIDGING EDGES BACK
ACROSS THE REGION TUESDAY WHILE THE SFC HIGH REMAINS NEARBY. THE
RIDGING PREVAILS THROUGH WEDNESDAY. WEDNESDAY NIGHT FINDS A MID
LEVEL TROF MOVING ACROSS THE ARROWHEAD. THE GFS IS SUFFERING FROM
CONVECTIVE/GRIDSCALE FEEDBACK AND PUSHES A LARGE COLD FRONT INTO NE
MN. MEANWHILE...THE ECMWF HAS A WEAK SFC TROF ALONG THE CANADIAN
BORDER WITH SOME LIGHT QPF WITH THE GEM FURTHER TO THE WEST WITH THE
TROF AND NO RAIN. USED A BLEND OF THE GEM/ECMWF FOR POPS. MODEL
DIFFERENCES BECOME QUITE LARGE THURSDAY AND FRIDAY WITH THE HANDLING
OF AN UPPER TROF AND ASSOCIATED FRONTAL BOUNDARY. KEPT WITH THE
BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 106 AM CDT SAT AUG 8 2015
A FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY MOVE INTO THE NORTHLAND
DURING THE FORECAST PERIOD. THIS HAS GENERATED SHOWERS AND STORMS
OVER WESTERN AND NORTH CENTRAL MINNESOTA. CURRENTLY STORMS ARE
MOVING THROUGH KINL. EXPECTING THIS ACTIVITY TO SPREAD EASTWARDS
AND AFFECT ALL OTHER TERMINALS...EXCEPT FOR KHYR BETWEEN 07Z AND
12Z. THIS MATCHES WELL WITH THE CURRENT RADAR TRENDS ALONG WITH
THE LAST SEVERAL HRRR RUNS.
EXPECTING ALL TERMINALS TO SEE EITHER IFR OR LIFR CONDITIONS AT
SOME POINT AS THE NIGHT PROGRESSES INTO THE EARLY MORNING HOURS.
MOST CONFIDENT OF LIFR CIGS AND VISBYS FOR KDLH AND KHYR UNTIL 14Z
TO 17Z.
WILL SEE ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT
DUE TO DAY TIME HEATING IN COMBINATION WITH THE FRONT MOVING
THROUGH MINNESOTA SATURDAY AFTERNOON. THINK THAT KINL AND KBRD MAY
BE ON THE BACKSIDE OF THE FRONT BY THE TIME THIS OCCURS...SO LEFT
IN AS VCSH...AND EVENTUALLY BROUGHT KINL AND KBRD TO VFR
CONDITIONS BETWEEN 21Z AND 02Z. EXPECTING ALL OTHER TERMINALS TO
SEE SHOWERS AND STORMS DURING THE AFTERNOON...HOWEVER UNSURE ON
THE EXACT LOCATION OF SPECIFIC STORMS...SO LEFT AS VCTS. SOME OF
THESE STORMS MAY BE STRONG DURING THE AFTERNOON AND HEADING INTO
THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 72 60 78 58 / 40 50 10 10
INL 78 54 74 55 / 40 10 0 10
BRD 79 60 80 58 / 50 40 20 10
HYR 76 60 78 57 / 20 30 20 20
ASX 74 60 78 58 / 30 40 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001>003.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037.
LS...NONE.
&&
$$
SHORT TERM...LE
LONG TERM...GSF
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
106 AM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 106 AM CDT SAT AUG 8 2015
UPDATED AVIATION DISCUSSION BELOW FOR THE 06Z TAF ISSUANCE
UPDATE ISSUED AT 841 PM CDT FRI AUG 7 2015
WE WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR THE TWIN PORTS
AND ALONG THE NORTH SHORE TONIGHT INTO SATURDAY MORNING.
VISIBILITIES CONTINUE TO DROP AND THAT TREND WILL CONTINUE
OVERNIGHT FOR MOST AREAS.
UPDATE ISSUED AT 807 PM CDT FRI AUG 7 2015
WE HAVE MADE SOME UPDATES TO ADJUST POPS/FOG/CLOUDS THIS EVENING.
A BROKEN LINE OF STORMS EXTENDED FROM SOUTHEAST MANITOBA INTO
EASTERN SOUTH DAKOTA THIS EVENING AND WAS MOVING TOWARD THE EAST.
THIS WAS OCCURRING IN AN AXIS OF MLCAPE AROUND 2000J/KG AND STEEP
LAPSE RATES. THE CONVECTION HAS SHOWN SOME SIGNS OF
WEAKENING AS IT PROGRESSES EAST...BUT A STRONG OR POSSIBLE
ISOLATED SEVERE STORM WILL BE POSSIBLE OVER OUR WESTERN ZONES
LATER THIS EVENING INTO THE EARLY MORNING HOURS.
FOG HAS PERSISTED AROUND LAKE SUPERIOR AND WE MAY HAVE TO ISSUE A
DENSE FOG ADVISORY FOR THE HEAD OF LAKE SUPERIOR NORTH ALONG
PORTIONS OF THE NORTH SHORE. SEVERAL OBSERVATIONS WERE DOWN TO A
QUARTER MILE. WE WILL WAIT A BIT LONGER BEFORE ISSUING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CDT FRI AUG 7 2015
MAIN CONCERN FOR TODAY IS THE POTENTIAL FOR THUNDERSTORMS LATE THIS
AFTERNOON ACROSS NORTH-CENTRAL MINNESOTA...FOG OVERNIGHT...AND RAIN
CHANCES THROUGH THE DAY SATURDAY. EARLY THIS AFTERNOON AN UPPER LOW
EVIDENT ON WATER VAPOR SATELLITE IMAGERY WAS TRACKING ACROSS
SOUTHERN SASKATCHEWAN EAST INTO SOUTHERN MANITOBA. THIS UPPER LOW
AND ACCOMPANY SFC LOW WILL LIFT NORTHEAST INTO NORTHWESTERN ONTARIO
OVER THE WEEKEND. A WEAK COLD FRONT ASSOCIATED WITH THIS LOW IS
CURRENTLY OVER EASTERN NORTH DAKOTA AND WILL MOVE EAST INTO
NORTHWESTERN MINNESOTA TONIGHT...THEN STALL OUT THROUGH MUCH OF
SATURDAY AS IT IS DRAPED FROM LAKE OF THE WOODS IN NORTHERN
MINNESOTA TO AROUND FARGO NORTH DAKOTA. THIS COLD FRONT WILL SERVE
AS A BOUNDARY FOR ANY STORM INITIATION TONIGHT...AND AS A DRIVER FOR
SHOWERS AND STORMS AS THEY MOVE ACROSS THE REGION TOMORROW.
TEMPERATURES WILL BE NEAR TO SLIGHTLY BELOW NORMAL...ESPECIALLY
ALONG THE NORTH SHORE OF LAKE SUPERIOR.
LATE TODAY...CLEARING SKIES FROM WEST TO EAST. A CU FIELD WAS
OBSERVED ON VISIBLE SATELLITE EARLY THIS AFTERNOON...NOT SURPRISING
GIVEN THE INSTABILITY OVER NORTH CENTRAL MINNESOTA...MUCAPE VALUES
1500-2000 J/KG. IN ADDITION TO THE AFOREMENTIONED COLD FRONT
CURRENTLY OVER EASTERN NORTH DAKOTA...A WEAK STATIONARY FRONT IS
CURRENTLY ANALYZED FROM LAKE OF THE WOODS SOUTHEAST TO ABOUT MOOSE
LAKE. WHILE MUCH OF THE CWA REMAINS CAPPED...THERE IS A NARROW
CORRIDOR WHICH SPC MESOANALYSIS INDICATES HAS VERY LITTLE CIN
LEFT...BUT LACK OF ANY LOCAL FORCING MECHANISM WILL LIKELY PREVENT
ANY STORM DEVELOPMENT THROUGH THE AFTERNOON.
TONIGHT...AN ISOLATED STORM OR TWO WILL FIRE ACROSS THE RED RIVER
VALLEY THIS EVENING AND MOVE EAST INTO NORTH CENTRAL/NORTHEAST
MINNESOTA TOWARDS THE MORNING. COVERAGE EXPECTED TO BE SPARSE...BUT
WITH ELEVATED INSTABILITY AND 25-35 KTS DEEP LAYER SHEAR COULD SEE
STORMS SUSTAIN INTO THE NIGHT. STORMS MAY BE CAPABLE OF SMALL
HAIL/GUSTY WINDS...BUT SEVERE THREAT SHOULD BE MINIMAL. ELSEWHERE
EXPECT AREAS OF FOG TO DEVELOP ESPECIALLY NEAR LAKE SUPERIOR.
OVERNIGHT LOWS IN THE MID TO UPPER 50S.
SATURDAY...SCATTERED SHOWERS AND ISOLATED STORMS THROUGH THE DAY AND
INTO THE NIGHT AS A COLD FRONT MOVES THROUGH. SEVERE THUNDERSTORMS
NOT EXPECTED. NOT EXPECTING A COMPLETE WASHOUT...TRYING TO
COMMUNICATE THIS WITH THE USE OF JUST 40-60 PERCENT POPS AND AREAL
COVERAGE WORDING FOR THE WEATHER GRIDS...BUT A FEW DOWNPOURS
POSSIBLE. HIGHS IN THE 70S...EXPECT NEAR LAKE SUPERIOR WHERE HIGHS
WILL BE IN THE MID TO UPPER 60S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM CDT FRI AUG 7 2015
VERY SLOW MOVING UPPER TROF AND ASSOCIATED LOW LEVEL FRONTAL ZONE
WILL MOVE ACROSS THE REGION SAT NITE/SUN BRINGING A CHANCE OF
SHOWERS/TSTORMS IN MOST AREAS. AT THIS TIME..IT APPEARS THAT THE
AXIS OF HIGHEST QUALITY LOW LEVEL MOISTURE WILL REMAIN SOUTH OF THE
DULUTH CWA. HOWEVER..THERE IS THE USUAL UNCERTAINTY IN
PLACEMENT/TIMING OF CONVECTIVE POTENTIAL THAT WILL BE LARGELY
DEPENDENT ON WHERE BOUNDARIES END UP AND OTHER CUMULATIVE EFFECTS
FROM SEVERAL ROUNDS OF CONVECTION BEFORE THIS TIME PERIOD. WITH A
WARM FRONTAL BOUNDARY PROGGED SOMEWHERE IN THE VICINITY OF THE I94
CORRIDOR AND THE NOSE OF A LLJ POINTED INTO WRN WI SAT NIGHT..THERE
APPEARS TO BE AT LEAST SOME POTENTIAL FOR HEAVY RAIN IN THE ERN HALF
OF OUR CWA SAT NIGHT INTO PERHAPS MIDDAY SUNDAY.
AT LEAST SOME LOW CHANCES FOR PRECIP ARE EXPECTED TO LINGER INTO
MONDAY AS THE FRONTAL ZONE IS EXPECTED TO TAKE ITS TIME MOVING
SOUTHEASTWARD. IT WILL LIKELY TAKE UNTIL SOMETIME MONDAY NIGHT WHEN
MORE SUBSTANTIAL LOW LEVEL RIDGING BUILDS BEFORE PRECIP WILL
COMPLETELY END. IN ADDITION..THERE COULD BE SOME SMALL RISK OF
SHOWERS ACROSS THE MN ARROWHEAD TUE..DEPENDING ON HOW COLD TEMPS GET
ALOFT.
THEREAFTER..HIGH PRESSURE SHOULD REMAIN IN CONTROL FOR MOST OF NEXT
WEEK..WITH WARM DAYS..AND COOL NIGHTS ESPECIALLY ACROSS INTERIOR NE
MINNESOTA. A WEAK FRONT INTERACTING WITH A BUILDING THERMAL RIDGE
COULD BRING SMALL CHANCES FOR TSTORMS TO NORTHERN MN WED NIGHT INTO
THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 106 AM CDT SAT AUG 8 2015
A FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY MOVE INTO THE NORTHLAND
DURING THE FORECAST PERIOD. THIS HAS GENERATED SHOWERS AND STORMS
OVER WESTERN AND NORTH CENTRAL MINNESOTA. CURRENTLY STORMS ARE
MOVING THROUGH KINL. EXPECTING THIS ACTIVITY TO SPREAD EASTWARDS
AND AFFECT ALL OTHER TERMINALS...EXCEPT FOR KHYR BETWEEN 07Z AND
12Z. THIS MATCHES WELL WITH THE CURRENT RADAR TRENDS ALONG WITH
THE LAST SEVERAL HRRR RUNS.
EXPECTING ALL TERMINALS TO SEE EITHER IFR OR LIFR CONDITIONS AT
SOME POINT AS THE NIGHT PROGRESSES INTO THE EARLY MORNING HOURS.
MOST CONFIDENT OF LIFR CIGS AND VISBYS FOR KDLH AND KHYR UNTIL 14Z
TO 17Z.
WILL SEE ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT
DUE TO DAY TIME HEATING IN COMBINATION WITH THE FRONT MOVING
THROUGH MINNESOTA SATURDAY AFTERNOON. THINK THAT KINL AND KBRD MAY
BE ON THE BACKSIDE OF THE FRONT BY THE TIME THIS OCCURS...SO LEFT
IN AS VCSH...AND EVENTUALLY BROUGHT KINL AND KBRD TO VFR
CONDITIONS BETWEEN 21Z AND 02Z. EXPECTING ALL OTHER TERMINALS TO
SEE SHOWERS AND STORMS DURING THE AFTERNOON...HOWEVER UNSURE ON
THE EXACT LOCATION OF SPECIFIC STORMS...SO LEFT AS VCTS. SOME OF
THESE STORMS MAY BE STRONG DURING THE AFTERNOON AND HEADING INTO
THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 59 78 58 77 / 40 20 10 10
INL 53 76 53 75 / 20 10 10 10
BRD 60 81 58 79 / 40 20 10 10
HYR 59 78 57 77 / 30 40 20 10
ASX 59 79 57 76 / 40 30 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037.
LS...NONE.
&&
$$
UPDATE...WL
SHORT TERM...JJM
LONG TERM...MILLER
AVIATION...WL
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
437 AM CDT SAT AUG 8 2015
.UPDATE:
ISSUED AT 434 AM CDT SAT AUG 8 2015
WILL BE ISSUING A DENSE FOG ADVISORY THROUGH 13Z FOR THE SOUTHERN
MISSOURI COUNTIES IN THE CWA WHERE THE VISIBILITY HAS DROPPED TO
1/4SM. HAVE ALSO ADJUSTED POPS UP TO LIKELY CATEGORY FOR THE
NORTHERN CWA WHERE REMNANTS OF THE MCS WILL BE TRACKING THIS
MORNING.
CVKING
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPOGATING SOUTHEAST INTO SOUTH CENTRAL ILLINOIS
ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH THIS
SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1055 PM CDT FRI AUG 7 2015
WEAKENING COLD FRONT EXTENDING FROM A SURFACE LOW OVER WI SW INTO
NORTHEAST MO WILL CONTINUE MOVING SOUTHEASTWARD LATE TONIGHT AND
DISSIPATE. COULD NOT RULE OUT AN ISOLATED SHOWER/STORM ALONG THIS
WEAK FRONT...BUT FOR NOW WILL LEAVE UIN TAF DRY. HIGH LEVEL
CLOUDINESS WILL STREAM EASTWARD FROM THE PLAINS LATE TONIGHT...
MAINLY FROM CONVECTION ACROSS KANSAS AND NEBRASKA. WITH LIGHT
SURFACE WINDS AND RELATIVELY HIGH SURFACE DEW POINTS...THERE MAY
BE SOME FOG LATE TONIGHT/EARLY SATURDAY MORNING...ALTHOUGH THE NAM
MOS GUIDANCE APPEARS OVERDONE ON ITS STRATUS/FOG FORECAST AT THE
TAF SITES. SOUTHEASTERLY SURFACE WINDS ON SATURDAY WITH SCATTERED
DIURNAL CUMULUS ALONG WITH HIGH LEVEL CLOUDS AGAIN.
SPECIFICS FOR KSTL: SOME HIGH LEVEL CLOUDS FOR LATE TONIGHT.
LIGHT E-SELY SURFACE WIND LATE TONIGHT WILL STRENGTHEN TO AROUND
7-8 KNOTS SATURDAY AFTERNOON. SCATTERED DIURNAL CUMULUS CLOUDS
WILL DEVELOP AGAIN FOR LATE SATURDAY MORNING AND AFTERNOON.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 91 76 95 75 / 10 20 30 40
QUINCY 87 71 89 70 / 50 60 40 20
COLUMBIA 90 75 94 72 / 30 20 20 40
JEFFERSON CITY 91 76 96 74 / 20 20 20 40
SALEM 87 72 91 73 / 10 10 30 40
FARMINGTON 88 72 94 74 / 5 10 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
358 AM CDT SAT AUG 8 2015
.DISCUSSION...
Issued at 357 AM CDT SAT AUG 8 2015
As was anticipated last night, High Plains convection has congealed
into an overnight MCS, which has made pretty good progression across
northern Kansas, into north central Kansas. Models have had a rough
time resolving exactly how this MCS will behave as it continues east.
NAM consistently indicates that this complex will lose steam as the
night progresses, but HRRR continues to insist that the complex will
continue it, albeit weakening along the way, into the KC metro around
sunrise. General thought as the morning progresses is a bit in the
middle between these two solutions. The low level jet, apparently
helping this complex persist is not very strong, but it also doesn`t
appear to weaken much as one gets closer to the KC Metro. However,
with the outflow from these storms already pushing out ahead of the
complex, there is a good bet that stabilization of the effective
layer will gradually occur and the storms will eventually lose their
strength. Have the best chance of rain occurring across the far
northwestern part of the CWA, in NW Missouri and NE Kansas, with
diminishing (but non-zero) chances farther south and east.
The focus then shifts to a complicated and conditional forecast for
Saturday. Heat headlines currently ongoing will be allowed to
continue, however confidence in these abnormally hot temperatures
isn`t quite as high as it was yesterday. The aforementioned storm
complex could change the evolution of the heat today across a good
portion of the area. If the HRRR has its way and the complex dives
all the way into the KC Metro it would bring at least some rain into
the morning hours, with likely some cloud debris lingering around
for a good portion of the morning. Even with all these qualifiers
it`s still anticipated that the surface will recover, despite the
stable rain cooled air moving through this morning. Expect heat
indices to jump into the 100 to 105 range this afternoon with some
locations perhaps reaching a little higher, mainly along and south
of the MO River.
That leads to the complications and conditions related to the storm
chances later this afternoon and this evening. Mid level flow
continues to reside over the central and northern plains with the
center of the mid level ridge well south of the forecast area in the
eastern southern plains. At the surface an unseasonably deep trough
will form across the central High Plains and eject into the lower
central plains. In response to this low to the west S/SE winds will
pick up during the day, and likely overcome the cooler air, causing
temperatures to jump back into the upper 80s, and very possibly the
lower 90s. Across far northern Missouri, where cloud debris will
likely be the thickest, as well as perhaps along or north of the
warm front temperatures won`t get quite as warm as areas along and
south of I-70. Depending on how well skies clear out this afternoon
another round of storms will be possible, most likely across SE
Nebraska, eastward across northern Missouri and southern Iowa. Most
models continue to indicate a scenario where storms indeed fire
later today. The lack of any appreciable mid level support for
ascent this afternoon will exaggerate the capping inversion, which
will keep storms at bay for at least the afternoon, into the evening
hours. By the 22z to 00z time period the low level jet at 850 mb
will pick up in intensity and likely give the final push needed to
get storms to go up, likely in SE Nebraska or NE Kansas. Should these
storms become surface based, which isn`t out of the question, a very
impressive thermal and wind profile will be in place to bring some
powerful storms. With the aforementioned SE surface flow, the
strengthening LLJ, as well as the westerly mid level flow around 40
kts. The wind profile will be ample for supercell storms to form
later this evening in the SE Neb/NW Mo/NE Ks area. ML CAPE values
approaching 2000 to 3000 J/KG will provide the necessary instability
to complement the deep layer shear nicely. Given that supercells are
possible, hail and wind would be the most likely hazards with these
storms; however not to be discounted, very impressive hodographs are
present across the area of concern, with very long and clockwise
curved hodographs. This would introduce a rather concerning tornado
risk, especially for early August. Given the weak forcing it`s
certainly possible that early storms will be somewhat discreet,
which would increase the concern for supercellular storms. However,
by 00z to 03z the discreet storms will likely congeal into a more
robust complex and drive eastward, likely along the MO/IA border,
bringing a wind and hail threat, along with a flash flooding threat.
Given the LLJ maintenance overnight and PWAT values approaching 2 to
2.5 inches it`s possible that areas along and north of HWY 36
tonight could see some flooding and/or flash flooding. By early
Sunday morning expect these storms to have moved off to the east and
chances for rain gradually diminishing through the day on Sunday.
For Sunday, warm conditions will continue for the forecast area,
again, mainly across the southern zones. Anticipate temperatures
again to reach the 90s, with heat indices in the 100 to 105 range
across areas along and south of the MO River. But again, depending
on how the area clears, the areal extent of the heat for Sunday is a
bit up in the air, so will forgo a heat headline for now, but one
may be necessary for areas along and south of the MO River.
For Sunday, into Monday the large ridge will shift a little back to
the west, putting the forecast area under more of an influence of
the large trough over the Great Lakes region as opposed to the
western ridge. A short wave trough will glide through the area on
Monday, which should bring another chance for some rain, as well as
a cooler air mass. For the rest of the week, expect temperatures to
be a bit more comfortable with temperatures generally in the 80s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1203 AM CDT SAT AUG 8 2015
Mainly VFR expected through the period. Main concern will be
potential thunderstorm complex reaching terminals in some weakened
form between 09-14Z. Still expect mainly VFR conditions with this
activity. Cloud canopy currently overspreading region will limit
shallow fog potential. Otherwise, southeast winds will increase to
AOA 12kts by mid- morning. Additional chances for storms during the
afternoon/evening look to remain north of terminals through TAF
period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY from 11 AM this morning to 9 PM CDT this evening
for KSZ025-057-060-102.
EXCESSIVE HEAT WARNING from 11 AM this morning to 9 PM CDT this
evening for KSZ103>105.
MO...HEAT ADVISORY from 11 AM this morning to 9 PM CDT this evening
for MOZ011>014-020>023-030-031-038-039-043>046-053-054.
EXCESSIVE HEAT WARNING from 11 AM this morning to 9 PM CDT this
evening for MOZ028-029-037.
&&
$$
DISCUSSION...Leighton
AVIATION...Blair
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
305 AM CDT SAT AUG 8 2015
.SHORT TERM...(Today through Sunday)
Issued at 305 AM CDT SAT AUG 08 2015
First concern is ongoing convection across northern Kansas.
Successive runs of the HRRR dissipates this area before it gets
into the forecast area as does the RAP. Given expanding ridging
would expect it to dissipate as it gets closer and stay north of
the area. Will monitor radar trends and update as needed. For now
will keep dry forecast for the morning hours.
Attention then turns to the aforementioned expanding ridge across
the area. This ridge will dominate the weather through Sunday with
increasing heat and humidity. Heat advisory already in effect for
much of the area from this afternoon through Sunday evening. Expect
afternoon heat indicies in the 100 to 110 degree range both days.
Biggest question will be the need to expand the advisory further
eastward. Eastern Ozarks best chance to hit advisory criteria would
be Sunday afternoon. Will allow day shift to evaluate it further.
.LONG TERM...(Sunday night through Friday)
Issued at 305 AM CDT SAT AUG 08 2015
Upper ridge retracts westward Sunday night and Monday allowing for a
surface frontal boundary to slip southward into the area. This will
bring our next chance for rain. Medium range models showing the
better chances across central Missouri from late Sunday night into
Monday morning.
Pattern then dominated by a northwest flow regime with a surface
high building southward into the area. This will result in quiet
and dry weather with near to slightly below normal temperatures.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1133 PM CDT FRI AUG 07 2015
Generally VFR conditions are expected at area terminals tonight
through Saturday. The exception may be patchy light fog late
tonight into early Friday morning which could lead to a brief
interval of MVFR visibilities. Otherwise a light southerly wind
will develop Saturday.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY from Noon today to 10 PM CDT Sunday for MOZ055-056-
066>069-077>081-088>096-101>105.
KS...HEAT ADVISORY from Noon today to 10 PM CDT Sunday for KSZ073-097-
101.
&&
$$
SHORT TERM...Raberding
LONG TERM...Raberding
AVIATION...Foster
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
256 AM CDT SAT AUG 8 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPOGATING SOUTHEAST INTO SOUTH CENTRAL ILLINOIS
ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH THIS
SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1055 PM CDT FRI AUG 7 2015
WEAKENING COLD FRONT EXTENDING FROM A SURFACE LOW OVER WI SW INTO
NORTHEAST MO WILL CONTINUE MOVING SOUTHEASTWARD LATE TONIGHT AND
DISSIPATE. COULD NOT RULE OUT AN ISOLATED SHOWER/STORM ALONG THIS
WEAK FRONT...BUT FOR NOW WILL LEAVE UIN TAF DRY. HIGH LEVEL
CLOUDINESS WILL STREAM EASTWARD FROM THE PLAINS LATE TONIGHT...
MAINLY FROM CONVECTION ACROSS KANSAS AND NEBRASKA. WITH LIGHT
SURFACE WINDS AND RELATIVELY HIGH SURFACE DEW POINTS...THERE MAY
BE SOME FOG LATE TONIGHT/EARLY SATURDAY MORNING...ALTHOUGH THE NAM
MOS GUIDANCE APPEARS OVERDONE ON ITS STRATUS/FOG FORECAST AT THE
TAF SITES. SOUTHEASTERLY SURFACE WINDS ON SATURDAY WITH SCATTERED
DIURNAL CUMULUS ALONG WITH HIGH LEVEL CLOUDS AGAIN.
SPECIFICS FOR KSTL: SOME HIGH LEVEL CLOUDS FOR LATE TONIGHT.
LIGHT E-SELY SURFACE WIND LATE TONIGHT WILL STRENGTHEN TO AROUND
7-8 KNOTS SATURDAY AFTERNOON. SCATTERED DIURNAL CUMULUS CLOUDS
WILL DEVELOP AGAIN FOR LATE SATURDAY MORNING AND AFTERNOON.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 91 76 95 75 / 10 20 30 40
QUINCY 87 71 89 70 / 20 60 40 20
COLUMBIA 90 75 94 72 / 10 20 20 40
JEFFERSON CITY 91 76 96 74 / 10 20 20 40
SALEM 87 72 91 73 / 10 10 30 40
FARMINGTON 88 72 94 74 / 10 10 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1148 PM CDT FRI AUG 7 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT FRI AUG 7 2015
THE PRIMARY FORECAST CONCERNS ARE IN REGARDS TO THE POTENTIAL FOR
TSTMS/RAIN LATER TONIGHT AND INTO SATURDAY...PLUS THE CHANCE OF
SEVERE WEATHER SATURDAY.
MAIN FEATURES FROM THE UPPER AIR MAPS THIS MORNING INCLUDED THE
FOLLOWING. AT 300 MB A 75 KT JET STREAK WAS OVER SRN CA PUNCHING TO
THE E/NE. THE 500 MB PATTERN IN GENERAL SHOWED TROUGHING ACROSS THE
W AND E COASTS AND A RIDGE CENTERED OVER TX/OK. CLOSED LOWS WERE
NOTED OVER SRN ALTA AND OVER CNTRL CA. 12 HOUR HEIGHT FALLS WERE
AROUND 50 METERS WITH THE CA SYSTEM...WHICH CONTINUED TO LIFT INTO
NV ACCORDING TO RECENT WATER VAPOR IMAGERY AND RECENT RUC MODEL
INITIALIZATIONS. A THERMAL RIDGE AT 700 MB EXTENDED FROM THE TX
PNHDL UP INTO CO. FAIRLY DECENT MOISTURE WAS NOTED AT 700 MB FROM
AZ INTO SRN NV WITH DEWPOINTS 5-8 DEGREES C. THE KOAX SOUNDING
THIS MORNING HAD ABOUT 0.94 INCHES OF PRECIPITABLE WATER (PW). THIS
WILL BE INCREASING OVER THE AREA TONIGHT. 12Z GFS SHOWED VALUES
APPROACHING 2 INCHES FOR MOST OF OUR AREA BY 12Z SAT AND NEAR 2.25
INCHES BY 00Z SUN. THE 12Z NAM WAS A BIT HIGHER AND MIGHT HAVE
BEEN A BIT OVERDONE.
PREVIOUS FORECAST TREND WAS FOR INCREASING POPS OVERNIGHT AND THAT
STILL SEEMS ON TRACK. WILL KEEP HIGHEST POPS PRIOR TO 12Z SAT OVER
ERN NE...SHIFTING HIGHEST NUMBERS TO NERN NE BY LATE MORNING. MID
LEVEL TEMPS ARE EXPECTED TO WARM SAT MORNING OVER THE SRN HALF OF
THE FCST AREA...SO SHIFTED HIGHEST POPS TO OUR WRN IA ZONES FOR THE
LATE AFTN AND EVENING. CONVECTIVE EVOLUTION AFTER THE MORNING STORMS
IS UNCERTAIN...BUT SHEAR PARAMETERS COULD BE FAVORABLE FOR SOME
SUPERCELLS IN THE AFTN AND EVENING. BEST SHOT FOR HEAVY RAIN WILL
BE ACROSS IOWA SATURDAY NIGHT.
STORM CHANCES SHOULD DIMINISH AFTER MIDNIGHT SATURDAY NIGHT...AND
SUNDAY RAIN CHANCES LOOK FAIRLY LOW. MID LEVEL RIDGE AXIS WILL START
TO BUILD FROM TX UP INTO SASK MONDAY WITH DECENT TROUGHING OVER THE
GREAT LAKES REGION.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 PM CDT FRI AUG 7 2015
A STRONG MID TROPOSPHERIC RIDGE WILL BE BUILDING AT THE START OF
THIS PERIOD OVER MID AMERICA. BY LATE WEEK...THE CENTER OF THE
ANTICYCLONE THAT STARTED OUT OVER TX/OK SHOULD RETROGRADE BACK
INTO NM AND CO. THIS PATTERN GENERALLY PRODUCES WARMER THAN NORMAL
TEMPERATURES (ESPECIALLY HIGHS) AND BELOW NORMAL PCPN. SO...BUMPED
UP HIGHS A BIT COMPARED TO A GFS/ECMWF BLEND.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1143 PM CDT FRI AUG 7 2015
VFR CONDITIONS STILL PREVAIL AT ALL SITES...BUT SHRA AND POSSIBLY
TSRA WILL AFFECT SITES TONIGHT AND INTO THE EARLY MORNING HOURS.
HAVE INCLUDED PREVAILING SHRA/TEMPO THUNDER AT ALL SITES...WITH
ACTIVITY WANING BY MID-MORNING. WITH CONSIDERABLE UNCERTAINTY
REGARDING CONVECTIVE EVOLUTION LATER TODAY/THIS EVENING...HAVE
OPTED TO KEEP MENTION OUT OF TAFS FOR NOW. POTENTIAL DOES EXIST
FOR SHRA/TSRA AT SITES FROM LATE AFTERNOON THROUGH EVENING...WITH
A SOMEWHAT HIGHER RISK AT KOMA/KLNK THAN KOFK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
413 AM CDT SAT AUG 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST LATER TODAY AND
INCLUDING THE SOUTH CENTRAL TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT REMAINS OVER THE NORTHERN PLAINS
WITH STACKED LOW PRESSURE MOVING SLOWLY EAST ACROSS SOUTHERN
MANITOBA AND UPPER LEVEL RIDGING OVER THE CENTRAL PLAINS. MOSTLY
CLEAR SKIES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. T/TD SPREADS AT OR NEAR ZERO OVER MANY OBSERVING SITES
OVER NORTHERN NORTH DAKOTA AND ACROSS BOTH THE WESTERN DEVILS LAKE
AND JAMES RIVER BASINS. LAST FEW HRRR RUNS CONTINUE TO INDICATE AT
LEAST PATCHY FOG DEVELOPMENT OVER THESE AREAS YET EARLY THIS
MORNING AND WILL LEAVE IN THE FORECAST.
EMBEDDED SHORT WAVE TROUGH/IMPULSE LIFTING EAST-NORTHEAST ACROSS
THE INTERMOUNTAIN WEST THIS MORNING WILL TRACK EASTWARD INTO THE
NORTHERN HIGH PLAINS TODAY...THEN INTO AND ACROSS THE DAKOTAS
LATER TONIGHT INTO SUNDAY. ASSOCIATED SURFACE LOW WILL MOVE FROM
WYOMING THIS MORNING INTO SOUTH DAKOTA LATER TODAY AND TONIGHT.
PRECIPITATION WILL START TO DEVELOP INTO SOUTHWEST NORTH DAKOTA
THIS AFTERNOON WITH THE APPROACH OF THE MID LEVEL WAVE AND AS THE
SFC LOW MOVES INTO WESTERN SOUTH DAKOTA. PRECIPITATION THEN
SPREADS SLOWLY EAST INTO MY SOUTH CENTRAL COUNTIES TONIGHT. RIDGE
OF SURFACE HIGH PRESSURE BUILDING OVER FAR SOUTH CENTRAL
CANADA/NORTHERN ND WILL KEEP MOST AREAS NORTH OF INTERSTATE 94
DRY. HEAVIEST RAINFALL EXPECTED TO REMAIN OVER SOUTH DAKOTA. CAPE
RATHER WEAK BUT ENOUGH TO LEAVE A SLIGHT CHANCE/ISOLATED MENTION
OF THUNDERSTORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 8 2015
THE FOCUS THIS MORNING IS ON SUBTROPICAL RIDGE LOCATION.
THE MAIN CHANGE IN MODEL CONSENSUS OVER THE PAST 48 HOURS HAS BEEN
THE WESTWARD SHIFTING OF THE SUBTROPICAL RIDGE AXIS FROM THE CENTRAL
DAKOTAS INTO WESTERN MONTANA BY WEDNESDAY. THE SLOWER PROGRESSION OF
CYCLONIC FLOW WILL ACT TO EXTEND THE DRY PERIOD NEXT WEEK AND
INCREASE HIGH TEMPERATURES ACROSS THE DAKOTAS.
GREATER UNCERTAINTY CREEPS INTO THE FORECAST ON WEDNESDAY NIGHT...AS
MID LEVEL SHORTWAVES MAKE IT INTO THE DAKOTAS IN A FEW GEFS
MEMBERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
LOW PRESSURE ACROSS SOUTHERN MANITOBA WILL MOVE SLOWLY EAST
TODAY...REPLACED WITH A SURFACE RIDGE. SKIES WILL BE MOSTLY CLEAR
NORTH WITH INCREASING CLOUDS SOUTH DURING THE DAY. VFR CONDITIONS
EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1154 PM CDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 312 PM CDT FRI AUG 7 2015
SEVERAL CONCERNS WITH THE FORECAST DURING THIS PERIOD. THE FIRST
COMES TONIGHT AND WHETHER THERE WILL BE ANY VALLEY FOG OR NOT. IN
FAVOR OF THE FOG FORMING IS THE LITTLE BIT OF RAIN THIS MORNING
AND THE CLOUDS THAT HAVE TRAPPED THIS MOISTURE. THE 07.12Z NAM IS
THE MOST AGGRESSIVE WITH SHOWING SATURATION OCCURRING AT THE
SURFACE FOR THE VALLEY LOCATIONS. THE NAM ALSO HAS THE MOST AMOUNT
OF WIND JUST ABOVE THE SURFACE FOR MORE MIXING...WHICH GOES
AGAINST FOG FORMATION. 07.17Z RAP SOUNDINGS WHILE HAVING A DEEPER
LAYER OF LIGHT WINDS...COMES CLOSE TO SATURATING AT THE SURFACE
AND THEN REALLY DRIES OUT JUST ABOVE THE SURFACE. THE 07.12Z GFS
IS EVEN DRIER THAN THE RAP...SO HAVE DOUBTS THAT THERE WILL BE A
LOT OF FOG IN THE VALLEYS TONIGHT. ANOTHER COMPLICATING FACTOR
COULD BE THE INCREASE IN HIGH LEVEL CLOUDS FOR LATE TONIGHT AHEAD
OF AN APPROACHING SHORT WAVE TROUGH. PATCHY VALLEY FOG WAS ALREADY
IN THE FORECAST AND DO NOT PLAN TO MAKE ANY CHANGES TO THIS.
WITH THE APPROACHING SHORT WAVE TROUGH...THE GFS SEEMS TO HAVE THE
MOST SUPPORT FROM THE OTHER MODELS WITH THE 07.12Z ECMWF LOOKING
SIMILAR ALONG WITH THE 07.12Z HI-RES ARW AND NMM. WATER VAPOR
SATELLITE INDICATES THIS WAVE IS COMING OUT OF THE ROCKIES OVER
EASTERN WYOMING AND NORTHERN COLORADO THIS AFTERNOON AND SHOULD
THEN TRACK EAST ACROSS IOWA INTO SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS BY LATE SATURDAY MORNING. THE GFS SUGGESTS THIS WAVE WILL
PRODUCE SOME WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER
ACROSS NORTHEAST IOWA INTO FAR SOUTHERN WISCONSIN LATE TONIGHT
INTO EARLY SATURDAY MORNING. THE BOUNDARY THAT WENT THROUGH TODAY
SHOULD BE HUNG UP OVER CENTRAL IOWA AND IT IS EXPECTED THAT WEAK
TO MODERATE FRONTOGENESIS WILL OCCUR NORTH OF THIS BOUNDARY. THE
BEST ISENTROPIC UP GLIDE ON THE 310K SURFACE IS EXPECTED TO
REMAIN SOUTH OF THE BOUNDARY ACROSS CENTRAL AND SOUTHERN IOWA WITH
POSSIBLY 1 TO 2 UBAR/S OVER NORTHEAST IOWA. THE GENERAL CONSENSUS
AMONG THE MODELS IS THAT A COMPLEX OF SHOWERS AND STORMS SHOULD
FORM OVER NEBRASKA TONIGHT AND MOVE EAST ALONG AND NORTH OF THE
BOUNDARY. THE GFS AND HI-RES ARW AND NMM WOULD SUGGEST THERE IS AT
LEAST A CHANCE THAT THIS COMPLEX SURVIVES LONG ENOUGH TO GET INTO
THE SOUTHERN PARTS OF THE FORECAST AREA WHILE THE 07.12Z ECMWF
STARTS TO DISSIPATE THE COMPLEX AND ONLY BRINGS IN SOME REMAINS
SATURDAY AFTERNOON ACROSS THE SOUTH. WILL BRING IN SOME 20 TO 40
PERCENT CHANCES ACROSS NORTHEAST IOWA SATURDAY MORNING FOR THIS
COMPLEX.
ANOTHER SHORT WAVE TROUGH IS THEN EXPECTED TO COME OUT OF THE
ROCKIES AND TRACK ACROSS THE REGION SATURDAY NIGHT. THE TRACK AND
FORCING LOOK TO BE VERY SIMILAR TO THE WAVE FOR LATE TONIGHT INTO
SATURDAY MORNING WITH THE EXCEPTION THAT THE SURFACE BOUNDARY
SHOULD GET PUSHED FARTHER SOUTH INTO SOUTHERN IOWA OR NORTHERN
MISSOURI. THE COMPLEX OF STORMS WITH THIS NEXT WAVE IS EXPECTED TO
FORM OVER SOUTHWEST IOWA AND THEN TRACK EAST AND SHOULD LARGELY
STAY TO THE SOUTH OF THE FORECAST AREA. THE GFS IS SLIGHTLY
FARTHER NORTH THAN THE ECMWF AND TO HONOR THIS WILL HAVE SOME 20
TO 40 PERCENT CHANCES FROM ABOUT INTERSTATE 90 SOUTH.
BY SUNDAY NIGHT THE MEAN RIDGE WILL BE TRYING TO BUILD OVER THE
ROCKIES WITH AN UPPER LEVEL LOW OVER NORTHERN ONTARIO. THIS WILL
START TO SET UP A NORTHWEST FLOW OVER THE REGION WITH THE
POSSIBILITY OF A WEAK SHORT WAVE TROUGH ROTATING AROUND THE UPPER
LEVEL LOW AND ACROSS THE AREA. THE FORCING WITH THIS WAVE LOOKS TO
BE RATHER WEAK...BUT IT COULD PUSH A WEAK SURFACE BOUNDARY INTO
THE AREA WITH THE POSSIBILITY OF SOME ACTIVITY ALONG IT. WILL
CARRY SOME 30 TO 40 PERCENT CHANCES SUNDAY FOR THIS FEATURE WITH
SOME LINGERING 20 TO 30 PERCENT CHANCES INTO SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 312 PM CDT FRI AUG 7 2015
ONCE THE SHORT WAVE TROUGH FROM SUNDAY NIGHT EXITS THE AREA...A
LARGE AREA OF HIGH PRESSURE WILL BUILD IN OVER THE UPPER MIDWEST.
THIS HIGH LOOKS TO DOMINATE THE REGION FROM MONDAY NIGHT THROUGH
WEDNESDAY NIGHT. THE ECMWF WOULD SUGGESTS IT HOLDS TIGHT OVER THE
REGION THROUGH THE END OF THE WEEK WHILE THE GFS BRINGS A COLD
FRONT ACROSS THE UPPER MIDWEST THURSDAY THROUGH FRIDAY. WILL JUST
CARRY SOME LOW 20 TO 30 PERCENT RAIN CHANCES LATE IN THE PERIOD TO
HONOR THE GFS SOLUTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1154 PM CDT FRI AUG 7 2015
STILL HAVE SOME CONCERN ABOUT VALLEY FOG AFFECTING KLSE OVERNIGHT.
THE TEMPERATURE/DEW POINT DEPARTURE IS CURRENTLY 4 DEGREES AND THE
WINDS ARE CALM AT THE OFFICE. THIS WOULD BE FAVORABLE FOR VALLEY
FOG. HOWEVER SOME MID TO HIGH LEVEL DEBRIS CLOUDS /FROM
CONVECTION IN THE DAKOTAS/ WILL BE MOVING SOUTHEAST INTO THE AREA
TONIGHT AND THE COMBINATION OF THESE CLOUDS ALONG WITH INCREASING
WINDS ALOFT MAY INHIBIT VALLEY FOG. DUE TO THIS...JUST OPTED TO
ADD BCFG TO THE TAF BETWEEN 08.10Z AND 08.14Z.
ON SATURDAY AND SATURDAY EVENING...A SHORT WAVE TROUGH MOVING EAST
ACROSS IOWA WILL KEEP MID CLOUDS ACROSS THE AREA THROUGH THIS TIME
PERIOD. WINDS THROUGHOUT THE PERIOD WILL BE SOUTHERLY AND LESS
THAN 10 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
502 AM MDT SAT AUG 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM MDT SAT AUG 8 2015
...ANOTHER ROUND OF THUNDERSTORMS TODAY...A FEW STRONG ACROSS THE
SOUTHEAST PLAINS...
MONSOON PLUME EXTENDS ACROSS CO WITH A COUPLE OF EMBEDDED WAVES
MOVING THROUGH SOUTHWEST FLOW ALOFT. THE FIRST IS MOVING ACROSS THE
SE MTS INTO THE ADJACENT PLAINS EARLY THIS MORNING. THIS WAVE IS
PRETTY WEAK...BUT IS ENHANCING SOME MID/HIGH CLOUD DECK OVER THE
EASTERN PORTIONS OF THE AREA...WITH SOME SPOTTY SHOWERS ACROSS THE
PLAINS AT TIMES. THIS WAVE SHOULD LIFT OFF TO THE NORTHEAST THROUGH
THE MORNING. MEANWHILE...SHOWERS WILL CONTINUE ALONG THE CONTDVD AS
THE NEXT WAVE ACROSS NW AZ LIFTS UP INTO THE 4 CORNERS REGION THIS
MORNING. THIS WAVE WILL MOVE ACROSS THE REMAINDER OF CO DURING THE
AFTERNOON. ACROSS THE PLAINS...SFC LOW IS POSITIONED ACROSS FAR
SOUTHEAST CO...WITH WEST TO NORTHWEST WINDS ALONG THE I-25 CORRIDOR
AND SOUTHERN PORTIONS OF THE SOUTHEAST PLAINS. MODELS SUGGEST A
WEAK NORTHERLY SURGE WILL WRAP AROUND THE NORTH SIDE OF THE SFC LOW
INTO THE SE PLAINS...WHICH WILL INCREASE DEW POINTS AGAIN FROM THE
LOWER TO MID 50S...TO MID-UPPER 50S NEAR THE BORDER BY AFTERNOON.
WINDS DON`T LOOK VERY STRONG ACROSS THE PLAINS...BUT THERE SHOULD BE
SOME CONVERGENCE ALONG THIS BOUNDARY WHICH SETS UP ACROSS SOUTHEAST
PLAINS. DEEP LAYER SHEAR LOOKS A LITTLE STRONGER TODAY...BUT CAPES
LOOK LOWER THAN YESTERDAY. EACH SUCCESSIVE RUN OF THE HRRR SEEMS TO
BE TRENDING THE DEW POINTS DOWNWARD ACROSS SE CO WITH HIGHER DEW
POINTS AND CAPES ACROSS SOUTHWEST KANSAS. WILL HAVE TO WATCH TRENDS
IN THE LATEST HIGH RES MODELS AND OBSERVATIONS TODAY TO HONE DOWN
THESE DETAILS. CERTAINLY ENOUGH MOISTURE WILL BE PRESENT FOR AT
LEAST ISOLATED TO SCATTERED THUNDERSTORMS. MAIN THREAT WILL BE
LOCALLY HEAVY RAINFALL...WHICH COULD OCCUR JUST ABOUT ANYWHERE.
DEPENDING ON THE POSITION OF THE BOUNDARY AND AMOUNT OF DEW POINT
RETURN...COULD SEE AN ISOLATED STRONG TO SEVERE THUNDERSTORM ACROSS
THE SOUTHEAST COUNTIES...NAMELY KIOWA...BENT...PROWERS...AND BACA
COUNTIES. LARGE HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY STORM
THREATS.
THUNDERSTORMS SHOULD DIMINISH FROM WEST TO EAST TONIGHT WITH MORE
DRYING EXPECTED TO SPREAD IN FROM THE WEST AS THE MONSOON PLUME
SHIFTS EASTWARD. THIS SHOULD RESULT IN COOLER LOWS TONIGHT THAN
THIS MORNING ACROSS THE WESTERN MOUNTAIN VALLEYS.
MEANWHILE...MODELS SPREAD HIGHER DEW POINTS BACK INTO THE SE
PLAINS...AND MAY HAVE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
FAR SOUTHEAST PLAINS TOWARDS MORNING. -KT
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 500 AM MDT SAT AUG 8 2015
NOT MANY ADJUSTMENTS REQUIRED DURING THE LONGER TERM WITH
RELATIVELY ACTIVE METEOROLOGICAL CONDITIONS ANTICIPATED. PRIMARY
METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES...POPS AND THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL AND STRONGER STORMS AT TIMES.
LATEST PV ANALYSIS...COMPUTER SIMULATIONS AND FORECAST MODEL
SOUNDINGS STILL SUGGEST THAT UPPER HIGH CENTERED OVER NORTHEASTERN
TEXAS AT 12Z SUNDAY WILL BEGIN PROGRESSING WEST AND BECOME
CENTERED OVER THE TEXAS PANHANDLE REGION BY TUESDAY. UPPER RIDGE
IS STILL PROJECTED TO BECOME CENTERED OVER THE NORTHERN NEW
MEXICO/COLORADO REGION FROM LATER WEDNESDAY INTO FRIDAY.
DEEPEST ATMOSPHERIC MOISTURE PROFILES DURING THE LONGER TERM ARE
STILL PROJECTED FROM SUNDAY INTO TUESDAY NIGHT. THE MOIST ATMOSPHERIC
PROFILE WILL INTERACT WITH FAVORABLE LOW-LEVEL WIND FLOW...THE
DAILY OROGRAPHIC CYCLE AND UPPER DISTURBANCES AT TIMES TO PRODUCE
GENERALLY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY INTO AT LEAST
TUESDAY NIGHT WITH SLIGHTLY DECREASED POPS THEN EXPECTED BY LATER
IN THE WEEK.
PER PREVIOUS DISCUSSIONS...ESPECIALLY DURING THE SUNDAY INTO
TUESDAY NIGHT TIME-FRAME...THE PROJECTED HIGHER PRECIPITABLE
WATER VALUES ARE EXPECTED TO GENERATE LOCALLY HEAVY RAINFALL
CAPABLE OF PRODUCING LOCALIZED FLASH FLOODING AT
TIMES...ESPECIALLY IF THE HEAVY RAINFALL IMPACTS RECENT BURN
SCARS. ALSO...STRONGER STORMS AT TIMES ARE ALSO ANTICIPATED
DUE TO SOMEWHAT ELEVATED CAPE...LI AND BULK SHEAR VALUES.
ALSO...GENERALLY ABOVE CLIMATOLOGICAL EARLY TO MID AUGUST
TEMPERATURES ARE STILL PROJECTED DURING THE MAJORITY OF THE LONGER
TERM WITH MONDAY AND TUESDAY HAVING THE HIGHEST POTENTIAL OF
EXPERIENCING BELOW SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 500 AM MDT SAT AUG 8 2015
VFR CONDITIONS EXPECT THIS MORNING AT THE TAF SITES...THOUGH
WILL HAVE TO WATCH KALS CLOSELY AS T/TD SPREADS ARE CLOSE. FOR NOW
THINK EXTENSIVE MID AND HIGH CLOUD COVER SHOULD PREVENT ANY PATCHY
GROUND FOG DEVELOPMENT. THUNDERSTORMS WILL DEVELOP OVER THE
MOUNTAINS...AND PALMER AND RATON MESA REGIONS BY AFTERNOON. AS
THESE THUNDERSTORMS SPREAD EASTWARD ACROSS THE LOWER
ELEVATIONS...ALL THREE TAF SITES COULD SEE VCTS AFTER 20-21Z.
GUSTY ERRATIC WINDS...AND VFR TO BRIEF MVFR CIGS/VIS WILL BE
POSSIBLE WITH THE STRONGER STORMS. THUNDERSTORMS SHOULD MOVE
EASTWARD AND DIMINISH THIS EVENING...WITH CONDITIONS REMAINING
VFR. COULD SEE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
SOUTHEAST PLAINS SATURDAY NIGHT...BUT FOR NOW MOST LIKELY AREA
APPEARS TO BE EAST OF THE I-25 CORRIDOR AND THE KCOS AND KPUB
TERMINALS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
902 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* WEST/NORTHWEST WINDS BECOMING NORTHEAST THIS AFTERNOON.
* MVFR CIGS/VIS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING.
* RAIN SUNDAY MORNING...WITH POSSIBLE THUNDER.
RODRIGUEZ/MM
//DISCUSSION...UPDATED 12Z...
VFR AND DRY CONDITIONS IN PLACE THIS MORNING AS WEAK SURFACE LOW
CONTINUES TO WEAKEN. SOME LOWER STRATUS HAD BRIEFLY DEVELOPED
EARLIER THIS MORNING BUT HAS ALREADY BEGUN TO ERODE AND WILL
CONTINUE TO DO SO THIS MORNING. HAVE MAINTAINED DRY CONDITIONS
THROUGH THIS AFTERNOON...BUT WITH AN ISOLATED SPRINKLE STILL
BRIEFLY POSSIBLE. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON. HIGHER CHANCES FOR PRECIP...REDUCED VIS AND LOWER
CEILINGS WILL ARRIVE LATE TONIGHT INTO EARLY SUNDAY MORNING WITH
THE APPROACH OF ANOTHER SYSTEM. SOME TIMING DIFFERENCES WITH THE
ONSET OF PRECIP WITH THE EXACT TIMING IN THE TAF LIKELY BEING
CHANGED BUT WITH ITS ARRIVAL...IT WILL LIKELY PERSIST THROUGH THE
REMAINING FORECAST PERIOD. HAVE LEFT OUT ANY MENTION OF THUNDER AT
THIS TIME WITH THE HIGHEST INSTABILITY TO THE SOUTH OF THE
TERMINALS...BUT WILL NEED TO MONITOR FOR POSSIBLE BETTER
DEVELOPMENT WHICH COULD LEAD TO AT LEAST ISOLATED THUNDER DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
* HIGH WITH MVFR CIGS/VIS LATE TONIGHT INTO SUNDAY
MORNING...MEDIUM LOW WITH EXACT TIMING.
* HIGH WITH RAIN SUNDAY MORNING...MEDIUM ON EXACT TIMING...LOW
WITH THUNDER CHANCES.
RODRIGUEZ/MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
650 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* WESTERLY WINDS BECOMING NORTHEAST THIS AFTERNOON.
* MVFR CIGS/VIS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING.
* RAIN SUNDAY MORNING...WITH POSSIBLE THUNDER.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
VFR AND DRY CONDITIONS IN PLACE THIS MORNING AS WEAK SURFACE LOW
CONTINUES TO WEAKEN. SOME LOWER STRATUS HAD BRIEFLY DEVELOPED
EARILER THIS MORNING BUT HAS ALREADY BEGUN TO ERODE AND WILL
CONTINUE TO DO SO THIS MORNING. HAVE MAINTAINED DRY CONDITIONS
THROUGH THIS AFTERNOON...BUT WITH AN ISOLATED SPRINKLE STILL
BRIEFLY POSSIBLE. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON. HIGHER CHANCES FOR PRECIP...REDUCED VIS AND LOWER
CEILINGS WILL ARRIVE LATE TONIGHT INTO EARLY SUNDAY MORNING WITH
THE APPROACH OF ANOTHER SYSTEM. SOME TIMING DIFFERENCES WITH THE
ONSET OF PRECIP WITH THE EXACT TIMING IN THE TAF LIKELY BEING
CHANGED BUT WITH ITS ARRIVAL...IT WILL LIKELY PERSIST THROUGH THE
REMAINING FORECAST PERIOD. HAVE LEFT OUT ANY MENTION OF THUNDER AT
THIS TIME WITH THE HIGHEST INSTABILITY TO THE SOUTH OF THE
TERMINALS...BUT WILL NEED TO MONITOR FOR POSSIBLE BETTER
DEVELOPMENT WHICH COULD LEAD TO AT LEAST ISOLATED THUNDER DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
* HIGH WITH MVFR CIGS/VIS LATE TONIGHT INTO SUNDAY MORNING...LOW
MEDIUM WITH EXACT TIMING.
* HIGH WITH RAIN SUNDAY MORNING...MEDIUM ON EXACT TIMING...LOW
WITH POSSIBLE THUNDER.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
501 AM CDT SAT AUG 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM CDT SAT AUG 8 2015
THUNDERSTORMS WERE MOVING ACROSS NORTH CENTRAL AND NORTHEAST
KANSAS THIS MORNING AT 09Z. THE LOW LEVEL JET HAS HELPED TO
MAINTAIN THE CONVECTION AS IT MOVES ACROSS THE CWA THIS MORNING.
THE STORMS ARE EXPECTED TO MOVE ACROSS NORTHEAST AND EAST CENTRAL
KANSAS THIS MORNING. THIS MAY COMPLICATE THE TEMPERATURE FORECAST
FOR LATER TODAY, BUT FOR NOW WILL CONTINUE WITH TEMPERATURES
REACHING THE LOWER 90S NEAR THE NEBRASKA BORDER TO AROUND 100 NEAR
CENTRAL KANSAS. AFTERNOON HEAT INDICES WILL RANGE FROM 105 TO 109
AND WILL KEEP THE HEAT ADVISORY GOING AS IS FOR TODAY.
THUNDERSTORMS ARE FORECAST TO REDEVELOP THIS AFTERNOON AND EVENING
NEAR A SURFACE TROUGH ACROSS SOUTHERN NEBRASKA AND BUILD SOUTHWEST
INTO NORTH CENTRAL KANSAS. A WAVE IS EXPECTED TO MOVE ACROSS
NEBRASKA AND NORTHERN KANSAS THIS EVENING AND INTO MISSOURI AND
IOWA BY SUNDAY MORNING. SHEAR AND INSTABILITY WILL BE FAVORABLE
FOR STRONG TO SEVERE CONVECTION AND WIND PROFILES SHOWING LARGE
LOOPED HODOGRAPHS, SO EXPECT LARGE HAIL, DAMAGING WINDS AND A
POSSIBLE TORNADO AS THE MAIN HAZARDS. HIGH MOISTURE CONTENT IN THE
ATMOSPHERE WILL LEAD TO RAINFALL RATES NEAR 2 INCHES PER HOUR
WHICH MAY LEAD TO FLASH FLOODING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM CDT SAT AUG 8 2015
EARLY MORNING SUNDAY A SHORTWAVE IS EXPECTED TO MOVE ACROSS EASTERN
NEBRASKA AND INTO IOWA WHILE A SURFACE FRONT EXTENDS ACROSS THE
FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS MAY BE ONGOING TO
START THE MORNING BEFORE MOVING OFF TO THE EAST. THE FRONTAL
BOUNDARY IS EXPECTED TO MOVE INTO EAST CENTRAL KANSAS GENERALLY
SOUTH OF INTERSTATE 35 BY LATE AFTERNOON. ANOTHER WAVE WILL EJECT
OUT OF THE ROCKIES AND MOVE ACROSS NORTHERN KANSAS IN THE AFTERNOON
AND THEN PHASE WITH A LONGER WAVELENGTH TROUGH DROPPING SOUTHEAST
FROM THE NORTHERN PLAINS SUNDAY NIGHT. MOISTURE WILL POOL NEAR AND
SOUTH OF THE BOUNDARY AS PRECIPITABLE WATER VALUES REMAIN AROUND
TWO INCHES. EXPECT ANOTHER ROUND OF STORMS TO DEVELOP NEAR THE
BOUNDARY WITH ELEVATED STORMS TO THE NORTH. LOW LEVEL JET WILL
INCREASE ISENTROPIC LIFT TO THE NORTH OF THE BOUNDARY INITIALLY,
BEFORE VEERING TO THE SOUTHWEST BY MONDAY MORNING. SHEAR AND
INSTABILITY WILL BE SUPPORTIVE OF A FEW STRONG STORMS SUNDAY
AFTERNOON AND SUNDAY NIGHT. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE
ESPECIALLY ACROSS EAST CENTRAL KANSAS. THE UPPER TROUGH WILL MOVE
OFF TO THE EAST BRINING AN END TO PRECIPITATION DURING THE DAY. THE
UPPER RIDGE THEN AMPLIFIES ACROSS THE ROCKIES INTO CENTRAL CANADA
AND SHARPENS IN THE TUESDAY THROUGH FRIDAY TIME PERIOD. SURFACE HIGH
PRESSURE WILL SLIDE INTO THE CENTRAL PLAINS AND REMAIN FOR MUCH OF
THE TUESDAY THROUGH FRIDAY TIME PERIOD. UPSLOPE CONVECTION ALONG THE
FRONT RANGE AND HIGH PLAINS IS EXPECTED TO REMAIN TO THE WEST OF THE
FORECAST AREA SO WILL MAINTAIN A DRY FORECAST. TEMPERATURES SUNDAY
WILL WARM INTO THE LOWER TO MID 90S SOUTH OF THE FRONT WITH MID 80S
NEAR THE NEBRASKA BORDER. AFTERNOON HEAT INDICES IN EAST CENTRAL
KANSAS WILL TOP OUT IN THE 100 TO 102 DEGREE RANGE. BELOW NORMAL
TEMPERATURES IN THE 80S ARE EXPECTED FOR THE REST OF THE PERIOD WITH
LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1135 PM CDT FRI AUG 7 2015
THERE IS QUITE A BIT OF UNCERTAINTY IN WHERE THE MCS WILL GO
DURING THE EARLY MORNING HOURS. THE HRRR HAS BEEN CONSISTENTLY
BRINGING THE ELEVATED STORMS THROUGH EASTERN KS, ALTHOUGH IT SEEMS
TO BE DELAYING THE PROGRESS TO MORE MID MORNING. MEANWHILE THE
OPERATIONAL MODELS CONTINUE TO FOCUS THE MOST LIKELY TRACK OF THE
STORMS ACROSS SOUTHERN NEB AND FAR NORTHERN KS. WITH PROFILER DATA
SHOWING THE DECENT LOW LEVEL JET VEERING TO THE SOUTH AND
SOUTHWEST, THINK THERE IS A CHANCE FOR ELEVATED STORMS TO MOVE
INTO THE TERMINALS SO WILL INCLUDE A VCTS WITH VFR CONDITIONS AND
MONITOR TRENDS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 9 PM CDT THIS EVENING FOR
KSZ010>012-021>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...65/53
LONG TERM...53
AVIATION...WOLTERS
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1036 AM CDT SAT AUG 8 2015
.UPDATE:
ISSUED AT 1033 AM CDT SAT AUG 8 2015
MCS REMNANTS HAVE BEEN STEADILY DECAYING ACROSS NORTH CENTRAL MO
AND CENTRAL MO. POPS HAVE BEEN REDUCED ACCORDINGLY.
KANOFSKY
&&
ISSUED AT 434 AM CDT SAT AUG 8 2015
WILL BE ISSUING A DENSE FOG ADVISORY THROUGH 13Z FOR THE SOUTHERN
MISSOURI COUNTIES IN THE CWA WHERE THE VISIBILITY HAS DROPPED TO
1/4SM. HAVE ALSO ADJUSTED POPS UP TO LIKELY CATEGORY FOR THE
NORTHERN CWA WHERE REMNANTS OF THE MCS WILL BE TRACKING THIS
MORNING.
CVKING
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPOGATING SOUTHEAST INTO SOUTH CENTRAL ILLINOIS
ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH THIS
SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM CDT SAT AUG 8 2015
LOW VSBYS IN FOG SHOULD IMPROVE OVER THE NEXT HOUR OR TWO TO VFR.
UNTIL THEN...MVFR AND IFR VSBYS WILL PREVAIL ACROSS PARTS OF
EASTERN AND CENTRAL MISSOURI. ADDITIONALLY...LIGHT SHOWERS
CURRENTLY OVER WESTERN MISSOURI WILL LIKELY DRIFT INTO PARTS OF
NORTHEAST MISSOURI BETWEEN 14Z AND 16Z. DON`T EXPECT MUCH IMPACT
FROM THIS LIGHT RAIN OTHER THAN WET RUNWAYS. ONCE FOG DISSIPATES
AND RAIN EVAPORATES EXPECT VFR FLIGHT CONDITIONS TO PREVAIL INTO
THE EVENING HOURS. ANOTHER COMPLEX OF STORMS IS EXPECTED TO FORM
TONIGHT OVER IOWA AND THE SOUTHERN FRINGES OF THE COMPLEX WILL
LIKELY IMPACT NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS AFTER
06Z.
SPECIFICS FOR KSTL:
VFR FLIGHT CONDITIONS AND LIGHT SOUTHEAST FLOW IS EXPECTED TO
PREVAIL AT LAMBERT AT LEAST THROUGH TONIGHT. THERE IS A SLIGHT
CHANCE OF ISOLATED THUNDERSTORMS LATE THIS AFTERNOON, BUT IF ANY
STORMS DO FORM THE AREAL COVERAGE IS EXPECTED TO BE VERY LOW.
THERE IS ANOTHER CHANCE FOR STORMS EARLY SUNDAY MORNING, BUT
CONFIDENCE IN THE THUNDERSTORM TRENDS IS LOW AT THIS TIME SO HAVE
LEFT MENTION OF STORMS OUR FOR NOW.
CARNEY
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 90 76 95 75 / 20 20 30 40
QUINCY 84 71 89 70 / 40 60 40 20
COLUMBIA 90 75 94 72 / 40 20 20 40
JEFFERSON CITY 91 76 96 74 / 30 20 20 40
SALEM 87 72 91 73 / 10 10 30 40
FARMINGTON 88 72 94 74 / 10 10 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
717 AM CDT SAT AUG 8 2015
.UPDATE:
ISSUED AT 434 AM CDT SAT AUG 8 2015
WILL BE ISSUING A DENSE FOG ADVISORY THROUGH 13Z FOR THE SOUTHERN
MISSOURI COUNTIES IN THE CWA WHERE THE VISIBILITY HAS DROPPED TO
1/4SM. HAVE ALSO ADJUSTED POPS UP TO LIKELY CATEGORY FOR THE
NORTHERN CWA WHERE REMNANTS OF THE MCS WILL BE TRACKING THIS
MORNING.
CVKING
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPOGATING SOUTHEAST INTO SOUTH CENTRAL ILLINOIS
ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH THIS
SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM CDT SAT AUG 8 2015
LOW VSBYS IN FOG SHOULD IMPROVE OVER THE NEXT HOUR OR TWO TO VFR.
UNTIL THEN...MVFR AND IFR VSBYS WILL PREVAIL ACROSS PARTS OF
EASTERN AND CENTRAL MISSOURI. ADDITIONALLY...LIGHT SHOWERS
CURRENTLY OVER WESTERN MISSOURI WILL LIKELY DRIFT INTO PARTS OF
NORTHEAST MISSOURI BETWEEN 14Z AND 16Z. DON`T EXPECT MUCH IMPACT
FROM THIS LIGHT RAIN OTHER THAN WET RUNWAYS. ONCE FOG DISSIPATES
AND RAIN EVAPORATES EXPECT VFR FLIGHT CONDITIONS TO PREVAIL INTO
THE EVENING HOURS. ANOTHER COMPLEX OF STORMS IS EXPECTED TO FORM
TONIGHT OVER IOWA AND THE SOUTHERN FRINGES OF THE COMPLEX WILL
LIKELY IMPACT NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS AFTER
06Z.
SPECIFICS FOR KSTL:
VFR FLIGHT CONDITIONS AND LIGHT SOUTHEAST FLOW IS EXPECTED TO
PREVAIL AT LAMBERT AT LEAST THROUGH TONIGHT. THERE IS A SLIGHT
CHANCE OF ISOLATED THUNDERSTORMS LATE THIS AFTERNOON, BUT IF ANY
STORMS DO FORM THE AREAL COVERAGE IS EXPECTED TO BE VERY LOW.
THERE IS ANOTHER CHANCE FOR STORMS EARLY SUNDAY MORNING, BUT
CONFIDENCE IN THE THUNDERSTORM TRENDS IS LOW AT THIS TIME SO HAVE
LEFT MENTION OF STORMS OUR FOR NOW.
CARNEY
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 90 76 95 75 / 20 20 30 40
QUINCY 84 71 89 70 / 70 60 40 20
COLUMBIA 90 75 94 72 / 40 20 20 40
JEFFERSON CITY 91 76 96 74 / 30 20 20 40
SALEM 87 72 91 73 / 20 10 30 40
FARMINGTON 88 72 94 74 / 10 10 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR CRAWFORD MO-
IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
634 AM CDT SAT AUG 8 2015
.DISCUSSION...
Issued at 357 AM CDT SAT AUG 8 2015
As was anticipated last night, High Plains convection has congealed
into an overnight MCS, which has made pretty good progression across
northern Kansas, into north central Kansas. Models have had a rough
time resolving exactly how this MCS will behave as it continues east.
NAM consistently indicates that this complex will lose steam as the
night progresses, but HRRR continues to insist that the complex will
continue it, albeit weakening along the way, into the KC metro around
sunrise. General thought as the morning progresses is a bit in the
middle between these two solutions. The low level jet, apparently
helping this complex persist is not very strong, but it also doesn`t
appear to weaken much as one gets closer to the KC Metro. However,
with the outflow from these storms already pushing out ahead of the
complex, there is a good bet that stabilization of the effective
layer will gradually occur and the storms will eventually lose their
strength. Have the best chance of rain occurring across the far
northwestern part of the CWA, in NW Missouri and NE Kansas, with
diminishing (but non-zero) chances farther south and east.
The focus then shifts to a complicated and conditional forecast for
Saturday. Heat headlines currently ongoing will be allowed to
continue, however confidence in these abnormally hot temperatures
isn`t quite as high as it was yesterday. The aforementioned storm
complex could change the evolution of the heat today across a good
portion of the area. If the HRRR has its way and the complex dives
all the way into the KC Metro it would bring at least some rain into
the morning hours, with likely some cloud debris lingering around
for a good portion of the morning. Even with all these qualifiers
it`s still anticipated that the surface will recover, despite the
stable rain cooled air moving through this morning. Expect heat
indices to jump into the 100 to 105 range this afternoon with some
locations perhaps reaching a little higher, mainly along and south
of the MO River.
That leads to the complications and conditions related to the storm
chances later this afternoon and this evening. Mid level flow
continues to reside over the central and northern plains with the
center of the mid level ridge well south of the forecast area in the
eastern southern plains. At the surface an unseasonably deep trough
will form across the central High Plains and eject into the lower
central plains. In response to this low to the west S/SE winds will
pick up during the day, and likely overcome the cooler air, causing
temperatures to jump back into the upper 80s, and very possibly the
lower 90s. Across far northern Missouri, where cloud debris will
likely be the thickest, as well as perhaps along or north of the
warm front temperatures won`t get quite as warm as areas along and
south of I-70. Depending on how well skies clear out this afternoon
another round of storms will be possible, most likely across SE
Nebraska, eastward across northern Missouri and southern Iowa. Most
models continue to indicate a scenario where storms indeed fire
later today. The lack of any appreciable mid level support for
ascent this afternoon will exaggerate the capping inversion, which
will keep storms at bay for at least the afternoon, into the evening
hours. By the 22z to 00z time period the low level jet at 850 mb
will pick up in intensity and likely give the final push needed to
get storms to go up, likely in SE Nebraska or NE Kansas. Should these
storms become surface based, which isn`t out of the question, a very
impressive thermal and wind profile will be in place to bring some
powerful storms. With the aforementioned SE surface flow, the
strengthening LLJ, as well as the westerly mid level flow around 40
kts. The wind profile will be ample for supercell storms to form
later this evening in the SE Neb/NW Mo/NE Ks area. ML CAPE values
approaching 2000 to 3000 J/KG will provide the necessary instability
to complement the deep layer shear nicely. Given that supercells are
possible, hail and wind would be the most likely hazards with these
storms; however not to be discounted, very impressive hodographs are
present across the area of concern, with very long and clockwise
curved hodographs. This would introduce a rather concerning tornado
risk, especially for early August. Given the weak forcing it`s
certainly possible that early storms will be somewhat discreet,
which would increase the concern for supercellular storms. However,
by 00z to 03z the discreet storms will likely congeal into a more
robust complex and drive eastward, likely along the MO/IA border,
bringing a wind and hail threat, along with a flash flooding threat.
Given the LLJ maintenance overnight and PWAT values approaching 2 to
2.5 inches it`s possible that areas along and north of HWY 36
tonight could see some flooding and/or flash flooding. By early
Sunday morning expect these storms to have moved off to the east and
chances for rain gradually diminishing through the day on Sunday.
For Sunday, warm conditions will continue for the forecast area,
again, mainly across the southern zones. Anticipate temperatures
again to reach the 90s, with heat indices in the 100 to 105 range
across areas along and south of the MO River. But again, depending
on how the area clears, the areal extent of the heat for Sunday is a
bit up in the air, so will forgo a heat headline for now, but one
may be necessary for areas along and south of the MO River.
For Sunday, into Monday the large ridge will shift a little back to
the west, putting the forecast area under more of an influence of
the large trough over the Great Lakes region as opposed to the
western ridge. A short wave trough will glide through the area on
Monday, which should bring another chance for some rain, as well as
a cooler air mass. For the rest of the week, expect temperatures to
be a bit more comfortable with temperatures generally in the 80s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 629 AM CDT SAT AUG 8 2015
Morning showers and thunderstorms will likely move out of the area by
mid morning, with VFR conditions prevailing. Winds will pick up out
of the southeast by mid to late morning around 15 to 20 kts. KSTJ
could see some thunderstorm activity later tonight, but the bulk of
it should remain north of KSTJ nearer to the IA/MO border.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY from Noon today to 9 PM CDT this evening for
KSZ025-057-060-102.
EXCESSIVE HEAT WARNING from Noon today to 9 PM CDT this evening
for KSZ103>105.
MO...HEAT ADVISORY from Noon today to 9 PM CDT this evening for
MOZ011>014-020>023-030-031-038-039-043>046-053-054.
EXCESSIVE HEAT WARNING from Noon today to 9 PM CDT this evening
for MOZ028-029-037.
&&
$$
DISCUSSION...Leighton
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1038 AM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH SUNDAY BRINGING
MAINLY DRY CONDITIONS AND COMFORTABLE TEMPERATURES. THE NEXT
SIGNIFICANT CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE MONDAY
INTO TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VISIBLE SATELLITE IMAGERY SHOWS A MID-HI CLOUD SHIELD MOVING
EASTWARD ASSOCIATED WITH A SHORT WAVE OVER THE GREAT LAKES. THIS
WAVE WAS SEEN WELL IN THE WATER VAPOR IMAGERY. THIS FEATURE HAS
SOME LIGHT PRECIP OR EVEN SOME VIRGA ASSOCIATED WITH IT SINCE IT
WAS MOISTURE STARVED. THIS WAVE WILL SPREAD MID-HI CLDS ACRS THE
REGION THIS AFTERNOON INTO THE EVENING. LOOKING AT KBUF RADAR THE
RADAR ECHOES WERE HAVING A DIFFICULT TIME PENETRATING INTO WRN NY
SUGGESTING ACVTY WAS DRYING UP. SO HAVE OPTED TO KEEP POPS LESS
THAN 15 PCT THRU AFTERNOON IN NY AND NC PA SIMILAR TO PREVIOUS
SHIFT. AT BEST MAYBE SOME AREA GETS A SPRINKLE OR TWO FROM THIS
BUT I FEEL THAT IS A LONG SHOT. SOUTH OF THIS WAVE IN PA THERE WAS
MAINLY CLEAR SKIES AND STRG INSOLATION AND THE LATEST NAM WAS
DEVELOPING ISLD CONVECTION OVER THE HIGHER TERRAIN OF THE
CATSKILLS...POCONOS AND OTHER HIGHLANDS OF NRN PA. THE 12Z NAM
HAS SFC BASED CAPES BETWEEN 500 AND 1000 J/KG IN THESE AREAS.
LOOKING AT THE LL MOISTURE FIELDS IN THE NAM MODEL VS
REALITY...IT APPEARS THE NAM IS A OVERDONE HERE. THIS WUD BE THE
ONLY OTHER CHC FOR ANY PRECIP IN THE REGION. THE LATEST HRRR MODEL
SHOWS NO RADAR ECHOES IN THE BGM FORECAST AREA THRU THIS EVENING.
THE LATEST RAP (WHICH DRYS THE BNDRY LAYER WAY TOO MUCH) BRINGS
SOME SPRINKLES TO THE FINGER LAKES THIS EVENING WITH THE ABV
MENTIONED WAVE. BUT GIVEN THE DRIER BNDRY LAYER IN THIS MODEL NO
CONVECTION POPS IN NE PA OR CATSKILLS. THE RAPS SFC DWPTS DROP
INTO THE 40S WHICH IS UNREALISTIC.
FOR TONIGHT...LEFT PREV SHIFTS SLGHT CHC FOR SHRA IN OUR SRN AND
SW ZONES WHICH IS FROM STUEBEN CO NY TO NE PA FOR NOW AS WE WAIT
FOR THE ALL THE NEW 12Z GUIDC. IF ANYTHING MIGHT HAVE TO PUT SLGHT
CHC FARTHER N TO ACCOUNT FOR THE GREAT LAKES SHORT WAVE WHICH
MOVES ACRS THE REGION. IN ANY EVENT...WE ARE NOT TALKING ABT MUCH
SENSIBLE WX OTHER THAN MAINLY CLDY SKIES TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
4 AM UPDATE...
LIMITED INSTABILITY AND MOISTURE...WITH ONLY WEAK SHORTWAVES
TRAVERSING WNW-ESE FLOW ALOFT...WILL KEEP SHOWER CHANCES /AND
COVERAGE/ SLIGHT AT BEST SUNDAY-SUNDAY NIGHT. HOWEVER...FOR MONDAY
INTO ESPECIALLY MONDAY NIGHT...MODEL CONSENSUS CONTINUES TO SHOW
AMPLIFYING TROUGH DIGGING INTO THE GREAT LAKES REGION MONDAY-
MONDAY NIGHT...WITH INCREASING MOISTURE AND INSTABILITY AHEAD OF
IT. AT THE SAME TIME...A SURFACE LOW IS DEPICTED AS TRACKING INTO
OUR REGION MONDAY NIGHT. THE MODELS DIFFER IN SOME DETAILS...SUCH
AS HIGHER PRECIPITABLE WATER VALUES IN THE NAM...AND A SLOWER
EVOLUTION IN THE ECMWF. BUT FOR THE GENERAL IDEA...MODELS ARE IN
FAIRLY GOOD AGREEMENT.
WE CONTINUE WITH A FORECAST OF INCREASING SHOWER CHANCES
MONDAY...PEAKING LATE MONDAY THROUGH ESPECIALLY MONDAY NIGHT WHEN
SHOWERS WILL BE ESPECIALLY LIKELY. WITH INSTABILITY ALSO
BECOMING PRESENT...THERE WILL BE A CHANCE OF THUNDERSTORMS AS
WELL...HOWEVER MID LEVEL LAPSE RATES AND SHEAR WILL BOTH BE ON THE
LOW SIDE SO SEVERE PROSPECTS ARE MINIMAL. THOUGH PRECIPITABLE
WATER VALUES WILL NOT BE VERY HIGH...THEY ARE FORECAST TO GET
TO AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL...WHICH COMBINED WITH
SLOW SYSTEM PROGRESSION COULD YIELD LOCALIZED HEAVY RAINFALL
/PERHAPS A FEW LOCATIONS GETTING MORE THAN AN INCH/. OVERALL
EXCESSIVE RAINFALL POTENTIAL DOES NOT APPEAR VERY SIGNIFICANT YET
BUT THIS WILL HAVE TO BE MONITORED.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
FOLLOWED CLOSE TO WPC GUIDANCE. OVERALL, UNSETTLED TO START THE
PERIOD WITH AN IMPROVING TREND LATER IN THE WEEK.
UPPER LEVEL TROUGH LINGERS OVER THE AREA MUCH OF THE WEEK. THE
RESULT WILL BE ABUNDANT CLOUDINESS WITH CONTINUING SCATTERED
SHOWERS AND THE CHANCE OF THUNDERSTORMS...ESPECIALLY DURING THE
AFTERNOON HOURS DUE TO DIURNAL HEATING. EXPECT THIS TO OCCUR ON
TUESDAY WITH SHOWERS AND ANY STORMS DYING DOWN AFTER SUNSET AND
THEN POPPING UP AGAIN WEDNESDAY AFTERNOON. BY THURSDAY, AS THE
DEEPER MOISTURE MOVES AWAY EXPECT MORE IN THE WAY OF SOME SUNSHINE
WITH ONLY A SLIGHT CHANCE OF SHOWERS FOLLOWED BY DRY WEATHER FOR
NEXT FRIDAY. THE UPPER LOW AND CLOUDINESS WILL KEEP TEMPS RUNNING
COOLER THAN AVERAGE FOR MOST OF THE LONG RANGE WITH HIGHS MAINLY
IN THE 70S AND LOWS IN THE 50S. BY NEXT FRIDAY, TEMPS RETURN TO
SEASONAL.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
DRY WX CONTS OVER THE AREA BRINGING VFR CONDS. XCPTN CONTS TO BE
LATE AT NGT WHEN LGT WINDS ALLOW VLY FOG TO DVLP. BRIEF
RESTRICTIONS TO IFR PSBL AT ELM LATE NGT...MVFR ELSEWHERE. LGT WLY
FLOW...ESP DURING THE DAY WITH MIXING...WILL CONT. DRAINAGE WINDS
TAKEOVER AT NGT.
.OUTLOOK...
SUN... EXCEPT FOR POSSIBLE EARLY MORNING RESTRICTIONS DUE TO FOG
(MAINLY KELM)...VFR IS EXPECTED.
MON-TUE... RESTRICTIONS POSSIBLE FROM SHOWERS/THUNDERSTORMS.
WED...VFR...BUT POTENTIAL BRIEF RESTRICTIONS IN SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/MDP
NEAR TERM...DJN
SHORT TERM...MDP
LONG TERM...PCF
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
934 AM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 934 AM CDT SAT AUG 8 2015
FOG HAS DISSIPATED ACROSS THE JAMES VALLEY AREA...WITH SOME LOW
CLOUDS STILL LINGERING IN LAMOURE COUNTY. ADJUSTED HOURLY
TEMPERATURE TRENDS...BUT OTHERWISE THE FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG HAS DISSIPATED NEAR THE JAMESTOWN ASOS...BUT THERE ARE
LIKELY STILL SOME PATCHES IN VALLEYS. THUS...LEFT PATCHY FOG IN
THE FORECAST FOR A COUPLE MORE HOURS. OTHERWISE...THE FORECAST
LOOKS TO BE ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST LATER TODAY AND
INCLUDING THE SOUTH CENTRAL TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT REMAINS OVER THE NORTHERN PLAINS
WITH STACKED LOW PRESSURE MOVING SLOWLY EAST ACROSS SOUTHERN
MANITOBA AND UPPER LEVEL RIDGING OVER THE CENTRAL PLAINS. MOSTLY
CLEAR SKIES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. T/TD SPREADS AT OR NEAR ZERO OVER MANY OBSERVING SITES
OVER NORTHERN NORTH DAKOTA AND ACROSS BOTH THE WESTERN DEVILS LAKE
AND JAMES RIVER BASINS. LAST FEW HRRR RUNS CONTINUE TO INDICATE AT
LEAST PATCHY FOG DEVELOPMENT OVER THESE AREAS YET EARLY THIS
MORNING AND WILL LEAVE IN THE FORECAST.
EMBEDDED SHORT WAVE TROUGH/IMPULSE LIFTING EAST-NORTHEAST ACROSS
THE INTERMOUNTAIN WEST THIS MORNING WILL TRACK EASTWARD INTO THE
NORTHERN HIGH PLAINS TODAY...THEN INTO AND ACROSS THE DAKOTAS
LATER TONIGHT INTO SUNDAY. ASSOCIATED SURFACE LOW WILL MOVE FROM
WYOMING THIS MORNING INTO SOUTH DAKOTA LATER TODAY AND TONIGHT.
PRECIPITATION WILL START TO DEVELOP INTO SOUTHWEST NORTH DAKOTA
THIS AFTERNOON WITH THE APPROACH OF THE MID LEVEL WAVE AND AS THE
SFC LOW MOVES INTO WESTERN SOUTH DAKOTA. PRECIPITATION THEN
SPREADS SLOWLY EAST INTO MY SOUTH CENTRAL COUNTIES TONIGHT. RIDGE
OF SURFACE HIGH PRESSURE BUILDING OVER FAR SOUTH CENTRAL
CANADA/NORTHERN ND WILL KEEP MOST AREAS NORTH OF INTERSTATE 94
DRY. HEAVIEST RAINFALL EXPECTED TO REMAIN OVER SOUTH DAKOTA. CAPE
RATHER WEAK BUT ENOUGH TO LEAVE A SLIGHT CHANCE/ISOLATED MENTION
OF THUNDERSTORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 8 2015
THE FOCUS THIS MORNING IS ON SUBTROPICAL RIDGE LOCATION.
THE MAIN CHANGE IN MODEL CONSENSUS OVER THE PAST 48 HOURS HAS BEEN
THE WESTWARD SHIFTING OF THE SUBTROPICAL RIDGE AXIS FROM THE CENTRAL
DAKOTAS INTO WESTERN MONTANA BY WEDNESDAY. THE SLOWER PROGRESSION OF
CYCLONIC FLOW WILL ACT TO EXTEND THE DRY PERIOD NEXT WEEK AND
INCREASE HIGH TEMPERATURES ACROSS THE DAKOTAS.
GREATER UNCERTAINTY CREEPS INTO THE FORECAST ON WEDNESDAY NIGHT...AS
MID LEVEL SHORTWAVES MAKE IT INTO THE DAKOTAS IN A FEW GEFS
MEMBERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG NEAR KJMS WILL DISSIPATE BY 13Z. LOW PRESSURE ACROSS
SOUTHERN MANITOBA WILL MOVE SLOWLY EAST TODAY...REPLACED WITH A
SURFACE RIDGE. SKIES WILL BE MOSTLY CLEAR NORTH WITH INCREASING
CLOUDS SOUTH DURING THE DAY. VFR CONDITIONS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
644 AM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG HAS DISSIPATED NEAR THE JAMESTOWN ASOS...BUT THERE ARE
LIKELY STILL SOME PATCHES IN VALLEYS. THUS...LEFT PATCHY FOG IN
THE FORECAST FOR A COUPLE MORE HOURS. OTHERWISE...THE FORECAST
LOOKS TO BE ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST LATER TODAY AND
INCLUDING THE SOUTH CENTRAL TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT REMAINS OVER THE NORTHERN PLAINS
WITH STACKED LOW PRESSURE MOVING SLOWLY EAST ACROSS SOUTHERN
MANITOBA AND UPPER LEVEL RIDGING OVER THE CENTRAL PLAINS. MOSTLY
CLEAR SKIES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. T/TD SPREADS AT OR NEAR ZERO OVER MANY OBSERVING SITES
OVER NORTHERN NORTH DAKOTA AND ACROSS BOTH THE WESTERN DEVILS LAKE
AND JAMES RIVER BASINS. LAST FEW HRRR RUNS CONTINUE TO INDICATE AT
LEAST PATCHY FOG DEVELOPMENT OVER THESE AREAS YET EARLY THIS
MORNING AND WILL LEAVE IN THE FORECAST.
EMBEDDED SHORT WAVE TROUGH/IMPULSE LIFTING EAST-NORTHEAST ACROSS
THE INTERMOUNTAIN WEST THIS MORNING WILL TRACK EASTWARD INTO THE
NORTHERN HIGH PLAINS TODAY...THEN INTO AND ACROSS THE DAKOTAS
LATER TONIGHT INTO SUNDAY. ASSOCIATED SURFACE LOW WILL MOVE FROM
WYOMING THIS MORNING INTO SOUTH DAKOTA LATER TODAY AND TONIGHT.
PRECIPITATION WILL START TO DEVELOP INTO SOUTHWEST NORTH DAKOTA
THIS AFTERNOON WITH THE APPROACH OF THE MID LEVEL WAVE AND AS THE
SFC LOW MOVES INTO WESTERN SOUTH DAKOTA. PRECIPITATION THEN
SPREADS SLOWLY EAST INTO MY SOUTH CENTRAL COUNTIES TONIGHT. RIDGE
OF SURFACE HIGH PRESSURE BUILDING OVER FAR SOUTH CENTRAL
CANADA/NORTHERN ND WILL KEEP MOST AREAS NORTH OF INTERSTATE 94
DRY. HEAVIEST RAINFALL EXPECTED TO REMAIN OVER SOUTH DAKOTA. CAPE
RATHER WEAK BUT ENOUGH TO LEAVE A SLIGHT CHANCE/ISOLATED MENTION
OF THUNDERSTORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 8 2015
THE FOCUS THIS MORNING IS ON SUBTROPICAL RIDGE LOCATION.
THE MAIN CHANGE IN MODEL CONSENSUS OVER THE PAST 48 HOURS HAS BEEN
THE WESTWARD SHIFTING OF THE SUBTROPICAL RIDGE AXIS FROM THE CENTRAL
DAKOTAS INTO WESTERN MONTANA BY WEDNESDAY. THE SLOWER PROGRESSION OF
CYCLONIC FLOW WILL ACT TO EXTEND THE DRY PERIOD NEXT WEEK AND
INCREASE HIGH TEMPERATURES ACROSS THE DAKOTAS.
GREATER UNCERTAINTY CREEPS INTO THE FORECAST ON WEDNESDAY NIGHT...AS
MID LEVEL SHORTWAVES MAKE IT INTO THE DAKOTAS IN A FEW GEFS
MEMBERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG NEAR KJMS WILL DISSIPATE BY 13Z. LOW PRESSURE ACROSS
SOUTHERN MANITOBA WILL MOVE SLOWLY EAST TODAY...REPLACED WITH A
SURFACE RIDGE. SKIES WILL BE MOSTLY CLEAR NORTH WITH INCREASING
CLOUDS SOUTH DURING THE DAY. VFR CONDITIONS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SCHECK
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1029 AM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL QUEBEC CANADA WILL RIDGE SOUTH INTO
THE AREA TODAY. WEAK LOW PRESSURE WILL MOVE OUT OF THE CENTRAL
UNITED STATES LATER SUNDAY AND SUNDAY NIGHT...BRINGING MORE HUMID
AND UNSETTLED CONDITIONS THAT WILL LAST INTO THE START OF THE NEW
WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE TO THE NORTH WILL KEEP MOST AREAS DRY AND PARTLY TO
MOSTLY SUNNY TODAY. THE REGION IS UNDER A GENERAL WEAKNESS IN THE
UPPER AIR PATTERN. THE APPROACH OF A JET STREAK OUT OF THE LOWER GR
LAKES LATER TODAY COULD PROVIDE JUST ENOUGH LIFT TO TRIGGER AN
ISOLATED SHOWER OR TWO. MID LEVEL LAPSE RATES ARE EXPECTED TO BE
WEAK AND WHILE THE MODELS DEVELOP SOME CAPE...IT WILL BE VERY
MEAGER. HRRR SHOWS SOME WIDELY SCATTERED SMALL CELLULAR CONVECTION
WHICH GENERALLY EQUATES TO NOT MUCH OF ANYTHING HAPPENING...SO I
BACKED OFF THE POPS PRETTY HARD...CONFINING THE VERY LOW CHANCES
FOR A POP UP SHOWER MAINLY TO OUR WESTERN HIGHER TERRAIN.
HIGH TEMPS TODAY WILL RANGE FROM THE MID 70S ACROSS THE LAUREL
HIGHLANDS AND PORTIONS OF THE NRN MTNS...TO THE U70S TO L80S
ACROSS THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
PERSISTENT...JET EXIT REGION AND ASSOCIATED WEAK-MDT LIFT WILL BE
OVR THE REGION TONIGHT AND SUNDAY. THIS HIGHER LEVEL UVVEL AND
CONTINUED LIGHT EASTERLY FLOW IN THE UPPER BLYR WILL HELP TO
MAINTAIN PLENTY OF CLOUDS AND SOME SPOTTY SHOWERS.
LOWS EARLY SUNDAY WILL BE IN THE MID TO UPPER 50S OVER THE
NORTHERN MOUNTAINS...AND LOWER TO MID 60S IN THE SOUTHERN VALLEYS.
CONDITIONS SHOULD WARM AND PARTIALLY CLEAR SUNDAY AS THE MEAN BLYR
FLOW WEAKENS AND BECOMES WEST OR NW. A LIGHT SHOWER CAN`T BE RULED
OUT SUNDAY...BUT MOST OF THEM SHOULD OCCUR FROM THE CENTRAL MTS TO
THE LAUREL HIGHLANDS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A WEAK TROUGH OF LOW PRESSURE AT THE SURFACE AND ALOFT SLIDE
SLOWLY SE ACROSS THE STATE EARLY NEXT WEEK.
USING THE GEFS ENSEMBLES THE STRONGEST FLOW AND MOISTURE REMAINS
TO THE NORTH AND EAST OF CENTRAL PA. THERE/S ONLY A SLIGHT CHANCE
OF SHOWERS SUNDAY AFTERNOON. THIS IS SPECIFICALLY THE RESULT OF A
WEAK SHORTWAVE RIDING N PERIPHERY OF MISS VALLEY UPPER RIDGE. GEFS
PLUMES INDICATE A GRADUAL WARMING TREND INTO THE WEEKEND...WITH
READINGS CLOSE TO AVERAGE FOR EARLY AUGUST.
THE MODELS FOR THE LONG RANGE PATTERN COME TO A FAIR AGREEMENT
THOUGH SLIGHT TIMING DIFFERENCES ARE PRESENT. THE NEXT WEATHER
SYSTEM...AND THE BEST CHANCE FOR PRECIPITATION WILL BE A COLD
FRONT THAT PASSES THROUGH TUESDAY. WITH SLOW MOVEMENT OF FRONT...
HAVE GIVEN A BROAD BRUSH OF POPS MONDAY NIGHT THROUGH TUESDAY
NIGHT. HAVE KEPT MAIN FRONTAL PASSAGE LATE TUESDAY
INTO TUE NIGHT...THOUGH CAN/T RULE OUT THE FRONT STALLING AND
PASSING WEDNESDAY. HIGHER PWATS WORK INTO THE REGION ON SW FLOW
AS HGTS FALL AHEAD OF APPROACHING TROF MONDAY...SO CHC OF
SHRA/TSRA CONTINUES. DEEPENING TROUGH POSSIBLY STALLED COLD FRONT
WILL LKLY RESULT IN SCATTERED SHRA/TSRA TUESDAY NIGHT INTO
WEDNESDAY. THE GEFS AND EC BOTH CURRENTLY INDICATE THE POSSIBILITY
OF HVY RAINFALL ACROSS EASTERN PA ASSOC WITH THIS SLOWING FRONT.
COOLER/DRIER WX IS LIKELY BY MIDWEEK AS THE LONG TERM PATTERN WILL
BE DOMINATED BY A ROTATING QUASI-STATIONARY UPPER LEVEL LOW
CENTERED OVER EASTERN CANADA. EXPECT THIS SYSTEM TO BRING COOL MID
LVL TEMPS OVR THE REGION AND COULD PROMOTE PM SHOWERS...ESP OVR
THE MTNS THROUGH THE LATTER HALF OF NEXT WEEK.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH MOST OF THE WEEKEND.
SCT-BKN MID CLOUDS SHOULD COVER MUCH OF THE AIRSPACE TODAY WITH
LOW CONFIDENCE IN A STRAY SHOWER...MAINLY OVER THE LAUREL
HIGHLANDS INTO THE NORTHERN MOUNTAINS THIS AFTERNOON AND EVENING.
SHORT DURATION SUB-VFR RESTRICTIONS ARE POSSIBLE DURING THE
PREDAWN AND EARLY MORNING HOURS SUNDAY DUE TO PATCHY FOG/LOW
CLOUDS.
MORE ACTIVE WX FCST INTO EARLY NEXT WEEK WITH SHOWERS/TSTMS LKLY
MON INTO TUE.
OUTLOOK...
MON-TUE...VFR-MVFR. SHOWERS LKLY/ISOLD TSTMS.
WED...MVFR-VFR CIGS/SCT SHOWERS WEST. MAINLY VFR CENTRAL/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
304 PM CDT SAT AUG 8 2015
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
A FEW ISOLATED SHOWERS AND THUNDERSTORMS HAVE POPPED UP ACROSS THE
STATE DURING THE LAST COUPLE OF HOURS AND THESE HAVE BEEN EXTREMELY
ISOLATED IN NATURE. WITH A STALLED BOUNDARY ACROSS THE STATE...DO
EXPECT A FEW MORE SHOWERS AND THUNDERSTORMS TO POP UP IN THE HEAT OF
THE DAY...WHICH THE HRRR HAS BEEN CONSISTENT IN SHOWING AS WELL.
SUNDAY WILL BE SLIGHTLY HOTTER AS THE RIDGE BUILDS INTO THE
AREA...THE AXIS OF HIGHEST DEW POINTS WILL SHIFT A BIT MORE TO THE
EAST. AS A RESULT...THIS WILL ADD NE ARKANSAS INTO THE HEAT ADVISORY.
A HOT DAY CAN BE EXPECTED ON MONDAY AS WELL WITH SLIGHTLY LOWER DEW
POINTS. AT THIS POINT IT APPEARS THE ONLY AREAS ABLE TO REACH
EXCESSIVE HEAT WARNING CRITERIA WILL BE ACROSS SE PORTIONS OF THE
CWA...BUT AT THIS POINT ITS BORDERLINE. WILL DEFER TO THE MID
SHIFT...AS THE NUMBERS ARE SO CLOSE TO CRITERIA. A FRONT WILL MOVE
THROUGH THE STATE ON MONDAY...WITH LITTLE IN THE WAY OF
PRECIPITATION EXPECTED UNTIL THE FRONT REACHES SOUTHERN ARKANSAS. IT
CONTINUES TO LOOK THAT THE BEST CHANCES FOR PRECIPITATION WILL BE TO
THE SOUTH OF THE STATE...BUT DID GO AND INCLUDE SLIGHT CHANCE POPS
ACROSS SOUTHERN PORTIONS OF THE STATE.
&&
.LONG TERM...WEDNESDAY THROUGH FRIDAY
SOME EXCESSIVE HEAT RELIEF IS IN STORE BEGINNING WEDNESDAY. AS
THE UPPER RIDGE SHIFTS WEST ALLOWING AND IN THE WAKE OF A WEAK
COLD FRONT MAX TEMPS DURING THIS PERIOD WILL RUN AT OR BELOW
NORMAL. DRIER CONDITIONS AS WELL AS DEWPOINTS FALL INTO THE UPPER
50S TO MID 60S. LOOKS TO BE A DRY PERIOD AS STABLE NORTHERLY FLOW
ALOFT AND WEAK NE SURFACE FLOW DOMINATE AND EMBEDDED UPPER LEVEL
DISTURBANCES SEEM UNLIKELY AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 92 74 99 79 / 10 0 0 10
CAMDEN AR 103 77 104 78 / 20 0 0 10
HARRISON AR 94 74 97 74 / 20 0 0 10
HOT SPRINGS AR 102 78 103 78 / 20 0 0 10
LITTLE ROCK AR 100 77 103 80 / 10 0 0 10
MONTICELLO AR 102 77 103 80 / 10 0 0 10
MOUNT IDA AR 102 75 102 74 / 20 0 0 10
MOUNTAIN HOME AR 93 74 98 75 / 20 0 0 10
NEWPORT AR 92 73 98 77 / 10 0 0 10
PINE BLUFF AR 100 76 103 78 / 10 0 0 10
RUSSELLVILLE AR 99 76 101 75 / 20 0 0 10
SEARCY AR 95 73 100 76 / 10 0 0 10
STUTTGART AR 96 75 101 77 / 10 0 0 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BAXTER-BOONE-
CLEBURNE-INDEPENDENCE-JACKSON-MARION-MONROE-NEWTON-SEARCY-STONE-
VAN BUREN-WOODRUFF.
HEAT ADVISORY FROM 11 AM TO 8 PM CDT SUNDAY FOR BAXTER-BOONE-
CLEBURNE-FULTON-INDEPENDENCE-IZARD-JACKSON-MARION-NEWTON-SEARCY-
SHARP-STONE-VAN BUREN.
EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR ARKANSAS-
BRADLEY-CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-
FAULKNER-GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-
LOGAN-LONOKE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-POPE-PRAIRIE-
PULASKI-SALINE-SCOTT-WHITE-YELL.
EXCESSIVE HEAT WARNING FROM 11 AM TO 8 PM CDT SUNDAY FOR
ARKANSAS-BRADLEY-CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-
DREW-FAULKNER-GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-
LOGAN-LONOKE-MONROE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-POPE-
PRAIRIE-PULASKI-SALINE-SCOTT-WHITE-WOODRUFF-YELL.
HEAT ADVISORY FROM 11 AM TO 8 PM CDT MONDAY FOR ARKANSAS-BRADLEY-
CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-
FAULKNER-GARLAND-GRANT-HOT SPRING-JACKSON-JEFFERSON-JOHNSON-
LINCOLN-LOGAN-LONOKE-MONROE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-
POPE-PRAIRIE-PULASKI-SALINE-SCOTT-VAN BUREN-WHITE-WOODRUFF-YELL.
&&
$$
SHORT TERM...65 / LONG TERM...32
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
245 PM MST SAT AUG 8 2015
.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EAST OF PHOENIX
TONIGHT...BUT STORM CHANCES WILL WANE ACROSS THE ENTIRE AREA ON
SUNDAY AS DRIER AIR MOVES INTO THE AREA. A RETURN TO A MORE TYPICAL
MONSOON FLOW IS EXPECTED BY THE MIDDLE OF NEXT WEEK...ALTHOUGH DRIER
AIR IS ONCE AGAIN FORECAST TO OVERSPREAD THE AREA BY THE END OF THE
WEEK.
&&
.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WELL-DEFINED SOUTHWESTERLY FLOW IN
THE 850 TO 300 MB LAYER BETWEEN A LOW PRESSURE SYSTEM ACROSS THE
NORTHERN ROCKIES AND AN ANTICYCLONE ACROSS TX. DRIER AIR CONTINUES TO
OVERSPREAD THE AREA AND IS MOST PRONOUNCED FURTHER WEST. AT THE
SURFACE...DEWPOINTS REMAIN ELEVATED IN THE WAKE OF YESTERDAY`S
RAINFALL...AND ARE AS HIGH AS MID TO UPPER 60S ACROSS THE PHOENIX
AREA.
LATEST SATELLITE IMAGERY AND REGIONAL WEBCAMS INDICATE THAT CU IS
STRUGGLING TO DEVELOP VERTICALLY ACROSS THE LOWER DESERTS. THIS IS
LIKELY DUE TO DRY AIR IN THE 850-750 MB LAYER AND A WARM BULGE
AROUND 700 MB EVIDENT IN SEVERAL ACARS PHX SOUNDINGS. LATEST
MESOANALYSIS IS THEREFORE LIKELY OVERESTIMATING INSTABILITY ACROSS
CENTRAL AZ. LATEST RUNS OF THE HRRR CONTINUE TO INITIATE CONVECTION
TOO EARLY AND SUBSEQUENTLY DELAY THE ONSET OF ISOLATED SHOWERS AND
THUNDERSTORMS LATER IN THE AFTERNOON.
A SLIGHT CHANCE OF THUNDERSTORMS WILL PERSIST INTO THIS
EVENING...THOUGH THE BEST CHANCE WILL MAINLY BE CONFINED TO THE
HIGHER TERRAIN EAST OF PHOENIX IN THE VICINITY OF THE DEEPER
MOISTURE. CONSENSUS OF THE LATEST LOCAL/NCEP/U OF AZ WRFS ALSO
SUGGEST NEGLIGIBLE CHANCES OF RAINFALL OR THUNDERSTORM-RELATED
IMPACTS THROUGH THIS EVENING.
&&
.PREVIOUS DISCUSSION...
DRIER AIR WILL ALMOST CERTAINLY OVERSPREAD THE ENTIRE AREA BY LATE
TONIGHT...EFFECTIVELY PUTTING THE BRAKES ON WIDESPREAD MONSOON
CONVECTION FOR THE NEXT SEVERAL DAYS. WHILE THERE WILL BE SMALL
POCKETS OF MOISTURE IN THE MOUNTAINS EAST OF PHOENIX...INSTABILITY
AND A SUFFICIENT TRIGGER APPEAR TO BE LACKING.
A RETURN TO A MORE TYPICAL MONSOON PATTERN IS EXPECTED BY
TUESDAY/WEDNESDAY AND THIS MORNING`S GFS AND ECMWF /AND ENSEMBLES/
SUGGEST AN IMPRESSIVE INCREASE IN MOISTURE. NOT ONLY THAT...BUT THEY
ALSO DEPICT A FAST MOVING 250-300MV PV ANOMALY IN THE AREA TUESDAY
AFTERNOON. INHERITED FORECAST DEPICTED ELEVATED POPS AND I SEE NO
REASON TO REVERSE THIS THINKING. WITH MOISTURE FORECAST TO REMAIN IN
PLACE ON WEDNESDAY AS WELL...BOTH DAYS COULD BE ACTIVE AT SOME POINT
OR ANOTHER. WEDNESDAY`S POPS ARE A BIT MORE BROAD-BRUSHED THAN I`D
LIKE BUT THERE`S ALWAYS A POSSIBILITY OF A REMNANT MCV TO KICK OFF
CONVECTION.
A BIT ATYPICAL FROM WHAT ONE WOULD EXPECT NORMALLY...BUT THE BL WILL
BEGIN TO DRY OUT FROM THURSDAY ONWARD DESPITE NORMALLY FAVORABLE
EASTERLY FLOW IN THE MID LEVELS. RATHER THAN PULLING MOISTURE
NORTHWARD FROM THE GULF OF CALIFORNIA...IT WOULD APPEAR THE UPPER
RIDGE WILL MIGRATE NORTHWARD AND ADVECT A DRY AIRMASS FROM TEXAS/NEW
MEXICO INTO PLACE BY THE END OF THE WEEK. DIDN`T WANT TO BUY INTO
THIS DRYING TREND AT FACE VALUE SINCE THE ENSEMBLES MAINTAIN SOME
DEGREE OF MOISTURE ACROSS THE AREA /AND SLIGHT VEERING IN THE MID
LEVEL FLOW WOULD KEEP MOISTURE IN PLACE/...THUS I MAINTAINED LOW END
CLIMO-LIKE POPS THROUGH THE END OF THE WEEK. IF DRY AIR ENDS UP
MATERIALIZING AS ADVERTISED IN THE DETERMINISTIC
GUIDANCE...TEMPERATURES WILL ALMOST CERTAINLY ECLIPSE THE 110 DEGREE
MARK ACROSS THE DESERTS AND I STARTED NUDGING HIGHS UP A BIT LATE IN
THE FORECAST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MAJORITY OF THE MONSOON STORM ACTIVITY WILL REMAIN ACROSS EASTERN AZ
TONIGHT...WITH ONLY THE SLIGHTEST OF CHANCES OF ANY ACTIVITY
SURVIVING INTO THE PHX METRO THIS EVENING. MONSOON MOISTURE BOUNDARY
REMAINS ACROSS THE SOUTH-CENTRAL AZ DESERTS...GENERATING THE CU
FIELDS WITH A STRAY...COMPACT...BUT SHORT-LIVED SHOWER OR TWO
SQUEEZING OUT OF THE TALLEST CU...HENCE THE VCSH IN THE KIWA TAF.
SKIES WILL GRADUALLY CLEAR INTO THE EVENING...WITH SOME FEW MID
LEVEL CIGS LINGERING. MOSTLY LIGHT WINDS TO CONTINUE INTO THE
EVENING...TAKING UP SWTSRLY HEADINGS LATER INTO THE AFTN AND
MAINTAINING THOSE LATER INTO THE EVENING THAN TYPICAL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
MOSTLY CLEAR SKIES AND PERIODS OF ELEVATED WEST TO SW WINDS TO
PERSIST FOR THE TAF PERIODS AS DRY AIR CONTINUES TO MOVE INTO THE
AREA FROM THE WEST.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A SUBTLE RETURN OF MONSOON MOISTURE COUPLED WITH SOME PASSING UPPER
LEVEL DISTURBANCES FROM THE SOUTHEAST WILL RAISE STORM CHANCES AND
HUMIDITIES FOR TUESDAY. STORM CHANCES WILL EXPAND OUT OF THE EASTERN
AZ HIGHER TERRAIN THROUGH THE LOWER DESERT LOCALES AND TOWARDS THE
CO RIVER VALLEY. CONDITIONS DRY OUT AGAIN BY THE MIDDLE PART OF THE
WEEK AND DAYTIME TEMPERATURES RESPOND IN KIND...WITH THE POTENTIAL
TO GO ABOVE SEASONALLY NORMAL READINGS. WINDS WILL BE LIGHT THROUGH
MUCH OF THE PERIOD FOLLOWING TYPICAL DIURNAL DIRECTIONS EXCEPT FOR
AFTERNOON UPSLOPE BREEZES GUSTING AT TIMES UP TO 20 MPH.
&&
.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...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
212 PM MST SAT AUG 8 2015
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EAST OF PHOENIX
TONIGHT...BUT STORM CHANCES WILL WANE ACROSS THE ENTIRE AREA ON
SUNDAY AS DRIER AIR MOVES INTO THE AREA. A RETURN TO A MORE TYPICAL
MONSOON FLOW IS EXPECTED BY THE MIDDLE OF NEXT WEEK...ALTHOUGH DRIER
AIR IS ONCE AGAIN FORECAST TO OVERSPREAD THE AREA BY THE END OF THE
WEEK.
&&
.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WELL-DEFINED SOUTHWESTERLY FLOW IN
THE 850 TO 300 MB LAYER BETWEEN A LOW PRESSURE SYSTEM ACROSS THE
NORTHERN ROCKIES AND AN ANTICYCLONE ACROSS TX. DRIER AIR CONTINUES TO
OVERSPREAD THE AREA AND IS MOST PRONOUNCED FURTHER WEST. AT THE
SURFACE...DEWPOINTS REMAIN ELEVATED IN THE WAKE OF YESTERDAY`S
RAINFALL...AND ARE AS HIGH AS MID TO UPPER 60S ACROSS THE PHOENIX
AREA.
LATEST SATELLITE IMAGERY AND REGIONAL WEBCAMS INDICATE THAT CU IS
STRUGGLING TO DEVELOP VERTICALLY ACROSS THE LOWER DESERTS. THIS IS
LIKELY DUE TO DRY AIR IN THE 850-750 MB LAYER AND A WARM BULGE
AROUND 700 MB EVIDENT IN SEVERAL ACARS PHX SOUNDINGS. LATEST
MESOANALYSIS IS THEREFORE LIKELY OVERESTIMATING INSTABILITY ACROSS
CENTRAL AZ. LATEST RUNS OF THE HRRR CONTINUE TO INITIATE CONVECTION
TOO EARLY AND SUBSEQUENTLY DELAY THE ONSET OF ISOLATED SHOWERS AND
THUNDERSTORMS LATER IN THE AFTERNOON.
A SLIGHT CHANCE OF THUNDERSTORMS WILL PERSIST INTO THIS
EVENING...THOUGH THE BEST CHANCE WILL MAINLY BE CONFINED TO THE
HIGHER TERRAIN EAST OF PHOENIX IN THE VICINITY OF THE DEEPER
MOISTURE. CONSENSUS OF THE LATEST LOCAL/NCEP/U OF AZ WRFS ALSO
SUGGEST NEGLIGIBLE CHANCES OF RAINFALL OR THUNDERSTORM-RELATED
IMPACTS THROUGH THIS EVENING.
&&
.PREVIOUS DISCUSSION...
DRIER AIR WILL ALMOST CERTAINLY OVERSPREAD THE ENTIRE AREA BY LATE
TONIGHT...EFFECTIVELY PUTTING THE BRAKES ON WIDESPREAD MONSOON
CONVECTION FOR THE NEXT SEVERAL DAYS. WHILE THERE WILL BE SMALL
POCKETS OF MOISTURE IN THE MOUNTAINS EAST OF PHOENIX...INSTABILITY
AND A SUFFICIENT TRIGGER APPEAR TO BE LACKING.
A RETURN TO A MORE TYPICAL MONSOON PATTERN IS EXPECTED BY
TUESDAY/WEDNESDAY AND THIS MORNING`S GFS AND ECMWF /AND ENSEMBLES/
SUGGEST AN IMPRESSIVE INCREASE IN MOISTURE. NOT ONLY THAT...BUT THEY
ALSO DEPICT A FAST MOVING 250-300MV PV ANOMALY IN THE AREA TUESDAY
AFTERNOON. INHERITED FORECAST DEPICTED ELEVATED POPS AND I SEE NO
REASON TO REVERSE THIS THINKING. WITH MOISTURE FORECAST TO REMAIN IN
PLACE ON WEDNESDAY AS WELL...BOTH DAYS COULD BE ACTIVE AT SOME POINT
OR ANOTHER. WEDNESDAY`S POPS ARE A BIT MORE BROAD-BRUSHED THAN I`D
LIKE BUT THERE`S ALWAYS A POSSIBILITY OF A REMNANT MCV TO KICK OFF
CONVECTION.
A BIT ATYPICAL FROM WHAT ONE WOULD EXPECT NORMALLY...BUT THE BL WILL
BEGIN TO DRY OUT FROM THURSDAY ONWARD DESPITE NORMALLY FAVORABLE
EASTERLY FLOW IN THE MID LEVELS. RATHER THAN PULLING MOISTURE
NORTHWARD FROM THE GULF OF CALIFORNIA...IT WOULD APPEAR THE UPPER
RIDGE WILL MIGRATE NORTHWARD AND ADVECT A DRY AIRMASS FROM TEXAS/NEW
MEXICO INTO PLACE BY THE END OF THE WEEK. DIDN`T WANT TO BUY INTO
THIS DRYING TREND AT FACE VALUE SINCE THE ENSEMBLES MAINTAIN SOME
DEGREE OF MOISTURE ACROSS THE AREA /AND SLIGHT VEERING IN THE MID
LEVEL FLOW WOULD KEEP MOISTURE IN PLACE/...THUS I MAINTAINED LOW END
CLIMO-LIKE POPS THROUGH THE END OF THE WEEK. IF DRY AIR ENDS UP
MATERIALIZING AS ADVERTISED IN THE DETERMINISTIC
GUIDANCE...TEMPERATURES WILL ALMOST CERTAINLY ECLIPSE THE 110 DEGREE
MARK ACROSS THE DESERTS AND I STARTED NUDGING HIGHS UP A BIT LATE IN
THE FORECAST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
THE UPPER LOW THAT HELPED TO DRAW MONSOON MOISTURE...AND
CONSIDERABLE SHOWER/THUNDERSTORM ACTIVITY INTO THE GREATER PHOENIX
AREA FRIDAY AFTERNOON/EVENING IS NOW MOVING AWAY FROM THE
REGION...INTO NE NV/SW ID. AS THIS LOW CENTER MOVES AWAY...DRIER
SOUTHWESTERLY FLOW IS EXPECTED TO OVERSPREAD SOUTH-CENTRAL
ARIZONA...WITH A HIGH PROBABILITY THAT THUNDERSTORM ACTIVITY WILL
REMAIN WELL EAST OF THE PHOENIX AREA TERMINALS TODAY. CURRENT BKN-
OVC CIGS ARE EXPECTED TO BECOME FEW-SCT BY THIS AFTERNOON/EVENING.
WINDS TO REVERT BACK TO TYPICAL DIURNAL TRENDS...BUT WITH WESTERLY
WINDS LINGERING LATER INTO THE EVENING HOURS THEN WHAT IS NORMALLY
SEEN THIS TIME OF YEAR.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DRY SOUTHWESTERLY FLOW ALOFT TO KEEP SKIES MAINLY CLEAR THROUGH THE
TAF PERIOD. WINDS TO REMAIN MAINLY FROM A WESTERLY DIRECTION AT KIPL
AND FROM A SOUTH-SOUTHWESTERLY DIRECTION AT KBLH THROUGH THE TAF
PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
INCREASING MOISTURE INTO EARLY NEXT WEEK WILL PUSH CHANCES OF
SHOWERS AND THUNDERSTORMS INTO THE SOUTHERN AND WESTERN ARIZONA
DESERTS. MINIMUM RELATIVE HUMIDITIES OF 10 TO 20 PERCENT RANGE WILL
BE COMMON ACROSS THE DESERTS THIS WEEKEND WITH SOME IMPROVEMENT
GOING INTO EARLY NEXT WEEK. DRIEST LOCATION WILL BE SOUTHEAST
CALIFORNIA THIS WEEKEND WITH MINIMUM RH VALUES INTO THE SINGLE
DIGITS. HIGH TEMPERATURES WILL BE AROUND OR SLIGHTLY ABOVE NORMAL
THROUGH THE PERIOD. WINDS WILL BE LIGHT THROUGH MUCH OF THE PERIOD
FOLLOWING TYPICAL DIURNAL DIRECTIONS EXCEPT FOR AFTERNOON UPSLOPE
BREEZES GUSTING AT TIMES UP TO 20 MPH.
&&
.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...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...PERCHA
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1125 AM MDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 956 AM MDT SAT AUG 8 2015
ADJUSTED POPS TO REFLECT LATEST HIGH RES MODEL GUIDANCE RUNS THIS
MORNING. LATEST GUIDANCE IN GOOD AGREEMENT FOR SCATTERED SHOWERS
AND THUNDERSTORMS OVER THE PALMER DIVIDE AND FAR SE CO THIS
AFTERNOON...INCLUDING BACA...BENT...PROWERS...AND KIOWA COUNTIES.
FAR SE CO MAY SEE A FEW STRONG TO SEVERE STORMS LATE THIS
AFTERNOON...AS 30-35 KNOTS OF 0-6 KM BULK SHEAR WILL BE PRESENT
WITH 1000-1500 J/KG OF CAPE AVAILABLE. UPPER LEVEL DISTURBANCES
WITHIN THE MONSOON PLUME WILL HELP TO INITIATE CONVECTION...BUT
THE LIMITING FACTOR COULD BE CAPE...WITH NAM AND HRRR SHOWING DEW
POINTS ONLY IN THE UPPER 40S TO LOW 50S ACROSS THE I-25 CORRIDOR
WITH VALUES SLIGHTLY HIGHER TOWARDS FAR SE CO. LUKINBEAL
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM MDT SAT AUG 8 2015
...ANOTHER ROUND OF THUNDERSTORMS TODAY...A FEW STRONG ACROSS THE
SOUTHEAST PLAINS...
MONSOON PLUME EXTENDS ACROSS CO WITH A COUPLE OF EMBEDDED WAVES
MOVING THROUGH SOUTHWEST FLOW ALOFT. THE FIRST IS MOVING ACROSS THE
SE MTS INTO THE ADJACENT PLAINS EARLY THIS MORNING. THIS WAVE IS
PRETTY WEAK...BUT IS ENHANCING SOME MID/HIGH CLOUD DECK OVER THE
EASTERN PORTIONS OF THE AREA...WITH SOME SPOTTY SHOWERS ACROSS THE
PLAINS AT TIMES. THIS WAVE SHOULD LIFT OFF TO THE NORTHEAST THROUGH
THE MORNING. MEANWHILE...SHOWERS WILL CONTINUE ALONG THE CONTDVD AS
THE NEXT WAVE ACROSS NW AZ LIFTS UP INTO THE 4 CORNERS REGION THIS
MORNING. THIS WAVE WILL MOVE ACROSS THE REMAINDER OF CO DURING THE
AFTERNOON. ACROSS THE PLAINS...SFC LOW IS POSITIONED ACROSS FAR
SOUTHEAST CO...WITH WEST TO NORTHWEST WINDS ALONG THE I-25 CORRIDOR
AND SOUTHERN PORTIONS OF THE SOUTHEAST PLAINS. MODELS SUGGEST A
WEAK NORTHERLY SURGE WILL WRAP AROUND THE NORTH SIDE OF THE SFC LOW
INTO THE SE PLAINS...WHICH WILL INCREASE DEW POINTS AGAIN FROM THE
LOWER TO MID 50S...TO MID-UPPER 50S NEAR THE BORDER BY AFTERNOON.
WINDS DON`T LOOK VERY STRONG ACROSS THE PLAINS...BUT THERE SHOULD BE
SOME CONVERGENCE ALONG THIS BOUNDARY WHICH SETS UP ACROSS SOUTHEAST
PLAINS. DEEP LAYER SHEAR LOOKS A LITTLE STRONGER TODAY...BUT CAPES
LOOK LOWER THAN YESTERDAY. EACH SUCCESSIVE RUN OF THE HRRR SEEMS TO
BE TRENDING THE DEW POINTS DOWNWARD ACROSS SE CO WITH HIGHER DEW
POINTS AND CAPES ACROSS SOUTHWEST KANSAS. WILL HAVE TO WATCH TRENDS
IN THE LATEST HIGH RES MODELS AND OBSERVATIONS TODAY TO HONE DOWN
THESE DETAILS. CERTAINLY ENOUGH MOISTURE WILL BE PRESENT FOR AT
LEAST ISOLATED TO SCATTERED THUNDERSTORMS. MAIN THREAT WILL BE
LOCALLY HEAVY RAINFALL...WHICH COULD OCCUR JUST ABOUT ANYWHERE.
DEPENDING ON THE POSITION OF THE BOUNDARY AND AMOUNT OF DEW POINT
RETURN...COULD SEE AN ISOLATED STRONG TO SEVERE THUNDERSTORM ACROSS
THE SOUTHEAST COUNTIES...NAMELY KIOWA...BENT...PROWERS...AND BACA
COUNTIES. LARGE HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY STORM
THREATS.
THUNDERSTORMS SHOULD DIMINISH FROM WEST TO EAST TONIGHT WITH MORE
DRYING EXPECTED TO SPREAD IN FROM THE WEST AS THE MONSOON PLUME
SHIFTS EASTWARD. THIS SHOULD RESULT IN COOLER LOWS TONIGHT THAN
THIS MORNING ACROSS THE WESTERN MOUNTAIN VALLEYS.
MEANWHILE...MODELS SPREAD HIGHER DEW POINTS BACK INTO THE SE
PLAINS...AND MAY HAVE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
FAR SOUTHEAST PLAINS TOWARDS MORNING. -KT
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 500 AM MDT SAT AUG 8 2015
NOT MANY ADJUSTMENTS REQUIRED DURING THE LONGER TERM WITH
RELATIVELY ACTIVE METEOROLOGICAL CONDITIONS ANTICIPATED. PRIMARY
METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES...POPS AND THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL AND STRONGER STORMS AT TIMES.
LATEST PV ANALYSIS...COMPUTER SIMULATIONS AND FORECAST MODEL
SOUNDINGS STILL SUGGEST THAT UPPER HIGH CENTERED OVER NORTHEASTERN
TEXAS AT 12Z SUNDAY WILL BEGIN PROGRESSING WEST AND BECOME
CENTERED OVER THE TEXAS PANHANDLE REGION BY TUESDAY. UPPER RIDGE
IS STILL PROJECTED TO BECOME CENTERED OVER THE NORTHERN NEW
MEXICO/COLORADO REGION FROM LATER WEDNESDAY INTO FRIDAY.
DEEPEST ATMOSPHERIC MOISTURE PROFILES DURING THE LONGER TERM ARE
STILL PROJECTED FROM SUNDAY INTO TUESDAY NIGHT. THE MOIST ATMOSPHERIC
PROFILE WILL INTERACT WITH FAVORABLE LOW-LEVEL WIND FLOW...THE
DAILY OROGRAPHIC CYCLE AND UPPER DISTURBANCES AT TIMES TO PRODUCE
GENERALLY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY INTO AT LEAST
TUESDAY NIGHT WITH SLIGHTLY DECREASED POPS THEN EXPECTED BY LATER
IN THE WEEK.
PER PREVIOUS DISCUSSIONS...ESPECIALLY DURING THE SUNDAY INTO
TUESDAY NIGHT TIME-FRAME...THE PROJECTED HIGHER PRECIPITABLE
WATER VALUES ARE EXPECTED TO GENERATE LOCALLY HEAVY RAINFALL
CAPABLE OF PRODUCING LOCALIZED FLASH FLOODING AT
TIMES...ESPECIALLY IF THE HEAVY RAINFALL IMPACTS RECENT BURN
SCARS. ALSO...STRONGER STORMS AT TIMES ARE ALSO ANTICIPATED
DUE TO SOMEWHAT ELEVATED CAPE...LI AND BULK SHEAR VALUES.
ALSO...GENERALLY ABOVE CLIMATOLOGICAL EARLY TO MID AUGUST
TEMPERATURES ARE STILL PROJECTED DURING THE MAJORITY OF THE LONGER
TERM WITH MONDAY AND TUESDAY HAVING THE HIGHEST POTENTIAL OF
EXPERIENCING BELOW SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1122 AM MDT SAT AUG 8 2015
VFR CONDITIONS EXPECTED AT THE TAF SITES THROUGH THE AFTERNOON AND
EARLY EVENING...WITH BRIEF MVFR CIGS/VIS POSSIBLE UNDER STRONGER
THUNDERSTORMS. SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE
MOUNTAINS...PALMER DIVIDE...AND RATON MESA THIS AFTERNOON BEFORE
SPREADING ACROSS THE EASTERN PLAINS. ALL THREE TAF SITES COULD SEE
VCTS AFTER 21-22Z WITH GUSTY OUTFLOW WINDS BEING THE PRIMARY
CONCERN. OVERNIGHT LASTEST MODEL GUIDANCE IS SUGGESTING A STRATUS
DECK DEVELOPING ACROSS THE EASTERN PLAINS AS OUTFLOW BOUNDARIES FROM
WESTERN KS AND SE UPSLOPE FLOW PUSH MOIST LOW LEVEL MOISTURE INTO
THE I-25 CORRIDOR. STARTING AROUND 08Z...KCOS AND KPUB WILL LIKELY
BE IMPACTED BY THE STRATUS DECK WITH MVFR TO BRIEF IFR CONDITIONS
POSSIBLE OVERNIGHT INTO EARLY TOMORROW MORNING DUE TO CIGS...WITH
STRATUS EXPECTED TO CLEAR OUT BY 15Z AS WINDS SHIFT TO A N/NE
COMPONENT AT KCOS AND KPUB. LUKINBEAL
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/HODANISH
AVIATION...AL/HODANISH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1013 AM MDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 956 AM MDT SAT AUG 8 2015
ADJUSTED POPS TO REFLECT LATEST HIGH RES MODEL GUIDANCE RUNS THIS
MORNING. LATEST GUIDANCE IN GOOD AGREEMENT FOR SCATTERED SHOWERS
AND THUNDERSTORMS OVER THE PALMER DIVIDE AND FAR SE CO THIS
AFTERNOON...INCLUDING BACA...BENT...PROWERS...AND KIOWA COUNTIES.
FAR SE CO MAY SEE A FEW STRONG TO SEVERE STORMS LATE THIS
AFTERNOON...AS 30-35 KNOTS OF 0-6 KM BULK SHEAR WILL BE PRESENT
WITH 1000-1500 J/KG OF CAPE AVAILABLE. UPPER LEVEL DISTURBANCES
WITHIN THE MONSOON PLUME WILL HELP TO INITIATE CONVECTION...BUT
THE LIMITING FACTOR COULD BE CAPE...WITH NAM AND HRRR SHOWING DEW
POINTS ONLY IN THE UPPER 40S TO LOW 50S ACROSS THE I-25 CORRIDOR
WITH VALUES SLIGHTLY HIGHER TOWARDS FAR SE CO. LUKINBEAL
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM MDT SAT AUG 8 2015
...ANOTHER ROUND OF THUNDERSTORMS TODAY...A FEW STRONG ACROSS THE
SOUTHEAST PLAINS...
MONSOON PLUME EXTENDS ACROSS CO WITH A COUPLE OF EMBEDDED WAVES
MOVING THROUGH SOUTHWEST FLOW ALOFT. THE FIRST IS MOVING ACROSS THE
SE MTS INTO THE ADJACENT PLAINS EARLY THIS MORNING. THIS WAVE IS
PRETTY WEAK...BUT IS ENHANCING SOME MID/HIGH CLOUD DECK OVER THE
EASTERN PORTIONS OF THE AREA...WITH SOME SPOTTY SHOWERS ACROSS THE
PLAINS AT TIMES. THIS WAVE SHOULD LIFT OFF TO THE NORTHEAST THROUGH
THE MORNING. MEANWHILE...SHOWERS WILL CONTINUE ALONG THE CONTDVD AS
THE NEXT WAVE ACROSS NW AZ LIFTS UP INTO THE 4 CORNERS REGION THIS
MORNING. THIS WAVE WILL MOVE ACROSS THE REMAINDER OF CO DURING THE
AFTERNOON. ACROSS THE PLAINS...SFC LOW IS POSITIONED ACROSS FAR
SOUTHEAST CO...WITH WEST TO NORTHWEST WINDS ALONG THE I-25 CORRIDOR
AND SOUTHERN PORTIONS OF THE SOUTHEAST PLAINS. MODELS SUGGEST A
WEAK NORTHERLY SURGE WILL WRAP AROUND THE NORTH SIDE OF THE SFC LOW
INTO THE SE PLAINS...WHICH WILL INCREASE DEW POINTS AGAIN FROM THE
LOWER TO MID 50S...TO MID-UPPER 50S NEAR THE BORDER BY AFTERNOON.
WINDS DON`T LOOK VERY STRONG ACROSS THE PLAINS...BUT THERE SHOULD BE
SOME CONVERGENCE ALONG THIS BOUNDARY WHICH SETS UP ACROSS SOUTHEAST
PLAINS. DEEP LAYER SHEAR LOOKS A LITTLE STRONGER TODAY...BUT CAPES
LOOK LOWER THAN YESTERDAY. EACH SUCCESSIVE RUN OF THE HRRR SEEMS TO
BE TRENDING THE DEW POINTS DOWNWARD ACROSS SE CO WITH HIGHER DEW
POINTS AND CAPES ACROSS SOUTHWEST KANSAS. WILL HAVE TO WATCH TRENDS
IN THE LATEST HIGH RES MODELS AND OBSERVATIONS TODAY TO HONE DOWN
THESE DETAILS. CERTAINLY ENOUGH MOISTURE WILL BE PRESENT FOR AT
LEAST ISOLATED TO SCATTERED THUNDERSTORMS. MAIN THREAT WILL BE
LOCALLY HEAVY RAINFALL...WHICH COULD OCCUR JUST ABOUT ANYWHERE.
DEPENDING ON THE POSITION OF THE BOUNDARY AND AMOUNT OF DEW POINT
RETURN...COULD SEE AN ISOLATED STRONG TO SEVERE THUNDERSTORM ACROSS
THE SOUTHEAST COUNTIES...NAMELY KIOWA...BENT...PROWERS...AND BACA
COUNTIES. LARGE HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY STORM
THREATS.
THUNDERSTORMS SHOULD DIMINISH FROM WEST TO EAST TONIGHT WITH MORE
DRYING EXPECTED TO SPREAD IN FROM THE WEST AS THE MONSOON PLUME
SHIFTS EASTWARD. THIS SHOULD RESULT IN COOLER LOWS TONIGHT THAN
THIS MORNING ACROSS THE WESTERN MOUNTAIN VALLEYS.
MEANWHILE...MODELS SPREAD HIGHER DEW POINTS BACK INTO THE SE
PLAINS...AND MAY HAVE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
FAR SOUTHEAST PLAINS TOWARDS MORNING. -KT
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 500 AM MDT SAT AUG 8 2015
NOT MANY ADJUSTMENTS REQUIRED DURING THE LONGER TERM WITH
RELATIVELY ACTIVE METEOROLOGICAL CONDITIONS ANTICIPATED. PRIMARY
METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES...POPS AND THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL AND STRONGER STORMS AT TIMES.
LATEST PV ANALYSIS...COMPUTER SIMULATIONS AND FORECAST MODEL
SOUNDINGS STILL SUGGEST THAT UPPER HIGH CENTERED OVER NORTHEASTERN
TEXAS AT 12Z SUNDAY WILL BEGIN PROGRESSING WEST AND BECOME
CENTERED OVER THE TEXAS PANHANDLE REGION BY TUESDAY. UPPER RIDGE
IS STILL PROJECTED TO BECOME CENTERED OVER THE NORTHERN NEW
MEXICO/COLORADO REGION FROM LATER WEDNESDAY INTO FRIDAY.
DEEPEST ATMOSPHERIC MOISTURE PROFILES DURING THE LONGER TERM ARE
STILL PROJECTED FROM SUNDAY INTO TUESDAY NIGHT. THE MOIST ATMOSPHERIC
PROFILE WILL INTERACT WITH FAVORABLE LOW-LEVEL WIND FLOW...THE
DAILY OROGRAPHIC CYCLE AND UPPER DISTURBANCES AT TIMES TO PRODUCE
GENERALLY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY INTO AT LEAST
TUESDAY NIGHT WITH SLIGHTLY DECREASED POPS THEN EXPECTED BY LATER
IN THE WEEK.
PER PREVIOUS DISCUSSIONS...ESPECIALLY DURING THE SUNDAY INTO
TUESDAY NIGHT TIME-FRAME...THE PROJECTED HIGHER PRECIPITABLE
WATER VALUES ARE EXPECTED TO GENERATE LOCALLY HEAVY RAINFALL
CAPABLE OF PRODUCING LOCALIZED FLASH FLOODING AT
TIMES...ESPECIALLY IF THE HEAVY RAINFALL IMPACTS RECENT BURN
SCARS. ALSO...STRONGER STORMS AT TIMES ARE ALSO ANTICIPATED
DUE TO SOMEWHAT ELEVATED CAPE...LI AND BULK SHEAR VALUES.
ALSO...GENERALLY ABOVE CLIMATOLOGICAL EARLY TO MID AUGUST
TEMPERATURES ARE STILL PROJECTED DURING THE MAJORITY OF THE LONGER
TERM WITH MONDAY AND TUESDAY HAVING THE HIGHEST POTENTIAL OF
EXPERIENCING BELOW SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 500 AM MDT SAT AUG 8 2015
VFR CONDITIONS EXPECT THIS MORNING AT THE TAF SITES...THOUGH
WILL HAVE TO WATCH KALS CLOSELY AS T/TD SPREADS ARE CLOSE. FOR NOW
THINK EXTENSIVE MID AND HIGH CLOUD COVER SHOULD PREVENT ANY PATCHY
GROUND FOG DEVELOPMENT. THUNDERSTORMS WILL DEVELOP OVER THE
MOUNTAINS...AND PALMER AND RATON MESA REGIONS BY AFTERNOON. AS
THESE THUNDERSTORMS SPREAD EASTWARD ACROSS THE LOWER
ELEVATIONS...ALL THREE TAF SITES COULD SEE VCTS AFTER 20-21Z.
GUSTY ERRATIC WINDS...AND VFR TO BRIEF MVFR CIGS/VIS WILL BE
POSSIBLE WITH THE STRONGER STORMS. THUNDERSTORMS SHOULD MOVE
EASTWARD AND DIMINISH THIS EVENING...WITH CONDITIONS REMAINING
VFR. COULD SEE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
SOUTHEAST PLAINS SATURDAY NIGHT...BUT FOR NOW MOST LIKELY AREA
APPEARS TO BE EAST OF THE I-25 CORRIDOR AND THE KCOS AND KPUB
TERMINALS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/HODANISH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
700 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY WEATHER THROUGH SUN AS LOW
PRESSURE REMAINS WELL OFFSHORE...THOUGH A SPOT SHOWER IS POSSIBLE
ACROSS THE INTERIOR SUN AFTERNOON. LOW PRESSURE WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES MON NIGHT INTO WED
MORNING. A TREND TOWARD DRIER WEATHER IS LIKELY THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
7 PM UPDATE...HIGH CIRRUS CLOUDS REMAIN IN PLACE ACROSS SOUTHERN
NEW ENGLAND THIS EVENING. MADE SOME ADJUSTMENTS TO THE SKY COVER
TO ACCOUNT FOR THE LATEST SATELLITE TRENDS. OTHERWISE...THE
FORECAST IS ON TRACK.
315 PM UPDATE...
PLENTY OF DIURNAL CU ACROSS INTERIOR WHERE HRRR AND 12Z NAM WANT
TO BRING SOME ISOLATED SHOWER ACTIVITY THIS AFTERNOON. COLUMN IS
FAIRLY DRY SO AM NOT BUYING INTO THAT...MODELS ARE MORE LIKELY
INDICATING BUILDING CU WHICH IS EVIDENT ON SATELLITE NEAR
BERKSHIRES.
MEANWHILE COASTAL LOW IS THROWING BACK SOME PATCHY MID AND HIGH
CLOUDS ALONG S COAST...CAPE COD AND ISLANDS. EXPECT THESE CLOUDS
TO THICKEN UP TONIGHT BUT NO RAIN EXPECTED AS BEST LIFT STAYS
OFFSHORE WITH PROGRESSIVE UPPER FLOW. SOME OF HIGH-RES MODELS
/HRRR...RAP AND ARW-WRF/ WANT TO BRING RAINFALL TO SE NEW ENGLAND
LATER TONIGHT BUT THAT LOOKS TO BE OVERDONE.
ANOTHER PLEASANTLY COOL NIGHT AHEAD WITH GOOD RADIATIONAL COOLING
CONDITIONS AWAY FROM INFLUENCE OF MID/HIGH CLOUDS NEAR S COAST.
LEANED TOWARD COOLER GFS LAMP GUIDANCE WHICH BRINGS LOWS INTO
UPPER 40S ACROSS NW MA AND MAINLY 50S ELSEWHERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
EXPECTING A GOOD AMOUNT OF CLOUDINESS NEAR CAPE COD AND ISLANDS
SUN DUE TO INCREASING NE FLOW ON PERIPHERY OF COASTAL LOW. MODEL
CROSS SECTIONS SHOW GOOD AMOUNT OF LOW LEVEL MOISTURE BELOW 950 MB
WHICH SHOULD BECOME TRAPPED. NO REAL MECHANISM FOR RAINFALL SO DRY
WEATHER ANTICIPATED AS DEEPER MOISTURE AND LIFT REMAIN WELL
OFFSHORE. SOME QUESTION AS TO WHETHER OR NOT LOW CLOUDS WILL BREAK
DURING AFTERNOON...BUT FOR NOW LEANED TOWARD THEM HANGING ON.
ACROSS INTERIOR...MODELS CONTINUE TO HINT AT POSSIBILITY OF FEW
SHOWERS BY AFTERNOON DUE TO SUBTLE LIFT FROM UPPER TROUGH. LOW
LEVEL CONVERGENCE IS MINIMAL DUE TO WEAK WIND FIELDS...SO ANY
ACTIVITY WOULD BE TIED TO TERRAIN. STABILITY PARAMETERS MARGINAL
SO EXPECT AN ISOLATED SHOWER OR PERHAPS A THUNDERSTORM ACROSS NW
AND POSSIBLY N CENTRAL MA.
HIGHS SHOULD BE A LITTLE COOLER THAN TODAY...ESPECIALLY NEAR COAST
DUE TO NE FLOW AND CLOUDINESS...RANGING FROM AROUND 70 ON OUTER
CAPE TO AROUND 80 FARTHER INLAND.
SUBSIDENCE AND SOME DRYING SUN NIGHT SHOULD LEAD TO AT LEAST
PARTIAL CLEARING...BUT CONTINUED ONSHORE FLOW MAY KEEP CLOUDS
LOCKED IN CLOSER TO COAST. LOWS SHOULD DROP BACK INTO 50S AND
LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* UNSETTLED WEATHER LIKELY LATE MON NIGHT THROUGH WED MORNING
* TEMPS SLIGHTLY BELOW NORMAL FOR MUCH OF THE WEEK
* POSSIBLE RETURN TO AUGUST HEAT FOR SATURDAY
OVERALL...MODELS ARE IN DECENT AGREEMENT THROUGH MUCH OF THE LONG
TERM. THERE ARE A COUPLE OF DISCREPANCIES THAT CONTINUE THROUGH THE
PERIOD. AS FAR AS SENSIBLE WEATHER GOES...THE MODELS ARE IN
AGREEMENT. LOOKING AT AN UPPER LEVEL TROUGH IN THE GREAT LAKES
MONDAY SLOWLY MOVING EASTWARD OVER THE NORTHEAST AND NEW ENGLAND BY
WEDNESDAY AND POTENTIALLY STALLING THERE THROUGH THE END OF THE
FORECAST PERIOD. THE ECMWF KEEPS THE PATTERN MORE AMPLIFIED...WHILE
THE GFS HAS A FLATTER FLOW AT THE MID-LEVELS WITH THE TROUGH
RETREATING INTO SOUTHEASTERN CANADA.
THIS TROUGH RESULTS IN LOW PRESSURE DEVELOPING IN THE GREAT LAKES
AND MOVING INTO QUEBEC TUESDAY. THE ECMWF PRODUCES A TRIPLE POINT
LOW OVER NEW JERSEY OFF THE MAIN LOW IN QUEBEC AND TRANSLATES THE
TRIPLE POINT LOW ALONG THE SOUTHERN NEW ENGLAND COAST. THE GFS
DEPICTS NO SUCH REDEVELOPMENT BUT KEEPS A STRONG SOUTHERLY FLOW
AHEAD OF THE COLD FRONT EXTENDING FROM THE QUEBEC LOW. THESE
DIFFERENCES COULD AFFECT THE OVERALL NATURE OF THE RAIN /WHETHER ITS
MORE STRATIFORM OR SHOWERY/ BUT REGARDLESS OF THE NATURE OR THE TYPE
OF SYSTEM...TUESDAY IS LIKELY TO BE WET. MODELS HINT THAT THE RAIN
COULD MOVE INTO OUR WESTERN ZONES LATE MONDAY NIGHT INTO EARLY
TUESDAY MORNING...BUT THE BULK OF THE RAIN APPEARS TO HOLD OFF TIL
AFTER 12Z TUESDAY. RAIN CONTINUES THROUGH TUESDAY INTO THE FIRST
PART OF THE DAY ON WEDNESDAY BUT THEN WILL TAPER OFF AS EITHER THE
FRONT MOVES THROUGH OR THE LOW PRESSURE EJECTS TOWARDS THE MARITIMES.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY WITH A POSSIBILITY OF A
FEW DIURNAL SHOWERS HERE AND THERE EACH DAY. TEMPERATURES ARE
EXPECTED TO BE BELOW TO NEAR NORMAL UNTIL THE WEEKEND WHEN DEPENDING
ON THE MODEL COULD SEE A RETURN TO AUGUST HEAT AND HUMIDITY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
00Z UPDATE...HIGH CONFIDENCE.
VFR TONIGHT WITH LIGHT N/NE WINDS. SHOULD SEE MVFR CIGS SPREAD
FROM OCEAN ONTO CAPE COD AND ISLANDS EARLY SUN MORNING. SOME
QUESTION AS TO WHETHER OR NOT CIGS SCT OUT OR LIFT TO VFR SUN
AFTERNOON. FOR NOW WE THINK CIGS WILL REMAIN MVFR THROUGH MUCH OF
DAY AND INTO SUN NIGHT. OTHERWISE VFR ELSEWHERE WITH BRIEF SHOWER
POSSIBLE ACROSS NW MA SUN AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF MVFR/IFR
CIGS/VSBYS ENTERING WESTERN ZONES LATE MONDAY NIGHT WITH -RA.
TUESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS LIKELY IN
WIDESPREAD RAIN/FOG.
WEDNESDAY...MODERATE CONFIDENCE. LINGERING MVFR/IFR CONDITIONS IN
DEPARTING RAIN. IMPROVING CONDITIONS THROUGH THE DAY.
THURSDAY...MODERATE CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF
BRIEF MVFR CONDITIONS IN DIURNAL -SHRA.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH SUN NIGHT.
DROPPED SCA ON OUTER S COASTAL WATERS WHERE SEAS HAVE SUBSIDED.
LIGHT N/NE WINDS GIVE WAY TO INCREASING NE WINDS SUN AND
ESPECIALLY SUN NIGHT...AS LOW PRESSURE PASSES WELL SE OF NEW
ENGLAND. SEAS SHOULD BEGIN TO BUILD LATER IN DAY AND COULD REACH 5
FT BY SUN NIGHT E AND S OF NANTUCKET...WHICH MAY REQUIRE SCA IN
LATER FORECASTS. DRY WEATHER EXPECTED THROUGH PERIOD.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. WINDS AND SEAS DIMINISH AS HIGH PRESSURE
BUILDS OVER THE WATERS.
TUESDAY...MODERATE CONFIDENCE. WINDS AND SEAS INCREASE AS EITHER A
COLD FRONT OR A LOW PRESSURE SYSTEM MOVE OVER THE WATERS. SMALL
CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR SEAS IF NOT WINDS AS
WELL. VISIBILITIES MAY BE LIMITED AT TIMES IN RAIN.
WEDNESDAY...MODERATE CONFIDENCE. WINDS AND SEAS DIMINISH AS LOW
PRESSURE PULLS AWAY FROM SOUTHERN NEW ENGLAND.
THURSDAY...MODERATE CONFIDENCE. QUIET BOATING WEATHER EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RLG/JWD
NEAR TERM...RLG/JWD
SHORT TERM...JWD
LONG TERM...RLG
AVIATION...RLG/JWD
MARINE...RLG/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
315 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY WEATHER THROUGH SUN AS LOW
PRESSURE REMAINS WELL OFFSHORE...THOUGH A SPOT SHOWER IS POSSIBLE
ACROSS THE INTERIOR SUN AFTERNOON. LOW PRESSURE WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES MON NIGHT INTO WED
MORNING. A TREND TOWARD DRIER WEATHER IS LIKELY THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
315 PM UPDATE...
PLENTY OF DIURNAL CU ACROSS INTERIOR WHERE HRRR AND 12Z NAM WANT
TO BRING SOME ISOLATED SHOWER ACTIVITY THIS AFTERNOON. COLUMN IS
FAIRLY DRY SO AM NOT BUYING INTO THAT...MODELS ARE MORE LIKELY
INDICATING BUILDING CU WHICH IS EVIDENT ON SATELLITE NEAR
BERKSHIRES.
MEANWHILE COASTAL LOW IS THROWING BACK SOME PATCHY MID AND HIGH
CLOUDS ALONG S COAST...CAPE COD AND ISLANDS. EXPECT THESE CLOUDS
TO THICKEN UP TONIGHT BUT NO RAIN EXPECTED AS BEST LIFT STAYS
OFFSHORE WITH PROGRESSIVE UPPER FLOW. SOME OF HIGH-RES MODELS
/HRRR...RAP AND ARW-WRF/ WANT TO BRING RAINFALL TO SE NEW ENGLAND
LATER TONIGHT BUT THAT LOOKS TO BE OVERDONE.
ANOTHER PLEASANTLY COOL NIGHT AHEAD WITH GOOD RADIATIONAL COOLING
CONDITIONS AWAY FROM INFLUENCE OF MID/HIGH CLOUDS NEAR S COAST.
LEANED TOWARD COOLER GFS LAMP GUIDANCE WHICH BRINGS LOWS INTO
UPPER 40S ACROSS NW MA AND MAINLY 50S ELSEWHERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
EXPECTING A GOOD AMOUNT OF CLOUDINESS NEAR CAPE COD AND ISLANDS
SUN DUE TO INCREASING NE FLOW ON PERIPHERY OF COASTAL LOW. MODEL
CROSS SECTIONS SHOW GOOD AMOUNT OF LOW LEVEL MOISTURE BELOW 950 MB
WHICH SHOULD BECOME TRAPPED. NO REAL MECHANISM FOR RAINFALL SO DRY
WEATHER ANTICIPATED AS DEEPER MOISTURE AND LIFT REMAIN WELL
OFFSHORE. SOME QUESTION AS TO WHETHER OR NOT LOW CLOUDS WILL BREAK
DURING AFTERNOON...BUT FOR NOW LEANED TOWARD THEM HANGING ON.
ACROSS INTERIOR...MODELS CONTINUE TO HINT AT POSSIBILITY OF FEW
SHOWERS BY AFTERNOON DUE TO SUBTLE LIFT FROM UPPER TROUGH. LOW
LEVEL CONVERGENCE IS MINIMAL DUE TO WEAK WIND FIELDS...SO ANY
ACTIVITY WOULD BE TIED TO TERRAIN. STABILITY PARAMETERS MARGINAL
SO EXPECT AN ISOLATED SHOWER OR PERHAPS A THUNDERSTORM ACROSS NW
AND POSSIBLY N CENTRAL MA.
HIGHS SHOULD BE A LITTLE COOLER THAN TODAY...ESPECIALLY NEAR COAST
DUE TO NE FLOW AND CLOUDINESS...RANGING FROM AROUND 70 ON OUTER
CAPE TO AROUND 80 FARTHER INLAND.
SUBSIDENCE AND SOME DRYING SUN NIGHT SHOULD LEAD TO AT LEAST
PARTIAL CLEARING...BUT CONTINUED ONSHORE FLOW MAY KEEP CLOUDS
LOCKED IN CLOSER TO COAST. LOWS SHOULD DROP BACK INTO 50S AND
LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* UNSETTLED WEATHER LIKELY LATE MON NIGHT THROUGH WED MORNING
* TEMPS SLIGHTLY BELOW NORMAL FOR MUCH OF THE WEEK
* POSSIBLE RETURN TO AUGUST HEAT FOR SATURDAY
OVERALL...MODELS ARE IN DECENT AGREEMENT THROUGH MUCH OF THE LONG
TERM. THERE ARE A COUPLE OF DISCREPANCIES THAT CONTINUE THROUGH THE
PERIOD. AS FAR AS SENSIBLE WEATHER GOES...THE MODELS ARE IN
AGREEMENT. LOOKING AT AN UPPER LEVEL TROUGH IN THE GREAT LAKES
MONDAY SLOWLY MOVING EASTWARD OVER THE NORTHEAST AND NEW ENGLAND BY
WEDNESDAY AND POTENTIALLY STALLING THERE THROUGH THE END OF THE
FORECAST PERIOD. THE ECMWF KEEPS THE PATTERN MORE AMPLIFIED...WHILE
THE GFS HAS A FLATTER FLOW AT THE MID-LEVELS WITH THE TROUGH
RETREATING INTO SOUTHEASTERN CANADA.
THIS TROUGH RESULTS IN LOW PRESSURE DEVELOPING IN THE GREAT LAKES
AND MOVING INTO QUEBEC TUESDAY. THE ECMWF PRODUCES A TRIPLE POINT
LOW OVER NEW JERSEY OFF THE MAIN LOW IN QUEBEC AND TRANSLATES THE
TRIPLE POINT LOW ALONG THE SOUTHERN NEW ENGLAND COAST. THE GFS
DEPICTS NO SUCH REDEVELOPMENT BUT KEEPS A STRONG SOUTHERLY FLOW
AHEAD OF THE COLD FRONT EXTENDING FROM THE QUEBEC LOW. THESE
DIFFERENCES COULD AFFECT THE OVERALL NATURE OF THE RAIN /WHETHER ITS
MORE STRATIFORM OR SHOWERY/ BUT REGARDLESS OF THE NATURE OR THE TYPE
OF SYSTEM...TUESDAY IS LIKELY TO BE WET. MODELS HINT THAT THE RAIN
COULD MOVE INTO OUR WESTERN ZONES LATE MONDAY NIGHT INTO EARLY
TUESDAY MORNING...BUT THE BULK OF THE RAIN APPEARS TO HOLD OFF TIL
AFTER 12Z TUESDAY. RAIN CONTINUES THROUGH TUESDAY INTO THE FIRST
PART OF THE DAY ON WEDNESDAY BUT THEN WILL TAPER OFF AS EITHER THE
FRONT MOVES THROUGH OR THE LOW PRESSURE EJECTS TOWARDS THE MARITIMES.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY WITH A POSSIBILITY OF A
FEW DIURNAL SHOWERS HERE AND THERE EACH DAY. TEMPERATURES ARE
EXPECTED TO BE BELOW TO NEAR NORMAL UNTIL THE WEEKEND WHEN DEPENDING
ON THE MODEL COULD SEE A RETURN TO AUGUST HEAT AND HUMIDITY.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
18Z UPDATE...HIGH CONFIDENCE.
VFR THIS AFTERNOON AND TONIGHT WITH LIGHT N/NE WINDS. SEA BREEZE
ALONG E MA COAST THIS AFTERNOON WHICH KEEP WINDS MORE E OR SE.
SHOULD SEE MVFR CIGS SPREAD FROM OCEAN ONTO CAPE COD AND ISLANDS
EARLY SUN MORNING. SOME QUESTION AS TO WHETHER OR NOT CIGS SCT OUT
OR LIFT TO VFR SUN AFTERNOON. FOR NOW WE THINK CIGS WILL REMAIN
MVFR THROUGH MUCH OF DAY AND INTO SUN NIGHT. OTHERWISE VFR
ELSEWHERE WITH BRIEF SHOWER POSSIBLE ACROSS NW MA SUN AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF MVFR/IFR
CIGS/VSBYS ENTERING WESTERN ZONES LATE MONDAY NIGHT WITH -RA.
TUESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS LIKELY IN
WIDESPREAD RAIN/FOG.
WEDNESDAY...MODERATE CONFIDENCE. LINGERING MVFR/IFR CONDITIONS IN
DEPARTING RAIN. IMPROVING CONDITIONS THROUGH THE DAY.
THURSDAY...MODERATE CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF
BRIEF MVFR CONDITIONS IN DIURNAL -SHRA.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH SUN NIGHT.
DROPPED SCA ON OUTER S COASTAL WATERS WHERE SEAS HAVE SUBSIDED.
LIGHT N/NE WINDS GIVE WAY TO INCREASING NE WINDS SUN AND
ESPECIALLY SUN NIGHT...AS LOW PRESSURE PASSES WELL SE OF NEW
ENGLAND. SEAS SHOULD BEGIN TO BUILD LATER IN DAY AND COULD REACH 5
FT BY SUN NIGHT E AND S OF NANTUCKET...WHICH MAY REQUIRE SCA IN
LATER FORECASTS. DRY WEATHER EXPECTED THROUGH PERIOD.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. WINDS AND SEAS DIMINISH AS HIGH PRESSURE
BUILDS OVER THE WATERS.
TUESDAY...MODERATE CONFIDENCE. WINDS AND SEAS INCREASE AS EITHER A
COLD FRONT OR A LOW PRESSURE SYSTEM MOVE OVER THE WATERS. SMALL
CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR SEAS IF NOT WINDS AS
WELL. VISIBILITIES MAY BE LIMITED AT TIMES IN RAIN.
WEDNESDAY...MODERATE CONFIDENCE. WINDS AND SEAS DIMINISH AS LOW
PRESSURE PULLS AWAY FROM SOUTHERN NEW ENGLAND.
THURSDAY...MODERATE CONFIDENCE. QUIET BOATING WEATHER EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RLG/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...RLG
AVIATION...RLG/JWD
MARINE...RLG/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
128 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY WEATHER THIS AFTERNOON AS LOW
PRESSURE REMAINS WELL OFFSHORE. A SPOT SHOWER IS POSSIBLE ON
SUNDAY. DRY WEATHER LINGERS INTO MONDAY. A LOW PRESSURE WILL
RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES MONDAY
NIGHT INTO WEDNESDAY. A TREND TOWARD DRIER WEATHER IS LIKELY
THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
130 PM UPDATE...
PLENTY OF DIURNAL CU ACROSS INTERIOR WHERE HRRR AND 12Z NAM WANT
TO BRING SOME ISOLATED SHOWER ACTIVITY THIS AFTERNOON. COLUMN IS
FAIRLY DRY SO AM NOT BUYING INTO THAT...MODELS ARE MORE LIKELY
INDICATING BUILDING CU. COASTAL LOW IS THROWING BACK SOME PATCHY
MID AND HIGH CLOUDS NEAR S COAST BUT DO NOT EXPECT THAT TO BE MUCH
OF AN ISSUE.
FORECAST HIGHS IN 70S/LOWER 80S ON TRACK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
SECONDARY LOW PRES WILL ONCE AGAIN SLIDE WELL S OF THE REGION. THE
INCREASE IN ISALLOBARIC FLOW WILL KEEP INTERIOR WINDS A BIT HIGHER
AND LEFTOVER CLOUDS ARE LIKELY TO LEAD TO WARMER MINS...ALTHOUGH
STILL IN THE UPPER 50S AND LOW 60S. DRY WX REMAINS THOUGH AS THE
PRECIP SHIELD SHOULD REMAIN WELL SE OF THE REGION...EVEN ACK.
SUN...
A BIT TRICKIER FORECAST FOR SUN. THERE ARE DIFFERENCES IN QPF
OUTPUT ACROSS THE INTERIOR OF MA/CT. NAM/MESOSCALE GUIDANCE IS
MOST ROBUST WHILE GFS/ECMWF ARE DRIER. THIS IS REFLECTED IN BUFKIT
SOUNDINGS...WITH NAM MORE MOIST AND AND GFS DRIER. PWATS ARE
DIFFERENT ALSO...WITH NEARLY 1 STD DEVIATION ABOVE NORMAL IN THE
NAM...NEAR NORMAL IN THE GFS/ECMWF. THERE IS A LIFT SOURCE IN THE
FORM OF A WEAK...BUT FAST MOVING SHORTWAVE WHICH SHOW SOME TIMING
DIFFERENCES. THEREFORE...CAN/T RULE OUT A SPOT SHOWER MAINLY FOR
WRN MA OR CT...BUT THE PRECIP SHIELD ASSOCIATED WITH LOW PRES
OFFSHORE REMAINS OFFSHORE. HOWEVER...CHANCE POPS WILL BE THE MAX
AS THEY ARE LIKELY TO BE FAIRLY SCATTERED AND RELATIVELY LIGHT
GIVEN THE LOWER END PWATS.
WILL ALSO INCLUDE THUNDER AS EACH MODEL SHOWS MODEST SFC
CAPE...PARTICULARLY IF THE NAM VERIFIES.
TEMPS REMAIN BELOW NORMAL UNDER RENEWED NE FLOW WITH LOW PRES NEAR
THE BENCHMARK. RANG BETWEEN LOW 70S AND LOW 80S EXPECTED.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS/T-STORMS AT TIMES LATE MONDAY INTO WEDNESDAY
* TEMPERATURES NEAR OR SLIGHTLY LOWER THAN NORMAL
SYNOPTIC OVERVIEW...
BROAD...FLAT MID-LEVEL FLOW OVER THE NORTHERN USA EVENTUALLY
AMPLIFIES INTO A MID-LEVEL TROUGH OVER THE EASTERN USA TOWARD THE
MIDDLE OF NEXT WEEK. THIS RESULTS IN AN ACTIVE PATTERN LATE MONDAY
INTO WEDNESDAY FOR SOUTHERN NEW ENGLAND. ENSEMBLES AND DETERMINISTIC
GUIDANCE ARE IN RATHER GOOD AGREEMENT ON THE LARGE SCALE FLOW...ALONG
WITH THE AMPLITUDE. BUT AS USUAL AT THIS TIME RANGE...ARE
STRUGGLING WITH THE INDIVIDUAL FRONTAL WAVES AND EXACT TIMING.
THUS FOLLOWED A MODEL BLEND FOR THIS PORTION OF THE FORECAST.
DAILY SENSIBLE WEATHER DETAILS...
SUNDAY NIGHT AND MONDAY...MOST OF THE GUIDANCE SUGGESTS DRY
WEATHER...ESPECIALLY FOR RI AND EASTERN MA...WITH A LOW RISK OF
SHOWER/T-STORMS LATE MONDAY FOR WESTERN MA AS MID LEVEL TROUGH
APPROACHES.
TUESDAY AND WEDNESDAY...MID LEVEL TROUGH AND ATTENDING FRONTAL WAVE
APPROACH. INCREASED RISK FOR SHOWERS AND THUNDERSTORMS. VERY MOIST
AIR EXPECTED...WITH DEW POINTS IN THE MID TO UPPER 60S. GIVEN MID
LEVEL TROUGH AMPLITUDE...AT LEAST MODEST FORCING FOR ASCENT IS
EXPECTED. THIS COMBINATION WILL RESULT IN A RISK FOR HEAVY
DOWNPOURS. WIND FIELDS ALOFT ARE MODEST...BUT INSTABILITY APPEARS
MARGINAL. GIVEN THE TIME RANGE HERE A LOW RISK OF STRONG STORMS.
THURSDAY AND FRIDAY...LATEST GUIDANCE CONTINUES TO SUGGEST THE MID
LEVEL TROUGH OVER THE NORTHEAST SHOULD BEGIN TO DEAMPLIFY. THIS WILL
RESULT IN A TREND TOWARD DRIER AND WARMER WEATHER LATE NEXT WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
18Z UPDATE...HIGH CONFIDENCE.
VFR THIS AFTERNOON AND TONIGHT WITH LIGHT N/NE WINDS. SEA BREEZE
ALONG E MA COAST THIS AFTERNOON WHICH KEEP WINDS MORE E OR SE.
SHOULD SEE MVFR CIGS SPREAD FROM OCEAN ONTO CAPE COD AND ISLANDS
EARLY SUN MORNING. SOME QUESTION AS TO WHETHER OR NOT CIGS SCT OUT
OR LIFT TO VFR SUN AFTERNOON. FOR NOW WE THINK CIGS WILL REMAIN
MVFR THROUGH MUCH OF DAY AND INTO SUN NIGHT. OTHERWISE VFR
ELSEWHERE WITH BRIEF SHOWER POSSIBLE ACROSS NW MA SUN AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /MONDAY THROUGH WEDNESDAY/...
FORECAST CONFIDENCE...HIGH CONFIDENCE MONDAY...THEN MODERATE
CONFIDENCE TUESDAY AND WEDNESDAY.
MONDAY...VFR WITH LOW RISK OF SHOWERS/T-STORMS LATE WESTERN MA/CT
TUESDAY AND WEDNESDAY...UNSETTLED. SCATTERED SHOWERS/THUNDERSTORMS.
MVFR TO IFR POSSIBLE. HEAVY DOWNPOURS POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
LIGHT N/NE FLOW THIS AFTERNOON ON WATERS. LEAVING SCA POSTED FOR
SEAS ON OUTER S COASTAL WATERS BUT CERTAINLY LOOKS MARGINAL AND
MAY DROP WITH 4 PM FORECAST.
TONIGHT INTO TOMORROW...MODERATE CONFIDENCE. NORTH TO NORTHEAST
FLOW REMAINS...BUT SHOULD BE GENERALLY BELOW THE 25 KT THRESHOLD
THANKS TO INFLUENCE OF HIGH PRES TO THE N. THIS SHOULD ALSO KEEP
SEAS BELOW 5 FEET...BUT THE PERSISTENT FLOW MAY INCREASE SWELLS
ALONG THE E COAST. FOR NOW...NOT CONFIDENT ENOUGH FOR AN SMALL
CRAFT ADVISORIES...BUT WILL NEED TO WATCH.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT...LIGHT E/NE WINDS. STRONGER WINDS SE OF NANTUCKET. E
SWELLS 3-5 FT.
MONDAY...WEAK HIGH PRESSURE. DRY WEATHER. LIGHT WINDS WITH SUBSIDING
EAST SWELLS.
TUESDAY AND WEDNESDAY...UNSETTLED...WITH SHOWERS AND THUNDERSTORMS
AS A FRONTAL WAVE APPROACHES.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ254-
255.
&&
$$
SYNOPSIS...BELK/DOODY
NEAR TERM...JWD
SHORT TERM...DOODY
LONG TERM...BELK
AVIATION...JWD
MARINE...JWD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 PM CDT SAT AUG 8 2015
.SHORT TERM...
320 PM CDT
THROUGH SUNDAY...
MAIN CONCERN IS WITH CONVECTIVE POTENTIAL LATE TONIGHT INTO
SUNDAY. RAOBS AND AIRCRAFT SOUNDINGS TODAY SHOWED AN ENVIRONMENT
HOSTILE TO PRECIP MAINTENANCE. THEREFORE DESPITE SOME FORCING FROM
A CONVECTIVELY INDUCED SHORTWAVE OVERHEAD...LIGHT RADAR ECHOES
OVER AREA ARE LIKELY VIRGA AND HAVE PULLED MENTION OF SPRINKLES
THE REST OF TODAY. CONVERGENT AXIS IN FRONTAL ZONE OF DISSIPATING
WEAK LOW OVER SOUTHERN LAKE MICHIGAN DID INITIATIVE SOME
CONVECTION OVER NORTH CENTRAL INDIANA...AND WOULD EXPECT FURTHER
DEVELOPMENT TO REMAIN EAST OF THE CWA. OVERALL...WITH PLENTY OF
CLOUD COVER WELL BACK TO THE WEST...INCLUDING PATCHY LOWER CLOUDS
IN SPOTS...JUST EXPECTING A MOSTLY CLOUDY REST OF THE DAY INTO
TONIGHT. VERY WEAK GRADIENT WILL YIELD LIGHT/CALM WINDS OVERNIGHT
AND LOW DEWPOINT SPREADS COULD SET STAGE FOR SOME PATCHY FOG OR
HAZE. LOW TEMPS WILL BE IN THE MID 60S TO AROUND 70.
FOCUS LATE TONIGHT INTO SUNDAY WILL BE ON MCS EXPECTED TO DEVELOP
OVER EASTERN NEBRASKA AND WESTERN IOWA THIS EVENING. MCS IS LIKELY
TO RIDE ALONG INSTABILITY AXIS THAT WILL MAINLY BE SOUTH OF THE
CWA OFF TO THE EAST-SOUTHEAST INTO SUNDAY MORNING. CONSENSUS OF
MODEL GUIDANCE IS TO KEEP INSTABILITY MINIMAL AT BEST FOR MUCH OF
THE CWA...LIMITING THUNDER POTENTIAL. CANNOT COMPLETELY RULE OUT
THUNDER GIVEN MODEST LOW LEVEL JET/WAA REGIME. RECENT HI-RES
CAMS...INCLUDING 4KM NAM AND EXPERIMENTAL HRRR DEPICT A REASONABLE
SCENARIO IN WHICH STRATIFORM NORTH OF MCS OVERSPREADS MUCH OF CWA
FROM WESTNORTHWEST TO EAST SOUTHEAST AFTER MIDNIGHT THROUGH MID
SUNDAY MORNING/BY WHICH TIME IT WILL PROBABLY BE DECAYING. HAVE
FOCUSED CATEGORICAL POPS INTO SOUTHERN CWA WHERE CONFIDENCE IS
HIGHEST IN WIDESPREAD COVERAGE. ITS POSSIBLE FAR NORTHEAST CWA
COULD SEE LITTLE OR NO RAIN. BEST CHANCE FOR HEAVY DOWNPOURS LOOKS
TO BE IN FAR SOUTHERN CWA WHERE MORE ROBUST CONVECTION COULD PASS
THROUGH...THOUGH ANY THREAT FOR STRONG TO SEVERE STORMS SHOULD
STAY SOUTHWEST OF THE CWA GIVEN ANTICIPATED DECAYING TREND OF MCS.
A GOOD DEAL OF UNCERTAINTY THE REMAINDER OF SUNDAY REGARDING
CONVECTIVE TRENDS. A SURFACE LOW LOOKS TO EVOLVE EASTWARD INTO THE
MID MISSISSIPPI VALLEY BY LATER IN THE DAY...WITH RETURN FLOW AND
WEST-SOUTHWEST LLJ ALSO DEVELOPING. LINGERING CLOUD COVER WILL
LIMIT DESTABILIZATION AND THUNDER POTENTIAL...ESPECIALLY FARTHER
NORTH UNTIL LATE DAY. ANOTHER SHORTWAVE WILL APPROACH FROM WEST IN
LATE AFTERNOON AND THERE SHOULD BE ENOUGH 925-850 MB MOISTURE
CONVERGENCE TO SUPPORT CHANCE POPS NORTH OF I-80 AND LIKELIESSOUTH
OF I-80. MODERATE WESTERLY MIDLEVEL FLOW WILL RESULT IN 30-40 KT
OF WEST-NORTHWEST 0-6KM SHEAR. THIS WILL SUPPORT SOME THREAT FOR
STRONG TO SEVERE STORMS WELL SOUTH OF I-80 CLOSER TO EXPECTED
TRACK OF SFC LOW AND WHERE TEMPS AROUND 80 AND LOW-MID 70S
DEWPOINTS COULD BRING SLIGHTLY BETTER INSTABILITY. MAIN THREAT
WOULD BE GUSTY TO DAMAGING WINDS...AS HAIL APPEARS UNLIKELY WITH
700-500 MB LAPSE RATES LESS THAN 6 CELSIUS PER KM. SUNDAY OVERALL
WILL BE A CLOUDY AND MUGGY DAY...WITH HIGHS IN THE MID 70S TO
AROUND 80.
RC
&&
.LONG TERM...
320 PM CDT
SUNDAY NIGHT THROUGH SATURDAY...
THE BEST CHANCE FOR PRECIP IN THE EXTENDED WILL BE SUNDAY EVENING
THROUGH MONDAY AFTERNOON...WITH VERY SLIGHT CHANCES OF PRECIP LATE
NEXT WEEK.
A COMPLEX OF STORMS WILL BE DIMINISHING OVER THE REGION SUNDAY
EVENING AND NIGHT. THE UPPER LEVEL VORTICITY PATTERN IS VERY CHAOTIC
WITH GUIDANCE INDICATING THE MAIN MCV WILL BE OVER CENTRAL IL AND
VORT STREAMERS ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE OVER
WISCONSIN. WITH SUCH A MESSY PATTERN...DECIDED TO ONLY MAKE MINOR
ADJUSTMENTS TO PRECIP CHANCES SUNDAY NIGHT. HAVE A CHANCE OF
THUNDERSTORMS ALONG AND EAST OF I-39 WITH BETTER CHANCES EAST OF I-
55. COULD SEE A FEW STRONG TO SEVERE STORMS SOUTH OF I-80 BUT
CONDITIONS WILL BE WEAKENING AS THE EVENING PROGRESSES.
OVERALL...HAVE LOW CONFIDENCE IN EXACTLY HOW SUNDAY NIGHT WILL PLAY
OUT DUE TO SO MANY MESOSCALE FEATURES AND WHETHER OR NOT THE
ATMOSPHERE WILL BE ABLE TO RECOVER FROM SUNDAY MORNING/S STORMS.
A SHORT WAVE MOVING WITH THE UPPER LEVEL TROUGH ROTATES THROUGH
MONDAY WITH A DECENT VORTICITY STREAMER. WENT WITH A CHANCE OF
SHOWERS AND STORMS MAINLY NORTH OF I-80 MONDAY. THINKING THE NAM IS
ONCE AGAIN TOO MOIST LEADING TO TOO MUCH CONVECTIVE DEVELOPMENT.
THINKING SHOWERS AND STORMS WILL DRIFT SOUTH OF THE IL/WI STATE LINE
MONDAY AFTERNOON AND THEN WEAKEN AS THEY CONTINUE TO SHIFT SOUTH
MONDAY EVENING. MONDAY EVENING MAY END UP BEING DRY...BUT DID NOT
HAVE ENOUGH CONFIDENCE IN A DRY FORECAST SO KEPT A SLIGHT CHANCE OF
SHOWERS AND STORMS ALONG AND SOUTH OF I-80 MONDAY EVENING.
THE UPPER LEVEL TROUGH AXIS SHIFTS EAST THROUGH WISCONSIN WITH
COOLER UPPER LEVEL AIR SINKING SOUTH THROUGH THE REGION. HIGH
PRESSURE THEN BUILDS IN FOR WEDNESDAY AND THURSDAY LEADING TO DRY
CONDITIONS THROUGH THURSDAY. HIGH TEMPS TUESDAY WILL BE AROUND
80...THEN IN THE UPPER 70S WEDNESDAY. LAKE BREEZES BOTH DAYS WILL
KEEP LOCATIONS ALONG THE LAKE IN THE MID 70S. TEMPS REBOUND INTO
THE LOW TO MID 80S THURSDAY WITH NO LAKE COOLING.
THE NEXT LOW PRESSURE SYSTEM MOVES OVER JAMES BAY THURSDAY EVENING
AND PUSHES THE HIGH PRESSURE SOUTH OVER THE OHIO VALLEY. THE LOWS
COLD FRONT SINKS SOUTH OVER FAR NORTHERN IL FRIDAY AFTERNOON SO HAVE
A SLIGHT CHANCE TO CHANCE OF SHOWERS AND STORMS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* WIND SHIFT TO NE AT ORD EXPECTED BY 00Z...PREVAILING SPEED
ANTICIPATED TO BE NEAR BUT JUST UNDER 10 KTS.
* MVFR CEILINGS IN FOG AND RAIN SUNDAY MORNING AND DAYTIME.
* ISOLATED THUNDERSTORM CHANCE SUNDAY.
MM/RATZER
//DISCUSSION...UPDATED 22Z...
LAKE BREEZE PUSHED INLAND SOUTH OF ORD...THOUGH COMPLEX NATURE OF
SFC PRESSURE GRADIENT ASSOCIATED WITH WEAK LOW MOVING SOUTHEAST
ACROSS LAKE MICHIGAN HAS HELD LAKE BREEZE EAST OF ORD THROUGH LATE
AFTERNOON. THIS WILL CHANGE NEXT 1-2 HOURS AS LARGER SCALE FLOW
PATTERN WHICH WAS SHIFTING TO THE NORTH...FLIPS OVER TO THE
NORTHEAST. WIND HAS SHIFTED AT KUGN...AND CAN BEGIN TO SEE
BOUNDARY MOVING SOUTHWEST IN TORD TDWR REFLECTIVITY OVER SOUTHEAST
LAKE CO IL. EXTRAPOLATION OF THIS FEATURE SUGGEST 2330-0000Z SHIFT
TO NORTHEAST FOR ORD. AS WITH MANY LAKE BREEZE/DENSITY CURRENTS...
SPEED MAY FLIRT WITH THE 10-15 KT RANGE BRIEFLY...THOUGH FORECAST
SOUNDINGS DEPICT WINDS LESS THAN 10 KTS THROUGH MIXED LAYER AND
EXPECTATION IS THAT PREVAILING WIND SPEED WILL BE JUST UNDER 10
KTS.
RATZER
PREVIOUS DISCUSSION FROM 18Z...
SURFACE ANALYSIS INDICATES A WEAK LOW AND ASSOCIATED
TROUGH/BOUNDARY WITHIN THE DOMINANT HIGH OVER MUCH OF THE GREAT
LAKES. THIS HAS CAUSED THE WIND FIELD TO BECOME QUITE CONVOLUTED
WITH A MESO- CYCLONE CENTERED NORTH OF CHICAGO. RADAR IMAGERY DOES
INDICATE A LAKE BREEZE PROGGED TO REACH ORD/MDW AROUND 19-20Z.
TIMING MAY NEED ADJUSTING IF THE BOUNDARY STALLS BETWEEN THE SHORE
AND ORD...BUT AT THIS PACE WINDS SHOULD BE NORTHEAST AT 20Z.
A MORE SUBSTANTIAL LOW WILL APPROACH INTO SUNDAY WITH
MOISTURE CONTENT ON THE RISE THROUGH TONIGHT. FORECAST SOUNDINGS
INDICATE A LOW LEVEL INVERSION FROM 09-13Z. SURFACE MOISTURE IS
ADEQUATE ENOUGH TO ALLOW FOR SOME FOG...FOLLOWED BY THE ARRIVAL OF
RAIN SUNDAY MORNING. RAIN/SHOWERY CONDITIONS ARE EXPECTED TO
PERSIST MUCH OF THE DAY AND THERE WILL MAY ALSO BE A PERIOD OF
THUNDER AS WELL. TIMING OF THUNDER IS UNDER QUESTION AS THE
INITIAL ARRIVAL OF THE LOW MAY SUPPORT A BRIEF UPTICK IN LAPSE
RATES...OTHERWISE WILL HAVE TO WAIT FOR ADDL SFC HEATING AFTER 20Z
SUNDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH IN WINDS
* MEDIUM IN MVFR FOG...MEDIUM HIGH IN RAIN.
* LOW IN THUNDER AND TIMING.
MM/RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
320 PM CDT
HIGH PRESSURE STRETCHES FROM QUEBEC THROUGH THE OHIO VALLEY WHILE
LOW PRESSURE IS OVER MANITOBA. BOTH SYSTEMS WILL SHIFT EAST WITH THE
LOW REACHING JAMES BAY BY MONDAY MORNING. AS SUCH LIGHT NORTHEAST
WINDS BECOME SOUTH TO SOUTHEAST SUNDAY. THE TROUGH ASSOCIATED WITH
THE LOWS COLD/STATIONARY FRONT SHIFTS THROUGH LATE SUNDAY NIGHT INTO
MONDAY MORNING WITH WINDS BECOMING NORTH BEHIND IT. A WEAK CLOSED
LOW FORMS OVER THE EASTERN GREAT LAKES MONDAY EVENING AND DEEPENS AS
IT SHIFTS NORTHEAST. AT THE SAME TIME HIGH PRESSURE WILL BE PUSHING
EAST OVER THE WESTERN GREAT LAKES. THIS WILL LEAD TO NORTH WINDS
INCREASING TO 10 TO 20 KT MONDAY NIGHT THROUGH TUESDAY NIGHT. WINDS
WEAKEN WEDNESDAY WITH THE HIGH OVERHEAD...AND THEN BACK TO SOUTHWEST
AS THE HIGH IS PUSHED SOUTH BY THE NEXT LOW OVER JAMES BAY THURSDAY.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
321 PM CDT SAT AUG 8 2015
.SHORT TERM...
320 PM CDT
THROUGH SUNDAY...
MAIN CONCERN IS WITH CONVECTIVE POTENTIAL LATE TONIGHT INTO
SUNDAY. RAOBS AND AIRCRAFT SOUNDINGS TODAY SHOWED AN ENVIRONMENT
HOSTILE TO PRECIP MAINTENANCE. THEREFORE DESPITE SOME FORCING FROM
A CONVECTIVELY INDUCED SHORTWAVE OVERHEAD...LIGHT RADAR ECHOES
OVER AREA ARE LIKELY VIRGA AND HAVE PULLED MENTION OF SPRINKLES
THE REST OF TODAY. CONVERGENT AXIS IN FRONTAL ZONE OF DISSIPATING
WEAK LOW OVER SOUTHERN LAKE MICHIGAN DID INITIATIVE SOME
CONVECTION OVER NORTH CENTRAL INDIANA...AND WOULD EXPECT FURTHER
DEVELOPMENT TO REMAIN EAST OF THE CWA. OVERALL...WITH PLENTY OF
CLOUD COVER WELL BACK TO THE WEST...INCLUDING PATCHY LOWER CLOUDS
IN SPOTS...JUST EXPECTING A MOSTLY CLOUDY REST OF THE DAY INTO
TONIGHT. VERY WEAK GRADIENT WILL YIELD LIGHT/CALM WINDS OVERNIGHT
AND LOW DEWPOINT SPREADS COULD SET STAGE FOR SOME PATCHY FOG OR
HAZE. LOW TEMPS WILL BE IN THE MID 60S TO AROUND 70.
FOCUS LATE TONIGHT INTO SUNDAY WILL BE ON MCS EXPECTED TO DEVELOP
OVER EASTERN NEBRASKA AND WESTERN IOWA THIS EVENING. MCS IS LIKELY
TO RIDE ALONG INSTABILITY AXIS THAT WILL MAINLY BE SOUTH OF THE
CWA OFF TO THE EAST-SOUTHEAST INTO SUNDAY MORNING. CONSENSUS OF
MODEL GUIDANCE IS TO KEEP INSTABILITY MINIMAL AT BEST FOR MUCH OF
THE CWA...LIMITING THUNDER POTENTIAL. CANNOT COMPLETELY RULE OUT
THUNDER GIVEN MODEST LOW LEVEL JET/WAA REGIME. RECENT HI-RES
CAMS...INCLUDING 4KM NAM AND EXPERIMENTAL HRRR DEPICT A REASONABLE
SCENARIO IN WHICH STRATIFORM NORTH OF MCS OVERSPREADS MUCH OF CWA
FROM WESTNORTHWEST TO EAST SOUTHEAST AFTER MIDNIGHT THROUGH MID
SUNDAY MORNING/BY WHICH TIME IT WILL PROBABLY BE DECAYING. HAVE
FOCUSED CATEGORICAL POPS INTO SOUTHERN CWA WHERE CONFIDENCE IS
HIGHEST IN WIDESPREAD COVERAGE. ITS POSSIBLE FAR NORTHEAST CWA
COULD SEE LITTLE OR NO RAIN. BEST CHANCE FOR HEAVY DOWNPOURS LOOKS
TO BE IN FAR SOUTHERN CWA WHERE MORE ROBUST CONVECTION COULD PASS
THROUGH...THOUGH ANY THREAT FOR STRONG TO SEVERE STORMS SHOULD
STAY SOUTHWEST OF THE CWA GIVEN ANTICIPATED DECAYING TREND OF MCS.
A GOOD DEAL OF UNCERTAINTY THE REMAINDER OF SUNDAY REGARDING
CONVECTIVE TRENDS. A SURFACE LOW LOOKS TO EVOLVE EASTWARD INTO THE
MID MISSISSIPPI VALLEY BY LATER IN THE DAY...WITH RETURN FLOW AND
WEST-SOUTHWEST LLJ ALSO DEVELOPING. LINGERING CLOUD COVER WILL
LIMIT DESTABILIZATION AND THUNDER POTENTIAL...ESPECIALLY FARTHER
NORTH UNTIL LATE DAY. ANOTHER SHORTWAVE WILL APPROACH FROM WEST IN
LATE AFTERNOON AND THERE SHOULD BE ENOUGH 925-850 MB MOISTURE
CONVERGENCE TO SUPPORT CHANCE POPS NORTH OF I-80 AND LIKELIKES
SOUTH OF I-80. MODERATE WESTERLY MIDLEVEL FLOW WILL RESULT IN
30-40 KT OF WEST-NORTHWEST 0-6KM SHEAR. THIS WILL SUPPORT SOME
THREAT FOR STRONG TO SEVERE STORMS WELL SOUTH OF I-80 CLOSER TO
EXPECTED TRACK OF SFC LOW AND WHERE TEMPS AROUND 80 AND LOW-MID
70S DEWPOINTS COULD BRING SLIGHTLY BETTER INSTABILITY. MAIN THREAT
WOULD BE GUSTY TO DAMAGING WINDS...AS HAIL APPEARS UNLIKELY WITH
700-500 MB LAPSE RATES LESS THAN 6 CELSIUS PER KM. SUNDAY OVERALL
WILL BE A CLOUDY AND MUGGY DAY...WITH HIGHS IN THE MID 70S TO
AROUND 80.
RC
&&
.LONG TERM...
320 PM CDT
SUNDAY NIGHT THROUGH SATURDAY...
THE BEST CHANCE FOR PRECIP IN THE EXTENDED WILL BE SUNDAY EVENING
THROUGH MONDAY AFTERNOON...WITH VERY SLIGHT CHANCES OF PRECIP LATE
NEXT WEEK.
A COMPLEX OF STORMS WILL BE DIMINISHING OVER THE REGION SUNDAY
EVENING AND NIGHT. THE UPPER LEVEL VORTICITY PATTERN IS VERY CHAOTIC
WITH GUIDANCE INDICATING THE MAIN MCV WILL BE OVER CENTRAL IL AND
VORT STREAMERS ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE OVER
WISCONSIN. WITH SUCH A MESSY PATTERN...DECIDED TO ONLY MAKE MINOR
ADJUSTMENTS TO PRECIP CHANCES SUNDAY NIGHT. HAVE A CHANCE OF
THUNDERSTORMS ALONG AND EAST OF I-39 WITH BETTER CHANCES EAST OF I-
55. COULD SEE A FEW STRONG TO SEVERE STORMS SOUTH OF I-80 BUT
CONDITIONS WILL BE WEAKENING AS THE EVENING PROGRESSES.
OVERALL...HAVE LOW CONFIDENCE IN EXACTLY HOW SUNDAY NIGHT WILL PLAY
OUT DUE TO SO MANY MESOSCALE FEATURES AND WHETHER OR NOT THE
ATMOSPHERE WILL BE ABLE TO RECOVER FROM SUNDAY MORNING/S STORMS.
A SHORT WAVE MOVING WITH THE UPPER LEVEL TROUGH ROTATES THROUGH
MONDAY WITH A DECENT VORTICITY STREAMER. WENT WITH A CHANCE OF
SHOWERS AND STORMS MAINLY NORTH OF I-80 MONDAY. THINKING THE NAM IS
ONCE AGAIN TOO MOIST LEADING TO TOO MUCH CONVECTIVE DEVELOPMENT.
THINKING SHOWERS AND STORMS WILL DRIFT SOUTH OF THE IL/WI STATE LINE
MONDAY AFTERNOON AND THEN WEAKEN AS THEY CONTINUE TO SHIFT SOUTH
MONDAY EVENING. MONDAY EVENING MAY END UP BEING DRY...BUT DID NOT
HAVE ENOUGH CONFIDENCE IN A DRY FORECAST SO KEPT A SLIGHT CHANCE OF
SHOWERS AND STORMS ALONG AND SOUTH OF I-80 MONDAY EVENING.
THE UPPER LEVEL TROUGH AXIS SHIFTS EAST THROUGH WISCONSIN WITH
COOLER UPPER LEVEL AIR SINKING SOUTH THROUGH THE REGION. HIGH
PRESSURE THEN BUILDS IN FOR WEDNESDAY AND THURSDAY LEADING TO DRY
CONDITIONS THROUGH THURSDAY. HIGH TEMPS TUESDAY WILL BE AROUND
80...THEN IN THE UPPER 70S WEDNESDAY. LAKE BREEZES BOTH DAYS WILL
KEEP LOCATIONS ALONG THE LAKE IN THE MID 70S. TEMPS REBOUND INTO
THE LOW TO MID 80S THURSDAY WITH NO LAKE COOLING.
THE NEXT LOW PRESSURE SYSTEM MOVES OVER JAMES BAY THURSDAY EVENING
AND PUSHES THE HIGH PRESSURE SOUTH OVER THE OHIO VALLEY. THE LOWS
COLD FRONT SINKS SOUTH OVER FAR NORTHERN IL FRIDAY AFTERNOON SO HAVE
A SLIGHT CHANCE TO CHANCE OF SHOWERS AND STORMS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE APPROACHING ORD AT 22Z.
* MVFR CEILINGS IN FOG AND RAIN SUNDAY MORNING AND DAYTIME.
* ISOLATED THUNDERSTORM CHANCE.
MM
//DISCUSSION...UPDATED 18Z...
SURFACE ANALYSIS INDICATES A WEAK LOW AND ASSOCIATED
TROUGH/BOUNDARY WITHIN THE DOMINANT HIGH OVER MUCH OF THE GREAT
LAKES. THIS HAS CAUSED THE WIND FIELD TO BECOME QUITE CONVOLUTED
WITH A MESO-CYCLONE CENTERED NORTH OF CHICAGO. RADAR IMAGERY DOES
INDICATE A LAKE BREEZE PROGGED TO REACH ORD/MDW AROUND 19-20Z.
TIMING MAY NEED ADJUSTING IF THE BOUNDARY STALLS BETWEEN THE
SHORE AND ORD...BUT AT THIS PACE WINDS SHOULD BE NORTHEAST AT 20Z.
A MORE SUBSTANTIAL LOW WILL APPROACH INTO SUNDAY WITH
MOISTURE CONTENT ON THE RISE THROUGH TONIGHT. FORECAST SOUNDINGS
INDICATE A LOW LEVEL INVERSION FROM 09-13Z. SURFACE MOISTURE IS
ADEQUATE ENOUGH TO ALLOW FOR SOME FOG...FOLLOWED BY THE ARRIVAL OF
RAIN SUNDAY MORNING. RAIN/SHOWERY CONDITIONS ARE EXPECTED TO
PERSIST MUCH OF THE DAY AND THERE WILL MAY ALSO BE A PERIOD OF
THUNDER AS WELL. TIMING OF THUNDER IS UNDER QUESTION AS THE
INITIAL ARRIVAL OF THE LOW MAY SUPPORT A BRIEF UPTICK IN LAPSE
RATES...OTHERWISE WILL HAVE TO WAIT FOR ADDL SFC HEATING AFTER 20Z
SUNDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM IN WINDS..LOW IN ORD LAKE BREEZE.
* MEDIUM IN MVFR FOG...MEDIUM HIGH IN RAIN.
* LOW IN THUNDER AND TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
320 PM CDT
HIGH PRESSURE STRETCHES FROM QUEBEC THROUGH THE OHIO VALLEY WHILE
LOW PRESSURE IS OVER MANITOBA. BOTH SYSTEMS WILL SHIFT EAST WITH THE
LOW REACHING JAMES BAY BY MONDAY MORNING. AS SUCH LIGHT NORTHEAST
WINDS BECOME SOUTH TO SOUTHEAST SUNDAY. THE TROUGH ASSOCIATED WITH
THE LOWS COLD/STATIONARY FRONT SHIFTS THROUGH LATE SUNDAY NIGHT INTO
MONDAY MORNING WITH WINDS BECOMING NORTH BEHIND IT. A WEAK CLOSED
LOW FORMS OVER THE EASTERN GREAT LAKES MONDAY EVENING AND DEEPENS AS
IT SHIFTS NORTHEAST. AT THE SAME TIME HIGH PRESSURE WILL BE PUSHING
EAST OVER THE WESTERN GREAT LAKES. THIS WILL LEAD TO NORTH WINDS
INCREASING TO 10 TO 20 KT MONDAY NIGHT THROUGH TUESDAY NIGHT. WINDS
WEAKEN WEDNESDAY WITH THE HIGH OVERHEAD...AND THEN BACK TO SOUTHWEST
AS THE HIGH IS PUSHED SOUTH BY THE NEXT LOW OVER JAMES BAY THURSDAY.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
309 PM CDT SAT AUG 8 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 307 PM CDT SAT AUG 8 2015
REMNANTS OF AN MCS OVER EASTERN MO AT MID AFTERNOON HAS ISOLATED
LIGHT SHOWERS AND SPRINKLES OVER CENTRAL IL WEST OF I-57 AND
DRIFTING EASTWARD. MOST OF OUR AREA SHOULD STAY DRY INTO THIS
EVENING WITH JUST A FEW LIGHT SHOWERS OR SPRINKLES POSSIBLE OVER
PARTS OF CENTRAL IL WITH PARTLY TO MOSTLY CLOUDY SKIES. ANOTHER MCS
WILL LIKELY DEVELOP OVER WESTERN IA AND FAR EASTERN NEBRASKA ON NOSE
OF AN 35-45 KT 850 MB SW JET THIS EVENING AND TRACK ESE ACROSS IA
AND EVENTUALLY INTO CENTRAL IL DURING OVERNIGHT. 4KM WRF AND TAIL
END OF HRRR MODEL SHOWS MOST OF CONVECTION SREADING EAST TOWARD IL
RIVER VALLEY BETWEEN 08Z-10Z AND APPROACHING I-57 AROUND 12Z.
CONTINUED MENTION OF HEAVY RAIN FROM PEORIA NW LATE TONIGHT AFTER
09Z/4 AM WITH QPF OVERNIGHT HALF TO THREE QUARTER INCHES AND LOCALLY
1 INCH FROM GALESBURG AND MACOMB WEST. SPC HAS MARGINAL RISK OF
SEVERE STORMS OVERNIGHT WEST OF PEORIA AND SPRINGFIELD FOR GUSTY
WINDS AND SMALL HAIL WHILE SLIGHT RISK OF SEVERE IS FROM QUINCY
WESTWARD ACROSS NORTHERN MO AND SOUTHERN IA. SE IL/WABASH RIVER
VALLEY WILL LIKELY STAY DRY MOST OF TONIGHT AND PATCHY FOG COULD
FORM OVERNIGHT IN FAR SOUTHEAST IL WHERE LESS CLOUD COVER. MUGGY
LOWS TONIGHT IN THE UPPER 60S AND LOWER 70S WHICH IS CLOSE TO
CURRENT DEWPOINTS AND LIGHT WINDS TONIGHT.
&&
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 307 PM CDT SAT AUG 8 2015
A THUNDERSTORM COMPLEX/MCS IS EXPECTED TO TRACK EASTWARD ACROSS
ILLINOIS SUNDAY MORNING...LIKELY WEAKENING THROUGH THE DAYTIME.
ALTHOUGH STILL WAITING FOR THIS SYSTEM TO DEVELOP AROUND EASTERN
NB/WESTERN IA THIS EVENING...RECENT TRENDS HAVE BEEN FOR SIMILAR
SYSTEMS TO DEVELOP SLIGHTLY SOUTHWARD FROM EARLY FORECASTS...AND
LATEST MODEL RUNS HINT AT THIS AS WELL. THEREFORE...HAVE TRENDED
HEAVIER PRECIPITATION AMOUNTS A BIT SOUTHWARD FROM PREVIOUS PACKAGE
WITH AMOUNTS FROM AROUND 1 TO 1.5 INCHES POSSIBLE NORTH OF I-72 AND
WEST OF I-55 BY NOON SUNDAY...WITH THE HIGHER END OF THAT RANGE MORE
LIKELY TOWARD THE GALESBURG AREA. LOWER AMOUNTS AND LOWER
PRECIPITATION CHANCES EXPECTED WITH THIS SYSTEM SOUTH OF I-72 TOWARD
THE EFFINGHAM/I-70 AREA.
A BIT OF A BREAK IN THUNDERSTORM ACTIVITY LIKELY FOR MIDDAY SUNDAY
AS THE OVERNIGHT SYSTEM MOVES OFF TO THE EAST. EXACT TIMING...CLOUD
COVER LEFT BEHIND...AND BOUNDARIES LEFT BEHIND FROM THE OVERNIGHT
SYSTEM WILL IMPACT THE POSSIBILITY OF ANOTHER THUNDERSTORM COMPLEX
DEVELOPING SUNDAY NIGHT. CURRENT MODEL CONSENSUS FORMS THIS FARTHER
SOUTH TOWARD THE OHIO VALLEY AREA AND HAVE TRENDED PRECIP CHANCES
TOWARD THAT AREA FOR SUNDAY NIGHT INTO MONDAY.
AFTER THAT...UPPER RIDGING WILL BUILD OVER THE CENTRAL CONUS AND
DEEP TROUGHING WILL DEVELOP DOWNSTREAM ACROSS THE GREAT LAKES/OHIO
RIVER VALLEY. AS A RESULT...MUCH OF THE EXTENDED BEYOND MONDAY IS
COOL/DRY. GFS/ECMWF SHOW THE NEXT FRONTAL BOUNDARY DROPPING INTO
THE GREAT LAKES AREA JUST NORTH OF CENTRAL IL FRIDAY. HOWEVER...BOTH
LARGELY DISSIPATE THE FEATURE AND WILL MENTION JUST A SLIGHT CHANCE
POP ACROSS THE NORTHERN HALF OF THE CWA ON FRIDAY UNTIL BETTER MODEL
CONSISTENCY IS ACHIEVED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1259 PM CDT SAT AUG 8 2015
WEAKENING MCS OVER CENTRAL MO WITH SCATTERED RAIN SHOWERS AS FAR
EAST AS THE IL RIVER TO CONTINUE TO WEAKEN IS IT PUSHES EAST
ACROSS CENTRAL IL THIS AFTERNOON. HAVE VCSH THIS AFTERNOON ALONG
WITH SCATTERED CUMULUS CLOUDS AND BROKEN MID/HIGH CLOUDS.
MEANWHILE A WEAK SURFACE TROF MOVING SE TOWARD DEC AND CMI EARLY
THIS AFTERNOON COULD TRIGGER VERY ISOLATED CONVECTION THIS
AFTERNOON ALONG WITH BROKEN MVFR CEILINGS 2-3K FT. ALSO SEEING A
WIND SHIFT FROM SW DIRECTION TO WNW GENERALLY LESS THAN 10 KTS.
ANOTHER MCS EXPECTED TO DEVELOP OVER IA THIS EVENING AND SPREAD SE
INTO CENTRAL IL OVERNIGHT INTO SUNDAY MORNING. HAVE MVFR VSBYS
3-5 MILES AND CEILINGS FROM 2-4K FT POSSIBLE WITH CONVECTION AT
PIA AT 08Z...NEAR I-55 AT BMI AND SPI BY 10Z AND CMI BY 12Z.
CONVECTION MORE LIKELY ALONG I-74 LATER TONIGHT INTO SUNDAY
MORNING AND EXPECTED TO DIMINISH LATE SUNDAY MORNING OR BY MIDDAY
SUNDAY. SSE WINDS OF 5-10 KTS EXPECTED BY LATER SUNDAY MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...ONTON
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
251 PM CDT SAT AUG 8 2015
.UPDATE...1154 AM CDT
12Z RAOBS AND RECENT AMDAR SOUNDINGS SHOW A SIGNIFICANT WARM NOSE
ABOVE 850 MB...AS WELL AS PLENTY OF DRY AIR BETWEEN 850 AND 700
MB. LIGHT STRATIFORM PRECIP REMNANTS ON NORTHERN EDGE OF EARLY
MORNING MCS OVER IOWA HAS BEEN ERODING WITH EASTWARD EXTENT AS IT
ENCOUNTERS HOSTILE ENVIRONMENT FOR PRECIP. SOME SCATTERED
SPRINKLES COULD GET INTO PORTIONS OF WEST AND SOUTHWEST CWA THIS
AFTERNOON AS THERE IS SOME FORCING FROM CONVECTIVELY INDUCED
SHORTWAVE. HOWEVER WOULD NOT EXPECT ANY ORGANIZED RAIN TO SURVIVE
INTO THE CWA. THE WARM NOSE ALOFT ALSO THROWS INTO DOUBT ANY
ISOLATED CONVECTION BEING ABLE TO INITIATE IN SOUTHEAST CWA THIS
AFTERNOON IN CONVERGENT AXIS OF DISSIPATING SURFACE LOW AND LAKE
BREEZE EXPECTED TO MOVE INLAND. CONVECTIVE TEMPS IN MID 90S MAKE
IT UNLIKELY THAT CAPE IS AS HIGH AS SHOWN ON SPC MESOANALYSIS...AS
RAP INITIALIZATION HAS A HIGH BIAS WITH TEMPS. SOME CUMULUS HAS
POPPED UP...BUT NOT APPEARING TOO AGITATED UNDER CIRRUS SHIELD.
HAVE KEPT JUST SLIGHT CHANCE POPS IN SOUTHEAST 1/3 OF CWA THIS
AFTERNOON.
OTHERWISE...TEMPERATURES ARE EXHIBITING A NORTH TO
SOUTH GRADIENT...DRIVEN BY LOWER STRATUS IN NORTHERN CWA KEEPING
TEMPS IN 70S WHILE LOWER-MID 80S IN SOUTHEAST 1/2 OF CWA GIVEN
THAT FILTERED SUN STILL MAKING IT THROUGH ADVANCING CIRRUS SHIELD
AND CUMULUS DEVELOPMENT. LAKE BREEZE WILL KEEP SHORE AREAS IN 70S
THIS AFTERNOON.
RC
&&
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE APPROACHING ORD AT 22Z.
* MVFR CEILINGS IN FOG AND RAIN SUNDAY MORNING AND DAYTIME.
* ISOLATED THUNDERSTORM CHANCE.
MM
//DISCUSSION...UPDATED 18Z...
SURFACE ANALYSIS INDICATES A WEAK LOW AND ASSOCIATED
TROUGH/BOUNDARY WITHIN THE DOMINANT HIGH OVER MUCH OF THE GREAT
LAKES. THIS HAS CAUSED THE WIND FIELD TO BECOME QUITE CONVOLUTED
WITH A MESO-CYCLONE CENTERED NORTH OF CHICAGO. RADAR IMAGERY DOES
INDICATE A LAKE BREEZE PROGGED TO REACH ORD/MDW AROUND 19-20Z.
TIMING MAY NEED ADJUSTING IF THE BOUNDARY STALLS BETWEEN THE
SHORE AND ORD...BUT AT THIS PACE WINDS SHOULD BE NORTHEAST AT 20Z.
A MORE SUBSTANTIAL LOW WILL APPROACH INTO SUNDAY WITH
MOISTURE CONTENT ON THE RISE THROUGH TONIGHT. FORECAST SOUNDINGS
INDICATE A LOW LEVEL INVERSION FROM 09-13Z. SURFACE MOISTURE IS
ADEQUATE ENOUGH TO ALLOW FOR SOME FOG...FOLLOWED BY THE ARRIVAL OF
RAIN SUNDAY MORNING. RAIN/SHOWERY CONDITIONS ARE EXPECTED TO
PERSIST MUCH OF THE DAY AND THERE WILL MAY ALSO BE A PERIOD OF
THUNDER AS WELL. TIMING OF THUNDER IS UNDER QUESTION AS THE
INITIAL ARRIVAL OF THE LOW MAY SUPPORT A BRIEF UPTICK IN LAPSE
RATES...OTHERWISE WILL HAVE TO WAIT FOR ADDL SFC HEATING AFTER 20Z
SUNDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM IN WINDS..LOW IN ORD LAKE BREEZE.
* MEDIUM IN MVFR FOG...MEDIUM HIGH IN RAIN.
* LOW IN THUNDER AND TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
100 PM CDT SAT AUG 8 2015
.UPDATE...
1154 AM CDT
12Z RAOBS AND RECENT AMDAR SOUNDINGS SHOW A SIGNIFICANT WARM NOSE
ABOVE 850 MB...AS WELL AS PLENTY OF DRY AIR BETWEEN 850 AND 700
MB. LIGHT STRATIFORM PRECIP REMNANTS ON NORTHERN EDGE OF EARLY
MORNING MCS OVER IOWA HAS BEEN ERODING WITH EASTWARD EXTENT AS IT
ENCOUNTERS HOSTILE ENVIRONMENT FOR PRECIP. SOME SCATTERED
SPRINKLES COULD GET INTO PORTIONS OF WEST AND SOUTHWEST CWA THIS
AFTERNOON AS THERE IS SOME FORCING FROM CONVECTIVELY INDUCED
SHORTWAVE. HOWEVER WOULD NOT EXPECT ANY ORGANIZED RAIN TO SURVIVE
INTO THE CWA. THE WARM NOSE ALOFT ALSO THROWS INTO DOUBT ANY
ISOLATED CONVECTION BEING ABLE TO INITIATE IN SOUTHEAST CWA THIS
AFTERNOON IN CONVERGENT AXIS OF DISSIPATING SURFACE LOW AND LAKE
BREEZE EXPECTED TO MOVE INLAND. CONVECTIVE TEMPS IN MID 90S MAKE
IT UNLIKELY THAT CAPE IS AS HIGH AS SHOWN ON SPC MESOANALYSIS...AS
RAP INITIALIZATION HAS A HIGH BIAS WITH TEMPS. SOME CUMULUS HAS
POPPED UP...BUT NOT APPEARING TOO AGITATED UNDER CIRRUS SHIELD.
HAVE KEPT JUST SLIGHT CHANCE POPS IN SOUTHEAST 1/3 OF CWA THIS
AFTERNOON.
OTHERWISE...TEMPERATURES ARE EXHIBITING A NORTH TO
SOUTH GRADIENT...DRIVEN BY LOWER STRATUS IN NORTHERN CWA KEEPING
TEMPS IN 70S WHILE LOWER-MID 80S IN SOUTHEAST 1/2 OF CWA GIVEN
THAT FILTERED SUN STILL MAKING IT THROUGH ADVANCING CIRRUS SHIELD
AND CUMULUS DEVELOPMENT. LAKE BREEZE WILL KEEP SHORE AREAS IN 70S
THIS AFTERNOON.
RC
&&
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE APPROACHING AT 20Z.
* MVFR CEILINGS IN FOG AND RAIN SUNDAY MORNING AND DAYTIME.
* ISOLATED THUNDERSTORM CHANCE.
MM
//DISCUSSION...UPDATED 18Z...
SURFACE ANALYSIS INDICATES A WEAK LOW AND ASSOCIATED
TROUGH/BOUNDARY WITHIN THE DOMINANT HIGH OVER MUCH OF THE GREAT
LAKES. THIS HAS CAUSED THE WIND FIELD TO BECOME QUITE CONVOLUTED
WITH A MESO-CYCLONE CENTERED NORTH OF CHICAGO. RADAR IMAGERY DOES
INDICATE A LAKE BREEZE PROGGED TO REACH ORD/MDW AROUND 19-20Z.
TIMING MAY NEED ADJUSTING IF THE BOUNDARY STALLS BETWEEN THE
SHORE AND ORD...BUT AT THIS PACE WINDS SHOULD BE NORTHEAST AT 20Z.
A MORE SUBSTANTIAL LOW WILL APPROACH INTO SUNDAY WITH
MOISTURE CONTENT ON THE RISE THROUGH TONIGHT. FORECAST SOUNDINGS
INDICATE A LOW LEVEL INVERSION FROM 09-13Z. SURFACE MOISTURE IS
ADEQUATE ENOUGH TO ALLOW FOR SOME FOG...FOLLOWED BY THE ARRIVAL OF
RAIN SUNDAY MORNING. RAIN/SHOWERY CONDITIONS ARE EXPECTED TO
PERSIST MUCH OF THE DAY AND THERE WILL MAY ALSO BE A PERIOD OF
THUNDER AS WELL. TIMING OF THUNDER IS UNDER QUESTION AS THE
INITIAL ARRIVAL OF THE LOW MAY SUPPORT A BRIEF UPTICK IN LAPSE
RATES...OTHERWISE WILL HAVE TO WAIT FOR ADDL SFC HEATING AFTER 20Z
SUNDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH IN WINDS AND LAKE BREEZE.
* MEDIUM IN MVFR FOG...MEDIUM HIGH IN RAIN.
* LOW IN THUNDER AND TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1154 AM CDT SAT AUG 8 2015
.UPDATE...
1154 AM CDT
12Z RAOBS AND RECENT AMDAR SOUNDINGS SHOW A SIGNIFICANT WARM NOSE
ABOVE 850 MB...AS WELL AS PLENTY OF DRY AIR BETWEEN 850 AND 700
MB. LIGHT STRATIFORM PRECIP REMNANTS ON NORTHERN EGDE OF EARLY
MORNING MCS OVER IOWA HAS BEEN ERODING WITH EASTWARD EXTENT AS IT
ENCOUNTERS HOSTILE ENVIRONMENT FOR PRECIP. SOME SCATTERED
SPRINKLES COULD GET INTO PORTIONS OF WEST AND SOUTHWEST CWA THIS
AFTERNOON AS THERE IS SOME FORCING FROM CONVECTIVELY INDUCED
SHORTWAVE. HOWEVER WOULD NOT EXPECT ANY ORGANIZED RAIN TO SURVIVE
INTO THE CWA. THE WARM NOSE ALOFT ALSO THROWS INTO DOUBT ANY
ISOLATED CONVECTION BEING ABLE TO INITIATE IN SOUTHEAST CWA THIS
AFTERNOON IN CONVERGENT AXIS OF DISSIPATING SURFACE LOW AND LAKE
BREEZE EXPECTED TO MOVE INLAND. CONVECTIVE TEMPS IN MID 90S MAKE
IT UNLIKELY THAT CAPE IS AS HIGH AS SHOWN ON SPC MESOANALYSIS...AS
RAP INITIALIZATION HAS A HIGH BIAS WITH TEMPS. SOME CUMULUS HAS
POPPED UP...BUT NOT APPEARING TOO AGITATED UNDER CIRRUS SHIELD.
HAVE KEPT JUST SLIGHT CHANCE POPS IN SOUTHEAST 1/3 OF CWA THIS
AFTERNOON.
OTHERWISE...TEMPERATURES ARE EXHIBITING A NORTH TO
SOUTH GRADIENT...DRIVEN BY LOWER STRATUS IN NORTHERN CWA KEEPING
TEMPS IN 70S WHILE LOWER-MID 80S IN SOUTHEAST 1/2 OF CWA GIVEN
THAT FILTERED SUN STILL MAKING IT THROUGH ADVANCING CIRRUS SHIELD
AND CUMULUS DEVELOPMENT. LAKE BREEZE WILL KEEP SHORE AREAS IN 70S
THIS AFTERNOON.
RC
&&
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE/NORTHEAST WINDS APPROACHING THIS AFTERNOON
* MVFR CIGS/VIS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING.
* RAIN AND ISOLATED THUNDER SUNDAY MORNING.
MM
//DISCUSSION...UPDATED 12Z...
VFR AND DRY CONDITIONS IN PLACE THIS MORNING AS WEAK SURFACE LOW
CONTINUES TO WEAKEN. SOME LOWER STRATUS HAD BRIEFLY DEVELOPED
EARLIER THIS MORNING BUT HAS ALREADY BEGUN TO ERODE AND WILL
CONTINUE TO DO SO THIS MORNING. HAVE MAINTAINED DRY CONDITIONS
THROUGH THIS AFTERNOON...BUT WITH AN ISOLATED SPRINKLE STILL
BRIEFLY POSSIBLE. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON. HIGHER CHANCES FOR PRECIP...REDUCED VIS AND LOWER
CEILINGS WILL ARRIVE LATE TONIGHT INTO EARLY SUNDAY MORNING WITH
THE APPROACH OF ANOTHER SYSTEM. SOME TIMING DIFFERENCES WITH THE
ONSET OF PRECIP WITH THE EXACT TIMING IN THE TAF LIKELY BEING
CHANGED BUT WITH ITS ARRIVAL...IT WILL LIKELY PERSIST THROUGH THE
REMAINING FORECAST PERIOD. HAVE LEFT OUT ANY MENTION OF THUNDER AT
THIS TIME WITH THE HIGHEST INSTABILITY TO THE SOUTH OF THE
TERMINALS...BUT WILL NEED TO MONITOR FOR POSSIBLE BETTER
DEVELOPMENT WHICH COULD LEAD TO AT LEAST ISOLATED THUNDER DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON TIMING.
* HIGH WITH MVFR CIGS/VIS LATE TONIGHT INTO SUNDAY
MORNING...MEDIUM LOW WITH TIMING.
* HIGH WITH RAIN SUNDAY MORNING...MEDIUM ON TIMING...LOW WITH
THUNDER CHANCES.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1107 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE/NORTHEAST WINDS APPROACHING THIS AFTERNOON
* MVFR CIGS/VIS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING.
* RAIN AND ISOLATED THUNDER SUNDAY MORNING.
MM
//DISCUSSION...UPDATED 12Z...
VFR AND DRY CONDITIONS IN PLACE THIS MORNING AS WEAK SURFACE LOW
CONTINUES TO WEAKEN. SOME LOWER STRATUS HAD BRIEFLY DEVELOPED
EARLIER THIS MORNING BUT HAS ALREADY BEGUN TO ERODE AND WILL
CONTINUE TO DO SO THIS MORNING. HAVE MAINTAINED DRY CONDITIONS
THROUGH THIS AFTERNOON...BUT WITH AN ISOLATED SPRINKLE STILL
BRIEFLY POSSIBLE. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON. HIGHER CHANCES FOR PRECIP...REDUCED VIS AND LOWER
CEILINGS WILL ARRIVE LATE TONIGHT INTO EARLY SUNDAY MORNING WITH
THE APPROACH OF ANOTHER SYSTEM. SOME TIMING DIFFERENCES WITH THE
ONSET OF PRECIP WITH THE EXACT TIMING IN THE TAF LIKELY BEING
CHANGED BUT WITH ITS ARRIVAL...IT WILL LIKELY PERSIST THROUGH THE
REMAINING FORECAST PERIOD. HAVE LEFT OUT ANY MENTION OF THUNDER AT
THIS TIME WITH THE HIGHEST INSTABILITY TO THE SOUTH OF THE
TERMINALS...BUT WILL NEED TO MONITOR FOR POSSIBLE BETTER
DEVELOPMENT WHICH COULD LEAD TO AT LEAST ISOLATED THUNDER DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON TIMING.
* HIGH WITH MVFR CIGS/VIS LATE TONIGHT INTO SUNDAY
MORNING...MEDIUM LOW WITH TIMING.
* HIGH WITH RAIN SUNDAY MORNING...MEDIUM ON TIMING...LOW WITH
THUNDER CHANCES.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
451 PM MDT SAT AUG 8 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 229 PM MDT SAT AUG 8 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS 595 DM RIDGE
ACROSS SOUTHERN PLAINS WITH PLUME OF PACIFIC MOISTURE STREAMING INTO
THE CENTRAL ROCKIES AND ACROSS OUR CWA. SEVERAL WEAK
RIPPLES/SHORTWAVE TROUGHS WITHIN THE H5/H7 SW FLOW ARE UPSTREAM OF
THE REGION WITH SOME ENHANCEMENT ACROSS THE HIGHER TERRAIN IN THE
CENTRAL AND SOUTHERN ROCKIES. AT THE SURFACE LOW PRESSURE EXTENDS
ACROSS EASTERN COLORADO AND SOUTHWEST KANSAS. STATIONARY/WARM
FRONT IS CURRENTLY JUST OVER THE SOUTHEAST PORTIONS OF OUR CWA.
THIS AFTERNOON-TONIGHT...BAROCLINIC ZONE EXTENDING ACROSS SE CWA AND
ACROSS EASTERN COLORADO WILL ACT AS FOCUS FOR INITIATION NEAR OUR CWA
AS HEIGHT FALLS AND INCREASING ISENTROPIC ASCENT MOVES SOUTH OF
INTERSTATE 70. STRONGEST PRECIP SIGNAL IS ALONG STATIONARY FRONT IN
THE SOUTH...ESPECIALLY BY ARW/HRRR. RAP ANALYSIS SHOWS CAPE VALUES
ALREADY AROUND 4000 J/KG IN THE SOUTHEAST...WITH EFFECTIVE BULK
SHEER VALUES IN EXCESS OF 40KT. WHILE THERE IS SOME LOW LEVEL
VEERING...OVERALL SEVERE INDICES FAVOR DAMAGING WINDS AND LARGE
HAIL WITH ON A SMALL THREAT FOR TORNADOS WITHIN PROXIMITY TO MAIN
TROUGH AXIS. VERY MOIST AIR MASS...THE POSSIBILITY FOR BACKBUILDING
ALONG FRONTAL ZONE...AND STORM MOTIONS GENERALLY LESS THAN 20KT WILL
TEND TO SUPPORT POTENTIAL FOR LOCALIZED FLASH FLOODING. HI RES
GUIDANCE IS INDICATING POTENTIAL FOR THUNDERSTORMS TO FORM INTO ONE
OR SEVERAL SMALL MCS CLUSTERS ACROSS THE SOUTHERN PART OF THE
FORECAST AREA. EARLIER GUIDANCE WAS SHOWING THIS SPREADING AS FAR
NORTH AS THE I-70 CORRIDOR.
WITH LINGERING WAA ACROSS THE SE CWA...ALONG WITH SEVERAL MORE
WEAK SHORTWAVES PASSING THROUGH THE REGION...SE PORTIONS OF THE
FORECAST AREA COULD CONTINUE TO SEE SHOWER/THUNDERSTORM ACTIVITY
LINGER THROUGH SUNDAY MORNING. TREND WILL BE FOR DECREASING
INSTABILITY...SO SEVERE THREAT SHOULD BE LIMITED TO JUST THE
EVENING HOURS. VERY MOIST AIR MASS AND LIGHT WINDS WILL ALSO TEND
TO SUPPORT POTENTIAL FOR FOG/STRATUS TO REDEVELOP BY SUNRISE.
SUNDAY...WITH WEAK FORCING AND LINGERING FRONT IN OUR SE...THERE
WILL BE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THROUGH MIDDAY. NAM
SHOWS INCREASING FORCING BY LATE MORNING EARLY AFTERNOON AS A
STRONGER TROUGH DIGS INTO THE NORTHERN PLAINS. OTHER GUIDANCE IS NOT
QUITE AS FAR SOUTH...PRIMARILY FAVORS THE SOUTHER PARTS OF OUR CWA
FOR BEST THUNDERSTORM CHANCES. THERE SHOULD BE ENOUGH
INSTABILITY/SHEER IN THE AFTERNOON TO SUPPORT AT LEAST A FEW MORE
ORGANIZED THUNDERSTORMS. LOW CONFIDENCE IN HI TEMP FORECAST AS (LIKE
TODAY) TEMPS WILL BE HIGHLY DEPENDENT ON STRATUS CLEARING AND TIMING
OF THUNDERSTORM ACTIVITY. THE AIR MASS ADVERTISED OVER THE CWA WITH
AVERAGE MIXING WOULD SUPPORT SEASONAL HIGHS IN THE UPPER 80S/LOWER
90S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM MDT SAT AUG 8 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. THIS FLOW BECOMES MORE OF A SPLIT WITH THE
TROUGHS OVER THE WESTERN AND EASTERN PORTIONS OF THE COUNTRY. OLD
CUTOFF LOW IS NOW BEING EJECTED INTO THE NORTH CENTRAL PORTION OF
THE COUNTRY. MONSOONAL MOISTURE CONTINUES TO PULLED UP INTO THE
REGION WITH EMBEDDED SHORTWAVE TROUGHS WITHIN THIS FLOW. AIR MASS
REMAINS MOIST THROUGH A SIGNIFICANT DEPTH.
AT JET LEVEL...THE GFS FOLLOWED BY THE NAM/CANADIAN WERE INITIALLY
DOING THE BEST HERE. AT MID LEVELS...MODELS WERE CLOSE WITH THE
GFS/CANADIAN/UKMET DOING SLIGHTLY BETTER. THE SREF AND NAM WERE
DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. MODELS WERE
HAVING A LITTLE TROUBLE ON THE LOW LEVEL THERMAL FIELD...THEY TENDED
TO BE TOO COOL. OVERALL WOULD HAVE TO GIVE A SLIGHT EDGE TO THE NAM
AND SREF.
SUNDAY NIGHT...LOOKS LIKE SOME WEAK BOUNDARY SAGS SOUTH ACROSS THE
AREA. MODELS ARE A LITTLE FASTER IN TAKING THE INITIAL SHORTWAVE
THROUGH ALTHOUGH THERE IS NOT VERY GOOD AGREEMENT IN THAT. MODELS
WANT TO BRING ANOTHER SHORTWAVE IN NORTHWEST FLOW DURING THE
OVERNIGHT HOURS WITH ALSO NOT A LOT OF AGREEMENT. RIGHT REAR
QUADRANT AFFECTS THE FAR NORTHERN PORTION OF THE AREA. WILL KEEP THE
SLIGHT TO LOW CHANCE POPS WITH A GRADUAL DECREASE THROUGH THE NIGHT.
LOOKS LIKE THERE WILL BE MAINLY STRATUS WITH NOT AS GOOD OF A CHANCE
OF FOG.
MONDAY/MONDAY NIGHT...RIDGE BEGINS TO BUILD INTO THE AREA WITH THE
UPPER JET BEING PUSHED FURTHER NORTH AWAY FROM THE AREA. AREA IS IN
POST FRONTAL UPSLOPE REGIME. RIDGING ALOFT LOOKS A LITTLE STRONGER
AND FURTHER WEST DURING THE DAY THAN WAS SHOWN YESTERDAY SO WILL
PUSH THE POPS FURTHER WEST. WILL HAVE SOME CLOUD COVER TO START THE
DAY WITH A COOLER AIR MASS AND UPSLOPE WINDS PRESENT THROUGH THE DAY
SO WILL DEFINITELY BE COOLER.
700 MB RIDGE MOVES A LITTLE TO THE EAST DURING THE NIGHT WITH
INCREASING LIFT COMING IN FROM THE SOUTHWEST. SO POPS SHOULD STAY
CONFINED TO THE SOUTHWEST HALF OF THE AREA WITH A GRADUAL INCREASE
THROUGH WITH STORMS NOT MOVING VERY FAST. THAT COMBINED WITH HIGH
PWS WILL SET THE STAGE MODERATE TO LOCALLY HEAVY RAINFALL.
TUESDAY...ABOVE MENTIONED SHORTWAVE RIDGE AND TROUGH CONTINUE TO
MOVE SLOWLY EAST THROUGH THE DAY. MOIST AIR MASS REMAIN IN PLACE
WITH INCREASING LIFT. IT IS POSSIBLE THAT THERE COULD BE SOME
PRECIPITATION AT THE BEGINNING AND THEN IT SHOULD GRADUALLY
INCREASE IN COVERAGE AND INTENSITY. SO HAVE THE HIGHER POPS IN THE
AFTERNOON.
EASTERLY WINDS...CLOUD COVER AND DEVELOPING PRECIPITATION SHOULD
KEEP TEMPERATURES SHOULD KEEP TEMPERATURES FROM WARMING VERY MUCH.
TUESDAY NIGHT THROUGH SATURDAY...DETERMINISTIC AND ENSEMBLE OUTPUT
IN BETTER AGREEMENT IN REGARDS TO THE EVOLUTION OF THE UPPER
PATTERN. ESSENTIALLY MODELS BUILD THE RIDGE...NOW CENTERED TO OUR
SOUTH...FURTHER TO THE WEST AND NORTH. THE DIFFERENCES INCREASE A
LITTLE TOWARD THE END OF THE PERIOD BUT NOT AS BAD AS YESTERDAY. THE
CENTER OF THE RIDGE WILL BE NEAR THE FOUR CORNERS REGION LEAVING A
WEAKER NORTHERLY FLOW OVER THE AREA.
IN THIS PATTERN WOULD ANTICIPATE THE SUBTROPICAL MOISTURE TO BE ABLE
TO ROTATE AROUND THE RIDGE WITH WEAK/SUBTLE SHORTWAVES ROTATING
AROUND IT. WPC PROGS SHOW A PERSISTENT FRONTAL BOUNDARY ALONG OR
OVER THE WESTERN PORTION OF THE AREA UNTIL THE LAST DAY WHEN A DRY
LINE/SURFACE TROUGH SETS UP IN THE SAME PLACE. WITH VERY SUBTLE
FEATURES...I CANNOT RULE OUT CHANCES FOR THUNDERSTORMS ALMOST EVERY
PERIOD.
SO ANY SLIGHT CHANCE TO LOW CHANCE POPS TO DRY CONDITIONS DO NOT
SEEM UNREASONABLE DEPENDING ON HOW THE DETAILS WORK OUT. SO ONCE
AGAIN DID NOT MAKE ANY CHANGES TO WHAT THE CRH_INIT GAVE ME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 440 PM MDT SAT AUG 8 2015
VFR CONDITIONS WILL CONTINUE THIS EVENING FOR KGLD AND KMCK. A
SHORTWAVE MOVING THROUGH THE REGION WILL BRING A SLIGHT CHANCE OF
A THUNDERSTORM TO KGLD THIS EVENING WITH A LESSER CHANCE AT KMCK.
OVERNIGHT BOUNDARY LAYER MOISTURE INCREASES TO THE POINT THAT
STRATUS AND FOG AND RESULTING MVFR CONDTIONS CAN BE EXPECTED AT
KGLD. CIGS AT KMCK SHOULD NOT BE AS LOW AS KGLD BUT WILL STILL BE
MVFR. VFR CONDITIONS RETURN BY LATE SUNDAY MORNING AND CONTINUE
THROUGH THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
309 PM MDT SAT AUG 8 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 229 PM MDT SAT AUG 8 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS 595 DM RIDGE
ACROSS SOUTHERN PLAINS WITH PLUME OF PACIFIC MOISTURE STREAMING INTO
THE CENTRAL ROCKIES AND ACROSS OUR CWA. SEVERAL WEAK
RIPPLES/SHORTWAVE TROUGHS WITHIN THE H5/H7 SW FLOW ARE UPSTREAM OF
THE REGION WITH SOME ENHANCEMENT ACROSS THE HIGHER TERRAIN IN THE
CENTRAL AND SOUTHERN ROCKIES. AT THE SURFACE LOW PRESSURE EXTENDS
ACROSS EASTERN COLORADO AND SOUTHWEST KANSAS. STATIONARY/WARM
FRONT IS CURRENTLY JUST OVER THE SOUTHEAST PORTIONS OF OUR CWA.
THIS AFTERNOON-TONIGHT...BAROCLINIC ZONE EXTENDING ACROSS SE CWA AND
ACROSS EASTERN COLORADO WILL ACT AS FOCUS FOR INITIATION NEAR OUR CWA
AS HEIGHT FALLS AND INCREASING ISENTROPIC ASCENT MOVES SOUTH OF
INTERSTATE 70. STRONGEST PRECIP SIGNAL IS ALONG STATIONARY FRONT IN
THE SOUTH...ESPECIALLY BY ARW/HRRR. RAP ANALYSIS SHOWS CAPE VALUES
ALREADY AROUND 4000 J/KG IN THE SOUTHEAST...WITH EFFECTIVE BULK
SHEER VALUES IN EXCESS OF 40KT. WHILE THERE IS SOME LOW LEVEL
VEERING...OVERALL SEVERE INDICES FAVOR DAMAGING WINDS AND LARGE
HAIL WITH ON A SMALL THREAT FOR TORNADOS WITHIN PROXIMITY TO MAIN
TROUGH AXIS. VERY MOIST AIR MASS...THE POSSIBILITY FOR BACKBUILDING
ALONG FRONTAL ZONE...AND STORM MOTIONS GENERALLY LESS THAN 20KT WILL
TEND TO SUPPORT POTENTIAL FOR LOCALIZED FLASH FLOODING. HI RES
GUIDANCE IS INDICATING POTENTIAL FOR THUNDERSTORMS TO FORM INTO ONE
OR SEVERAL SMALL MCS CLUSTERS ACROSS THE SOUTHERN PART OF THE
FORECAST AREA. EARLIER GUIDANCE WAS SHOWING THIS SPREADING AS FAR
NORTH AS THE I-70 CORRIDOR.
WITH LINGERING WAA ACROSS THE SE CWA...ALONG WITH SEVERAL MORE
WEAK SHORTWAVES PASSING THROUGH THE REGION...SE PORTIONS OF THE
FORECAST AREA COULD CONTINUE TO SEE SHOWER/THUNDERSTORM ACTIVITY
LINGER THROUGH SUNDAY MORNING. TREND WILL BE FOR DECREASING
INSTABILITY...SO SEVERE THREAT SHOULD BE LIMITED TO JUST THE
EVENING HOURS. VERY MOIST AIR MASS AND LIGHT WINDS WILL ALSO TEND
TO SUPPORT POTENTIAL FOR FOG/STRATUS TO REDEVELOP BY SUNRISE.
SUNDAY...WITH WEAK FORCING AND LINGERING FRONT IN OUR SE...THERE
WILL BE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THROUGH MIDDAY. NAM
SHOWS INCREASING FORCING BY LATE MORNING EARLY AFTERNOON AS A
STRONGER TROUGH DIGS INTO THE NORTHERN PLAINS. OTHER GUIDANCE IS NOT
QUITE AS FAR SOUTH...PRIMARILY FAVORS THE SOUTHER PARTS OF OUR CWA
FOR BEST THUNDERSTORM CHANCES. THERE SHOULD BE ENOUGH
INSTABILITY/SHEER IN THE AFTERNOON TO SUPPORT AT LEAST A FEW MORE
ORGANIZED THUNDERSTORMS. LOW CONFIDENCE IN HI TEMP FORECAST AS (LIKE
TODAY) TEMPS WILL BE HIGHLY DEPENDENT ON STRATUS CLEARING AND TIMING
OF THUNDERSTORM ACTIVITY. THE AIR MASS ADVERTISED OVER THE CWA WITH
AVERAGE MIXING WOULD SUPPORT SEASONAL HIGHS IN THE UPPER 80S/LOWER
90S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM MDT SAT AUG 8 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. THIS FLOW BECOMES MORE OF A SPLIT WITH THE
TROUGHS OVER THE WESTERN AND EASTERN PORTIONS OF THE COUNTRY. OLD
CUTOFF LOW IS NOW BEING EJECTED INTO THE NORTH CENTRAL PORTION OF
THE COUNTRY. MONSOONAL MOISTURE CONTINUES TO PULLED UP INTO THE
REGION WITH EMBEDDED SHORTWAVE TROUGHS WITHIN THIS FLOW. AIR MASS
REMAINS MOIST THROUGH A SIGNIFICANT DEPTH.
AT JET LEVEL...THE GFS FOLLOWED BY THE NAM/CANADIAN WERE INITIALLY
DOING THE BEST HERE. AT MID LEVELS...MODELS WERE CLOSE WITH THE
GFS/CANADIAN/UKMET DOING SLIGHTLY BETTER. THE SREF AND NAM WERE
DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. MODELS WERE
HAVING A LITTLE TROUBLE ON THE LOW LEVEL THERMAL FIELD...THEY TENDED
TO BE TOO COOL. OVERALL WOULD HAVE TO GIVE A SLIGHT EDGE TO THE NAM
AND SREF.
SUNDAY NIGHT...LOOKS LIKE SOME WEAK BOUNDARY SAGS SOUTH ACROSS THE
AREA. MODELS ARE A LITTLE FASTER IN TAKING THE INITIAL SHORTWAVE
THROUGH ALTHOUGH THERE IS NOT VERY GOOD AGREEMENT IN THAT. MODELS
WANT TO BRING ANOTHER SHORTWAVE IN NORTHWEST FLOW DURING THE
OVERNIGHT HOURS WITH ALSO NOT A LOT OF AGREEMENT. RIGHT REAR
QUADRANT AFFECTS THE FAR NORTHERN PORTION OF THE AREA. WILL KEEP THE
SLIGHT TO LOW CHANCE POPS WITH A GRADUAL DECREASE THROUGH THE NIGHT.
LOOKS LIKE THERE WILL BE MAINLY STRATUS WITH NOT AS GOOD OF A CHANCE
OF FOG.
MONDAY/MONDAY NIGHT...RIDGE BEGINS TO BUILD INTO THE AREA WITH THE
UPPER JET BEING PUSHED FURTHER NORTH AWAY FROM THE AREA. AREA IS IN
POST FRONTAL UPSLOPE REGIME. RIDGING ALOFT LOOKS A LITTLE STRONGER
AND FURTHER WEST DURING THE DAY THAN WAS SHOWN YESTERDAY SO WILL
PUSH THE POPS FURTHER WEST. WILL HAVE SOME CLOUD COVER TO START THE
DAY WITH A COOLER AIR MASS AND UPSLOPE WINDS PRESENT THROUGH THE DAY
SO WILL DEFINITELY BE COOLER.
700 MB RIDGE MOVES A LITTLE TO THE EAST DURING THE NIGHT WITH
INCREASING LIFT COMING IN FROM THE SOUTHWEST. SO POPS SHOULD STAY
CONFINED TO THE SOUTHWEST HALF OF THE AREA WITH A GRADUAL INCREASE
THROUGH WITH STORMS NOT MOVING VERY FAST. THAT COMBINED WITH HIGH
PWS WILL SET THE STAGE MODERATE TO LOCALLY HEAVY RAINFALL.
TUESDAY...ABOVE MENTIONED SHORTWAVE RIDGE AND TROUGH CONTINUE TO
MOVE SLOWLY EAST THROUGH THE DAY. MOIST AIR MASS REMAIN IN PLACE
WITH INCREASING LIFT. IT IS POSSIBLE THAT THERE COULD BE SOME
PRECIPITATION AT THE BEGINNING AND THEN IT SHOULD GRADUALLY
INCREASE IN COVERAGE AND INTENSITY. SO HAVE THE HIGHER POPS IN THE
AFTERNOON.
EASTERLY WINDS...CLOUD COVER AND DEVELOPING PRECIPITATION SHOULD
KEEP TEMPERATURES SHOULD KEEP TEMPERATURES FROM WARMING VERY MUCH.
TUESDAY NIGHT THROUGH SATURDAY...DETERMINISTIC AND ENSEMBLE OUTPUT
IN BETTER AGREEMENT IN REGARDS TO THE EVOLUTION OF THE UPPER
PATTERN. ESSENTIALLY MODELS BUILD THE RIDGE...NOW CENTERED TO OUR
SOUTH...FURTHER TO THE WEST AND NORTH. THE DIFFERENCES INCREASE A
LITTLE TOWARD THE END OF THE PERIOD BUT NOT AS BAD AS YESTERDAY. THE
CENTER OF THE RIDGE WILL BE NEAR THE FOUR CORNERS REGION LEAVING A
WEAKER NORTHERLY FLOW OVER THE AREA.
IN THIS PATTERN WOULD ANTICIPATE THE SUBTROPICAL MOISTURE TO BE ABLE
TO ROTATE AROUND THE RIDGE WITH WEAK/SUBTLE SHORTWAVES ROTATING
AROUND IT. WPC PROGS SHOW A PERSISTENT FRONTAL BOUNDARY ALONG OR
OVER THE WESTERN PORTION OF THE AREA UNTIL THE LAST DAY WHEN A DRY
LINE/SURFACE TROUGH SETS UP IN THE SAME PLACE. WITH VERY SUBTLE
FEATURES...I CANNOT RULE OUT CHANCES FOR THUNDERSTORMS ALMOST EVERY
PERIOD.
SO ANY SLIGHT CHANCE TO LOW CHANCE POPS TO DRY CONDITIONS DO NOT
SEEM UNREASONABLE DEPENDING ON HOW THE DETAILS WORK OUT. SO ONCE
AGAIN DID NOT MAKE ANY CHANGES TO WHAT THE CRH_INIT GAVE ME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1139 AM MDT SAT AUG 8 2015
1500-2500 KFT STRATUS SHOULD CLEAR BY THE VALID TAF PERIOD AT KGLD.
SHORT RANGE GUIDANCE AND SATELLITE TRENDS INDICATE THIS SHOULD
WILL LINGER AT KMCK THROUGH THE EARLY AFTERNOON BEFORE LIFTING.
SCATTERED THUNDERSTORM WILL DEVELOP MAINLY SOUTH OF INTERSTATE
70...WITH ACTIVITY MOVING WITHIN THE VICINITY OF KGLD AFTER 00Z.
NOT A LOT OF CONFIDENCE COVERAGE AT KGLD WILL NECESSITATE MORE
THAN VCTS MENTION AT THIS POINT...SO WE WILL NEED TO MONITOR
TRENDS AS THUNDERSTORMS INITIATE SOUTH AND TRACK NORTHEAST. WITH
VERY MOIST AIR MASS IN PLACE EXPECT STRATUS/FOG TO REDEVELOP
09-10Z. THERE IS A POSSIBILITY BASED ON HI RES GUIDANCE OF VLIFR
CONDITIONS AROUND 12Z AT KGLD AND KMCK...HOWEVER GUIDANCE ISNT
SHOWING A LOT OF CONSISTENCY AND IT MAY END UP BEING MORE OF A
TEMPORARY CONDITION. IN ANY CASE STRATUS/FOG SHOULD CLEAR WITH
RISING SUN MID MORNING SUNDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
229 PM MDT SAT AUG 8 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 229 PM MDT SAT AUG 8 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS 595 DM RIDGE
ACROSS SOUTHERN PLAINS WITH PLUME OF PACIFIC MOISTURE STREAMING INTO
THE CENTRAL ROCKIES AND ACROSS OUR CWA. SEVERE WEAK
RIPPLES/SHORTWAVE TROUGHS WITHIN THE H5/H7 SW FLOW ARE UPSTREAM OF
THE REGION WITH SOME ENHANCEMENT ACROSS THE HIGHER TERRAIN IN THE
CENTRAL AND SOUTHERN ROCKIES. AT THE SURFACE LOW PRESSURE EXTENDS
ACROSS EASTERN COLORADO AND SOUTHWEST KANSAS. STATIONARY/WARM FRONT
IS CURRENTLY JUST OVER THE SOUTHEAST PORTIONS OF OUR CWA.
THIS AFTERNOON-TONIGHT...BAROCLINIC ZONE EXTENDING ACROSS SE CWA AND
ACROSS EASTERN COLORADO WILL ACT AS FOCUS FOR INITIATION NEAR OUR CWA
AS HEIGHT FALLS AND INCREASING ISENTROPIC ASCENT MOVES SOUTH OF
INTERSTATE 70. STRONGEST PRECIP SIGNAL IS ALONG STATIONARY FRONT IN
THE SOUTH...ESPECIALLY BY ARW/HRRR. RAP ANALYSIS SHOWS CAPE VALUES
ALREADY AROUND 4000 J/KG IN THE SOUTHEAST...WITH EFFECTIVE BULK
SHEER VALUES IN EXCESS OF 40KT. WHILE THERE IS SOME LOW LEVEL
VEERING...OVERALL SEVERE INDICES FAVOR DAMAGING WINDS AND LARGE
HAIL WITH ON A SMALL THREAT FOR TORNADOS WITHIN PROXIMITY TO MAIN
TROUGH AXIS. VERY MOIST AIR MASS...THE POSSIBILITY FOR BACKBUILDING
ALONG FRONTAL ZONE...AND STORM MOTIONS GENERALLY LESS THAN 20KT WILL
TEND TO SUPPORT POTENTIAL FOR LOCALIZED FLASH FLOODING. HI RES
GUIDANCE IS INDICATING POTENTIAL FOR THUNDERSTORMS TO FORM INTO ONE
OR SEVERAL SMALL MCS CLUSTERS ACROSS THE SOUTHERN PART OF THE
FORECAST AREA. EARLIER GUIDANCE WAS SHOWING THIS SPREADING AS FAR
NORTH AS THE I-70 CORRIDOR.
WITH LINGERING WAA ACROSS THE SE CWA...ALONG WITH SEVERAL MORE WEAK
SHORTWAVES PASSING THROUGH THE REGION...SE PORTIONS OF THE FORECAST
AREA COULD CONTINUE TO SEE SHOWER/THUNDERSTORM ACTIVITY LINGER
THROUGH SUNDAY MORNING. TREND WILL BE FOR DECREASING
INSTABILITY...SO SEVERE THREAT SHOULD BE LIMITED TO JUST THE EVENING
HOURS. VERY MOIST AIR MASS AND LIGHT WINDS WILL ALSO TEND TO SUPPORT
POTENTIAL FOR FOG/STRATUS TO REDEVELOP BY SUNRISE.
SUNDAY...WITH WEAK FORCING AND LINGERING FRONT IN OUR SE...THERE
WILL BE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THROUGH MIDDAY. NAM
SHOWS INCREASING FORCING BY LATE MORNING EARLY AFTERNOON AS A
STRONGER TROUGH DIGS INTO THE NORTHERN PLAINS. OTHER GUIDANCE IS NOT
QUITE AS FAR SOUTH...PRIMARILY FAVORS THE SOUTHER PARTS OF OUR CWA
FOR BEST THUNDERSTORM CHANCES. THERE SHOULD BE ENOUGH
INSTABILITY/SHEER IN THE AFTERNOON TO SUPPORT AT LEAST A FEW MORE
ORGANIZED THUNDERSTORMS. LOW CONFIDENCE IN HI TEMP FORECAST AS (LIKE
TODAY) TEMPS WILL BE HIGHLY DEPENDENT ON STRATUS CLEARING AND TIMING
OF THUNDERSTORM ACTIVITY. THE AIR MASS ADVERTISED OVER THE CWA WITH
AVERAGE MIXING WOULD SUPPORT SEASONAL HIGHS IN THE UPPER 80S/LOWER
90S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 222 AM MDT SAT AUG 8 2015
AN UPPER LEVEL RIDGE WILL BE IN PLACE OVER THE TRI STATE AREA TO
START OFF THE LONG TERM PERIOD TUESDAY. THE CENTRAL AREA OF HIGH
PRESSURE WILL CONTINUE TO RETROGRADE AND INCREASE IN AMPLITUDE OVER
THE ROCKY MOUNTAIN RANGE AND THE NORTHERN PLAINS WEDNESDAY. WITH
THE PRESENCE OF THE UPPER RIDGE...JET AREAS AND POCKETS OF VORTICITY
WILL REMAIN WELL AWAY FROM THE TRI STATE AREA...WHICH WILL BRING
UPPER STABILITY FOR THE REST OF THE FORECAST PERIOD.
AT THE SURFACE...A COOLER AIR MASS WITH A SURFACE HIGH PRESSURE
FILTERING INTO THE PLAINS BEHIND A COLD FRONTAL PASSAGE WILL BRING
COOLER HIGH TEMPERATURES IN THE MID TO UPPER 80S ON TUESDAY. ON THE
FRONT SIDE OF THE HIGH PRESSURE SYSTEM...EASTERLY UPSLOPE FLOW WILL
BRING MOISTURE INTO THE HIGH PLAINS DURING THE MORNING HOURS BEFORE
SURFACE WINDS SHIFT TO THE SOUTH/SOUTHEAST. GFS/ECMWF HINT AT A
SURFACE DRY LINE POSITIONED MORE ALONG THE SOUTHWESTERN PORTION OF
THE FORECAST AREA...SO THUNDERSTORMS LOOK MORE LIKELY TO FORM ALONG
THE VICINITY OF THE FORECAST AREA ALONG THIS BOUNDARY. A DEVELOPING
SURFACE TROUGH IN EASTERN COLORADO MAY ALLOW STORMS TO DEVELOP
ELSEWHERE WITH CAPE AND MOISTURE PROFILES SUFFICIENT ENOUGH FOR
DEVELOPMENT.
THE UPPER LEVEL HIGH WILL THEN MOVE AND BECOME POSITIONED DIRECTLY
OVER THE TRI STATE AREA FOR THE END OF THE COMING WEEK...WHICH WILL
DRY OUT CONDITIONS WITH A LACK OF UPPER OR SURFACE FORCING.
EXPECTING TEMPERATURES IN THE LOW TO MID 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1139 AM MDT SAT AUG 8 2015
1500-2500 KFT STRATUS SHOULD CLEAR BY THE VALID TAF PERIOD AT KGLD.
SHORT RANGE GUIDANCE AND SATELLITE TRENDS INDICATE THIS SHOULD
WILL LINGER AT KMCK THROUGH THE EARLY AFTERNOON BEFORE LIFTING.
SCATTERED THUNDERSTORM WILL DEVELOP MAINLY SOUTH OF INTERSTATE
70...WITH ACTIVITY MOVING WITHIN THE VICINITY OF KGLD AFTER 00Z.
NOT A LOT OF CONFIDENCE COVERAGE AT KGLD WILL NECESSITATE MORE
THAN VCTS MENTION AT THIS POINT...SO WE WILL NEED TO MONITOR
TRENDS AS THUNDERSTORMS INITIATE SOUTH AND TRACK NORTHEAST. WITH
VERY MOIST AIR MASS IN PLACE EXPECT STRATUS/FOG TO REDEVELOP
09-10Z. THERE IS A POSSIBILITY BASED ON HI RES GUIDANCE OF VLIFR
CONDITIONS AROUND 12Z AT KGLD AND KMCK...HOWEVER GUIDANCE ISNT
SHOWING A LOT OF CONSISTENCY AND IT MAY END UP BEING MORE OF A
TEMPORARY CONDITION. IN ANY CASE STRATUS/FOG SHOULD CLEAR WITH
RISING SUN MID MORNING SUNDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
316 PM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 250 PM EDT SAT AUG 8 2015
THE UPPER GREAT LAKES REGION WILL BE BETWEEN UPPER LEVEL FEATURES
OVER THE NEXT 24 HOURS...LEADING TO SOME UNCERTAINTY IN THE COVERAGE
AND AMOUNT OF PRECIPITATION THAT WILL OCCUR AHEAD OF THE COLD FRONT
TONIGHT. THE MAIN SHORTWAVE IS CURRENTLY LOCATED JUST TO THE EAST OF
LAKE WINNIPEG AND HAS A 1002MB SURFACE LOW LOCATED WITH IT. A COLD
FRONT STRETCHES SOUTH-SOUTHEAST FROM THIS LOW AND INTO NORTHERN
MINNESOTA (CURRENTLY FROM THE LAKE OF THE WOODS TO JUST TO THE EAST
OF FARGO). HAVE SEEN SOME SHOWERS AND THUNDERSTORMS DEVELOP AROUND
PARK RAPIDS MINNESOTA A COUPLE HOURS AGO AND THEY HAVE BEEN MAKING
THERE WAY TO THE EAST TOWARDS LEECH LAKE AHEAD OF THAT FRONT AND IN
THE RIBBON OF DEEPER MOISTURE FROM 925-700MB AHEAD OF THE ASSOCIATED
TROUGH. OVER THE U.P....THE ABUNDANT DRY AIR SEEN ABOVE 700MB ON THE
12Z KGRB SOUNDING AND ON RAP ANALYSIS DATA...ASSOCIATED WITH THE
SURFACE RIDGE FROM A HIGH NEAR JAMES BAY...HAS BEEN LIMITING THE
EASTWARD EXTENT OF THE OF SHOWERS AS THEY MOVE INTO WESTERN LAKE
SUPERIOR. BUT WITH THE MOISTURE BELOW 700MB...HAVE SEEN DIURNAL CU
FILL IN THE GAPS FROM EARLIER TODAY BETWEEN THE SOUTHEASTERLY FLOW
UPSLOPE FOG AND LOW CLOUDS. TEMPERATURES HAVE WARMED INTO THE 70S
ACROSS THE AREA...WITH THE WARMEST VALUES OVER THE EAST WITH MORE
SUNSHINE. FINALLY FARTHER TO THE SOUTH...A SHORTWAVE ROUNDING THE
UPPER RIDGE OVER TEXAS/OKLAHOMA LED TO AN MCS MOVING THROUGH
NORTHEAST KANSAS AND SOUTHWEST MISSOURI EARLY THIS MORNING AND IT
HAS SINCE DISSIPATED. BUT WITH ANOTHER WAVE ROUNDING THE RIDGE
THROUGH NEBRASKA...WOULD EXPECT REDEVELOPMENT TO THE EAST OF THAT
AREA OVER THE NEXT COUPLE OF HOURS.
WITH THE SOUTHERN SHORTWAVE STAYING WELL TO THE SOUTH OF THE
AREA...THE MAIN FOCUS WILL BE WITH THE UPPER LOW NEAR LAKE WINNIPEG
SLOWLY WEAKENING AS IT MOVES EAST TOWARDS JAMES BAY. THIS WILL LEAD
TO THE SURFACE LOW FOLLOWING SUIT AND SLOWLY DRAGGING THE COLD FRONT
EAST ACROSS THE CWA. HAVE ALREADY SEEN SHOWERS/THUNDERSTORMS DEVELOP
IN NORTHERN MINNESOTA AHEAD OF THE FRONT AND WITH THE STORM MOTION
VALUES INDICATING EASTWARD MOVEMENT UP TO 30KTS...WOULD EXPECT THE
SHOWERS TO SPREAD EAST INTO WESTERN LAKE SUPERIOR AND EVENTUALLY THE
WESTERN U.P. TONIGHT. LIKE LAST NIGHT AND TODAY...THEY WILL BE
BATTLING THE EXISTING DRY MID LEVEL AIR AS THEY MOVE OUT AHEAD OF
THE SLOW MOVING SURFACE-850MB TROUGH...SO WOULD EXPECT SOME
DIMINISHMENT AS THEY HEAD TO THE EAST AND INTO THE CWA TONIGHT.
WOULD EXPECT SOME MARGINALLY SEVERE STORMS TO MOVE INTO WESTERN LAKE
SUPERIOR BEFORE THE DRY AIR AND LOSS OF DIURNAL HEATING STARTS TO
TAKE ITS TOLL. OVER THE CENTRAL AND EASTERN U.P....AM EXPECTED SOME
PATCHY GROUND FOG TO DEVELOP TONIGHT. THICKNESS WILL DEPEND ON THE
AMOUNT OF DECOUPLING THAT OCCURS TONIGHT. HAVE SHOWN THE THICKEST
FOG (AREAS COVERAGE) OVER THE CENTRAL U.P. FOR SOUTHERN
MARQUETTE...DICKINSON...DELTA...AND NORTHERN MENOMINEE COUNTIES.
WITH THE COLD FRONT STILL OFF TO THE WEST OF THE U.P. ON SUNDAY
MORNING...EXPECT THERE TO BE TIME FOR DIURNAL HEATING TO INCREASE
THE POTENTIAL FOR SHOWERS/THUNDERSTORMS OVER THE WEST/CENTRAL U.P.
DURING THE AFTERNOON. MODELS HAVE A VARIETY OF IDEAS ON ML CAPE
VALUES...RANGING FROM 250-2000 J/KG TOMORROW AFTERNOON JUST AHEAD OF
THE FRONT. LOOKING AT MODIFIED SOUNDINGS AND MEAN ML CAPE VALUES
FROM THE NCAR ENSEMBLES AND SREF...FEEL THAT VALUES AROUND 500-750
J/KG ARE A FAIRLY REASONABLE EXPECTATION AT THIS POINT. WITH 0-6KM
BULK SHEAR VALUES GENERALLY AROUND 25-30KTS...THERE IS THE POTENTIAL
FOR AN ISOLATED STRONGER STORM TOMORROW AFTERNOON. THAT MATCHES THE
IDEA FROM UPDRAFT VELOCITY/HELICITY FROM THE CAM/S AND CAM
ENSEMBLES. WITH WET BULB ZERO VALUES NEARING 10KFT AND FREEZING
LEVEL ABOVE 12KFT...THINK THAT WILL COMBINE WITH THE MARGINAL SHEAR
TO KEEP THE HAIL THREAT BORDERLINE. LIKED THE PREVIOUS SHIFTS
HANDLING OF THE DEVELOPMENT OF THE SHOWERS/THUNDERSTORMS ACROSS THE
CENTRAL U.P. (RAMPING UP TO LOCALIZED LIKELY VALUES OVER MARQUETTE
COUNTY) AND HAVE ONLY MADE MINOR ADJUSTMENTS BASED OFF LATEST MODEL
TRENDS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM EDT SAT AUG 8 2015
AFTER ANY LINGERING SHOWERS END ON MON FOLLOWING A SUN NGT COLD
FROPA...THE NW FLOW BTWN A BLDG UPR RDG IN THE PLAINS AND AN
AMPLIFYING TROF OVER ERN NAMERICA WL BE THE DOMINATING INFLUENCE ON
UPR MI WX EARLY IN THE WEEK. THE RESULT WL BE A RETURN OF DRY AND
COOLER WX FOR THE MOST PART MON INTO WED. THE NEXT CHC OF SHOWERS/TS
WL ARRIVE WITH WARMER AIR WED NGT THRU THU NGT AHEAD OF A SHRTWV
MOVING OVER THE TOP OF THE RDG/THRU NW ONTARIO AND ITS ATTENDANT
COLD FNT. HI PRES TRAILING THIS COLD FNT SHOULD BRING A SEASONABLE
AIRMASS/DRIER WX LATE IN THE WEEK.
SUN NGT...SHRTWV DRIFTING ESEWD THRU FAR NORTHERN ONTARIO WL REACH
NEAR JAMES BAY BY 12Z MON AND DRAG ATTENDANT COLD FNT SLOWLY THRU
THE UPR LKS. SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE
ONTARIO SHRTWV WL BE REMAIN TO THE N AND H85 THETA E ADVECTION/
DEEPER MSTR INFLOW WL BE WEAK AT BEST...EXPECT NO MORE THAN A CHC OF
SHOWERS/TS. THE BEST CHC FOR THIS PCPN WL BE IN THE EVNG OVER
CENTRAL UPR MI...WHERE AXIS OF SOMEWHAT HIER H85 THETA E WL BE
PRESENT AT TIME WHEN DAYTIME HEATING WL STILL BE A FACTOR. THE
MAJORITY OF THE MODELS SHOW A TRAILING SHRTWV/AREA OF HIER MID LVL
MSTR/SOME DPVA AND H7-3 QVECTOR CNVGC APRCHG FM CENTRAL MN FOLLOWING
THE COLD FROPA. HOWEVER...NOCTURNAL COOLING AND LLVL DRYING/
NEGATIVE H85 THETA E ADVCTN WL LIMIT THE COVERAGE/INTENSITY OF ANY
SHOWERS THAT MIGHT ACCOMPANYING THIS HIER LVL FORCING. EXPECT THE
LOWEST MIN TEMPS OVER THE W...WHERE H85 TEMPS ARE FCST TO FALL TO
ARND 11C BY DAYBREAK.
MON...EXPECT ANY LINGERING SHOWERS OVER THE E AND SCENTRAL TO
DIMINISH WITH ARRIVAL OF DEEP DRYING/INCRSG LLVL ACYC NNW FLOW AHEAD
OF CNDN HI PRES BLDG INTO MANITOBA. LINGERING MID CLDS WL GIVE WAY
TO SOME DIURNAL CU/SC IN THE AFTN. EXPECT HI TEMPS MAINLY IN THE 70S
TO NEAR 80 OVER THE SCNTRL WITH H85 TEMPS IN THE 12-14C RANGE.
LOCATIONS NEAR LK SUP WL BE COOLEST WITH A NW FLOW OFF THE WATER.
MON NGT THRU TUE NGT...ARRIVAL OF MORE VIGOROUS DEEP LYR QVECTOR
DVGC/SUBSIDENCE UNDER CONFLUENT NW FLOW ALOFT BTWN PLAINS RDG/ERN
TROF AND H85 TEMPS FALLING AS LO AS 8 TO 10C IN THE LLVL NLY FLOW
AHEAD OF CNDN HI PRES BLDG TOWARD THE UPR LKS WL RESULT IN A PERIOD
OF COOLER AND DRIER WX FOR THE CWA. SOME OF THE MODELS HAVE BEEN
GENERATING SOME LGT PCPN MAINLY DURING DAYTIME HEATING ON TUE
ACCOMPANYING THE PASSAGE OF A SHRTWV IN THE NW FLOW. BUT ABSENCE OF
ANY MSTR INFLOW...LARGER SCALE NEGATIVE DYNAMIC FORCING/SUBSIDENCE
THAT WL MAINTAIN MID LVL CAPPING SHOWN ON THE GFS FCST SDNGS AS WELL
AS DIFFLUENT LLVL FLOW WARRANTS MAINTAINING GOING DRY FCST FOR NOW.
BUT THERE WL BE A GOOD DEAL OF DIURNAL CU ON TUE UNDER INCOMING H85
THERMAL TROF. EXPECT LO TEMPS ON TUE NGT TO FALL INTO THE 40S AT THE
COOLER INTERIOR LOCATIONS WITH MOCLR SKIES/LIGHT WINDS AS THE SFC HI
PRES MOVES OVHD.
WED...AS THE HI CENTER DRIFTS TO THE S...THE LLVL FLOW WL TURN TO
THE WSW. THE WARMING RELATED TO SOME WAA AND CONTINUED SUBSIDENCE
UNDER THE SLOWLY EXPANDING PLAINS RDG/RISING HGTS IS FCST TO BOOST
H85 TEMPS TO ARND 16C OVER THE W LATE IN THE DAY. EXPECT A WARMER
DAY THAN ON TUE...WITH HI TEMPS AT LEAST APRCHG 80 ESPECIALLY OVER
THE W AWAY FM LK MODERATION...EVEN IF SOME WAA CLDS SPILL OVER THE
CWA IN THE AFTN.
WED NGT THRU THU NGT...ALTHOUGH THERE ARE SOME DIFFERENCES IN THE
DETAILS AS EXPECTED SO FAR INTO THE FUTURE...THE LONGER RANGE
GUIDANCE INDICATES A SHRTWV RIDING OVER THE PLAINS RDG WL DROP SEWD
THRU NW ONTARIO ON THU/THU NGT AND DRAG A COLD FNT THRU THE UPR LKS
ON THU NGT. SOME OF THE MODELS GENERATE SOME LGT PCPN AS EARLY AS
WED NGT IN THE WSW FLOW/WAA BTWN THE RETREATING HI PRES TO THE S AND
FALLING MSLP OVER SCENTRAL CANADA AHEAD OF THE SHRTWV. BUT LINGERING
LLVL ACYC FLOW AND RELATIVE DRYNESS OF AIRMASS INDICATE ANY SHOWERS
WL BE WIDELY SCT AT BEST. A BETTER CHC FOR SHOWERS/TS APPEARS WL
COME LATE THU/THU EVNG WITH THE ARRIVAL OF SOME DEEP LYR QVECTOR
CNVGC ASSOCIATED WITH THE ONTARIO SHRTWV AND AHEAD OF APRCHG COLD
FNT DURING PERIOD OF DAYTIME HEATING. THE 12Z GFS IS MOST VIGOROUS
WITH THIS DISTURBANCE AND INDICATES THE POTENTIAL FOR SOME SVR
STORMS WITH MUCAPE FCST AS HI AS 2500 J/KG AND DEEP LYR SHEAR UP TO
40 KTS. THE 12Z ECMWF/CNDN MODELS SHOW A LESS IMPRESSIVE SCENARIO
WITH WEAKER MSTR RETURN. GIVEN MODEL DIFFERENCES AND UNCERTAINTY ON
THE DEGREE OF MSTR RETURN WITH SHARPEST FORCING REMAINING TO THE
NE...CONSENSUS LO CHC POPS AT THIS POINT SEEM REASONABLE. THU LOOKS
TO BE THE WARMEST DAY OF THE WEEK UNDER THERMAL RDG/H85 TEMPS UP TO
18-20C AHEAD OF INCOMING COLD FNT.
FRI/SAT...HI PRES TRAILING THE SHRTWV SHOULD BRING DRY AND SOMEWHAT
COOLER WX AT LEAST ON FRI/FRI NGT. THERE IS SOME UNCERTAINTY ON HOW
QUICKLY WAA SHOWERS/TS RETURN BTWN THE RETREATING HI AND ANOTHER
SHRTWV RIDING OVER THE PLAINS RDG LATER ON SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 150 PM EDT SAT AUG 8 2015
VFR DIURNAL CLOUDS WILL BE THE MAIN SHORT TERM CONCERN. THESE
CEILINGS HAVE BEEN GRADUALLY RISING WITH DAYTIME HEATING AND MIXING
AND EXPECT THAT TO CONTINUE INTO THE AFTERNOON AND THE HIGH END
MVFR CEILINGS SHOULD TRANSITION TO VFR WITHIN THE NEXT COUPLE
HOURS. OTHERWISE...A COLD FRONT FROM MINNESOTA THAT WILL MOVE
ACROSS THE AREA ON SUNDAY MAY PUSH A COUPLE SHOWERS THROUGH THE
WESTERN HALF OF UPPER MICHIGAN AND ONLY HAD ENOUGH CONFIDENCE TO
INCLUDE VCSH AT KCMX OVERNIGHT AND LATE IN THE PERIOD AT KSAW. ALSO
FOR KSAW...DEPENDING ON THE AMOUNT OF SCATTERING OF THE CLOUDS THIS
EVENING...COULD SEE LIFR-IFR CONDITIONS DEVELOP WITH PATCHY GROUND
FOG OVERNIGHT TONIGHT. HAVE WENT WITH LOW END MVFR VISIBILITIES FOR
NOW...BUT WILL BE SOMETHING TO MONITOR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 250 PM EDT SAT AUG 8 2015
A LOW MOVING FROM JUST EAST OF LAKE WINNIPEG TO JAMES BAY THIS
WEEKEND WILL SWEEP A SURFACE TROUGH ACROSS LAKE SUPERIOR ON
SUNDAY...LEADING TO A SHIFT IN THE WINDS FROM A LIGHT SOUTH TO
SOUTHEASTERLY DIRECTION TO THE NORTHWEST BY MONDAY. WITH A
GENERALLY LIGHT PRESSURE GRADIENT IN PLACE...EXPECT WINDS TO STAY
BELOW 20KTS THROUGH THE PERIOD...ESPECIALLY AFTER TUESDAY WHEN HIGH
PRESSURE WILL SETTLE OVER THE GREAT LAKES REGION FOR THE MIDDLE OF
NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
250 PM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 250 PM EDT SAT AUG 8 2015
THE UPPER GREAT LAKES REGION WILL BE BETWEEN UPPER LEVEL FEATURES
OVER THE NEXT 24 HOURS...LEADING TO SOME UNCERTAINTY IN THE COVERAGE
AND AMOUNT OF PRECIPITATION THAT WILL OCCUR AHEAD OF THE COLD FRONT
TONIGHT. THE MAIN SHORTWAVE IS CURRENTLY LOCATED JUST TO THE EAST OF
LAKE WINNIPEG AND HAS A 1002MB SURFACE LOW LOCATED WITH IT. A COLD
FRONT STRETCHES SOUTH-SOUTHEAST FROM THIS LOW AND INTO NORTHERN
MINNESOTA (CURRENTLY FROM THE LAKE OF THE WOODS TO JUST TO THE EAST
OF FARGO). HAVE SEEN SOME SHOWERS AND THUNDERSTORMS DEVELOP AROUND
PARK RAPIDS MINNESOTA A COUPLE HOURS AGO AND THEY HAVE BEEN MAKING
THERE WAY TO THE EAST TOWARDS LEECH LAKE AHEAD OF THAT FRONT AND IN
THE RIBBON OF DEEPER MOISTURE FROM 925-700MB AHEAD OF THE ASSOCIATED
TROUGH. OVER THE U.P....THE ABUNDANT DRY AIR SEEN ABOVE 700MB ON THE
12Z KGRB SOUNDING AND ON RAP ANALYSIS DATA...ASSOCIATED WITH THE
SURFACE RIDGE FROM A HIGH NEAR JAMES BAY...HAS BEEN LIMITING THE
EASTWARD EXTENT OF THE OF SHOWERS AS THEY MOVE INTO WESTERN LAKE
SUPERIOR. BUT WITH THE MOISTURE BELOW 700MB...HAVE SEEN DIURNAL CU
FILL IN THE GAPS FROM EARLIER TODAY BETWEEN THE SOUTHEASTERLY FLOW
UPSLOPE FOG AND LOW CLOUDS. TEMPERATURES HAVE WARMED INTO THE 70S
ACROSS THE AREA...WITH THE WARMEST VALUES OVER THE EAST WITH MORE
SUNSHINE. FINALLY FARTHER TO THE SOUTH...A SHORTWAVE ROUNDING THE
UPPER RIDGE OVER TEXAS/OKLAHOMA LED TO AN MCS MOVING THROUGH
NORTHEAST KANSAS AND SOUTHWEST MISSOURI EARLY THIS MORNING AND IT
HAS SINCE DISSIPATED. BUT WITH ANOTHER WAVE ROUNDING THE RIDGE
THROUGH NEBRASKA...WOULD EXPECT REDEVELOPMENT TO THE EAST OF THAT
AREA OVER THE NEXT COUPLE OF HOURS.
WITH THE SOUTHERN SHORTWAVE STAYING WELL TO THE SOUTH OF THE
AREA...THE MAIN FOCUS WILL BE WITH THE UPPER LOW NEAR LAKE WINNIPEG
SLOWLY WEAKENING AS IT MOVES EAST TOWARDS JAMES BAY. THIS WILL LEAD
TO THE SURFACE LOW FOLLOWING SUIT AND SLOWLY DRAGGING THE COLD FRONT
EAST ACROSS THE CWA. HAVE ALREADY SEEN SHOWERS/THUNDERSTORMS DEVELOP
IN NORTHERN MINNESOTA AHEAD OF THE FRONT AND WITH THE STORM MOTION
VALUES INDICATING EASTWARD MOVEMENT UP TO 30KTS...WOULD EXPECT THE
SHOWERS TO SPREAD EAST INTO WESTERN LAKE SUPERIOR AND EVENTUALLY THE
WESTERN U.P. TONIGHT. LIKE LAST NIGHT AND TODAY...THEY WILL BE
BATTLING THE EXISTING DRY MID LEVEL AIR AS THEY MOVE OUT AHEAD OF
THE SLOW MOVING SURFACE-850MB TROUGH...SO WOULD EXPECT SOME
DIMINISHMENT AS THEY HEAD TO THE EAST AND INTO THE CWA TONIGHT.
WOULD EXPECT SOME MARGINALLY SEVERE STORMS TO MOVE INTO WESTERN LAKE
SUPERIOR BEFORE THE DRY AIR AND LOSS OF DIURNAL HEATING STARTS TO
TAKE ITS TOLL. OVER THE CENTRAL AND EASTERN U.P....AM EXPECTED SOME
PATCHY GROUND FOG TO DEVELOP TONIGHT. THICKNESS WILL DEPEND ON THE
AMOUNT OF DECOUPLING THAT OCCURS TONIGHT. HAVE SHOWN THE THICKEST
FOG (AREAS COVERAGE) OVER THE CENTRAL U.P. FOR SOUTHERN
MARQUETTE...DICKINSON...DELTA...AND NORTHERN MENOMINEE COUNTIES.
WITH THE COLD FRONT STILL OFF TO THE WEST OF THE U.P. ON SUNDAY
MORNING...EXPECT THERE TO BE TIME FOR DIURNAL HEATING TO INCREASE
THE POTENTIAL FOR SHOWERS/THUNDERSTORMS OVER THE WEST/CENTRAL U.P.
DURING THE AFTERNOON. MODELS HAVE A VARIETY OF IDEAS ON ML CAPE
VALUES...RANGING FROM 250-2000 J/KG TOMORROW AFTERNOON JUST AHEAD OF
THE FRONT. LOOKING AT MODIFIED SOUNDINGS AND MEAN ML CAPE VALUES
FROM THE NCAR ENSEMBLES AND SREF...FEEL THAT VALUES AROUND 500-750
J/KG ARE A FAIRLY REASONABLE EXPECTATION AT THIS POINT. WITH 0-6KM
BULK SHEAR VALUES GENERALLY AROUND 25-30KTS...THERE IS THE POTENTIAL
FOR AN ISOLATED STRONGER STORM TOMORROW AFTERNOON. THAT MATCHES THE
IDEA FROM UPDRAFT VELOCITY/HELICITY FROM THE CAM/S AND CAM
ENSEMBLES. WITH WET BULB ZERO VALUES NEARING 10KFT AND FREEZING
LEVEL ABOVE 12KFT...THINK THAT WILL COMBINE WITH THE MARGINAL SHEAR
TO KEEP THE HAIL THREAT BORDERLINE. LIKED THE PREVIOUS SHIFTS
HANDLING OF THE DEVELOPMENT OF THE SHOWERS/THUNDERSTORMS ACROSS THE
CENTRAL U.P. (RAMPING UP TO LOCALIZED LIKELY VALUES OVER MARQUETTE
COUNTY) AND HAVE ONLY MADE MINOR ADJUSTMENTS BASED OFF LATEST MODEL
TRENDS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 506 AM EDT SAT AUG 8 2015
DURING THE LONG TERM...MID LEVEL LOW CURRENTLY OVER SRN MANITOBA IS
FCST TO MOVE SLOWLY E INTO NRN ONTARIO BY SUN MORNING. AS THIS
FEATURE CONTINUES TO SHIFT SLOWLY E...A BUILDING RIDGE TO THE LEE OF
THE ROCKIES WILL FORCE A DEEPENING TROF INTO ERN NAMERICA DURING THE
FIRST HALF OF NEXT WEEK. THIS TROF WILL LIKELY LINGER THRU THE REST
OF THE WEEK. PRIOR TO THE DEEPENING TROF...A SERIES OF SHORTWAVES
TRACKING ACROSS THE PLAINS TO THE GREAT LAKES WILL PROVIDE SOME
OPPORTUNITY FOR SHRA/TSTMS. DEEPENING ERN TROF AND RESULTING NW FLOW
INTO THE GREAT LAKES DURING THE FIRST HALF OF NEXT WEEK WILL THEN
BRING DRY WEATHER. HOWEVER...TYPICAL FOR SUMMERTIME NW FLOW...ANY
SUBTLE SHORTWAVE DROPPING THRU THE AREA COULD SPARK ISOLD AFTN
CONVECTION. PCPN CHANCES WILL RETURN LATE IN THE WEEK AS THERE ARE
INDICATIONS OF A DECENT SHORTWAVE ROUNDING THE WRN PLAINS RIDGE AND
THEN DROPPING INTO THE ERN TROF. THIS WOULD RESULT IN POSSIBLE
CONVECTION WITH LOW-LEVEL JET/WAA REGIME AHEAD OF WAVE AND ALSO WITH
COLD FRONT THAT WOULD DROP S INTO THE GREAT LAKES. AS FOR TEMPS...
AFTER READINGS NOT TOO FAR FROM NORMAL (ON THE WARM SIDE OF NORMAL
FOR MOST LOCATIONS)...DEVELOPING NW FLOW EARLY NEXT WEEK WILL DROP
TEMPS TO BLO NORMAL...BUT NOT SIGNIFICANTLY AS THERE WON`T BE A TAP
OF CHILLY AIR FROM NORTHERN CANADA. ABOVE NORMAL TEMPS WILL RETURN
BY THU AHEAD OF THE AFOREMENTIONED SHORTWAVE ROUNDING THE RIDGE.
SOME COOLING SHOULD THEN FOLLOW BY THE WEEKEND...DEPENDING ON HOW
SHARPLY THE SHORTWAVE DROPS INTO THE ERN TROF.
BEGINNING SUN/SUN NIGHT...MID LEVEL LOW CURRENTLY OVER SRN MANITOBA
WILL HAVE OPENED UP AND WILL BE DRIFTING ACROSS NRN ONTARIO. TO THE
S OF THIS FEATURE...THERE REMAINS UNCERTAINTY IN THE WEAKER
SHORTWAVE ENERGY TRACKING ACROSS THE PLAINS TO THE GREAT LAKES...
PARTICULARLY WITH RESPECT TO WHERE CONVECTION WILL BE FIRING WITH
THESE MORE SUBTLE FEATURES. HOWEVER...THERE HAS BEEN A FAIRLY
CONSISTENT SIGNAL IN THE MODELS FOR A SUBTLE SFC WAVE AND MORE
SUBSTANTIAL CONVECTIVE ACTIVITY TRACKING EASTWARD FROM VCNTY OF IA
EARLY SUN ON THE NRN EDGE OF STRONG INSTABILITY IN THAT AREA. THIS
WILL HELP KEEP STRONG INSTABILITY FROM BUILDING N ALONG COLD FRONT
THAT WILL BE MOVING INTO THE UPPER LAKES SUN/SUN NIGHT IN
ASSOCIATION WITH THE NRN ONTARIO SHORTWAVE. AHEAD OF APPROACHING
COLD FRONT...NAM/GFS SHOW MLCAPE INCREASING TO ROUGHLY 500 TO
1500J/KG OVER THE W HALF OF UPPER MI SUN (NAM AS HIGH AS 2000J/KG).
WHILE THERE MAY BE A FEW SHRA IN THE MORNING...APPROACHING COLD
FRONT AND WEAK DEEP LAYER QVECTOR CONVERGENCE SHOULD SPARK SCT
CONVECTION IN THE AFTN WHICH WILL THEN SPREAD E INTO SUN NIGHT
ALONG/AHEAD OF PASSING COLD FRONT. WITH DEEP LAYER SHEAR NO GREATER
THAN AROUND 25KT...NOT ANTICIPATING ANY SVR STORMS. HOWEVER...IF
INSTABILITY ENDS UP AT OR ABOVE THE HIGH END OF THE CURRENTLY
EXPECTED RANGE...COULDN`T RULE OUT A BRIEF ISOLD SVR STORM. LATEST
SPC OUTLOOKS DO NOT HIGHLIGHT UPPER MI FOR A SVR RISK SUN/SUN
NIGHT...AND THAT LOOKS RIGHT ON TRACK.
ON MON...COLD FRONT SHOULD BE JUST E OF THE FCST AREA AT 12Z...
ENDING THE RISK OF MORE ORGANIZED PCPN. THE NAM STILL MANAGES TO
BUILD MLCAPE UPWARDS OF 1500J/KG OVER THE SCNTRL AND E...BUT THE GFS
SHOWS LESS THAN 50J/KG. SINCE OTHER MODELS SUPPORT THE GFS WITH A
STRONGER PRES GRADIENT BTWN HIGH PRES BUILDING INTO THE NRN PLAINS
AND LOW PRES/COLD FRONT TO THE E...WILL FAVOR THE THE DRIER/LACK OF
INSTABILITY GFS SOLUTION. WILL LINGER SCHC POPS FOR SHRA OVER THE E
EARLY. OTHERWISE...PLAN TO CARRY A DRY FCST ON MON. EXPECT HIGHS IN
THE 70S...BUT IT WILL BE COOLER NEAR LAKE SUPERIOR...ESPECIALLY OVER
THE E UNDER NNW WINDS THERE.
MON NIGHT THRU WED...BUILDING UPPER RIDGE WITH AXIS ROUGHLY OVER THE
WRN HIGH PLAINS WILL FORCE A DEEPENING ERN NAMERICA TROF AND NW FLOW
OVER THE GREAT LAKES...RESULTING IN COOLER WEATHER...BUT ONLY A
LITTLE BLO NORMAL FOR EARLY/MID AUG. IN THE INTERIOR...NIGHTTIME MIN
TEMPS WILL PROBABLY BE IN THE 40S IN THE USUAL COOL SPOTS. THERE
CONTINUES TO BE SOME INDICATION OF A WEAK SHORTWAVE DROPPING THRU
THE UPPER LAKES ON TUE WHICH COULD GENERATE A FEW ISOLD SHRA WITH
DAYTIME HEATING. AT THIS POINT...THE POTENTIAL IS STILL LOW ENOUGH
TO PRECLUDE A MENTION OF PCPN IN THE FCST FOR TUE. WITH UPPER TROF
SHIFTING A BIT FARTHER E ON WED AND SFC HIGH PRES MORE FIRMLY OVER
THE AREA...DRY WEATHER IS EXPECTED TO CONTINUE. MAX TEMPS WILL BE A
LITTLE HIGHER ON WED.
THU/FRI...TRENDS IN MEDIUM RANGE GUIDANCE ARE FOR A STRONGER
SHORTWAVE TO CUT THRU THE NRN PORTION OF THE WRN RIDGE AND THEN DROP
MORE SHARPLY TO THE SE INTO THE ERN NAMERICA TROF LATE NEXT WEEK. IF
THIS TREND CONTINUES WITH THE NEXT SET OF MEDIUM RANGE GUIDANCE...
THEN SHRA/TSTM CHANCES WILL NEED TO BE INCREASED FOR THU...WITH PCPN
POSSIBLE AS EARLY AS WED DEPENDING ON WHERE WAA IS FOCUSED AHEAD OF
THE SHORTWAVE. THE 00Z ECWMF/GFS INDICATE COLD FRONT WILL BE S OF
THE AREA BY FRI...LEADING TO A DRY DAY AND SOME COOLING. WILL WAIT
TO SEE IF THESE TRENDS FOR THU/FRI HOLD UP IN THE NEXT ROUND OF
GUIDANCE BEFORE SHIFTING FCST MORE STRONGLY TOWARD THIS SOLUTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 150 PM EDT SAT AUG 8 2015
VFR DIURNAL CLOUDS WILL BE THE MAIN SHORT TERM CONCERN. THESE
CEILINGS HAVE BEEN GRADUALLY RISING WITH DAYTIME HEATING AND MIXING
AND EXPECT THAT TO CONTINUE INTO THE AFTERNOON AND THE HIGH END
MVFR CEILINGS SHOULD TRANSITION TO VFR WITHIN THE NEXT COUPLE
HOURS. OTHERWISE...A COLD FRONT FROM MINNESOTA THAT WILL MOVE
ACROSS THE AREA ON SUNDAY MAY PUSH A COUPLE SHOWERS THROUGH THE
WESTERN HALF OF UPPER MICHIGAN AND ONLY HAD ENOUGH CONFIDENCE TO
INCLUDE VCSH AT KCMX OVERNIGHT AND LATE IN THE PERIOD AT KSAW. ALSO
FOR KSAW...DEPENDING ON THE AMOUNT OF SCATTERING OF THE CLOUDS THIS
EVENING...COULD SEE LIFR-IFR CONDITIONS DEVELOP WITH PATCHY GROUND
FOG OVERNIGHT TONIGHT. HAVE WENT WITH LOW END MVFR VISIBILITIES FOR
NOW...BUT WILL BE SOMETHING TO MONITOR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 250 PM EDT SAT AUG 8 2015
A LOW MOVING FROM JUST EAST OF LAKE WINNIPEG TO JAMES BAY THIS
WEEKEND WILL SWEEP A SURFACE TROUGH ACROSS LAKE SUPERIOR ON
SUNDAY...LEADING TO A SHIFT IN THE WINDS FROM A LIGHT SOUTH TO
SOUTHEASTERLY DIRECTION TO THE NORTHWEST BY MONDAY. WITH A
GENERALLY LIGHT PRESSURE GRADIENT IN PLACE...EXPECT WINDS TO STAY
BELOW 20KTS THROUGH THE PERIOD...ESPECIALLY AFTER TUESDAY WHEN HIGH
PRESSURE WILL SETTLE OVER THE GREAT LAKES REGION FOR THE MIDDLE OF
NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
335 PM CDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 336 PM CDT SAT AUG 8 2015
THE MAIN SHORT TERM CONCERN IS THE CONVECTIVE THREAT INTO THE
EVENING AND REDEVELOPING SUNDAY.
WIDELY SCATTERED SHOWERS CONTINUE TO MOVE EAST ACROSS THE AREA.
SOME HEATING OCCURRED TO THE WEST AND SOUTH AS CLOUDS CLEARED SOME.
THE LATEST SPC MESOSCALE ANALYSIS SHOWS MLCAPE 1500-200 J/KG OVER
THE MN PORTION OF THE AREA. BEST SHEAR IS LOCATED OVER NORTHEAST MN
IN THE AREA WHERE A MORE CONCENTRATED AREA OF STORMS CURRENTLY
RESIDES. ANY REAL SEVERE POTENTIAL WILL BE FOUND IN THIS AREA INTO
THE EVENING...POSSIBLE MAKING IT INTO THE NORTHEAST PORTION OF THE
CWA. WILL CONTINUE THE HIGHER CHANCE POPS IN THIS AREA...TRAILING
OFF TO SLIGHT CHANCE TO THE SOUTH. UPPER TROUGH MOVING ACROSS THE
NORTHERN PORTION OF THE STATE SHOULD DRIVE MAIN CONVECTIVE THREAT
OVER THE NORTHEAST. ALSO...SHOULD SEE STORMS GRADUALLY WEAKEN WITH
THE LOSS OF HEATING INTO THE EVENING.
AT THE MOMENT...FEEL THERE WILL BE ENOUGH CLOUD COVER AROUND FROM
THE FRONT TO THE NORTH AND THE MCS TO THE SOUTH TO LIMIT SIGNIFICANT
FOG. HOWEVER...IF THE SKY CLEARS OUT SIGNIFICANTLY LATE
TONIGHT...FOG MAY BECOME MORE OF AN ISSUE WITH LIGHT WINDS AND
HIGHER DEWPOINTS AROUND.
THE SURFACE FRONT DROPS INTO THE AREA SUNDAY WITH ATTENDANT CHANCE
OF -TSRA MAINLY IN THE AFTERNOON. WE CURRENTLY HAVE A MARGINAL
SEVERE RISK OVER THE SOUTHWEST PORTION OVER THE CWA...WHICH LOOKS
BEST AT THIS TIME.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 336 PM CDT SAT AUG 8 2015
THE LONG TERM FORECAST IS BOOK-ENDED WITH SHOWER AND
THUNDERSTORM CHANCES...BUT WILL BE MARKED OVERALL BY DRY AND
BENIGN WEATHER.
SUNDAY NIGHT THE WASHED OUT BOUNDARY WILL BE STRETCHED FROM
SOUTHERN MN INTO CENTRAL WI. THIS WILL BE THE MOST LIKELY
OPPORTUNITY FOR SHOWERS AND THUNDERSTORMS AS A SHORTWAVE MOVES
OVERHEAD ON THE NORTHERN PERIPHERY OF THE SOUTHERN PLAINS MID
LEVEL RIDGE. MOISTURE CONVERGENCE IS ADMITTEDLY BETTER TO THE
SOUTH...BUT WE WILL HAVE PLENTY OF ANTECEDENT MOISTURE TO COMBINE
WITH THE LIFT PROVIDED BY THE SHORTWAVE TROUGH.
MONDAY MORNING WILL LIKELY BE MET WITH LINGERING SHOWERS AND
THUNDERSTORMS OVER SOUTHEAST MN...BUT EXPECT THE BOUNDARY AND
ASSOCIATED PRECIP TO BE OUT OF THE AREA BY THE AFTERNOON.
MONDAY NIGHT AND TUESDAY BRINGS THE ARRIVAL OF BROAD SURFACE HIGH
PRESSURE...WHICH WILL TRANSLATE TO LIGHT WINDS...MOSTLY
CLEAR/SUNNY SKIES...AND SEASONAL TEMPS. COULD SEE SOME FOG
FORMATION DURING THE OVERNIGHT PERIODS...BUT AN OTHERWISE A BENIGN
WEATHER FORECAST WITH FEW CONCERNS IS ANTICIPATED INTO THURSDAY.
THURSDAY NOW LOOKS TO FEATURE SMALL SHOWER AND THUNDERSTORM
CHANCES WITH THE ARRIVAL OF A WEAK BOUNDARY ACROSS THE AREA AS A
WEAK MID LEVEL TROUGH SKIRTS THE INTERNATIONAL BORDER. HAVE
INCLUDED 20-30 POPS ON THURSDAY AND THURSDAY NIGHT...BUT IT
CERTAINLY DOES NOT LOOK TO BE A WASHOUT.
HIGH TEMPS THROUGH THE PERIOD WILL VARY FROM THE UPPER 70S TO
LOWER 80S...WITH THE EXCEPTION OF THURSDAY WHEN SLIGHTLY HIGHER
TEMPS ARE EXPECTED AHEAD OF THE APPROACHING BOUNDARY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1255 PM CDT SAT AUG 8 2015
-SHRA/ISOLD -TSRA OVER MUCH OF CENTRAL MN LATE THIS MORNING. THIS
ARE BEING GENERATED AHEAD OF SURFACE BOUNDARY OVER THE DAKOTAS
WITH SOME WEAK LOWER LEVEL FRONTOGENESIS/WAA. LATEST HRRR TRENDS
SHOW THIS AREA MOVING EAST THE REST OF THE AFTERNOON. SOME
REDEVELOPMENT EXPECTED ALONG/AHEAD OF THE BOUNDARY...MAINLY
OVER THE NORTHWEST AREA/KAXN/KSTC INTO THE EVENING. APPEAR
ACTIVITY WILL BE MAINLY DIURNAL WITH WEAKENING TREND EXPECTED BY
SUNSET. MVFR CIGS CURRENTLY OVER WISCONSIN WILL LIFT THIS
AFTERNOON AND MAY BREAK OUT IN SPOTS. OTHERWISE MAINLY VFR OUTSIDE
OF -SHRA/-TSRA WHICH WILL REMAIN WIDELY SCT/ISOLD. IF THE SKY
CLEARS OUT SIGNIFICANTLY...WILL LIKELY SEE MORE FOG DEVELOP. MOST
OF THE AREA IS EXPECTED TO MAINTAIN SOME CLOUD COVER WHICH SHOULD
LIMIT SIGNIFICANT FOG AT TAF SITES.
KMSP...VFR EXPECTED WITH MIX OF CLOUD HEIGHTS INTO THE AFTERNOON.
-SHRA BAND OVER CENTRAL MN WILL AFFECT THE AREA THROUGH ABOUT 22Z
OR SO. CONFIDENCE ON THUNDER IS LOW AT THIS TIME. BETTER CHANCE OF
THAT NEAR THE SURFACE BOUNDARY TO THE NORTHWEST AND IN SOME
CLEARING OVER SOUTH CENTRAL MN. SHOULD SEE ANY SHOWERS COME TO AN
END THIS EVENING AND THEN REDEVELOPMENT POSSIBLE INTO SUNDAY
AFTERNOON/EVENING WITH THE FRONT. SFC WINDS SE-S THIS AFTERNOON
BECOMING LIGHT OVERNIGHT.
/OUTLOOK FOR KMSP/
SUN NITE....VFR. CHC MVFR CIGS -TSRA. WINDS NW 5-10 KNOTS.
MON-TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1254 PM CDT SAT AUG 8 2015
.UPDATED FOR 18Z AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM CDT SAT AUG 8 2015
MAIN CONCERN FOR THE SHORT TERM REMAINS THE CHANCE OF SHOWERS AND
THUNDERSTORMS. TROUGH EXTENDING FROM LARGE UPPER LOW IN SOUTHERN
MANITOBA EXTENDS TO MN AND SD...BUT ITS SOUTHERN REACH IS CERTAINLY
BEING AFFECTED BY THE MCS IN IOWA. HEIGHTS BEGIN RISING SLIGHTLY
THIS AFTERNOON ONCE THE MCS PASSES THE REGION. SLIGHT RIDGING
CONTINUES INTO THIS EVENING OVER MN AND WI...UNTIL THE NEXT WEAK
SHORT WAVE APPROACHES LATE TONIGHT...BUT THE IMPACT OF THAT WILL
MAINLY BE ON SUNDAY. HAVE KEPT POPS FOR LATE TONIGHT IN WESTERN
SECTIONS.
MEANWHILE...SPOTTY SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP
EARLY THIS MORNING FROM NORTHERN MN INTO SE SD AND SW MN. SHEAR
VALUES ARE OK FOR STORMS BUT LOW AND MID LEVEL LAPSE RATES ARE
RATHER POOR TODAY AND TONIGHT. A VARIETY OF CAMS DID FLAG THE RECENT
DEVELOPMENT OF STORMS IN EASTERN SD...AND THIS IS EVIDENT IN THE
STORMS RECENTLY DEVELOPED IN EASTERN SD. WILL NEED TO CONTINUE THE
MENTION OF POPS THIS MORNING...ESPECIALLY IN WEST CENTRAL AND
CENTRAL MN. MAIN THERMAL GRADIENT IS DRAPED FROM NORTHEAST MN TO THE
WEST CENTRAL...AND THIS IS WHERE STORMS COULD REDEVELOP LATER THIS
AFTERNOON WITH ENOUGH HEATING.
LOW CLOUDS FROM RICE LAKE TO EAU CLAIRE AREA WILL GRADUALLY DIMINISH
LATER THIS MORNING. A LITTLE DENSE FOG HAS FORMED JUST ON THE
PERIPHERY OF THE LOW CLOUDS...BUT THIS SHOULD DISSIPATE DURING THE
MID MORNING AFTER SOME HEATING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 418 AM CDT SAT AUG 8 2015
MINNESOTA AND WISCONSIN WILL BE BETWEEN DISTURBANCES ON SUNDAY.
THE SATURDAY NIGHT MCS ACROSS IOWA WILL BE HEADED EAST ACROSS
NORTHERN AND CENTRAL IL SUNDAY MORNING...WITH THE LAST OF THE
WESTERN ENERGY EJECTING EASTWARD ACROSS THE DAKOTAS BY AFTERNOON.
THIS LEAVES THE AREA WITH LITTLE TO SUPPORT THUNDERSTORM
DEVELOPMENT UNTIL THE NORTHERN PLAINS ENERGY ARRIVES SUNDAY NIGHT.
POPS WERE INCREASED ACROSS MN SUNDAY NIGHT AS THIS WAVE TRACKS
EAST SOUTHEASTWARD ON THE NORTHEAST PERIPHERY OF THE RETROGRADING
MID LEVEL RIDGE TO THE SOUTH. MODELS ARE IN PRETTY GOOD AGREEMENT
IN ADVERTISING SHOWERS AND THUNDERSTORMS ACROSS WRN/SRN MN SUNDAY
NIGHT. RAINFALL AMOUNTS SHOULD NOT BE ALL THAT SIGNIFICANT ON A
WIDESPREAD BASIS WITH THE ABSENCE OF A LLJ HELPING TO ORGANIZE
THE ACTIVITY...BUT PW VALUES NEARING 1.75 INCHES WILL LEND
CREDENCE TO LOCALIZED HEAVY RAINFALL RATES TOWARD SOUTHWESTERN
MINNESOTA.
AFTER THAT PIECE OF ENERGY EXITS TO THE SOUTHEAST MONDAY
MORNING...SURFACE HIGH PRESSURE WILL SLOWLY TRACK SOUTHEAST ACROSS
THE MISSISSIPPI VALLEY NEXT WEEK. A GRADUAL WARMING TREND CAN BE
EXPECTED WITH THICKNESSES BUILDING THROUGH THE WEEK. COULD SEE A
WEAK FRONT PUSH THROUGH LATE WEEK IF ANOTHER TROUGH SWINGS THROUGH
EASTERN CANADA. THIS WOULD BRING THE NEXT LOW CHANCE OF STORMS.
OTHERWISE...SEVERAL DAYS OF DRY WEATHER ARE EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1255 PM CDT SAT AUG 8 2015
-SHRA/ISOLD -TSRA OVER MUCH OF CENTRAL MN LATE THIS MORNING. THIS
ARE BEING GENERATED AHEAD OF SURFACE BOUNDARY OVER THE DAKOTAS
WITH SOME WEAK LOWER LEVEL FRONTOGENESIS/WAA. LATEST HRRR TRENDS
SHOW THIS AREA MOVING EAST THE REST OF THE AFTERNOON. SOME
REDEVELOPMENT EXPECTED ALONG/AHEAD OF THE BOUNDARY...MAINLY
OVER THE NORTHWEST AREA/KAXN/KSTC INTO THE EVENING. APPEAR
ACTIVITY WILL BE MAINLY DIURNAL WITH WEAKENING TREND EXPECTED BY
SUNSET. MVFR CIGS CURRENTLY OVER WISCONSIN WILL LIFT THIS
AFTERNOON AND MAY BREAK OUT IN SPOTS. OTHERWISE MAINLY VFR OUTSIDE
OF -SHRA/-TSRA WHICH WILL REMAIN WIDELY SCT/ISOLD. IF THE SKY
CLEARS OUT SIGNIFICANTLY...WILL LIKELY SEE MORE FOG DEVELOP. MOST
OF THE AREA IS EXPECTED TO MAINTAIN SOME CLOUD COVER WHICH SHOULD
LIMIT SIGNIFICANT FOG AT TAF SITES.
KMSP...VFR EXPECTED WITH MIX OF CLOUD HEIGHTS INTO THE AFTERNOON.
-SHRA BAND OVER CENTRAL MN WILL AFFECT THE AREA THROUGH ABOUT 22Z
OR SO. CONFIDENCE ON THUNDER IS LOW AT THIS TIME. BETTER CHANCE OF
THAT NEAR THE SURFACE BOUNDARY TO THE NORTHWEST AND IN SOME
CLEARING OVER SOUTH CENTRAL MN. SHOULD SEE ANY SHOWERS COME TO AN
END THIS EVENING AND THEN REDEVELOPMENT POSSIBLE INTO SUNDAY
AFTERNOON/EVENING WITH THE FRONT. SFC WINDS SE-S THIS AFTERNOON
BECOMING LIGHT OVERNIGHT.
/OUTLOOK FOR KMSP/
SUN NITE....VFR. CHC MVFR CIGS -TSRA. WINDS NW 5-10 KNOTS.
MON-TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TDK
LONG TERM...BORGHOFF
AVIATION...DWE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1252 PM CDT SAT AUG 8 2015
.UPDATE:
ISSUED AT 1033 AM CDT SAT AUG 8 2015
MCS REMNANTS HAVE BEEN STEADILY DECAYING ACROSS NORTH CENTRAL MO
AND CENTRAL MO. POPS HAVE BEEN REDUCED ACCORDINGLY.
KANOFSKY
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPAGATING SOUTHEAST INTO SOUTH CENTRAL
ILLINOIS ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH
THIS SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1234 PM CDT SAT AUG 8 2015
SPECIFICS FOR KUIN: LIGHT RAIN SHOWERS ARE POSSIBLE AT KUIN
THROUGH 08/19Z. INITIALLY EASTERLY WINDS WILL BECOME SOUTHEASTERLY
TO SOUTHERLY THROUGH THE PERIOD. A THUNDERSTORM COMPLEX IS
EXPECTED TO DEVELOP UPSTREAM OVERNIGHT AND REACH KUIN AFTER
09/06Z. THERE IS SOME UNCERTAINTY ON WHERE THE COMPLEX WILL FORM
AND WHEN IT MIGHT REACH KUIN.
SPECIFICS FOR KCOU: INITIALLY SOUTHEASTERLY WINDS WILL BECOME
SOUTHWESTERLY THROUGH THE TAF PERIOD IN RESPONSE TO AN APPROACHING
LOW PRESSURE CENTER. A THUNDERSTORM COMPLEX IS EXPECTED TO
DEVELOP UPSTREAM OVERNIGHT AND REACH KCOU AFTER 08/03Z. THERE IS
SOME UNCERTAINTY ON WHERE THE COMPLEX WILL FORM AND WHEN IT MIGHT
REACH KCOU.
SPECIFICS FOR KSTL, KSUS, KCPS: LIGHT WINDS HAVE BEEN SLOW TO
BECOME SOUTHEASTERLY THIS MORNING. LIGHT NORTHWEST TO WEST WINDS
MAY PERSIST FOR A FEW MORE HOURS BEFORE TURNING SOUTHEASTERLY IN
RESPONSE TO A DEVELOPING SURFACE LOW OVER KS. LIGHT WINDS AT KCOU
HAVE RECENTLY TURNED SOUTHEASTERLY, SUGGESTING THAT THE WIND
DIRECTION SHOULD FOLLOW SUIT AT ST. LOUIS METRO AREA TERMINALS
WITHIN THE NEXT 2-5 HOURS. A THUNDERSTORM COMPLEX IS EXPECTED TO
DEVELOP UPSTREAM OVERNIGHT AND PROGRESS SOUTHEASTWARDS, EVENTUALLY
REACHING THE TERMINALS AFTER 09/09Z.
KANOFSKY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1250 PM CDT SAT AUG 8 2015
...AVIATION UPDATE...
.SHORT TERM...(Today through Sunday)
Issued at 305 AM CDT SAT AUG 08 2015
First concern is ongoing convection across northern Kansas.
Successive runs of the HRRR dissipates this area before it gets
into the forecast area as does the RAP. Given expanding ridging
would expect it to dissipate as it gets closer and stay north of
the area. Will monitor radar trends and update as needed. For now
will keep dry forecast for the morning hours.
Attention then turns to the aforementioned expanding ridge across
the area. This ridge will dominate the weather through Sunday with
increasing heat and humidity. Heat advisory already in effect for
much of the area from this afternoon through Sunday evening. Expect
afternoon heat indicies in the 100 to 110 degree range both days.
Biggest question will be the need to expand the advisory further
eastward. Eastern Ozarks best chance to hit advisory criteria would
be Sunday afternoon. Will allow day shift to evaluate it further.
.LONG TERM...(Sunday night through Friday)
Issued at 305 AM CDT SAT AUG 08 2015
Upper ridge retracts westward Sunday night and Monday allowing for a
surface frontal boundary to slip southward into the area. This will
bring our next chance for rain. Medium range models showing the
better chances across central Missouri from late Sunday night into
Monday morning.
Pattern then dominated by a northwest flow regime with a surface
high building southward into the area. This will result in quiet
and dry weather with near to slightly below normal temperatures.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Pilots flying in and out of the southwest Missouri airports will
experience VFR conditions over the next 24 hours.
Southeast surface winds will be common as cloud cover begins to
clear out for the rest of today and tonight.
Thunderstorms will once again develop tonight, however, they are
expected to remain north of the Ozarks.
Safe Travels.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY until 10 PM CDT Sunday for MOZ055-056-066>069-
077>081-088>096-101>105.
KS...HEAT ADVISORY until 10 PM CDT Sunday for KSZ073-097-101.
&&
$$
SHORT TERM...Raberding
LONG TERM...Raberding
AVIATION...Cramer
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1231 PM CDT SAT AUG 8 2015
.DISCUSSION...
Issued at 357 AM CDT SAT AUG 8 2015
As was anticipated last night, High Plains convection has congealed
into an overnight MCS, which has made pretty good progression across
northern Kansas, into north central Kansas. Models have had a rough
time resolving exactly how this MCS will behave as it continues east.
NAM consistently indicates that this complex will lose steam as the
night progresses, but HRRR continues to insist that the complex will
continue it, albeit weakening along the way, into the KC metro around
sunrise. General thought as the morning progresses is a bit in the
middle between these two solutions. The low level jet, apparently
helping this complex persist is not very strong, but it also doesn`t
appear to weaken much as one gets closer to the KC Metro. However,
with the outflow from these storms already pushing out ahead of the
complex, there is a good bet that stabilization of the effective
layer will gradually occur and the storms will eventually lose their
strength. Have the best chance of rain occurring across the far
northwestern part of the CWA, in NW Missouri and NE Kansas, with
diminishing (but non-zero) chances farther south and east.
The focus then shifts to a complicated and conditional forecast for
Saturday. Heat headlines currently ongoing will be allowed to
continue, however confidence in these abnormally hot temperatures
isn`t quite as high as it was yesterday. The aforementioned storm
complex could change the evolution of the heat today across a good
portion of the area. If the HRRR has its way and the complex dives
all the way into the KC Metro it would bring at least some rain into
the morning hours, with likely some cloud debris lingering around
for a good portion of the morning. Even with all these qualifiers
it`s still anticipated that the surface will recover, despite the
stable rain cooled air moving through this morning. Expect heat
indices to jump into the 100 to 105 range this afternoon with some
locations perhaps reaching a little higher, mainly along and south
of the MO River.
That leads to the complications and conditions related to the storm
chances later this afternoon and this evening. Mid level flow
continues to reside over the central and northern plains with the
center of the mid level ridge well south of the forecast area in the
eastern southern plains. At the surface an unseasonably deep trough
will form across the central High Plains and eject into the lower
central plains. In response to this low to the west S/SE winds will
pick up during the day, and likely overcome the cooler air, causing
temperatures to jump back into the upper 80s, and very possibly the
lower 90s. Across far northern Missouri, where cloud debris will
likely be the thickest, as well as perhaps along or north of the
warm front temperatures won`t get quite as warm as areas along and
south of I-70. Depending on how well skies clear out this afternoon
another round of storms will be possible, most likely across SE
Nebraska, eastward across northern Missouri and southern Iowa. Most
models continue to indicate a scenario where storms indeed fire
later today. The lack of any appreciable mid level support for
ascent this afternoon will exaggerate the capping inversion, which
will keep storms at bay for at least the afternoon, into the evening
hours. By the 22z to 00z time period the low level jet at 850 mb
will pick up in intensity and likely give the final push needed to
get storms to go up, likely in SE Nebraska or NE Kansas. Should these
storms become surface based, which isn`t out of the question, a very
impressive thermal and wind profile will be in place to bring some
powerful storms. With the aforementioned SE surface flow, the
strengthening LLJ, as well as the westerly mid level flow around 40
kts. The wind profile will be ample for supercell storms to form
later this evening in the SE Neb/NW Mo/NE Ks area. ML CAPE values
approaching 2000 to 3000 J/KG will provide the necessary instability
to complement the deep layer shear nicely. Given that supercells are
possible, hail and wind would be the most likely hazards with these
storms; however not to be discounted, very impressive hodographs are
present across the area of concern, with very long and clockwise
curved hodographs. This would introduce a rather concerning tornado
risk, especially for early August. Given the weak forcing it`s
certainly possible that early storms will be somewhat discreet,
which would increase the concern for supercellular storms. However,
by 00z to 03z the discreet storms will likely congeal into a more
robust complex and drive eastward, likely along the MO/IA border,
bringing a wind and hail threat, along with a flash flooding threat.
Given the LLJ maintenance overnight and PWAT values approaching 2 to
2.5 inches it`s possible that areas along and north of HWY 36
tonight could see some flooding and/or flash flooding. By early
Sunday morning expect these storms to have moved off to the east and
chances for rain gradually diminishing through the day on Sunday.
For Sunday, warm conditions will continue for the forecast area,
again, mainly across the southern zones. Anticipate temperatures
again to reach the 90s, with heat indices in the 100 to 105 range
across areas along and south of the MO River. But again, depending
on how the area clears, the areal extent of the heat for Sunday is a
bit up in the air, so will forgo a heat headline for now, but one
may be necessary for areas along and south of the MO River.
For Sunday, into Monday the large ridge will shift a little back to
the west, putting the forecast area under more of an influence of
the large trough over the Great Lakes region as opposed to the
western ridge. A short wave trough will glide through the area on
Monday, which should bring another chance for some rain, as well as
a cooler air mass. For the rest of the week, expect temperatures to
be a bit more comfortable with temperatures generally in the 80s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1231 PM CDT SAT AUG 8 2015
Main concerns with afternoon forecast involve possibilities for
renewed convection later today/evening as a seasonably strong sfc
low tracks east from the central High Plains. Current thinking is
main show will remain north of Kansas City terminals later
tonight...with main threats confined to STJ after the 00z time
frame. Considering the amount of uncertainty on just where convection
does form...have decided to offer a VCTS mention at STJ beginning at
2z or so. Once convective trends are better established...updates
will be issued accordingly. Otherwise...expect VFR conditions at
remaining sites with southeast winds eventually becoming southwest
after 12z Sunday morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 9 PM CDT this evening for KSZ025-057-060-102.
EXCESSIVE HEAT WARNING until 9 PM CDT this evening for
KSZ103>105.
MO...HEAT ADVISORY until 9 PM CDT this evening for MOZ011>014-020>023-
030-031-038-039-043>046-053-054.
EXCESSIVE HEAT WARNING until 9 PM CDT this evening for MOZ028-
029-037.
&&
$$
DISCUSSION...Leighton
AVIATION...32
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
315 PM CDT SAT AUG 8 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 315 PM CDT SAT AUG 8 2015
NO BIG CHANGES FROM PREVIOUS THINKING...MAIN CONCERN IS POTENTIAL
FOR SEVERE WEATHER AND HEAVY RAIN. THE SEVERE THREAT WOULD MAINLY
BE PRIOR TO 06Z TONIGHT AND THEN ALSO LATE SUN AFTN/SUN EVENING.
HEAVY RAIN THREAT IS PRIOR TO ABOUT 08Z TONIGHT...AND MAINLY IN
SWRN IA.
JET PATTERN AT 12Z SHOWED 300 MB WINDS OF 50 TO 80 KNOTS FROM SRN
CA INTO SD/ND/MN. A 500 MB LOW WAS OVER SRN ID AT 12Z BUT WATER
VAPOR IMAGERY/RECENT RUC MODEL INITILIZATIONS SHOWED IT HAD MOVED
TO NEAR THE ID/MT/WY BORDER AREA AS OF EARLY THIS AFTN. THIS WILL
CONTINUE TO TRACK SLOWLY NEWD/EWD TONIGHT. THE 19Z KOAX SOUNDING
SHOWED THAT THE MID LEVELS HAD WARMED A BIT SINCE 12Z. OUR 12Z
700 MB TEMP WAS 7.6 C BUT HAD INCREASED TO 10.7 C AS OF 19Z.
19Z SPC MESOANALYSIS SHOWED THAT THERE WAS STILL QUITE A BIT OF
LOWEST 100 MB CONVECTIVE INHIBITION (MLCIN) AND MOST OF THE AREA
WAS NOT OVERLY UNSTABLE. HIGHEST MLCAPE WAS NEAR THE KS BORDER...
AROUND 2000 J/KG. CAP WAS WEAKEST FROM SWRN KS INTO PARTS OF CNTRL
KS AS OF MID AFTN...NEAR AND AHEAD OF SFC LOW PRES CENTER.
THERE REMAINS A CONDITIONAL THREAT OF SEVERE WEATHER FOR MOST OF
THE AREA. 0-6 KM SHEAR IS EXPECTED TO BE ADEQUATE FOR ROTATING
STORMS...BUT THERE IS SOME UNCERTAINTY AS TO WHEN AND WHERE
STRONG/SEVERE STORMS MAY FORM. THE MODELS OFFER VARYING SOLUTIONS.
ONE THING WE SAY IS THAT IT DOES APPEAR THAT BEST FOCUS WILL
SHIFT TO IA AND NRN MO LATER TONIGHT WITH A 30-50 KNOT LOW LEVEL
JET. LOWS SHOULD RANGE FROM MID 60S N TO AROUND 70 S.
WILL KEEP STORM CHANCES OVERNIGHT AND SUNDAY MORNING FOR AT LEAST
PARTS OF THE FCST AREA. BETTER POTENTIAL THOUGH APPEARS TO BE
LATER IN THE DAY ACRS OUR NRN ZONES...AS A FRONTAL SYSTEM DROPS
INTO THE AREA. KEPT SOME LOW POPS FOR LATE SUNDAY NIGHT AND MONDAY
BUT NOT IMPRESSED WITH RAIN POTENTIAL IN THOSE PERIODS FOR NOW...
ESPECIALLY MONDAY WHEN SURFACE RIDGE AXIS WILL BE BUILDING DOWN
ACROSS THE REGION.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT AUG 8 2015
PCPN CHANCES LOOK TO BE 14 PERCENT OR LESS FROM MONDAY NIGHT
ONWARD...SO FCST TEXT WILL NOT HAVE ANY MENTION OF TSTMS IN THOSE
PERIODS. 500 MB RIDGE IS EXPECTED TO BUILD W AND N FROM OK AND TX
MUCH OF THE WEEK...THEN FLATTEN A BIT BY NEXT WEEKEND AS TROUGH
MOVES EAST FROM THE PACIFIC NW AND NRN ROCKIES. LEFT A BLEND OF
GFS AND ECMWF TEMPS IN THE EXTENDED PERIOD...BUT HIGHS MAY END UP
BEING A BIT WARMER THAN THAT.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1217 PM CDT SAT AUG 8 2015
GENERALLY VFR CONDITIONS ARE EXPECTED INTO THE OVERNIGHT PERIOD.
WE WILL SEE A BKN MID AND HIGH LEVEL DECK THROUGH THE DAY TODAY
AND LIGHT SOUTHEAST WINDS. THERE IS SOME THREAT OF SHRA AT
KLNK/KOMA LATE THIS AFTN INTO THE EARLY EVENING AND WILL INCLUDE A
TEMPO GROUP FOR THESE TAFS. OVERNIGHT WE EXPECT SOME IFR CIGS
DEVELOP FOR KOMA/KOFK...WHICH MAY GET CLOSE TO KLNK BY SUN MRNG.
WE WILL ALSO SEE SOME MVFR VSBY OVERNIGHT AS WELL. CONDITIONS
SHOULD IMPROVE BY MID TO LATE MORNING SUNDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS ELKO NV
325 PM PDT SAT AUG 8 2015
.SYNOPSIS...REMNANT MOISTURE WILL FUEL ISOLATED TO SCATTERED
THUNDERSTORMS THIS AFTERNOON. DRIER CONDITIONS ANTICIPATED SUNDAY
AND MONDAY. THE MONSOON WILL RETURN OVER EASTERN NEVADA MIDWEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY. THE LONGWAVE PATTERN FEATURES
AN H5 LOW OVER IDAHO...AND A CLOSED LOW UPSTREAM OFF THE COAST OF
BRITISH COLUMBIA...AND A DOME OF HIGH PRESSURE OVER TEXAS.
SUFFICIENT LI`S AND CAPES FOR CONVECTION INTO THE EVENING...AND
BOTH THE HRRR AND THE 18Z NAM PINGING INTO TSRA FOR THE LKN CWA.
THE CONVECTIVE TEMP FOR 21Z IS 77F FOR KEKO WITH A PW OF .73 OF AN
INCH. THE 18Z RUN OF THE GFS IS MORE STABLE...BUT...POPS WERE
HEDGED TOWARDS A NAM/HRRR COMPROMISE AND REALTIME OBSERVATIONS.
AS TIME ELAPSES...EXPECT THE PWS TO DRY OUT...AND EXPECT AFTERNOON
TEMPERATURES TO REMAIN SLIGHTLY BELOW NORMAL FOR THE MONTH OF
AUGUST.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY. THE LONG TERM MODELS ARE
IN MUCH BETTER AGREEMENT TODAY THAN PREVIOUSLY. EVEN DEPICTING THE
SLUG OF MOISTURE COMING UP OUT OF THE GULF OF CALI WED INTO THU IS
NICELY DONE. THIS IS IN AGREEMENT WITH PREVIOUS IDEAS...TOO.
OVERALL...THERE IS NOT MUCH CHANGE TO THE PREVIOUS FORECAST PACKAGE
OTHER THAN SOME TWEAKS TO MAKE SURE WE AGREE WITH SURROUNDING
OFFICES` FORECASTS. TEMPS WILL BE NEAR NORMAL WITH A LITTLE COOL
DOWN DUE TO CLOUDS. MOSTLY DRY PERIOD WITH INCREASED SOUTHWEST FLOW
FROM PACIFIC LOW COMING IN FIRST PART. ISOLATED MAINLY SOLAR DRIVEN
TERRAIN ENHANCED THUNDERSTORMS COULD OCCUR LATE MONDAY INTO TUESDAY
OVER WHITE PINE COUNTY AND THE JARBIDGE AREA. LOW AND CENTRAL NOAM
RIDGE WORK IN TANDEM WEDNESDAY TO BRING SOME LIMITED RH INTO EASTERN
NEVADA SO HAVE KEPT LOW POP MOSTLY THERE WED AND THUR.
WITH INCREASE OF CONVECTION WEDNESDAY AND THURSDAY AND TIGHTENING OF
GRADIENT ALOFT MIXING WINDS DOWN...COULD SEE SOME FIRE WX CONCERNS
MID TO LATE WEEK.
FRIDAY AND SATURDAY...DRIER AS UPPER LOW OPENS UP AND MOVES
NORTHEAST INTO THE NORTHERN ROCKIES.
&&
.AVIATION...REMNANT MOISTURE AND INSTABILITY HAS ALLOWED FOR
AFTERNOON CUMULUS DEVELOPMENT. CHANCE OF SHOWERS/STORMS, ALTHOUGH
SLIGHT, POSSIBLE THROUGH THE EVENING FOR KEKO, KWMC, AND KELY WITH
THE BEST POTENTIAL IN KEKO. THIS ACTIVITY SHOULD DISSIPATE AFTER
SUNDOWN AND DRY AND VFR CONDITIONS EXPECTED FOR SUN.
&&
.FIRE WEATHER...MORE LIGHTNING POSSIBLE THIS AFTERNOON...WITH THE
BEST LIGHTNING SHOW OVER 467 TODAY SO FAR. EXPECTING A DRYING
TREND...BUT BY MIDWEEK MODELS HINT AT ANOTHER MONSOON SURGE.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
97/98/98/97
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
307 PM EDT SAT AUG 8 2015
.SYNOPSIS...
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL MOVE NORTHEAST
AND ALLOW DRIER AND COOLER AIR TO SETTLE OVER THE AREA THROUGH
EARLY NEXT WEEK. RAIN CHANCES WILL INCREASE TUESDAY INTO WEDNESDAY
AS A COLD FRONT MAKES ITS WAY THROUGH THE REGION. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT LATE WEDNESDAY INTO THE EARLY PART
OF NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...THE SURFACE LOW WAS LOCATED OFFSHORE OF CAPE
HATTERAS AND LIFTING NORTHEAST. STRATOCU WILL PERSIST IN WRAPAROUND
CIRCULATION THROUGH THE REMAINDER OF THE AFTERNOON. A FEW VERY SMALL
AND ISOLATED SHOWERS HAVE POPPED UP ALONG THE NORTHERN TIER OF THE
CWA. THE HRRR DOES DEVELOP SOME OF THIS ACTIVITY FURTHER AS IS
MOVES SOUTHWARD SO AM INCLINED TO KEEP A SMALL POP FOR ISOLATED
SHOWERS THROUGH SUNSET.
OVERNIGHT...LOW CLOUDS SHOULD CONTINUE TO DECREASE HOWEVER MAY SEE
SOME UPPER-LEVEL REMNANTS FROM THE DYING MCC IN THE PLAINS. LIGHT
NNE FLOW OVERNIGHT WILL HINDER FOG DEVELOPMENT BUT WILL LET MIN
TEMPS FALL JUST BELOW CLIMO MOST AREAS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...AGREEABLE AND EARLY FALL-TYPE FEEL DAYBREAK
SUNDAY WITH MINIMUMS HAVING DIPPED INTO THE UPPER 60S MOST AREAS
BUT WELL REMOVED FROM RECORD LOWS FOR AUGUST 9TH OF 60 AT ILM IN
1997...60 AT FLO IN 2002...AND 62 AT CRE IN 2004. SUNSHINE WILL BE
MORE IN ABUNDANCE SUNDAY AND MONDAY COMPARED TO RECENT DAYS. THE
RELATIVELY LOW DEWPOINT READINGS WILL RESULT IN AN AIR-MASS WHICH
IS PLEASANTLY VOID OF HIGH HUMIDITY CONTENT...ALTHOUGH RETURN FLOW
AND INCREASING ABSOLUTE HUMIDITY WILL LIKELY BE OBSERVED LATE MON.
LATE MONDAY NIGHT INTO VERY EARLY TUESDAY AN APPROACHING SHORTWAVE
AND ASSOCIATED FRONTAL SYSTEM WILL DELIVER A CHANCE OF RAINFALL.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...THE MAIN FOCUS OF THE EXTENDED WILL BE ON
THE COLD FRONT MOVING ACROSS THE REGION LATE TUESDAY INTO EARLY
WEDNESDAY. A POTENT MID LEVEL SHORTWAVE WILL MOVE ACROSS THE GREAT
LAKES/MIDWEST ALONG WITH THIS FRONT. MEDIUM RANGE GUIDANCE SHOWS
FEW CHANGES THIS AFTERNOON AND WE CONTINUE TO ADVERTISE GOOD
CHANCE POPS FOR TUESDAY AND INTO PART OF WEDNESDAY. THE FRONT
MAKES IT ALL THE WAY TO THE FLORIDA PANHANDLE INITIALLY THEN
STALLS. SOME GUIDANCE SHOWS THE FRONT A LITTLE FURTHER TO THE
NORTH BEFORE WASHING OUT. WILL KEEP SLIGHT CHANCE POPS IN FOR
LATER PERIODS TO ADDRESS. TEMPERATURES THROUGHOUT THE PERIOD ARE
WITHIN A COUPLE OF DEGREES OF CLIMATOLOGY.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...STUBBORN STRATUS WILL SLOWLY RISE AND SCATTER BY MID
AFTERNOON. ALMOST A DUE NORTH WIND TODAY...GUSTY NEAR THE COAST.
CLEARING SKIES TONIGHT WITH SOME PATCHY FOG POSSIBLE...MAINLY
INLAND. FOG SHOULD STAY IN THE MVFR RANGE. SUNDAY...A NICE
AVIATION DAY WITH NEARLY CLEAR SKIES AND A LIGHT NORTHEAST WIND
AND WEAK HIGH PRESSURE IN PLACE. SOME ISOLATED CONVECTION IS
POSSIBLE OVER THE WESTERN PORTION OF THE REGION...LIKELY AFTER THE
TAF TIME WINDOW.
EXTENDED OUTLOOK...SCATTERED STORMS POSSIBLE ON MONDAY AND
TUESDAY...WITH PERIODS OF MVFR POSSIBLE. OTHERWISE EXPECT VFR
THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...THE SURFACE LOW WAS LOCATED OFF THE COAST OF
CAPE HATTERAS AND MOVING NORTHEAST THIS AFTERNOON. A NORTHERLY
WIND TRAJECTORY ON THE BACK SIDE OF THE LOW WILL CONTINUE
OVERNIGHT...AND THE PRESSURE GRADIENT WILL TREND WEAKER. THERE IS
AN OUTSIDE CHANCE OF A STRAY SHOWER OVERNIGHT...HOWEVER FOR THE
MOST PART EXPECT NO SIGNIFICANT REDEVELOPMENT OVER THE WATERS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...N-NE WINDS WILL BE GRACING THE 0-20 NM WATERS
DAYBREAK SUNDAY WITH SURFACE LOW PRESSURE ABOUT 100 NM OFFSHORE OF
CAPE HATTERAS. LATE SUNDAY A TRANSITION PERIOD...AS WINDS SWING
FROM THE SE 12 KT OR LESS. SE WINDS MONDAY WILL INCREASE MONDAY
NIGHT TO 13-18 KT AND BECOME S-SSW AHEAD OF AN APPROACHING LOW
PRESSURE SYSTEM FROM THE WEST. NO ADVISORIES APPEAR TO BE NEEDED
FOR THIS TIME PERIOD CURRENTLY. A FEW MARINE TSTMS ARE POSSIBLE
VERY EARLY TUESDAY BY THE PRE-DAWN HOURS. SEAS SUNDAY MAINLY NE
WAVES 3-4 FT EVERY 5-6 SECONDS. SEAS MONDAY ENE 2-3 FT EVERY 6-7
SECONDS AND ESE WAVES 1-2 FT EVERY 10 SECONDS.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...SOUTHWEST WINDS OF 15-20 KNOTS WILL PERSIST
OVER THE WATERS TUESDAY INTO WEDNESDAY MORNING. A COLD FRONT WILL
EASE ACROSS THE WATERS WEDNESDAY WITH WINDS TURNING TO NORTHWEST
WITH A VERY LIGHT SPEED. BY THURSDAY HIGH PRESSURE BUILDS IN
FURTHER ALLOWING A BETTER DEFINED NORTHEAST FLOW TO DEVELOP.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CRM
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...DL/CRM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1240 PM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 1240 PM CDT SAT AUG 8 2015
LATEST RADAR LOOPS INDICATE ONLY SMALL SHOWERS...LIKELY FROM MIDDLE
CLOUDS...ALONG THE ND/SD BORDER IN THE FAR WEST. MAY OR MAY NOT BE
REACHING THE GROUND. LATEST ITERATIONS OF THE HRRR HAVE INDICATED
SHOWERS ADVANCING NORTHEASTWARD A BIT SLOWER THAN EXPECTED. HAVE
LOWERED CHANCES OF SHOWERS EARLY THIS AFTERNOON...THEN INCREASED
TO SCATTERED/LIKELY CHANCES OF THUNDERSHOWERS IN THE SOUTHWEST BY
MID-AFTERNOON. ALSO RAISED THE FORECAST MAX TEMPERATURES IN THE
SOUTH CENTRAL/SOUTHEAST PART OF THE STATE WITH CLOUD COVER IN SD
NOT YET REACHING NORTHWARD INTO THE STATE AND HOURLY TRENDS ON THE
UPSWING A BIT HIGHER THAN IN PREVIOUS FORECAST.
UPDATE ISSUED AT 934 AM CDT SAT AUG 8 2015
FOG HAS DISSIPATED ACROSS THE JAMES VALLEY AREA...WITH SOME LOW
CLOUDS STILL LINGERING IN LAMOURE COUNTY. ADJUSTED HOURLY
TEMPERATURE TRENDS...BUT OTHERWISE THE FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG HAS DISSIPATED NEAR THE JAMESTOWN ASOS...BUT THERE ARE
LIKELY STILL SOME PATCHES IN VALLEYS. THUS...LEFT PATCHY FOG IN
THE FORECAST FOR A COUPLE MORE HOURS. OTHERWISE...THE FORECAST
LOOKS TO BE ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST LATER TODAY AND
INCLUDING THE SOUTH CENTRAL TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT REMAINS OVER THE NORTHERN PLAINS
WITH STACKED LOW PRESSURE MOVING SLOWLY EAST ACROSS SOUTHERN
MANITOBA AND UPPER LEVEL RIDGING OVER THE CENTRAL PLAINS. MOSTLY
CLEAR SKIES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. T/TD SPREADS AT OR NEAR ZERO OVER MANY OBSERVING SITES
OVER NORTHERN NORTH DAKOTA AND ACROSS BOTH THE WESTERN DEVILS LAKE
AND JAMES RIVER BASINS. LAST FEW HRRR RUNS CONTINUE TO INDICATE AT
LEAST PATCHY FOG DEVELOPMENT OVER THESE AREAS YET EARLY THIS
MORNING AND WILL LEAVE IN THE FORECAST.
EMBEDDED SHORT WAVE TROUGH/IMPULSE LIFTING EAST-NORTHEAST ACROSS
THE INTERMOUNTAIN WEST THIS MORNING WILL TRACK EASTWARD INTO THE
NORTHERN HIGH PLAINS TODAY...THEN INTO AND ACROSS THE DAKOTAS
LATER TONIGHT INTO SUNDAY. ASSOCIATED SURFACE LOW WILL MOVE FROM
WYOMING THIS MORNING INTO SOUTH DAKOTA LATER TODAY AND TONIGHT.
PRECIPITATION WILL START TO DEVELOP INTO SOUTHWEST NORTH DAKOTA
THIS AFTERNOON WITH THE APPROACH OF THE MID LEVEL WAVE AND AS THE
SFC LOW MOVES INTO WESTERN SOUTH DAKOTA. PRECIPITATION THEN
SPREADS SLOWLY EAST INTO MY SOUTH CENTRAL COUNTIES TONIGHT. RIDGE
OF SURFACE HIGH PRESSURE BUILDING OVER FAR SOUTH CENTRAL
CANADA/NORTHERN ND WILL KEEP MOST AREAS NORTH OF INTERSTATE 94
DRY. HEAVIEST RAINFALL EXPECTED TO REMAIN OVER SOUTH DAKOTA. CAPE
RATHER WEAK BUT ENOUGH TO LEAVE A SLIGHT CHANCE/ISOLATED MENTION
OF THUNDERSTORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 8 2015
THE FOCUS THIS MORNING IS ON SUBTROPICAL RIDGE LOCATION.
THE MAIN CHANGE IN MODEL CONSENSUS OVER THE PAST 48 HOURS HAS BEEN
THE WESTWARD SHIFTING OF THE SUBTROPICAL RIDGE AXIS FROM THE CENTRAL
DAKOTAS INTO WESTERN MONTANA BY WEDNESDAY. THE SLOWER PROGRESSION OF
CYCLONIC FLOW WILL ACT TO EXTEND THE DRY PERIOD NEXT WEEK AND
INCREASE HIGH TEMPERATURES ACROSS THE DAKOTAS.
GREATER UNCERTAINTY CREEPS INTO THE FORECAST ON WEDNESDAY NIGHT...AS
MID LEVEL SHORTWAVES MAKE IT INTO THE DAKOTAS IN A FEW GEFS
MEMBERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1240 PM CDT SAT AUG 8 2015
LOW PRESSURE ACROSS SOUTHERN MANITOBA WILL MOVE SLOWLY EAST
TODAY...REPLACED WITH A SURFACE RIDGE. SOME SCATTERED CU AT
KISN/KMOT ON THE SOUTHWEST EDGE OF THE INFLUENCE OF THE MANITOBA
LOW. FOR SOUTHERN ND TAFS...EXPECTING INCREASING CLOUDS DURING THE
AFTERNOON/EVENING...BEGINNING WITH MID LEVEL CLOUDS AND BECOMING
MVFR LATE TONIGHT. BEST CHANCE OF SHOWERS REACHING THE I94 CORRIDOR
WHERE TAF SITES RESIDE IS LATE. EXPECT SHOWERS AND SCATTERED
THUNDERSTORMS TO OCCUR THIS AFTERNOON/EVENING SOUTH OF THE TAF
SITES...AT KHEI...LINTON FOR EXAMPLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...JV
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
518 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL QUEBEC CANADA WILL RIDGE SOUTH INTO
THE AREA TODAY. WEAK LOW PRESSURE WILL MOVE OUT OF THE OHIO VALLEY
LATER SUNDAY AND SUNDAY NIGHT...BRINGING MORE HUMID AND
UNSETTLED CONDITIONS THAT WILL BRING RAIN THE TO THE REGION MONDAY
AND TUESDAY. HIGH PRESSURE SHOULD DOMINATE THE REST OF THE COMING
WORK WEEK FROM WEDNESDAY TO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WEAK UPPER TROFFING AND SOME UPWARD VERTICAL MOTION BEING FORCED
BY THE APPROACHING LEFT EXIT OF AN UPPER JET STREAK HAVE ALLOWED
THE SKY TO FILL WITH PUFFY CU. SO FAR JUST LIGHT RETURNS ON
RADAR...SOME OVER SOMERSET COUNTY AND A FEW OTHERS NORTH OF THE NY
BORDER. RAP MESO ANAL SHOWS A FINGER CAPE EXCEEDING 1000J POKING
UP INTO WESTERN PA...WITH INSTABILITY OVER CENTRAL AREAS MUCH MORE
SUPPRESSED. ENSEMBLES SHOW SMALL CHANCE POPS...FOR THE NEXT 6-8
HOURS...OVER THE LAURELS WITH THE SREF WETTER THAN THE SEEMINGLY
MORE REASONABLE GEFS. HRRR SUPPORTS THE IDEA OF JUST SOME SMALL
CELLULAR CONVECTION DEVELOPING OVER THE NEXT FEW HOURS...THEN
DYING AFTER SUNDOWN...LEAVING THE BULK OF THE OVERNIGHT PRECIP-
FREE.
OVERNIGHT LOWS IN THE MID 50S TO MID 60S WILL BE VERY NEAR NORMAL
FOR EARLY AUGUST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
CONDITIONS SHOULD WARM AND PARTIALLY CLEAR SUNDAY AS THE UPPER
HEIGHTS CONTINUE TO SLOWLY BUILD AND THE MEAN BLYR FLOW WEAKENS
AND BECOMES WEST OR NW.
WEAK SHORTWAVE ENERGY RIDING THE BUILDING RIDGE IS TIMED INTO THE
REGION DURING MAX HEATING...LEADING TO THE DEVELOPMENT OF A BIT
MORE IN THE WAY OF INSTABILITY THAN TODAY. I STILL KEPT POPS ON
THE LOW SIDE...BUT THE AREA COVERAGE FOR THE CHANCE OF A POP-UP
SHOWER OR THUNDERSTORMS WILL BE A BIT LARGER...MAINLY SUNDAY
AFTERNOON.
HIGH TEMPS WILL RANGE FROM NEAR 80 OVER THE FAR NORTH TO MID 80S
OVER THE FAR SOUTH. VERY NEAR OR MAYBE A TAD BELOW NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AN APPROACHING COLD FRONT AND DEEPENING TROUGH OVER EASTERN NORTH
AMERICA WILL BE THE KEY PLAYER IN THE WEATHER DURING THIS PERIOD.
THE FRONT COULD PROVIDE US RAIN MON-TUE AND THE DEEPENING TROUGH
COOL DRY WEATHER WED-FRI.
WARM MOIST AIR WILL MOVE IN AHEAD OF THE APPROACHING COLD FRONT.
THIS WILL INCREASE THE CHANCE OF RAIN OVERNIGHT MONDAY INTO
TUESDAY. BASED ON THE NCEP GEFS AND SREF-PARA THE CHANCE OF RAIN
GOES UP SLOWLY SUNDAY NIGHT INTO MONDAY EVENING. THEN IT COMES UP
FAST MONDAY AFTERNOON AND OVERNIGHT INTO TUESDAY.
AT THIS TIME BEST CHANCE OF RAIN SHOULD BE AROUND 2 PM MONDAY
UNTIL ABOUT 8 AM TUESDAY. THE RAIN PROBABILITIES IN THE GEFS BEGIN
TO DROP OFF FAST AFTER 8 AM TUESDAY. POPS GET LOW AFTER 8 PM
TUESDAY AND THE REST OF THE PERIOD WED-FRIDAY LOOKS TO BE DRY AT
THIS TIME.
THE POTENTIAL FOR A WIDESPREAD 0.5 TO 0.8 INCH RAINFALL EVENT IS
CURRENTLY FORECAST AS THE FRONTAL SYSTEM MOVES ACROSS THE STATE.
BIAS CORRECTING THESE DATA WOULD IMPLY PERHAPS 0.25 TO 0.50 INCHES
OF RAIN IS MORE LIKELY.
THE SURGE OF HIGH PW AIR MONDAY-TUESDAY IS REPLACED BY BELOW
NORMALLY LOW PW AIR WEDNESDAY INTO FRIDAY. IT WILL BE VERY DRY
AFTER THE RAIN. IN ADDITION TO THE DRY AIR...THE GEFS AND NAEFS
FORECAST BELOW NORMAL 850 HPA TEMPERATURES IMPLYING WEDNESDAY-FRIDAY
WILL BE SLIGHTLY COOLER THAN NORMAL. THE TEMPERATURES SHOULD BEGIN
TO REBOUND ON FRIDAY AND INTO NEXT WEEKEND. SHOULD BE A COOL DRY
PERIOD.
THE FLY IN THE OINTMENT IS ALWAYS THE COLD AIR ALOFT WHICH COULD
TRIGGER ISOLATED SHOWERS OUR COARSER LONGER RANGE MODELS WILL NOT
PICK UP ON. WE CANNOT RULE OUT ISOLATED INSTABILITY SHOWERS
WEDNESDAY AFTERNOON AND WE HAVE NO SKILL FORECASTING THESE AT 4
DAYS OUT. BUT THE DEEP TROUGH AND MID-LEVEL COOL AIR IS A PATTERN
WHICH MIGHT FAVOR SUCH A SCENARIO WEDNESDAY AND POSSIBLY THURSDAY
BUT WOULD NOT PUT THAT IN FORECAST AT THIS TIME RANGE.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
A FEW SHOWERS ACROSS THE SW.
ADDED VCSH TO JST.
OTHERWISE MINOR ADJUSTMENTS TO 21Z TAF PACKAGE.
EARLIER DISCUSSION BELOW.
MAINLY VFR CONDITIONS EXPECTED THROUGH SUNDAY.
SCT-BKN CUMULUS CLOUDS HAVE DEVELOPED AND WILL COVER MUCH OF THE
AIRSPACE THROUGH LATE DAY WITH A SMALL CHANCE OF A STRAY
SHOWER...MAINLY OVER THE LAUREL HIGHLANDS INTO THE NORTHERN
MOUNTAINS THROUGH EVENING.
SLOWLY INCREASING LOW LEVEL MOISTURE OVERNIGHT WILL LEAD TO THE
POSSIBILITY OF A FEW HOURS OF MVFR/IFR AROUND SUNRISE. CONDITIONS
WILL IMPROVE RAPIDLY AFTER SUNRISE SUNDAY WITH ANOTHER DAY VERY
MUCH LIKE TODAY...WITH HIGH BASED CLOUDS AND LIGHT WINDS. THERE
COULD BE A STRAY AFTERNOON OR EVENING SHOWER/THUNDERSTORMS IN
SPOTS.
OUTLOOK...
MON-TUE...VFR-MVFR. SHOWERS LKLY/ISOLD TSTMS.
WED...MVFR-VFR CIGS/SCT SHOWERS WEST. MAINLY VFR CENTRAL/EAST.
THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...GRUMM
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
254 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL QUEBEC CANADA WILL RIDGE SOUTH INTO
THE AREA TODAY. WEAK LOW PRESSURE WILL MOVE OUT OF THE OHIO VALLEY
LATER SUNDAY AND SUNDAY NIGHT...BRINGING MORE HUMID AND
UNSETTLED CONDITIONS THAT WILL BRING RAIN THE TO THE REGION MONDAY
AND TUESDAY. HIGH PRESSURE SHOULD DOMINATE THE REST OF THE COMING
WORK WEEK FROM WEDNESDAY TO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK UPPER TROFFING AND SOME UPWARD VERTICAL MOTION BEING FORCED
BY THE APPROACHING LEFT EXIT OF AN UPPER JET STREAK HAVE ALLOWED
THE SKY TO FILL WITH PUFFY CU. SO FAR JUST LIGHT RETURNS ON
RADAR...SOME OVER SOMERSET COUNTY AND A FEW OTHERS NORTH OF THE NY
BORDER. RAP MESO ANAL SHOWS A FINGER CAPE EXCEEDING 1000J POKING
UP INTO WESTERN PA...WITH INSTABILITY OVER CENTRAL AREAS MUCH MORE
SUPPRESSED. ENSEMBLES SHOW SMALL CHANCE POPS...FOR THE NEXT 6-8
HOURS...OVER THE LAURELS WITH THE SREF WETTER THAN THE SEEMINGLY
MORE REASONABLE GEFS. HRRR SUPPORTS THE IDEA OF JUST SOME SMALL
CELLULAR CONVECTION DEVELOPING OVER THE NEXT FEW HOURS...THEN
DYING AFTER SUNDOWN...LEAVING THE BULK OF THE OVERNIGHT PRECIP-
FREE.
OVERNIGHT LOWS IN THE MID 50S TO MID 60S WILL BE VERY NEAR NORMAL
FOR EARLY AUGUST.
&&
.SHORT TERM /SUNDAY/...
CONDITIONS SHOULD WARM AND PARTIALLY CLEAR SUNDAY AS THE UPPER
HEIGHTS CONTINUE TO SLOWLY BUILD AND THE MEAN BLYR FLOW WEAKENS
AND BECOMES WEST OR NW.
WEAK SHORTWAVE ENERGY RIDING THE BUILDING RIDGE IS TIMED INTO THE
REGION DURING MAX HEATING...LEADING TO THE DEVELOPMENT OF A BIT
MORE IN THE WAY OF INSTABILITY THAN TODAY. I STILL KEPT POPS ON
THE LOW SIDE...BUT THE AREA COVERAGE FOR THE CHANCE OF A POP-UP
SHOWER OR THUNDERSTORMS WILL BE A BIT LARGER...MAINLY SUNDAY
AFTERNOON.
HIGH TEMPS WILL RANGE FROM NEAR 80 OVER THE FAR NORTH TO MID 80S
OVER THE FAR SOUTH. VERY NEAR OR MAYBE A TAD BELOW NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AN APPROACHING COLD FRONT AND DEEPENING TROUGH OVER EASTERN NORTH
AMERICA WILL BE THE KEY PLAYER IN THE WEATHER DURING THIS PERIOD.
THE FRONT COULD PROVIDE US RAIN MON-TUE AND THE DEEPENING TROUGH
COOL DRY WEATHER WED-FRI.
WARM MOIST AIR WILL MOVE IN AHEAD OF THE APPROACHING COLD FRONT.
THIS WILL INCREASE THE CHANCE OF RAIN OVERNIGHT MONDAY INTO
TUESDAY. BASED ON THE NCEP GEFS AND SREF-PARA THE CHANCE OF RAIN
GOES UP SLOWLY SUNDAY NIGHT INTO MONDAY EVENING. THEN IT COMES UP
FAST MONDAY AFTERNOON AND OVERNIGHT INTO TUESDAY.
AT THIS TIME BEST CHANCE OF RAIN SHOULD BE AROUND 2 PM MONDAY
UNTIL ABOUT 8 AM TUESDAY. THE RAIN PROBABILITIES IN THE GEFS BEGIN
TO DROP OFF FAST AFTER 8 AM TUESDAY. POPS GET LOW AFTER 8 PM
TUESDAY AND THE REST OF THE PERIOD WED-FRIDAY LOOKS TO BE DRY AT
THIS TIME.
THE POTENTIAL FOR A WIDESPREAD 0.5 TO 0.8 INCH RAINFALL EVENT IS
CURRENTLY FORECAST AS THE FRONTAL SYSTEM MOVES ACROSS THE STATE.
BIAS CORRECTING THESE DATA WOULD IMPLY PERHAPS 0.25 TO 0.50 INCHES
OF RAIN IS MORE LIKELY.
THE SURGE OF HIGH PW AIR MONDAY-TUESDAY IS REPLACED BY BELOW
NORMALLY LOW PW AIR WEDNESDAY INTO FRIDAY. IT WILL BE VERY DRY
AFTER THE RAIN. IN ADDITION TO THE DRY AIR...THE GEFS AND NAEFS
FORECAST BELOW NORMAL 850 HPA TEMPERATURES IMPLYING WEDNESDAY-FRIDAY
WILL BE SLIGHTLY COOLER THAN NORMAL. THE TEMPERATURES SHOULD BEGIN
TO REBOUND ON FRIDAY AND INTO NEXT WEEKEND. SHOULD BE A COOL DRY
PERIOD.
THE FLY IN THE OINTMENT IS ALWAYS THE COLD AIR ALOFT WHICH COULD
TRIGGER ISOLATED SHOWERS OUR COARSER LONGER RANGE MODELS WILL NOT
PICK UP ON. WE CANNOT RULE OUT ISOLATED INSTABILITY SHOWERS
WEDNESDAY AFTERNOON AND WE HAVE NO SKILL FORECASTING THESE AT 4
DAYS OUT. BUT THE DEEP TROUGH AND MID-LEVEL COOL AIR IS A PATTERN
WHICH MIGHT FAVOR SUCH A SCENARIO WEDNESDAY AND POSSIBLY THURSDAY
BUT WOULD NOT PUT THAT IN FORECAST AT THIS TIME RANGE.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS EXPECTED THROUGH SUNDAY.
SCT-BKN CUMULUS CLOUDS HAVE DEVELOPED AND WILL COVER MUCH OF THE
AIRSPACE THROUGH LATE DAY WITH A SMALL CHANCE OF A STRAY
SHOWER...MAINLY OVER THE LAUREL HIGHLANDS INTO THE NORTHERN
MOUNTAINS THROUGH EVENING.
SLOWLY INCREASING LOW LEVEL MOISTURE OVERNIGHT WILL LEAD TO THE
POSSIBILITY OF A FEW HOURS OF MVFR/IFR AROUND SUNRISE. CONDITIONS
WILL IMPROVE RAPIDLY AFTER SUNRISE SUNDAY WITH ANOTHER DAY VERY
MUCH LIKE TODAY...WITH HIGH BASED CLOUDS AND LIGHT WINDS. THERE
COULD BE A STRAY AFTERNOON OR EVENING SHOWER/THUNDERSTORMS IN
SPOTS.
OUTLOOK...
MON-TUE...VFR-MVFR. SHOWERS LKLY/ISOLD TSTMS.
WED...MVFR-VFR CIGS/SCT SHOWERS WEST. MAINLY VFR CENTRAL/EAST.
THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...GRUMM
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
218 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL QUEBEC CANADA WILL RIDGE SOUTH INTO
THE AREA TODAY. WEAK LOW PRESSURE WILL MOVE OUT OF THE OHIO VALLEY
LATER SUNDAY AND SUNDAY NIGHT...BRINGING MORE HUMID AND
UNSETTLED CONDITIONS THAT WILL LAST INTO THE START OF THE NEW WORK
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK UPPER TROFFING AND SOME UPWARD VERTICAL MOTION BEING FORCED
BY THE APPROACHING LEFT EXIT OF AN UPPER JET STREAK HAVE ALLOWED
THE SKY TO FILL WITH PUFFY CU. SO FAR JUST LIGHT RETURNS ON
RADAR...SOME OVER SOMERSET COUNTY AND A FEW OTHERS NORTH OF THE NY
BORDER. RAP MESO ANAL SHOWS A FINGER CAPE EXCEEDING 1000J POKING
UP INTO WESTERN PA...WITH INSTABILITY OVER CENTRAL AREAS MUCH MORE
SUPPRESSED. ENSEMBLES SHOW SMALL CHANCE POPS...FOR THE NEXT 6-8
HOURS...OVER THE LAURELS WITH THE SREF WETTER THAN THE SEEMINGLY
MORE REASONABLE GEFS. HRRR SUPPORTS THE IDEA OF JUST SOME SMALL
CELLULAR CONVECTION DEVELOPING OVER THE NEXT FEW HOURS...THEN
DYING AFTER SUNDOWN...LEAVING THE BULK OF THE OVERNIGHT PRECIP-
FREE.
OVERNIGHT LOWS IN THE MID 50S TO MID 60S WILL BE VERY NEAR NORMAL
FOR EARLY AUGUST.
&&
.SHORT TERM /SUNDAY/...
CONDITIONS SHOULD WARM AND PARTIALLY CLEAR SUNDAY AS THE UPPER
HEIGHTS CONTINUE TO SLOWLY BUILD AND THE MEAN BLYR FLOW WEAKENS
AND BECOMES WEST OR NW.
WEAK SHORTWAVE ENERGY RIDING THE BUILDING RIDGE IS TIMED INTO THE
REGION DURING MAX HEATING...LEADING TO THE DEVELOPMENT OF A BIT
MORE IN THE WAY OF INSTABILITY THAN TODAY. I STILL KEPT POPS ON
THE LOW SIDE...BUT THE AREA COVERAGE FOR THE CHANCE OF A POP-UP
SHOWER OR THUNDERSTORMS WILL BE A BIT LARGER...MAINLY SUNDAY
AFTERNOON.
HIGH TEMPS WILL RANGE FROM NEAR 80 OVER THE FAR NORTH TO MID 80S
OVER THE FAR SOUTH. VERY NEAR OR MAYBE A TAD BELOW NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A WEAK TROUGH OF LOW PRESSURE AT THE SURFACE AND ALOFT SLIDE
SLOWLY SE ACROSS THE STATE EARLY NEXT WEEK.
USING THE GEFS ENSEMBLES THE STRONGEST FLOW AND MOISTURE REMAINS
TO THE NORTH AND EAST OF CENTRAL PA. THERE/S ONLY A SLIGHT CHANCE
OF SHOWERS SUNDAY AFTERNOON. THIS IS SPECIFICALLY THE RESULT OF A
WEAK SHORTWAVE RIDING N PERIPHERY OF MISS VALLEY UPPER RIDGE. GEFS
PLUMES INDICATE A GRADUAL WARMING TREND INTO THE WEEKEND...WITH
READINGS CLOSE TO AVERAGE FOR EARLY AUGUST.
THE MODELS FOR THE LONG RANGE PATTERN COME TO A FAIR AGREEMENT
THOUGH SLIGHT TIMING DIFFERENCES ARE PRESENT. THE NEXT WEATHER
SYSTEM...AND THE BEST CHANCE FOR PRECIPITATION WILL BE A COLD
FRONT THAT PASSES THROUGH TUESDAY. WITH SLOW MOVEMENT OF FRONT...
HAVE GIVEN A BROAD BRUSH OF POPS MONDAY NIGHT THROUGH TUESDAY
NIGHT. HAVE KEPT MAIN FRONTAL PASSAGE LATE TUESDAY
INTO TUE NIGHT...THOUGH CAN/T RULE OUT THE FRONT STALLING AND
PASSING WEDNESDAY. HIGHER PWATS WORK INTO THE REGION ON SW FLOW
AS HGTS FALL AHEAD OF APPROACHING TROF MONDAY...SO CHC OF
SHRA/TSRA CONTINUES. DEEPENING TROUGH POSSIBLY STALLED COLD FRONT
WILL LKLY RESULT IN SCATTERED SHRA/TSRA TUESDAY NIGHT INTO
WEDNESDAY. THE GEFS AND EC BOTH CURRENTLY INDICATE THE POSSIBILITY
OF HVY RAINFALL ACROSS EASTERN PA ASSOC WITH THIS SLOWING FRONT.
COOLER/DRIER WX IS LIKELY BY MIDWEEK AS THE LONG TERM PATTERN WILL
BE DOMINATED BY A ROTATING QUASI-STATIONARY UPPER LEVEL LOW
CENTERED OVER EASTERN CANADA. EXPECT THIS SYSTEM TO BRING COOL MID
LVL TEMPS OVR THE REGION AND COULD PROMOTE PM SHOWERS...ESP OVR
THE MTNS THROUGH THE LATTER HALF OF NEXT WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS EXPECTED THROUGH SUNDAY.
SCT-BKN CUMULUS CLOUDS HAVE DEVELOPED AND WILL COVER MUCH OF THE
AIRSPACE THROUGH LATE DAY WITH A SMALL CHANCE OF A STRAY
SHOWER...MAINLY OVER THE LAUREL HIGHLANDS INTO THE NORTHERN
MOUNTAINS THROUGH EVENING.
SLOWLY INCREASING LOW LEVEL MOISTURE OVERNIGHT WILL LEAD TO THE
POSSIBILITY OF A FEW HOURS OF MVFR/IFR AROUND SUNRISE. CONDITIONS
WILL IMPROVE RAPIDLY AFTER SUNRISE SUNDAY WITH ANOTHER DAY VERY
MUCH LIKE TODAY...WITH HIGH BASED CLOUDS AND LIGHT WINDS. THERE
COULD BE A STRAY AFTERNOON OR EVENING SHOWER/THUNDERSTORMS IN
SPOTS.
OUTLOOK...
MON-TUE...VFR-MVFR. SHOWERS LKLY/ISOLD TSTMS.
WED...MVFR-VFR CIGS/SCT SHOWERS WEST. MAINLY VFR CENTRAL/EAST.
THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
234 PM CDT SAT AUG 8 2015
.SHORT TERM...
BIGGEST CHANGE FROM EARLIER FORECASTS WAS TO EXPAND ISOLATED STORM
MENTION EASTWARD ACROSS MUCH OF THE CAPROCK THIS EVENING. EARLY
AFTERNOON ANALYSIS INDICATES A FAVORABLE COLLOCATION OF SURFACE
TROUGHING AND STEEP MID-LEVEL LAPSE RATES JUST WEST OF THE TX-NM
BORDER. SURFACE DEWPOINTS AREA WIDE ARE RUNNING 5-15 DEGS HIGHER
THAN THIS TIME YESTERDAY AND ARE YIELDING 1000-2000 J/KG OF MLCAPE
ACROSS THE SOUTH PLAINS. ALREADY NOTICING SOME CU BUILDING SOUTH OF
CVS AT 19Z AS DEEP MIXING THERE CATAPULTS PARCELS TO THEIR CCL
LEVELS. THIS THEME SHOULD EXPAND SOUTHWARD ALONG THE SURFACE TROUGH
WITH A FEW STORMS LIKELY TO BE DOTTING OUR WESTERN ZONES BY LATE
AFTERNOON. AS THESE PULSE-TYPE CELLS MOVE SLOWLY NORTHEAST...OUTFLOW
REGENERATION OF NEW STORMS SEEMS PLAUSIBLE THROUGH EARLY EVENING IN
LIGHT OF MEAGER CIN. HRRR HAS BEEN QUITE ADAMANT IN BLOSSOMING A
LARGER COVERAGE OF STORMS BEFORE SUNSET...BUT WITH NO DISCERNIBLE
BACKGROUND SUPPORT AVAILABLE IT SEEMS A SAFER BET TO KEEP PRECIP
MENTION ON THE ISOLATED SIDE. A DECENT NOCTURNAL LLJ MAY KEEP SOME
SEMBLANCE OF THESE EARLIER STORMS INTACT AFTER MIDNIGHT.
SUNDAY WILL SEE A TALL AND CLOSED ANTICYCLONE RETROGRADE TO CENTRAL
TEXAS COMPLETE WITH RISING HEIGHTS AND THICKNESSES LOCALLY. THIS
PROCESS WILL HELP REORIENT THE SURFACE TROUGH FROM N-S TO NE-SW
ACROSS THE WRN TX PANHANDLE INTO ERN NM. BEST STORM CHANCES SHOULD
PLAY OUT IN THE NRN PANHANDLE NEAR THE INTERSECTION OF THE TROUGH
AND A STALLING FRONT...BUT DEEP MIXING AND WEAK CAPE IN OUR NW
COUNTIES COULD SPUR A FEW LATE AFTERNOON STORMS. OTHERWISE...MAX
TEMPS LOOK TO SHAKE OUT A DEGREE OR TWO WARMER THAN TODAY.
.LONG TERM...
UPPER LEVEL RIDGE IS EXPECTED TO BE CENTERED OVER EAST
TEXAS SUNDAY EVENING WHILST VIGOROUS UPPER LEVEL LOW SLIDES DOWN THE
COAST OF BRITISH COLUMBIA. THE STRENGTH OF THE RIDGE IS EXPECTED TO
BE SUFFICIENTLY STRONG TO HOLD THE LOW OFF THE PACIFIC NORTHWEST
COAST AT LEAST THROUGH 120 HOURS BEFORE IT EJECTS NEWRD INTO SRN
CANADA. TO OUR NORTH A SHORTWAVE PASSES EARLY MONDAY ACROSS THE
CENTRAL PLAINS FOLLOWED BY ANOTHER SURGE OF ENERGY ROTATING ABOUT
HUDSON BAY LOW EARLY TUESDAY BEFORE RIDGE BUILDS STRONGLY ALL THE
WAY UP TO NUNAVUT. AS THE HIGH SLOWLY RETROGRADES...FLOW WILL
BECOME MORE NORTHERLY TO NORTHEASTERLY WITH TIME AND THIS SHOULD
HELP COOL TEMPS A BIT IN THE LATTER EXTENDED.
BEST RAIN CHANCES DURING THE EXTENDED WILL EXIST FROM SUNDAY EVENING
INTO TUESDAY AS FRONTAL BOUNDARY SAGS INTO THE REGION. HIGHEST
POTENTIAL WILL EXIST NORTH AND WEST. TRENDS HAVE BEEN EDGING THE
BOUNDARY FURTHER SOUTH WITH EACH RUN AND THIS CERTAINLY FITS THE
PATTERN THIS SUMMER. THINGS LOOK TO DRY OUT ON WEDNESDAY WITH
PERHAPS A FEW SCT SHOWERS NEAR THE ESCARPMENT BUT OVERALL TRENDING
DRIER FOR THE REMAINDER OF THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 94 67 90 / 20 20 20 30
TULIA 66 95 68 92 / 20 0 20 30
PLAINVIEW 65 95 70 93 / 20 0 10 20
LEVELLAND 68 96 70 95 / 20 0 10 20
LUBBOCK 71 98 72 96 / 20 0 10 10
DENVER CITY 68 98 69 96 / 20 0 10 10
BROWNFIELD 68 98 70 96 / 20 0 10 10
CHILDRESS 73 102 75 99 / 0 0 10 20
SPUR 70 101 72 99 / 0 0 10 0
ASPERMONT 75 104 75 103 / 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/26
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 241 PM CDT SAT AUG 8 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE CENTERED OVER NORTHERN LAKE MICHIGAN...AND NOSING INTO
THE SOUTHERN PART OF THE STATE. MEANWHILE...A COLD FRONT IS SLOWLY
MOVING INTO NE MINNESOTA WHERE SMALL CLUSTERS OF THUNDERSTORMS
OCCASIONALLY DEVELOP. A FEW OTHER STORMS HAVE FIRED OVER SOUTHERN
MINNESOTA IN A WARM ADVECTION ZONE. OTHERWISE...LOW LEVEL COOL AIR
HAS DELAYED CLEARING ACROSS MUCH OF THE REGION EXCEPT FOR FAR N-C
WISCONSIN WHERE SKIES ARE STARTING TO CLEAR. AREAS OF SPRINKLES OR
LIGHT RAIN ARE FALLING OUT OF A MID-DECK OVER WESTERN AND SOUTHERN
WISCONSIN...BUT HAVE BEEN DISSIPATING AS THEY APPROACH CENTRAL
WISCONSIN. FORECAST CONCERNS INCLUDE CLOUD TRENDS AND THUNDERSTORM
POTENTIAL OVER THE NEXT 24 HOURS.
TONIGHT...MID-LEVEL WARM ADVECTION WILL RAMP UP OVER SOUTHWEST
WISCONSIN...WHILE A COLD FRONT SAGS INTO NORTHWEST WISCONSIN LATE.
THE MAJORITY OF SHORT-TERM GUIDANCE SUGGESTS ANY CONVECTION THAT
DEVELOPS OVER SOUTHERN MINNESOTA AND NORTHERN IOWA WILL DROP TO THE
SOUTHEAST OF THE AREA TONIGHT. A BETTER CHANCE OF SHOWERS AND
STORMS LOOK TO OCCUR OVER N-C WISCONSIN ALONG THE FRONT WHERE
ELEVATED INSTABILITY WILL SHIFT INTO LATE IN THE NIGHT. THIS SEEMS
REASONABLE SINCE ISOLATED CONVECTION HAS BEEN OCCURRING ALL DAY OVER
NE MINNESOTA. SO LEFT A SLIGHT CHANCE TO ACCOUNT FOR THAT.
OTHERWISE...CLOUD TRENDS CONTINUE TO POSE A HEADACHE. EAST TO
SOUTHEAST LOW LEVEL FLOW WILL CONTINUE TO COLD ADVECT THROUGH THE
EVENING OVER EASTERN WISCONSIN...BELOW A WARM LAYER CENTERED AROUND
850MB. THIS WOULD ARGUE TO SLOW DOWN THE CLEARING TREND LATER THIS
AFTERNOON AND EVENING. IF CLEARING DOES OCCUR...PATCHY FOG COULD
BECOME AN ISSUE...BUT THATS MAINLY OVER CENTRAL AND N-C WI. LOWS IN
THE UPPER 50S TO LOW 60S.
SUNDAY...WEAK MID-LEVEL WARM ADVECTION WILL SPREAD OVER NORTHEAST
WISCONSIN AS THE COLD FRONT STALLS ACROSS NW WISCONSIN. COULD HAVE
A FEW LIGHT SHOWERS/SPRINKLES GRAZE THE SOUTHERN FORECAST AREA IN
THE WARM ADVECTION ZONE...MAINLY IN THE MORNING. MOST OF THE
ATTENTION WILL BE PLACED ON THE COLD FRONT THOUGH. ISOLATED
CONVECTION WILL OCCUR ACROSS N-C WISCONSIN DURING THE
MORNING...BEFORE INSTABILITY BUILDS THROUGH THE AFTERNOON. PROGGED
SOUNDINGS INDICATE AMPLE INSTABILITY (ML CAPE UP TO 2000 J/KG)...BUT
0-6KM BULK SHEARS ARE ONLY AROUND 20 KTS. THESE PROGGED CONDITIONS
WOULD ARGUE FOR PULSE TYPE STORMS...WITH A FEW STRONG OR ISOLATED
SEVERE STORMS POSSIBLE. THE BEST COVERAGE OF STORMS APPEARS TO BE
AFTER 3 PM IN THE AFTERNOON. HIGHS RANGING FROM THE UPPER 70S NORTH
TO MID 80S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 241 PM CDT SAT AUG 8 2015
A WEAK LOW PRESSURE SYSTEM OVER MANITOBA WILL MOVE EAST TO
SOUTHERN HUDSON BAY DURING THE NEXT COUPLE OF DAYS. THE LOW WILL
DRAG A COLD FRONT ACROSS WISCONSIN. THERE WILL BE A CHANCE FOR
SHOWERS AND THUNDERSTORMS AHEAD OF AND ALONG THE FRONT...ENDING
MONDAY AFTERNOON AS NORTHWEST WINDS FOLLOW IN AND MOISTURE GETS
SCOURED OUT OF THE AREA. ONLY AN ISOLATED SHOWER OR TWO IS
EXPECTED MONDAY NIGHT.
AFTER THE FRONT MOVES ON BY...A HIGH PRESSURE RIDGE WILL
STRENGTHEN OVER THE U.S. PLAINS STATES/MIDWEST. THE LONGWAVE
PATTERN OVER NORTH AMERICA WILL BECOME INCREASINGLY AMPLIFIED AND
A LOW PRESSURE TROUGH WILL EXPAND SOUTH OVER THE EASTERN UNITED
STATES. THIS PATTERN WILL PRODUCE A NORTHWEST FLOW OVER WISCONSIN
AND CREATE CONSIDERABLE UNCERTAINTY IN PRECIPITATION PREDICTION
FOR THE WORK WEEK. HOWEVER...THE PREDICTION OF TEMPERATURES
SHOULD BE RELIABLY WITHIN THE NORMAL TO SLIGHTLY BELOW NORMAL
RANGE FOR THIS TIME OF THE YEAR THROUGH NEXT WEEKEND. THE BLEND
OF MODELS SUGGESTS THAT...AFTER MONDAY...THE NEXT SIGNIFICANT
CHANCE FOR PRECIPITATION COMES ON FRIDAY AS A SHORTWAVE RIDES DOWN
ON THE NORTHWEST FLOW OUT OF CANADA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1206 PM CDT SAT AUG 8 2015
CIGS WILL GRADUALLY RISE THIS AFTERNOON WITH FURTHER
DAYTIME HEATING. CENTRAL AND N-C WI WILL SEE SLOWER IMPROVEMENT
THAN TAF SITES OVER EASTERN WI. MOSTLY VFR TONIGHT...THOUGH VSBYS
WILL LIKELY DROP LATE TONIGHT DUE TO A COMBO OF LIGHT WINDS AND HIGH
HUMIDITY. A COLD FRONT WILL MOVE INTO NORTH-CENTRAL WISCONSIN ON
SUNDAY BRINGING A THREAT OF SHOWERS AND STORMS. IMPACTS COULD BE
FELT AS EARLY AS MID-MORNING AT RHI BUT UNCERTAINTY OF TIMING IS
RATHER HIGH. ANY STORMS ARE NOT EXPECTED TO REACH INTO CENTRAL OR
EAST-CENTRAL WI TAF SITES UNTIL LATE IN THE DAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ML
AVIATION.......MPC