Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/01/13
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1043 PM MDT MON JUL 29 2013
.UPDATE...
ISSUED AT 925 PM MDT MON JUL 29 2013
ACTIVE EVENING WITH JET CORE OVERHEAD AND SPEED MAX OF 80 KT SEEN
IN 00Z KGJT SOUNDING. IN ADDITION SHORTWAVE UPSTREAM OVER NORTHERN
UTAH CONTINUES TO MOVE EAST SUPPORTING THE LATEST ROUND OF
THUNDERSTORMS...ONE ENTERING NW CO AND THE OTHER FOLLOWING ON THE
HEELS OF EARLIER STRONG CONVECTION THAT TRACKED FROM CANYONLANDS
ALMOST DUE EAST OVER THE UNCOMPAHGRE PLATEAU...MONTROSE AND
GUNNISON. HRRR MODEL ADVERTISED AND IS HANDLING THESE TWO
SEPARATE AREAS VERY WELL ALTHOUGH PERHAPS A COUPLE OF HOURS SLOW.
EXPECT THIS ROUND TO BE THE LAST ONE FOR THE NIGHT...CLEARING THE
DIVIDE BY 4 AM. AREA UNDER MODERATE DEEP LAYER SHEAR AND
RELATIVELY HIGHER MUCAPES WHICH IS HELPING TO KEEP STORMS A LITTLE
BETTER ORGANIZED AND LONGER-LIVED. HOWEVER...DUE TO THE GENERAL
DOWNWARD TREND IN INTENSITY WITH STABILIZATION OVERNIGHT...FLASH
FLOOD WATCH HAS BEEN ALLOWED TO EXPIRE. REMAINING STORMS WILL BE
WEAKER...ALTHOUGH STILL CAPABLE OF PRODUCING BRIEF AND LOCALLY
HEAVY RAIN.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
220 PM MDT MON JUL 29 2013
SHORT WAVE ENERGY OVER UTAH WILL STREAM EASTWARD AND WILL BE THE
PRIMARY TRIGGER FOR LOCALIZED HEAVY SHOWERS. THE PRIME AREA
APPEARS TO BE THE MIDDLE SECTION OF THE FORECAST AREA...WITH THE
ENVIRONMENT ACROSS THE FAR SOUTH AND NEAR THE WYOMING BORDER NOT
AS CONDUCIVE FOR RECEIVING HEAVY SHOWERS. SPEED MAXIMA ALOFT IS
ASSOCIATED WITH THE SHORT WAVE AND MAY ENHANCE STORM TOP
DIVERGENCE AND HELP GENERATE LOCALIZED STRONG CELLS WITH SMALL
HAIL. THE PRIMARY THREAT REMAINS HEAVY RAINERS FROM TRAINING
CELLS. WITH SOME AREAS HAVING RECEIVED SIGNIFICANT RAINFALL THE
PAST TWO DAYS...THE FLASH FLOOD THREAT IS ELEVATED FOR THE
REMAINDER OF THE DAY. GIVEN THAT THE MOISTURE STREAM TRAILS BACK
TO NE NEVADA...SHOWERS WITH EMBEDDED STORMS MAY LINGER ACROSS THE
NORTH UNTIL LATE.
TUESDAY AND TUESDAY NIGHT...HIGH PRESSURE RIDGE BUILDS BEHIND DEPARTING
SHORT WAVE FOR INCREASED SUBSIDENCE AND DRY ADVECTION ALOFT. THIS
WEAKENS THE MONSOONAL MOISTURE STREAM INTO THE FOUR CORNERS AREA.
ACROSS THE NORTH... MOISTURE STREAM IS WEAKENING BUT STILL EXIST
FOR SCATTERED SHOWERS AND STORMS OVER NW COLORADO. ACROSS THE SRN
HALF WHERE LESS MID LEVEL FLOW EXISTS...DIABATIC HEATING OVER THE
HIGH TERRAIN WILL BE THE PRIMARY CONVECTIVE TRIGGER. AFTERNOON
CONVECTION SHOULD DIMINISH QUICKLY NEAR SUNSET AND BECOME MOSTLY
CLEAR OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
220 PM MDT MON JUL 29 2013
DRY CONDITIONS WITH VERY LIGHT WESTERLY FLOW CONTINUE THROUGH
WEDNESDAY NIGHT UNDER HIGH PRESSURE BEFORE A SHIFT TO
SOUTH/SOUTHWESTERLY FLOW. BY THURSDAY AFTERNOON PWAT VALUES
INCREASE TO A CONVECTION- FAVORABLE 0.8 TO 1.0 INCH OVER MUCH OF
THE AREA...ESPECIALLY OVER SOUTHEAST UTAH. TWO UPPER LEVEL
DISTURBANCES LOOK TO MOVE THROUGH EARLY THURSDAY MORNING AND
THURSDAY AFTERNOON...WHICH SUPPORT SCATTERED CONVECTION AROUND THE
AREA ESPECIALLY ALONG THE COLORADO RIVER CORRIDOR. AREAS IN
NORTHERN COLORADO/UTAH MAY SEE SHOWER INITIATION BY THE UPPER LEVEL JET AS
WELL. THE FIRST BURST OF ENERGY WILL BE WEAK...BUT MAY ALLOW SOME
THURSDAY MORNING CONVECTION UP OVER ELEVATED AREAS OF CENTRAL
COLORADO. CONVECTIVE ACTIVITY WILL INCREASE WITH SOLAR HEATING AND
WHILE A FEW LIGHT SHOWERS MAY PERSIST THROUGH THE NIGHT...MOST
WILL DISSIPATE AFTER SUNSET THURSDAY EVENING ONCE THE SHEAR AXIS
MOVES THROUGH THE AREA.
12Z GFS SHOWS A THIRD WEAK SHORTWAVE THURSDAY NIGHT ALONG THE
SOUTHERN UT/CO BORDER...BUT THE ECMWF HAS NOT RESOLVED THIS
FEATURE YET. A COUPLE OF SMALL DISTURBANCES ARE SCATTERED AMONG THE WX
MODELS THROUGH SATURDAY BUT WITH THESE DIFFERING OPINIONS...NOT
INCLINED TO FORECAST ENHANCED POPS FOR ANY OF THE FEATURES PAST
THURSDAY NIGHT.
SATURDAY NIGHT THROUGH MONDAY...LOW CONFIDENCE WITH LONG RANGE FORECAST
AT THIS TIME. GFS HAS HIGH PRESSURE PROGGED TO SHIFT SOUTHEAST AS
LOW PRESSURE MOVES EAST ALONG THE CANADA/US BORDER OVER NORTHERN
MONTANA. THIS WOULD CUT OFF THE MONSOONAL MOISTURE PLUME AGAIN
LIKELY UNTIL MID NEXT WEEK SOMETIME. 12Z ECMWF DIFFERS IN SHIFTING
THE TRANSPORT WINDS TO WESTERLY ON SUNDAY EVENING AND CONTINUING
DAILY DIURNAL SHOWERS INTO NEXT WEEK ALONG THE RIDGE AXIS.
TEMPERATURES WILL REMAIN NEAR NORMAL THROUGH MIDWEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1043 PM MDT MON JUL 29 2013
KMTJ...KASE AND KEGE WILL HAVE SHRA IN THE VICINITY THROUGH
09Z...POSSIBLY A LITTLE THUNDER AT KMTJ. VFR CONDITIONS WILL
PREVAIL WITH DIURNAL CYCLE OF WINDS TAKING OVER. CONVECTION AFT
18Z TUE SHOULD BE LIMITED TO THE MOUNTAINS...WITH DRIER AIR
SPREADING IN FROM THE WEST. CONFIDENCE A LITTLE HIGHER THAN ON 00Z
ISSUANCE...SO HAVE PUT VCTS AT KASE AND KEGE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...BWM
SHORT TERM...PF
LONG TERM...JAM
AVIATION...BWM
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
902 PM EDT Wed Jul 31 2013
.NEAR TERM [Rest of Tonight]...
The large scale longwave pattern has become more amplified. This is
highlighted by ridge over Wrn states with high centered over NM, a
trough over Ern states and and ridge over Wrn Atlc. Of particular
local interest is trough. Series of strong shortwaves continue to
move drop SEWD contributing to deepening full latitude trough from
Hudson Bay to SE region. This gives CWA WNW mid level and NW
upper level steering flow. Mid-eve satellite water vapor pix shows
lead shortwave moving across Ern CWA with subsidence/NVA in its
wake moving into WRN AL. At surface, looking south, high over SW
Atlc with ridge Swwd across Cntrl FL and into Cntrl Gulf of Mex.
Looking north, low over KY with cold front Swwd to stationary
front over Cntrl GA to SW AL then to low over NE TX. This places
local area in a type 4 (SW 5-10 mph) low level flow which favors
seabreeze/boundary clashes.
Ample showers and tstms were generated during the early to mid
evening via the Gulf seabreeze and mesoscale boundary clashes
enhanced by deepening trough and passing shortwave. Lingering lift
with shortwave combined with NWLY steering flow and surface
features will yield high pops til at least midnight as reflected
on area radar. Then subsidence aloft will encroach especially SW
third of CWA farthest from exiting shortwave. All this reflected
in RAP13 soundings. i.e. TAE with 2.02 inch PWAT at 00z dropping
to around 1.7 inches by sunrise. However DHN closer to shortwave
remains above 2 inch PWAT.
All HI RES models agree to some degree with SW-NE pop gradient, high
POPs and storms transitioning into rain thru 06z. CAM (mirrored
by NM4) very bullish 40-80% thru 06z then 0-50% 06z-12z. Local
Confidence tool with 30-60% thru 06z then 20-40% thru 12z. HRRR and
ARW a little less bullish but still good chance of convection Ern
half of CWA thru 06z. Local WRF least bullish. With high PWATs
and weak steering flow cant discount brief heavy rains especially
ERN counties. Will go with 30-70% SW-NE POP gradient 00z-06z,
then 40-30% W-E gradient. Clouds will yield another warm and muggy
night with inland lows in the low to mid 70s. SREF, Glamp and NM4
implying some light fog mainly Nrn tier counties of AL/GA with
best chance of residual moisture.
&&
.SHORT TERM [Thursday Through Friday Night]...
Large upper trough and associated shortwave energy will begin to
move off to our northeast Thursday, and will be replaced by an upper
ridge Friday and Saturday. PWAT values should remain near or above
2" on Thursday, and combined with the remaining upper level energy,
elevated chances of precipitation will continue through the
afternoon and early evening hours. From Thursday night through
Saturday, drier air aloft will move into the region as the ridge
builds, and therefore chances of precipitation will decrease during
this period. However, the sea breeze should continue to spark some
isolated showers and thunderstorms each afternoon under light
southwesterly flow, especially in our Florida counties. Highs should
remain in the upper 80s-lower 90s on Thursday, but could rise into
the mid 90s across our region on Friday with diminishing cloud cover
and precipitation chances.
&&
.LONG TERM [Saturday through Wednesday]...
Zonal flow pattern at upper levels should remain in place through
the weekend, with the jet stream over the northern U.S. and a ridge
in place over the southern tier of states. Precipitation chances
will remain low over our area Saturday and Sunday, with scattered
showers and thunderstorms possible mainly during the afternoon and
evening hours. During the beginning of the next week, moisture is
expected to increase over the Southeast, and another upper shortwave
could potentially impact our area, leading to increased precipitation
chances during this time.
&&
.AVIATION [Through 00Z Friday]...
Showers and thunderstorms will taper off through the evening, with
lingering impacts most likely at KECP, KTLH, and KVLD. Thereafter,
may see some low cigs around sunrise, with IFR conditions most
likely at KABY and KTLH. Additional thunderstorms are expected
Thursday afternoon.
&&
.MARINE...
With a broad area of weak high pressure to our south in the Gulf,
SW and W winds around 10 kts or less and seas of 1 ft or less will
prevail through the period. Brief periods of increased winds may
occur with showers and thunderstorms.
&&
.FIRE WEATHER...
A cold front will gradually drop south into the northern Gulf on
Thursday bringing a good chance of showers and thunderstorms. The
front will weaken on Friday with drier air spreading southward
into our area. However, minimum relative humidities will remain
well above red flag levels through Friday and then into the next
work week.
&&
.HYDROLOGY...
The Choctawhatchee at Bruce has dropped to minor flooding as of 7am
EDT, and will slowly fall to below flood stage late this week.
Precipitable Water values are well above average, and there will be
widespread thunderstorm activity with multiple mesoscale boundary
interactions. This type of pattern suggests that isolated flash
flooding is possible if storms persist or train over smaller
fast-responding basins or urban areas.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 73 92 73 95 73 / 60 50 20 30 10
Panama City 78 88 75 90 76 / 50 40 20 20 10
Dothan 73 91 73 95 73 / 60 50 10 20 10
Albany 73 89 72 94 73 / 70 60 20 20 10
Valdosta 72 93 72 97 72 / 70 50 30 30 20
Cross City 74 90 72 91 71 / 50 40 20 30 20
Apalachicola 77 88 75 89 75 / 40 40 20 20 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
Near Term/Marine/Fire Wx...Block
Short Term/Long Term...Moore/Lahr
Aviation...Camp
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
248 AM EDT Tue Jul 30 2013
.NEAR TERM [Through Today]...
The upper trough continues to lift northeast across the Northeast
and eastern Canada leaving a broad ridge stretching across the Gulf
Coast. Overall steering flow will remain light today resulting in a
type 1 sea breeze regime. We used some sea breeze climo in today`s
forecast but tempered to account for lower than normal precipitable
water north of the FL border. We also blended in some of the CAM and
MOS data. The result is chance PoPs (30-40%) across the southern
half of the CWA and slight chance (20%) across the northern half.
These latter areas will be a bit hotter with highs in the mid 90s.
VLD could once again reach upper 90s. In FL, look for highs mainly
in the lower 90s inland and upper 80s near the coast.
&&
.SHORT TERM [Tonight Through Thursday]...
Beginning tonight, another shortwave will slide out of the
Mississippi Valley, into the Southeast. The effects of this will
be to nudge the mid/upper layer ridge back to the west and begin
the transition back to the all too familiar pattern highlighted
by a trough over much of the eastern part of the country, and a
persistent ridge centered over the Southwest/Southern Plains.
At the surface, high pressure over the northern Gulf will weaken
and the surface pattern across the Southeast will likely be
dominated by some sort of broad, weak, low pressure in the form of
a trough.
The surface trough will likely be the main focus for thunderstorm
development, and the distribution of rain will be highly dependent
on the exact positioning of the trough. On Wednesday, there will
most likely be some sort of mixed contribution from the Gulf Coast
Seabreeze and the trough, while Thursday will likely be too
disturbed to discern an organized seabreeze circulation.
Localized flooding may be a concern as precipitable water values
rise to slightly above seasonal averages. This will primarily be a
concern on Wednesday when cloud bearing steering flow will be
rather weak, and storms may easily link to mesoscale/synoptic
boundaries. By Thursday, a more steady westerly steering flow
should become established, lessening the flooding threat. However,
in general do not expect any sort of widespread flooding concerns
as average storm totals Wed-Thurs should be around the 0.5 to 1.5
inch range.
The severe weather potential remains low at this time. The best
chance for any strong to severe storm development appears to be on
Thursday, closer to southeast Alabama should the arrival of
steeper mid-level lapse rates time up just right with afternoon
storms. The primary threat would be damaging wind gusts.
&&
.LONG TERM [Thursday Night through Monday]...
The pattern will remain fairly into Friday, as the parent upper
level trough builds south over the Southeast and moist air
remains in place over our region. While this feature is expected
to move into the Atlantic by the weekend and will be replaced by
an upper ridge, PWAT values are forecast to remain near 2" over
our region through the rest of the period, and a stationary front
is projected to remain just north of our region throughout this
period. As a result, scattered showers and thunderstorms will
remain possible each day, especially during the afternoon and
early evenings. Temperatures should remain fairly seasonable, with
highs in the low 90s and lows in the 70s.
&&
.AVIATION [Beginning 06Z Tuesday]...
Hi res guidance including the HRRR indicate that there is a much
lower chance for low cigs this morning. We are mainly calling for
a period of MVFR visibility. ECP may briefly see an MVFR ceiling
in the hours surrounding sunrise. Overall convective coverage will
be low enough to preclude mention in the DHN and ABY TAFs.
Convection will be mentioned in the vicinity only at ECP, TLH and
VLD.
&&
.MARINE...
High pressure transitioning to a broad, weak, low pressure pattern
will keep wind and seas calm through the weekend. Scattered
showers and thunderstorms will be most common Wed-Fri, with typical
summertime nocturnal storms otherwise.
&&
.FIRE WEATHER...
Red Flag conditions are not anticipated this week. Dispersion
indices will remain very low today.
&&
.HYDROLOGY...
Water levels on all area river systems are on the downward trend,
and for the most part will remain this way for the next several
days. With above average rain chances mid to late week, these
decreases may slow a bit or hold steady. At this time, only a few
rivers remain in flood, most significantly the Choctawhatchee
River near Bruce which should remain in moderate flood stage
through late week. Outside of these few rivers, flooding will not
be a concern, even with rain chances on the rise by mid week. The
only exceptions will be if an isolated storm gets pinned over a
basin for an extended period of time. This would be most likely on
Wednesday.
More specific stage information, as well as the latest river
forecasts can be found at the following link:
http:/goo.gl/Lpg4a1
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 93 74 90 73 90 / 40 20 40 20 60
Panama City 89 76 87 76 87 / 30 10 20 10 30
Dothan 95 74 89 72 90 / 20 20 50 20 60
Albany 95 73 89 73 89 / 20 20 40 30 60
Valdosta 96 74 90 73 89 / 30 20 50 30 60
Cross City 93 73 89 73 88 / 30 30 30 20 40
Apalachicola 89 75 87 75 86 / 20 10 20 10 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Wool
SHORT TERM...Harrigan
LONG TERM...Moore/Harrigan
AVIATION...Wool
MARINE...Harrigan
FIRE WEATHER...Wool
HYDROLOGY...Harrigan
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
218 PM CDT TUE JUL 30 2013
.DISCUSSION...
931 AM CDT
UPDATED MORNING POP/WEATHER GRIDS TO ACCOUNT FOR CURRENT RADAR
TRENDS AND ALSO BOOSTED POPS THIS AFTERNOON...MAINLY FOR SOUTH AND
SOUTHWEST PORTIONS OF THE AREA. FORECAST SOUNDINGS FROM ORD ARE
STILL SHOWING CONSIDERABLE DRY AIR AROUND 800MB FOR THE METRO
AREA...BUT OBVIOUSLY THE AIR IS FAIRLY WELL SATURATED FARTHER TO
THE SOUTHWEST. THE CURRENT TRENDS ARE DEPICTED NICELY BY MOISTURE
CONVERGENCE FIELDS IN THE RAP MODEL...SO HAVE LEANED TOWARD THAT
EVOLUTION FOR THE REST OF THE DAY. MAY NEED FURTHER UPDATES IF
ACTIVITY SHOWS GOOD SIGNS OF HOLDING TOGETHER LATER INTO THE
AFTERNOON. GIVEN EXISTING AND FORECAST CAPE TRENDS AND SOUNDING
PROFILES...MAY ALSO NEED TO ADD MENTION OF THUNDERSTORMS LATER
TODAY...BUT MID LEVEL LAPSE RATES ARE ONLY MARGINALLY FAVORABLE.
LENNING
//PREV DISCUSSION...
323 AM CDT
TODAY...
SFC RIDGING CONTINUES TO BE AN INFLUENCE ON THE REGION...DESPITE
DRIFTING EAST OF THE CWFA AND BECOMING CENTERED OVER THE EASTERN
OHIO VALLEY THIS MORNING. IR IMAGERY DEPICTS A COMPLEX OF
THUNDERSTORMS ACROSS THE SOUTHERN PLAINS...WITH REGIONAL RADAR
SHOWING PRECIP RETURNS LIFTING INTO NORTHEAST MISSOURI/SOUTHEAST
IOWA. FOR MUCH OF THE DAY TODAY EXPECT SFC RIDGING TO CONTINUE TO
KEEP PRECIP WEST/SOUTHWEST OF THE CWFA. GUIDANCE HOLDS ONTO THE
SOUTHEAST FLOW AT THE SFC...WITH SOUNDINGS SUGGESTING CONSIDERABLE
DRY AIR THRU 15Z THEN SLOWLY MOISTENING FROM THE TOP DOWN. PWAT
VALUES SLOWLY INCREASE...HOVERING ARND 1.8" BY LATE THIS AFTN/EVE.
BY 18Z EXPECT SCATTERED PRECIP TO BEGIN PUSHING OVER THE CWFA. BASED
ON THE SOUNDINGS CONVECTIVE POTENTIAL REMAINS VERY LOW...EXCEPT FOR
FAR SOUTHERN AREAS OF THE CWFA. OTHERWISE EXPECT PRECIP TO REMAIN
LIGHT IN INTENSITY AND MINIMAL COVERAGE.
WITH GRADUAL THICKENING OF THE CLOUD SHIELD...TEMPS WILL INITIALLY
WARM THEN THE RATE OF CLIMB WILL BEGIN TO SLOW GIVEN THE INCREASED
MOISTURE IN THE ATMOSPHERE. STILL THINK THAT TEMPS WILL WARM TO THE
MID 70S...HOWEVER IF CLOUDS CAN THICKEN FASTER THIS MORNING TEMPS
MAY STRUGGLE TO WARM BEYOND THE LOW 70S.
CONFIDENCE...MEDIUM.
TONIGHT THROUGH WEDNESDAY...
WEAK SHORTWAVE CONTINUES TO LIFT NORTHEAST ACROSS MISSOURI LATE THIS
AFTN/EARLY EVE...WHILE ANTI-CYCLONIC FLOW OVER THE OHIO VALLEY
CONTINUES TO PROVIDE A DRY INFLUENCE ON THE NEAR SFC ENVIRONMENT
ACROSS NORTHERN IL/NORTHWEST IN. SFC WINDS APPEAR TO HOLD FROM THE
SOUTHEAST...AND UNDER A LIGHT GRADIENT WILL LIKELY BE LESS THAN 10
MPH. THIS COULD BE JUST ENOUGH OF A DRY FLOW IN THE LLVLS TO HOLD
FULL SATURATION OF THE PROFILE. GUIDANCE DOES INDICATE A SLOW
MOISTENING OF THE LOW/MID LVLS AFT 21Z THIS AFTN...WITH PWAT VALUES
STEADILY INCREASING TO ARND 1.5-1.8". THE TREND HAS BEEN DRIER AND
FURTHER SOUTH WITH THIS SYSTEM...HOWEVER JUST ENOUGH MOISTURE COULD
LIFT OVERHEAD AND WITH SOME OMEGA OR LIFT PRESENT...SPRINKLES/LIGHT
SHRA COULD DEVELOP LATE THIS EVENING/OVERNIGHT. LOCAL HI-RES WRF
SOLUTION KEEPS ALL PRECIP TO THE SOUTH OF A PONTIAC TO FOWLER LINE.
HAVE TRIMMED BACK ON POPS TO THE HIGH TEENS...AND EXPECT COVERAGE TO
BE MINIMAL WITH PRECIP TONIGHT. IN ADDITION DROPLET SIZE WILL BE
SMALL AS WELL...WHICH COULD TRANSLATE INTO DRIZZLE OR CHANGING
PRECIP TO SPRINKLES INSTEAD OF SHOWERS.
WITH A 500MB WAVE RATHER FLAT...THIS SYSTEM WILL REMAIN PROGRESSIVE
AND PUSH TO THE EAST BY WED MORNING. ALONG THE BACK EDGE OF THE
DEPARTING WEAK SFC WAVE IT APPEARS SOME DIFLUENT FLOW TRIES TO
DEVELOP AND COULD BRING A BRIEF END TO THE PRECIP BY DAYBREAK WED.
THEN THE FOCUS TURNS TOWARDS AN ADVANCING FRONTAL BOUNDARY THAT WILL
BE SLIDING INTO THE UPPER MIDWEST EARLY WED.
LLVL FLOW WILL BECOME SOUTHERLY TO SOUTHWESTERLY AHEAD OF THE COLD
FRONT...WITH MARGINAL INSTABILITY DEVELOPING IN THE AFTN HOURS WED.
WITH THE LACK OF STRONG SHEAR AND MODEL SOUNDINGS INDICATING SOME
DRY AIR IN THE NEAR SFC...IT IS CONCEIVABLE THAT MUCH OF WED COULD
BE DRY. AS PREVIOUSLY NOTED IN REGARDS TO THE LCL HI-RES WRF...THIS
SOLUTION CONTINUES THE DRY THEME FOR WED. AT THIS POINT HAVE ONLY
TRIMMED BACK ON POPS FOR WED...AND FOCUSED THE TIMING TOWARDS THE
AFTN/EVE HOURS OR CLOSER TO FROPA. 500MB TROUGH AXIS APPEARS TO PUSH
INTO THE WESTERN GREAT LAKES ARND 00Z THUR...WITH DIMINISHING LLVL
MOISTURE. MID-LVL SHEAR WILL INCREASE AS THE BNDRY NEARS...AND WITH
MARGINAL INSTABILITY COULD ALLOW SOME ISOLATED THUNDERSTORMS TO
DEVELOP LATE WED AFTN.
IN REGARDS TO TEMPS TONIGHT...EXPECT CONSIDERABLE CLOUD COVER TO
HOLD TEMPS SLIGHTLY WARMER OR IN THE MID 60S AWAY FROM LAKE MICHIGAN
AND UPR 60S CLOSER TO THE LAKE. THEN FOR WED TEMPS WILL BE SLIGHTLY
WARMER AND CLOSER TO 80 DEG. IF THE SOUTH/SOUTHWEST FLOW IS SLIGHTLY
STRONGER WED IN ADVANCE OF THE FRONT...TEMPS MAY BE ABLE TO WARM
FURTHER OR 80-83 DEG.
CONFIDENCE...MEDIUM.
CONFIDENCE IN PRECIP...LOW.
THURSDAY THROUGH FRIDAY...
500MB TROUGH QUICKLY SLIDES OVERHEAD WITH ANTI-CYCLONIC FLOW
BUILDING INTO THE REGION FROM THE WEST. THIS WILL AID IN PROVIDING
DRY WEATHER FOR THUR/THUR NIGHT. SFC RIDGE PUSHES FURTHER SOUTH
ACROSS THE TENN VALLEY FRI...WHILE A LOBE OF VORTICITY IS PROGGED TO
SLIDE SOUTHEAST ACROSS THE WESTERN GREAT LAKES FRI. THIS APPEARS TO
BE ASSOCIATED WITH A FRONTAL BOUNDARY...WHICH MAY HAVE SOME PRECIP
ACCOMPANYING FROPA FRI/FRI EVE. ALTHOUGH THE SETUP LOOKS MORE
FAVORABLE FOR A DRY FROPA AS ANTI-CYCLONIC FLOW WILL BE DEPARTING
WITH YET ANOTHER ANTI-CYCLONIC FLOW SLIDING SOUTHEAST ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST FRI NIGHT.
TEMPS CONTINUE TO BE UNSEASONABLY COOL...WITH AFTN HIGHS STRUGGLING
TO WARM BEYOND THE UPR 70S IN MANY LOCATIONS. A FEW SITES MAY TOUCH
80 DEG FRI AFTN.
CONFIDENCE...MEDIUM.
SATURDAY THROUGH MONDAY...
EXTENDED PERIODS CONTINUE TO FEATURE A COOL NORTHWEST SETUP WITH
ENSEMBLES DEMONSTRATING MINIMAL NOISE OR DIFFERENCES. THE STRENGTH
OF THE DOWNSTREAM RIDGE OVER THE CANADIAN MARITIME DOES EXHIBIT SOME
WEAKENING SUN...WHICH SHOULD ALLOW THE GREAT LAKES TROUGH TO WEAKEN
AND PUSH EAST. HOWEVER PROGRESSING TOWARDS THE FINAL FEW
PERIODS...HIGH LATITUDE RIDGING IS PROGGED TO DEVELOP OVER THE NORTH
ATLANTIC AND STRETCH WEST ACROSS WESTERN CANADA. IF THIS SOLUTION
VERIFIES...FLOW ACROSS THE GREAT LAKES REGION WILL LIKELY REMAIN IN
A UNSEASONABLY COOL SETUP.
OPERATIONAL SOLUTIONS HAVE SFC RIDGING BUILDING IN FOR SAT AND
LINGERING THRU SUN NGT...WHICH WILL PROVIDE DRY WEATHER. THEN THE
500MB FLOW BEGINS TO FLATTEN AND BECOME MORE FLUID...WITH A FRONTAL
BOUNDARY AND A WEAK SYSTEM APPROACHING THE REGION TOWARDS THE FINAL
PERIODS WITH A CHANCE OF PRECIP FOR EARLY NEXT WEEK.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SCATTERED -SHRA OVER AREA TIL LATER AFTERNOON.
* ANOTHER PERIOD OF -SHRA/-RA MID EVENING INTO LATE NIGHT.
* VFR DETERIORATING TO MVFR WITH EVENING PRECIP.
* CONTINUED DETERIORATION FROM MVFR TO IFR OVERNIGHT THEN GRADUAL
IMPROVEMENT BACK THROUGH MVFR TO VFR DURING EARLY TO MID WED
AFTERNOON.
TRS
//DISCUSSION...UPDATED 18Z...
DISTURBANCE CONTINUES TO MOVE E FROM IA AND MO TO MS RIVER IN
ZONAL FLOW AT MIDDAY. WATER VAPOR SATELLITE LOOP SHOWS A COUPLE
MINOR DISTURBANCES FURTHER UPSTREAM OVER EASTERN NE AND EASTERN WY
ALSO MOVING E WITH THE ZONAL FLOW WITH A STRONGER ONE MOVING
ACROSS THE NORTHERN PLAINS TOWARD THE UPPER MIDWEST. MODELS
SUGGEST THAT IT WILL PHASE WITH THE MID MS VALLEY DISTURBANCE WITH
THE NORTHERN PORTION OF THE RESULTING MID LEVEL TROUGH MOVING
ACROSS NORTHERN IL DURING THE NIGHT.
MODELS HANDLE SURFACE LOW ASSOCIATED WITH THE MID LEVEL TROUGH
DIFFERENTLY WITH GEM AND NAM MOVING IT E OR ENE FROM W CENTRAL IL
OVERNIGHT WHILE 30.00Z ECMWF AND 12Z GFS KEEP THE LOW CENTER IN
SOUTHERN IL. ISENTROPIC SURFACES SHOW MODERATE UPGLIDE ACROSS THE
LOCAL AREA TONIGHT AND QPF FIELDS INDICATE LIGHT PRECIP
ACCUMULATIONS RESULTING SO FEEL A PERIOD OF TEMPO -SHRA WARRANTED
FOR MID EVE INTO LATE OVERNIGHT.
AREAS OF MVFR HAS SPREAD INTO NE AND N CENTRAL IL LATE MORNING-
EARLY AFTERNOON WITH AREAS OF IFR FURTHER TO THE W...MAINLY ACROSS
WESTERN AND SOUTHERN IA. MOISTURE PROGS INDICATE THAT THE LOWER
LEVELS MOISTEN UP BY EARLY THIS EVENING. WITH MOIST LOW LEVELS
FROM SHOWERS AND LIGHT LOW LEVEL FLOW OVERNIGHT ANTICIPATE
CEILINGS TO FALL TO IFR. DURING THE MID MORNING WED EXPECT
IMPROVEMENT TO MVFR AND EVENTUALLY VFR THOUGH TIMING NOT VERY
CERTAIN DUE TO THE VARYING HANDLING OF SURFACE FEATURES AND THEIR
INFLUENCE ON ON QUICKLY N AND NW LOW LEVEL FLOW GETS ESTABLISHED
ACROSS THE REGION.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE ALL ELEMENTS EARLY AFTERNOON.
* MODERATE CONFIDENCE IN TIMING ONSET OF MVFR AND IFR CONDITIONS
LATE AFTERNOON AND TONIGHT.
* HIGH CONFIDENCE THAT IF ANY ISOLD TS DEVELOP THIS AFTERNOON
THEN WILL REMAIN S OF MDW AND ORD.
* LOW CONFIDENCE IN TIMING OF IMPROVEMENT TO MVFR THEN VFR DURING
WED MORNING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...CHANCE OF TSRA.
* THURSDAY...DRY/VFR.
* FRIDAY...CHANCE OF TSRA.
* SATURDAY AND SUNDAY...DRY/VFR.
* MONDAY...CHANCE OF TSRA.
&&
.MARINE...
215 PM...BROAD HIGH PRESSURE EXTENDS FROM SOUTHERN ONTARIO THROUGH
THE OHIO VALLEY TO THE SERN CONUS WHILE LOW PRESSURE DEVELOPS OVER
NRN WINNIPEG WITH A WEAK FRONTAL TROUGH EXTENDING SOUTH INTO THE
NORTHERN PLAINS. GENERALLY SOUTHERLY WINDS WILL PERSIST OVER THE
LAKE WHILE THE HIGH SLOWLY MOVES TO THE EAST AND THE TROUGH AND
ASSOCIATED COLD FRONT MOVE INTO THE UPPER MISSISSIPPI VALLEY
TOMORROW. IN THE MEAN TIME...WEAK LOW PRESSURE OVER THE SRN PLAINS
WILL TRACK INTO SRN IL TOMORROW...TURNING WINDS OVER THE SRN
PORTIONS OF THE LAKE LIGHT AND NELY. A MODEST PRESSURE GRADIENT
WILL REMAIN IN PLACE OVER THE NRN PORTIONS OF THE LAKE...KEEPING
SWLY WINDS ARND 15-20KT INTO TOMORROW EVENING. THE WEAK COLD FRONT
WILL PUSH ACROSS THE LAKE WEDNESDAY NIGHT AND WINDS OVER THE LAKE
WILL GRADUALLY TURN NWLY. WITH A LACK OF STRONG COLD ADVECTION OR
A STRONG PRESSURE RISE-FALL COUPLET WITH THE FROPA...WINDS SHOULD
ONLY INCREASE TO 15-20KT FOLLOWING THE FROPA LATE WEDNESDAY NIGHT
AND EARLY THURSDAY MORNING BEFORE BACKING WLY AND DIMINISHING TO
ARND 10KT. WEAK HIGH PRESSURE WILL SETTLE INTO THE NRN PLAINS
THURSDAY NIGHT AND FRIDAY AND SPREAD EAST ACROSS THE WESTERN GREAT
LAKES THROUGH THE WEEKEND...KEEPING WINDS GENERALLY WESTERLY AND
IN THE 5-10KT RANGE.
KREIN
&&
.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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
120 PM CDT TUE JUL 30 2013
.DISCUSSION...
931 AM CDT
UPDATED MORNING POP/WEATHER GRIDS TO ACCOUNT FOR CURRENT RADAR
TRENDS AND ALSO BOOSTED POPS THIS AFTERNOON...MAINLY FOR SOUTH AND
SOUTHWEST PORTIONS OF THE AREA. FORECAST SOUNDINGS FROM ORD ARE
STILL SHOWING CONSIDERABLE DRY AIR AROUND 800MB FOR THE METRO
AREA...BUT OBVIOUSLY THE AIR IS FAIRLY WELL SATURATED FARTHER TO
THE SOUTHWEST. THE CURRENT TRENDS ARE DEPICTED NICELY BY MOISTURE
CONVERGENCE FIELDS IN THE RAP MODEL...SO HAVE LEANED TOWARD THAT
EVOLUTION FOR THE REST OF THE DAY. MAY NEED FURTHER UPDATES IF
ACTIVITY SHOWS GOOD SIGNS OF HOLDING TOGETHER LATER INTO THE
AFTERNOON. GIVEN EXISTING AND FORECAST CAPE TRENDS AND SOUNDING
PROFILES...MAY ALSO NEED TO ADD MENTION OF THUNDERSTORMS LATER
TODAY...BUT MID LEVEL LAPSE RATES ARE ONLY MARGINALLY FAVORABLE.
LENNING
//PREV DISCUSSION...
323 AM CDT
TODAY...
SFC RIDGING CONTINUES TO BE AN INFLUENCE ON THE REGION...DESPITE
DRIFTING EAST OF THE CWFA AND BECOMING CENTERED OVER THE EASTERN
OHIO VALLEY THIS MORNING. IR IMAGERY DEPICTS A COMPLEX OF
THUNDERSTORMS ACROSS THE SOUTHERN PLAINS...WITH REGIONAL RADAR
SHOWING PRECIP RETURNS LIFTING INTO NORTHEAST MISSOURI/SOUTHEAST
IOWA. FOR MUCH OF THE DAY TODAY EXPECT SFC RIDGING TO CONTINUE TO
KEEP PRECIP WEST/SOUTHWEST OF THE CWFA. GUIDANCE HOLDS ONTO THE
SOUTHEAST FLOW AT THE SFC...WITH SOUNDINGS SUGGESTING CONSIDERABLE
DRY AIR THRU 15Z THEN SLOWLY MOISTENING FROM THE TOP DOWN. PWAT
VALUES SLOWLY INCREASE...HOVERING ARND 1.8" BY LATE THIS AFTN/EVE.
BY 18Z EXPECT SCATTERED PRECIP TO BEGIN PUSHING OVER THE CWFA. BASED
ON THE SOUNDINGS CONVECTIVE POTENTIAL REMAINS VERY LOW...EXCEPT FOR
FAR SOUTHERN AREAS OF THE CWFA. OTHERWISE EXPECT PRECIP TO REMAIN
LIGHT IN INTENSITY AND MINIMAL COVERAGE.
WITH GRADUAL THICKENING OF THE CLOUD SHIELD...TEMPS WILL INITIALLY
WARM THEN THE RATE OF CLIMB WILL BEGIN TO SLOW GIVEN THE INCREASED
MOISTURE IN THE ATMOSPHERE. STILL THINK THAT TEMPS WILL WARM TO THE
MID 70S...HOWEVER IF CLOUDS CAN THICKEN FASTER THIS MORNING TEMPS
MAY STRUGGLE TO WARM BEYOND THE LOW 70S.
CONFIDENCE...MEDIUM.
TONIGHT THROUGH WEDNESDAY...
WEAK SHORTWAVE CONTINUES TO LIFT NORTHEAST ACROSS MISSOURI LATE THIS
AFTN/EARLY EVE...WHILE ANTI-CYCLONIC FLOW OVER THE OHIO VALLEY
CONTINUES TO PROVIDE A DRY INFLUENCE ON THE NEAR SFC ENVIRONMENT
ACROSS NORTHERN IL/NORTHWEST IN. SFC WINDS APPEAR TO HOLD FROM THE
SOUTHEAST...AND UNDER A LIGHT GRADIENT WILL LIKELY BE LESS THAN 10
MPH. THIS COULD BE JUST ENOUGH OF A DRY FLOW IN THE LLVLS TO HOLD
FULL SATURATION OF THE PROFILE. GUIDANCE DOES INDICATE A SLOW
MOISTENING OF THE LOW/MID LVLS AFT 21Z THIS AFTN...WITH PWAT VALUES
STEADILY INCREASING TO ARND 1.5-1.8". THE TREND HAS BEEN DRIER AND
FURTHER SOUTH WITH THIS SYSTEM...HOWEVER JUST ENOUGH MOISTURE COULD
LIFT OVERHEAD AND WITH SOME OMEGA OR LIFT PRESENT...SPRINKLES/LIGHT
SHRA COULD DEVELOP LATE THIS EVENING/OVERNIGHT. LOCAL HI-RES WRF
SOLUTION KEEPS ALL PRECIP TO THE SOUTH OF A PONTIAC TO FOWLER LINE.
HAVE TRIMMED BACK ON POPS TO THE HIGH TEENS...AND EXPECT COVERAGE TO
BE MINIMAL WITH PRECIP TONIGHT. IN ADDITION DROPLET SIZE WILL BE
SMALL AS WELL...WHICH COULD TRANSLATE INTO DRIZZLE OR CHANGING
PRECIP TO SPRINKLES INSTEAD OF SHOWERS.
WITH A 500MB WAVE RATHER FLAT...THIS SYSTEM WILL REMAIN PROGRESSIVE
AND PUSH TO THE EAST BY WED MORNING. ALONG THE BACK EDGE OF THE
DEPARTING WEAK SFC WAVE IT APPEARS SOME DIFLUENT FLOW TRIES TO
DEVELOP AND COULD BRING A BRIEF END TO THE PRECIP BY DAYBREAK WED.
THEN THE FOCUS TURNS TOWARDS AN ADVANCING FRONTAL BOUNDARY THAT WILL
BE SLIDING INTO THE UPPER MIDWEST EARLY WED.
LLVL FLOW WILL BECOME SOUTHERLY TO SOUTHWESTERLY AHEAD OF THE COLD
FRONT...WITH MARGINAL INSTABILITY DEVELOPING IN THE AFTN HOURS WED.
WITH THE LACK OF STRONG SHEAR AND MODEL SOUNDINGS INDICATING SOME
DRY AIR IN THE NEAR SFC...IT IS CONCEIVABLE THAT MUCH OF WED COULD
BE DRY. AS PREVIOUSLY NOTED IN REGARDS TO THE LCL HI-RES WRF...THIS
SOLUTION CONTINUES THE DRY THEME FOR WED. AT THIS POINT HAVE ONLY
TRIMMED BACK ON POPS FOR WED...AND FOCUSED THE TIMING TOWARDS THE
AFTN/EVE HOURS OR CLOSER TO FROPA. 500MB TROUGH AXIS APPEARS TO PUSH
INTO THE WESTERN GREAT LAKES ARND 00Z THUR...WITH DIMINISHING LLVL
MOISTURE. MID-LVL SHEAR WILL INCREASE AS THE BNDRY NEARS...AND WITH
MARGINAL INSTABILITY COULD ALLOW SOME ISOLATED THUNDERSTORMS TO
DEVELOP LATE WED AFTN.
IN REGARDS TO TEMPS TONIGHT...EXPECT CONSIDERABLE CLOUD COVER TO
HOLD TEMPS SLIGHTLY WARMER OR IN THE MID 60S AWAY FROM LAKE MICHIGAN
AND UPR 60S CLOSER TO THE LAKE. THEN FOR WED TEMPS WILL BE SLIGHTLY
WARMER AND CLOSER TO 80 DEG. IF THE SOUTH/SOUTHWEST FLOW IS SLIGHTLY
STRONGER WED IN ADVANCE OF THE FRONT...TEMPS MAY BE ABLE TO WARM
FURTHER OR 80-83 DEG.
CONFIDENCE...MEDIUM.
CONFIDENCE IN PRECIP...LOW.
THURSDAY THROUGH FRIDAY...
500MB TROUGH QUICKLY SLIDES OVERHEAD WITH ANTI-CYCLONIC FLOW
BUILDING INTO THE REGION FROM THE WEST. THIS WILL AID IN PROVIDING
DRY WEATHER FOR THUR/THUR NIGHT. SFC RIDGE PUSHES FURTHER SOUTH
ACROSS THE TENN VALLEY FRI...WHILE A LOBE OF VORTICITY IS PROGGED TO
SLIDE SOUTHEAST ACROSS THE WESTERN GREAT LAKES FRI. THIS APPEARS TO
BE ASSOCIATED WITH A FRONTAL BOUNDARY...WHICH MAY HAVE SOME PRECIP
ACCOMPANYING FROPA FRI/FRI EVE. ALTHOUGH THE SETUP LOOKS MORE
FAVORABLE FOR A DRY FROPA AS ANTI-CYCLONIC FLOW WILL BE DEPARTING
WITH YET ANOTHER ANTI-CYCLONIC FLOW SLIDING SOUTHEAST ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST FRI NIGHT.
TEMPS CONTINUE TO BE UNSEASONABLY COOL...WITH AFTN HIGHS STRUGGLING
TO WARM BEYOND THE UPR 70S IN MANY LOCATIONS. A FEW SITES MAY TOUCH
80 DEG FRI AFTN.
CONFIDENCE...MEDIUM.
SATURDAY THROUGH MONDAY...
EXTENDED PERIODS CONTINUE TO FEATURE A COOL NORTHWEST SETUP WITH
ENSEMBLES DEMONSTRATING MINIMAL NOISE OR DIFFERENCES. THE STRENGTH
OF THE DOWNSTREAM RIDGE OVER THE CANADIAN MARITIME DOES EXHIBIT SOME
WEAKENING SUN...WHICH SHOULD ALLOW THE GREAT LAKES TROUGH TO WEAKEN
AND PUSH EAST. HOWEVER PROGRESSING TOWARDS THE FINAL FEW
PERIODS...HIGH LATITUDE RIDGING IS PROGGED TO DEVELOP OVER THE NORTH
ATLANTIC AND STRETCH WEST ACROSS WESTERN CANADA. IF THIS SOLUTION
VERIFIES...FLOW ACROSS THE GREAT LAKES REGION WILL LIKELY REMAIN IN
A UNSEASONABLY COOL SETUP.
OPERATIONAL SOLUTIONS HAVE SFC RIDGING BUILDING IN FOR SAT AND
LINGERING THRU SUN NGT...WHICH WILL PROVIDE DRY WEATHER. THEN THE
500MB FLOW BEGINS TO FLATTEN AND BECOME MORE FLUID...WITH A FRONTAL
BOUNDARY AND A WEAK SYSTEM APPROACHING THE REGION TOWARDS THE FINAL
PERIODS WITH A CHANCE OF PRECIP FOR EARLY NEXT WEEK.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SCATTERED -SHRA OVER AREA TIL LATER AFTERNOON.
* ANOTHER PERIOD OF -SHRA/-RA MID EVENING INTO LATE NIGHT.
* VFR DETERIORATING TO MVFR WITH EVENING PRECIP.
* CONTINUED DETERIORATION FROM MVFR TO IFR OVERNIGHT THEN GRADUAL
IMPROVEMENT BACK THROUGH MVFR TO VFR DURING EARLY TO MID WED
AFTERNOON.
TRS
//DISCUSSION...UPDATED 18Z...
DISTURBANCE CONTINUES TO MOVE E FROM IA AND MO TO MS RIVER IN
ZONAL FLOW AT MIDDAY. WATER VAPOR SATELLITE LOOP SHOWS A COUPLE
MINOR DISTURBANCES FURTHER UPSTREAM OVER EASTERN NE AND EASTERN WY
ALSO MOVING E WITH THE ZONAL FLOW WITH A STRONGER ONE MOVING
ACROSS THE NORTHERN PLAINS TOWARD THE UPPER MIDWEST. MODELS
SUGGEST THAT IT WILL PHASE WITH THE MID MS VALLEY DISTURBANCE WITH
THE NORTHERN PORTION OF THE RESULTING MID LEVEL TROUGH MOVING
ACROSS NORTHERN IL DURING THE NIGHT.
MODELS HANDLE SURFACE LOW ASSOCIATED WITH THE MID LEVEL TROUGH
DIFFERENTLY WITH GEM AND NAM MOVING IT E OR ENE FROM W CENTRAL IL
OVERNIGHT WHILE 30.00Z ECMWF AND 12Z GFS KEEP THE LOW CENTER IN
SOUTHERN IL. ISENTROPIC SURFACES SHOW MODERATE UPGLIDE ACROSS THE
LOCAL AREA TONIGHT AND QPF FIELDS INDICATE LIGHT PRECIP
ACCUMULATIONS RESULTING SO FEEL A PERIOD OF TEMPO -SHRA WARRANTED
FOR MID EVE INTO LATE OVERNIGHT.
AREAS OF MVFR HAS SPREAD INTO NE AND N CENTRAL IL LATE MORNING-
EARLY AFTERNOON WITH AREAS OF IFR FURTHER TO THE W...MAINLY ACROSS
WESTERN AND SOUTHERN IA. MOISTURE PROGS INDICATE THAT THE LOWER
LEVELS MOISTEN UP BY EARLY THIS EVENING. WITH MOIST LOW LEVELS
FROM SHOWERS AND LIGHT LOW LEVEL FLOW OVERNIGHT ANTICIPATE
CEILINGS TO FALL TO IFR. DURING THE MID MORNING WED EXPECT
IMPROVEMENT TO MVFR AND EVENTUALLY VFR THOUGH TIMING NOT VERY
CERTAIN DUE TO THE VARYING HANDLING OF SURFACE FEATURES AND THEIR
INFLUENCE ON ON QUICKLY N AND NW LOW LEVEL FLOW GETS ESTABLISHED
ACROSS THE REGION.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE ALL ELEMENTS EARLY AFTERNOON.
* MODERATE CONFIDENCE IN TIMING ONSET OF MVFR AND IFR CONDITIONS
LATE AFTERNOON AND TONIGHT.
* HIGH CONFIDENCE THAT IF ANY ISOLD TS DEVELOP THIS AFTERNOON
THEN WILL REMAIN S OF MDW AND ORD.
* LOW CONFIDENCE IN TIMING OF IMPROVEMENT TO MVFR THEN VFR DURING
WED MORNING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...CHANCE OF TSRA.
* THURSDAY...DRY/VFR.
* FRIDAY...CHANCE OF TSRA.
* SATURDAY AND SUNDAY...DRY/VFR.
* MONDAY...CHANCE OF TSRA.
&&
.MARINE...
305 AM...BROAD HIGH PRESSURE OVER THE LAKES REGION AND EXTENDING
INTO THE MID ATLANTIC WILL SLOWLY MOVE EAST TODAY AND TONIGHT AS
LOW PRESSURE OF NORTHERN MANITOBA MOVES EAST TO NEAR JAMES BAY BY
THURSDAY MORNING. SOUTHERLY WINDS WILL CONTINUE INTO WEDNESDAY
AFTERNOON WHEN A TRAILING COLD FRONT FROM THE LOW MOVES ACROSS THE
LAKE SHIFTING WINDS NORTHWEST. AS HIGH PRESSURE MOVES FROM THE
NORTHERN PLAINS WEDNESDAY NIGHT TO THE OHIO VALLEY THURSDAY
NIGHT...THE GRADIENT TIGHTENS SOME WEDNESDAY NIGHT INTO THURSDAY
MORNING ACROSS THE SOUTHERN HALF OR SO OF THE LAKE AND WHILE A
PERIOD OF 15-20 KTS LOOKS POSSIBLE...COULD BE SOME HIGHER GUSTS
INTO THE MID 20KT RANGE TOWARD THURSDAY MORNING. SPEEDS DIMINISH
THURSDAY NIGHT BUT WINDS REMAIN GENERALLY WESTERLY UNTIL ANOTHER
COLD FRONT MOVES ACROSS THE LAKES REGION FRIDAY AND FRIDAY NIGHT.
CMS
&&
.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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1142 AM CDT TUE JUL 30 2013
.DISCUSSION...
931 AM CDT
UPDATED MORNING POP/WEATHER GRIDS TO ACCOUNT FOR CURRENT RADAR
TRENDS AND ALSO BOOSTED POPS THIS AFTERNOON...MAINLY FOR SOUTH AND
SOUTHWEST PORTIONS OF THE AREA. FORECAST SOUNDINGS FROM ORD ARE
STILL SHOWING CONSIDERABLE DRY AIR AROUND 800MB FOR THE METRO
AREA...BUT OBVIOUSLY THE AIR IS FAIRLY WELL SATURATED FARTHER TO
THE SOUTHWEST. THE CURRENT TRENDS ARE DEPICTED NICELY BY MOISTURE
CONVERGENCE FIELDS IN THE RAP MODEL...SO HAVE LEANED TOWARD THAT
EVOLUTION FOR THE REST OF THE DAY. MAY NEED FURTHER UPDATES IF
ACTIVITY SHOWS GOOD SIGNS OF HOLDING TOGETHER LATER INTO THE
AFTERNOON. GIVEN EXISTING AND FORECAST CAPE TRENDS AND SOUNDING
PROFILES...MAY ALSO NEED TO ADD MENTION OF THUNDERSTORMS LATER
TODAY...BUT MID LEVEL LAPSE RATES ARE ONLY MARGINALLY FAVORABLE.
LENNING
//PREV DISCUSSION...
323 AM CDT
TODAY...
SFC RIDGING CONTINUES TO BE AN INFLUENCE ON THE REGION...DESPITE
DRIFTING EAST OF THE CWFA AND BECOMING CENTERED OVER THE EASTERN
OHIO VALLEY THIS MORNING. IR IMAGERY DEPICTS A COMPLEX OF
THUNDERSTORMS ACROSS THE SOUTHERN PLAINS...WITH REGIONAL RADAR
SHOWING PRECIP RETURNS LIFTING INTO NORTHEAST MISSOURI/SOUTHEAST
IOWA. FOR MUCH OF THE DAY TODAY EXPECT SFC RIDGING TO CONTINUE TO
KEEP PRECIP WEST/SOUTHWEST OF THE CWFA. GUIDANCE HOLDS ONTO THE
SOUTHEAST FLOW AT THE SFC...WITH SOUNDINGS SUGGESTING CONSIDERABLE
DRY AIR THRU 15Z THEN SLOWLY MOISTENING FROM THE TOP DOWN. PWAT
VALUES SLOWLY INCREASE...HOVERING ARND 1.8" BY LATE THIS AFTN/EVE.
BY 18Z EXPECT SCATTERED PRECIP TO BEGIN PUSHING OVER THE CWFA. BASED
ON THE SOUNDINGS CONVECTIVE POTENTIAL REMAINS VERY LOW...EXCEPT FOR
FAR SOUTHERN AREAS OF THE CWFA. OTHERWISE EXPECT PRECIP TO REMAIN
LIGHT IN INTENSITY AND MINIMAL COVERAGE.
WITH GRADUAL THICKENING OF THE CLOUD SHIELD...TEMPS WILL INITIALLY
WARM THEN THE RATE OF CLIMB WILL BEGIN TO SLOW GIVEN THE INCREASED
MOISTURE IN THE ATMOSPHERE. STILL THINK THAT TEMPS WILL WARM TO THE
MID 70S...HOWEVER IF CLOUDS CAN THICKEN FASTER THIS MORNING TEMPS
MAY STRUGGLE TO WARM BEYOND THE LOW 70S.
CONFIDENCE...MEDIUM.
TONIGHT THROUGH WEDNESDAY...
WEAK SHORTWAVE CONTINUES TO LIFT NORTHEAST ACROSS MISSOURI LATE THIS
AFTN/EARLY EVE...WHILE ANTI-CYCLONIC FLOW OVER THE OHIO VALLEY
CONTINUES TO PROVIDE A DRY INFLUENCE ON THE NEAR SFC ENVIRONMENT
ACROSS NORTHERN IL/NORTHWEST IN. SFC WINDS APPEAR TO HOLD FROM THE
SOUTHEAST...AND UNDER A LIGHT GRADIENT WILL LIKELY BE LESS THAN 10
MPH. THIS COULD BE JUST ENOUGH OF A DRY FLOW IN THE LLVLS TO HOLD
FULL SATURATION OF THE PROFILE. GUIDANCE DOES INDICATE A SLOW
MOISTENING OF THE LOW/MID LVLS AFT 21Z THIS AFTN...WITH PWAT VALUES
STEADILY INCREASING TO ARND 1.5-1.8". THE TREND HAS BEEN DRIER AND
FURTHER SOUTH WITH THIS SYSTEM...HOWEVER JUST ENOUGH MOISTURE COULD
LIFT OVERHEAD AND WITH SOME OMEGA OR LIFT PRESENT...SPRINKLES/LIGHT
SHRA COULD DEVELOP LATE THIS EVENING/OVERNIGHT. LOCAL HI-RES WRF
SOLUTION KEEPS ALL PRECIP TO THE SOUTH OF A PONTIAC TO FOWLER LINE.
HAVE TRIMMED BACK ON POPS TO THE HIGH TEENS...AND EXPECT COVERAGE TO
BE MINIMAL WITH PRECIP TONIGHT. IN ADDITION DROPLET SIZE WILL BE
SMALL AS WELL...WHICH COULD TRANSLATE INTO DRIZZLE OR CHANGING
PRECIP TO SPRINKLES INSTEAD OF SHOWERS.
WITH A 500MB WAVE RATHER FLAT...THIS SYSTEM WILL REMAIN PROGRESSIVE
AND PUSH TO THE EAST BY WED MORNING. ALONG THE BACK EDGE OF THE
DEPARTING WEAK SFC WAVE IT APPEARS SOME DIFLUENT FLOW TRIES TO
DEVELOP AND COULD BRING A BRIEF END TO THE PRECIP BY DAYBREAK WED.
THEN THE FOCUS TURNS TOWARDS AN ADVANCING FRONTAL BOUNDARY THAT WILL
BE SLIDING INTO THE UPPER MIDWEST EARLY WED.
LLVL FLOW WILL BECOME SOUTHERLY TO SOUTHWESTERLY AHEAD OF THE COLD
FRONT...WITH MARGINAL INSTABILITY DEVELOPING IN THE AFTN HOURS WED.
WITH THE LACK OF STRONG SHEAR AND MODEL SOUNDINGS INDICATING SOME
DRY AIR IN THE NEAR SFC...IT IS CONCEIVABLE THAT MUCH OF WED COULD
BE DRY. AS PREVIOUSLY NOTED IN REGARDS TO THE LCL HI-RES WRF...THIS
SOLUTION CONTINUES THE DRY THEME FOR WED. AT THIS POINT HAVE ONLY
TRIMMED BACK ON POPS FOR WED...AND FOCUSED THE TIMING TOWARDS THE
AFTN/EVE HOURS OR CLOSER TO FROPA. 500MB TROUGH AXIS APPEARS TO PUSH
INTO THE WESTERN GREAT LAKES ARND 00Z THUR...WITH DIMINISHING LLVL
MOISTURE. MID-LVL SHEAR WILL INCREASE AS THE BNDRY NEARS...AND WITH
MARGINAL INSTABILITY COULD ALLOW SOME ISOLATED THUNDERSTORMS TO
DEVELOP LATE WED AFTN.
IN REGARDS TO TEMPS TONIGHT...EXPECT CONSIDERABLE CLOUD COVER TO
HOLD TEMPS SLIGHTLY WARMER OR IN THE MID 60S AWAY FROM LAKE MICHIGAN
AND UPR 60S CLOSER TO THE LAKE. THEN FOR WED TEMPS WILL BE SLIGHTLY
WARMER AND CLOSER TO 80 DEG. IF THE SOUTH/SOUTHWEST FLOW IS SLIGHTLY
STRONGER WED IN ADVANCE OF THE FRONT...TEMPS MAY BE ABLE TO WARM
FURTHER OR 80-83 DEG.
CONFIDENCE...MEDIUM.
CONFIDENCE IN PRECIP...LOW.
THURSDAY THROUGH FRIDAY...
500MB TROUGH QUICKLY SLIDES OVERHEAD WITH ANTI-CYCLONIC FLOW
BUILDING INTO THE REGION FROM THE WEST. THIS WILL AID IN PROVIDING
DRY WEATHER FOR THUR/THUR NIGHT. SFC RIDGE PUSHES FURTHER SOUTH
ACROSS THE TENN VALLEY FRI...WHILE A LOBE OF VORTICITY IS PROGGED TO
SLIDE SOUTHEAST ACROSS THE WESTERN GREAT LAKES FRI. THIS APPEARS TO
BE ASSOCIATED WITH A FRONTAL BOUNDARY...WHICH MAY HAVE SOME PRECIP
ACCOMPANYING FROPA FRI/FRI EVE. ALTHOUGH THE SETUP LOOKS MORE
FAVORABLE FOR A DRY FROPA AS ANTI-CYCLONIC FLOW WILL BE DEPARTING
WITH YET ANOTHER ANTI-CYCLONIC FLOW SLIDING SOUTHEAST ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST FRI NIGHT.
TEMPS CONTINUE TO BE UNSEASONABLY COOL...WITH AFTN HIGHS STRUGGLING
TO WARM BEYOND THE UPR 70S IN MANY LOCATIONS. A FEW SITES MAY TOUCH
80 DEG FRI AFTN.
CONFIDENCE...MEDIUM.
SATURDAY THROUGH MONDAY...
EXTENDED PERIODS CONTINUE TO FEATURE A COOL NORTHWEST SETUP WITH
ENSEMBLES DEMONSTRATING MINIMAL NOISE OR DIFFERENCES. THE STRENGTH
OF THE DOWNSTREAM RIDGE OVER THE CANADIAN MARITIME DOES EXHIBIT SOME
WEAKENING SUN...WHICH SHOULD ALLOW THE GREAT LAKES TROUGH TO WEAKEN
AND PUSH EAST. HOWEVER PROGRESSING TOWARDS THE FINAL FEW
PERIODS...HIGH LATITUDE RIDGING IS PROGGED TO DEVELOP OVER THE NORTH
ATLANTIC AND STRETCH WEST ACROSS WESTERN CANADA. IF THIS SOLUTION
VERIFIES...FLOW ACROSS THE GREAT LAKES REGION WILL LIKELY REMAIN IN
A UNSEASONABLY COOL SETUP.
OPERATIONAL SOLUTIONS HAVE SFC RIDGING BUILDING IN FOR SAT AND
LINGERING THRU SUN NGT...WHICH WILL PROVIDE DRY WEATHER. THEN THE
500MB FLOW BEGINS TO FLATTEN AND BECOME MORE FLUID...WITH A FRONTAL
BOUNDARY AND A WEAK SYSTEM APPROACHING THE REGION TOWARDS THE FINAL
PERIODS WITH A CHANCE OF PRECIP FOR EARLY NEXT WEEK.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CHANCE OF LIGHT SHOWERS LATE MORNING THROUGH AFTERNOON...BETTER
CHANCE THIS MID EVENING INTO LATE TONIGHT.
* POTENTIAL FOR IFR CIGS MID EVENING INTO WED MORNING.
TRS
//DISCUSSION...UPDATED 12Z...
AN AREA OF SHOWERS/RAIN OVER WESTERN IL CONTINUES TO SPREAD NORTH
AND NORTHEAST THIS MORNING AND IS SLOWLY ERODING ON THE NORTHERN
EDGE AS IT ENCOUNTERS DRIER AIR. SHORT TERM/HI RES GUIDANCE IS IN
FAIR AGREEMENT THAT THIS ERODING TREND WILL CONTINUE THIS MORNING.
BUT DO EXPECT THIS ACTIVITY TO REACH A RFD/DKB/ARR LINE...AT LEAST
IN THE FORM OF SPRINKLES. ADDITIONAL SHOWERS MAY DEVELOP LATER
THIS AFTERNOON AND CONTINUE INTO THIS EVENING BUT CONFIDENCE
REGARDING COVERAGE IS FAIRLY LOW AND INCLUDED VICINITY MENTION BUT
STILL EXPECT MANY DRY HOURS.
WINDS WILL REMAIN SOUTHEASTERLY INTO THIS EVENING WITH SPEEDS
INCREASING INTO THE 7-10KT RANGE. ITS POSSIBLE A MORE TRADITIONAL
LAKE BREEZE MAY DEVELOP THIS AFTERNOON...ESPECIALLY FROM CHICAGO
NORTH INTO LAKE COUNTY IL. HOW FAR INLAND IT MOVES IS UNCERTAIN
AND TRENDS WILL NEED TO BE MONITORED INTO THIS AFTERNOON. SPEEDS
WILL DIMINISH THIS EVENING WITH LIGHT AND VARIABLE OR CALM WINDS
EXPECTED TONIGHT.
THE LOW LEVELS CONTINUE TO MOISTEN THROUGH THE EVENING AND INTO
THE OVERNIGHT HOURS. THERE IS A FAIRLY EXTENSIVE AREA OF LIFR/IFR
CIGS ACROSS THE CENTRAL PLAINS AND SOME OF THIS WILL LIKELY SHIFT
EAST TONIGHT. MOST CONFIDENT OF THIS REACHING RFD BUT FOR THE REST
OF THE TAFS...HAVE JUST INCLUDED SCATTERED IFR MENTION FOR NOW. CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH FOR -RA/-SHRA ACROSS LOCAL AREA LATE MORNING THOUGH
AFTERNOON.
* HIGH FOR ADDITIONAL -RA/-SHRA MID EVENING INTO OVERNIGHT.
* HIGH FOR MVFR CIGS AND VSBYS DEVELOPING THIS EVE AD PERSISTING
OVERNIGHT...MODERATE FOR LOWERING TO IFR CIGS.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...CHANCE OF TSRA.
* THURSDAY...DRY/VFR.
* FRIDAY...CHANCE OF TSRA.
* SATURDAY AND SUNDAY...DRY/VFR.
* MONDAY...CHANCE OF TSRA.
&&
.MARINE...
305 AM...BROAD HIGH PRESSURE OVER THE LAKES REGION AND EXTENDING
INTO THE MID ATLANTIC WILL SLOWLY MOVE EAST TODAY AND TONIGHT AS
LOW PRESSURE OF NORTHERN MANITOBA MOVES EAST TO NEAR JAMES BAY BY
THURSDAY MORNING. SOUTHERLY WINDS WILL CONTINUE INTO WEDNESDAY
AFTERNOON WHEN A TRAILING COLD FRONT FROM THE LOW MOVES ACROSS THE
LAKE SHIFTING WINDS NORTHWEST. AS HIGH PRESSURE MOVES FROM THE
NORTHERN PLAINS WEDNESDAY NIGHT TO THE OHIO VALLEY THURSDAY
NIGHT...THE GRADIENT TIGHTENS SOME WEDNESDAY NIGHT INTO THURSDAY
MORNING ACROSS THE SOUTHERN HALF OR SO OF THE LAKE AND WHILE A
PERIOD OF 15-20 KTS LOOKS POSSIBLE...COULD BE SOME HIGHER GUSTS
INTO THE MID 20KT RANGE TOWARD THURSDAY MORNING. SPEEDS DIMINISH
THURSDAY NIGHT BUT WINDS REMAIN GENERALLY WESTERLY UNTIL ANOTHER
COLD FRONT MOVES ACROSS THE LAKES REGION FRIDAY AND FRIDAY NIGHT.
CMS
&&
.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 CHICAGO/ROMEOVILLE IL
947 AM CDT TUE JUL 30 2013
.DISCUSSION...
931 AM CDT
UPDATED MORNING POP/WEATHER GRIDS TO ACCOUNT FOR CURRENT RADAR
TRENDS AND ALSO BOOSTED POPS THIS AFTERNOON...MAINLY FOR SOUTH AND
SOUTHWEST PORTIONS OF THE AREA. FORECAST SOUNDINGS FROM ORD ARE
STILL SHOWING CONSIDERABLE DRY AIR AROUND 800MB FOR THE METRO
AREA...BUT OBVIOUSLY THE AIR IS FAIRLY WELL SATURATED FARTHER TO
THE SOUTHWEST. THE CURRENT TRENDS ARE DEPICTED NICELY BY MOISTURE
CONVERGENCE FIELDS IN THE RAP MODEL...SO HAVE LEANED TOWARD THAT
EVOLUTION FOR THE REST OF THE DAY. MAY NEED FURTHER UPDATES IF
ACTIVITY SHOWS GOOD SIGNS OF HOLDING TOGETHER LATER INTO THE
AFTERNOON. GIVEN EXISTING AND FORECAST CAPE TRENDS AND SOUNDING
PROFILES...MAY ALSO NEED TO ADD MENTION OF THUNDERSTORMS LATER
TODAY...BUT MIDLEVEL LAPSE RATES ARE ONLY MARGINALLY FAVORABLE.
LENNING
&&
.PREV DISCUSSION...
323 AM CDT
TODAY...
SFC RIDGING CONTINUES TO BE AN INFLUENCE ON THE REGION...DESPITE
DRIFTING EAST OF THE CWFA AND BECOMING CENTERED OVER THE EASTERN
OHIO VALLEY THIS MORNING. IR IMAGERY DEPICTS A COMPLEX OF
THUNDERSTORMS ACROSS THE SOUTHERN PLAINS...WITH REGIONAL RADAR
SHOWING PRECIP RETURNS LIFTING INTO NORTHEAST MISSOURI/SOUTHEAST
IOWA. FOR MUCH OF THE DAY TODAY EXPECT SFC RIDGING TO CONTINUE TO
KEEP PRECIP WEST/SOUTHWEST OF THE CWFA. GUIDANCE HOLDS ONTO THE
SOUTHEAST FLOW AT THE SFC...WITH SOUNDINGS SUGGESTING CONSIDERABLE
DRY AIR THRU 15Z THEN SLOWLY MOISTENING FROM THE TOP DOWN. PWAT
VALUES SLOWLY INCREASE...HOVERING ARND 1.8" BY LATE THIS AFTN/EVE.
BY 18Z EXPECT SCATTERED PRECIP TO BEGIN PUSHING OVER THE CWFA. BASED
ON THE SOUNDINGS CONVECTIVE POTENTIAL REMAINS VERY LOW...EXCEPT FOR
FAR SOUTHERN AREAS OF THE CWFA. OTHERWISE EXPECT PRECIP TO REMAIN
LIGHT IN INTENSITY AND MINIMAL COVERAGE.
WITH GRADUAL THICKENING OF THE CLOUD SHIELD...TEMPS WILL INITIALLY
WARM THEN THE RATE OF CLIMB WILL BEGIN TO SLOW GIVEN THE INCREASED
MOISTURE IN THE ATMOSPHERE. STILL THINK THAT TEMPS WILL WARM TO THE
MID 70S...HOWEVER IF CLOUDS CAN THICKEN FASTER THIS MORNING TEMPS
MAY STRUGGLE TO WARM BEYOND THE LOW 70S.
CONFIDENCE...MEDIUM.
TONIGHT THROUGH WEDNESDAY...
WEAK SHORTWAVE CONTINUES TO LIFT NORTHEAST ACROSS MISSOURI LATE THIS
AFTN/EARLY EVE...WHILE ANTI-CYCLONIC FLOW OVER THE OHIO VALLEY
CONTINUES TO PROVIDE A DRY INFLUENCE ON THE NEAR SFC ENVIRONMENT
ACROSS NORTHERN IL/NORTHWEST IN. SFC WINDS APPEAR TO HOLD FROM THE
SOUTHEAST...AND UNDER A LIGHT GRADIENT WILL LIKELY BE LESS THAN 10
MPH. THIS COULD BE JUST ENOUGH OF A DRY FLOW IN THE LLVLS TO HOLD
FULL SATURATION OF THE PROFILE. GUIDANCE DOES INDICATE A SLOW
MOISTENING OF THE LOW/MID LVLS AFT 21Z THIS AFTN...WITH PWAT VALUES
STEADILY INCREASING TO ARND 1.5-1.8". THE TREND HAS BEEN DRIER AND
FURTHER SOUTH WITH THIS SYSTEM...HOWEVER JUST ENOUGH MOISTURE COULD
LIFT OVERHEAD AND WITH SOME OMEGA OR LIFT PRESENT...SPRINKLES/LIGHT
SHRA COULD DEVELOP LATE THIS EVENING/OVERNIGHT. LOCAL HI-RES WRF
SOLUTION KEEPS ALL PRECIP TO THE SOUTH OF A PONTIAC TO FOWLER LINE.
HAVE TRIMMED BACK ON POPS TO THE HIGH TEENS...AND EXPECT COVERAGE TO
BE MINIMAL WITH PRECIP TONIGHT. IN ADDITION DROPLET SIZE WILL BE
SMALL AS WELL...WHICH COULD TRANSLATE INTO DRIZZLE OR CHANGING
PRECIP TO SPRINKLES INSTEAD OF SHOWERS.
WITH A 500MB WAVE RATHER FLAT...THIS SYSTEM WILL REMAIN PROGRESSIVE
AND PUSH TO THE EAST BY WED MORNING. ALONG THE BACK EDGE OF THE
DEPARTING WEAK SFC WAVE IT APPEARS SOME DIFLUENT FLOW TRIES TO
DEVELOP AND COULD BRING A BRIEF END TO THE PRECIP BY DAYBREAK WED.
THEN THE FOCUS TURNS TOWARDS AN ADVANCING FRONTAL BOUNDARY THAT WILL
BE SLIDING INTO THE UPPER MIDWEST EARLY WED.
LLVL FLOW WILL BECOME SOUTHERLY TO SOUTHWESTERLY AHEAD OF THE COLD
FRONT...WITH MARGINAL INSTABILITY DEVELOPING IN THE AFTN HOURS WED.
WITH THE LACK OF STRONG SHEAR AND MODEL SOUNDINGS INDICATING SOME
DRY AIR IN THE NEAR SFC...IT IS CONCEIVABLE THAT MUCH OF WED COULD
BE DRY. AS PREVIOUSLY NOTED IN REGARDS TO THE LCL HI-RES WRF...THIS
SOLUTION CONTINUES THE DRY THEME FOR WED. AT THIS POINT HAVE ONLY
TRIMMED BACK ON POPS FOR WED...AND FOCUSED THE TIMING TOWARDS THE
AFTN/EVE HOURS OR CLOSER TO FROPA. 500MB TROUGH AXIS APPEARS TO PUSH
INTO THE WESTERN GREAT LAKES ARND 00Z THUR...WITH DIMINISHING LLVL
MOISTURE. MID-LVL SHEAR WILL INCREASE AS THE BNDRY NEARS...AND WITH
MARGINAL INSTABILITY COULD ALLOW SOME ISOLATED THUNDERSTORMS TO
DEVELOP LATE WED AFTN.
IN REGARDS TO TEMPS TONIGHT...EXPECT CONSIDERABLE CLOUD COVER TO
HOLD TEMPS SLIGHTLY WARMER OR IN THE MID 60S AWAY FROM LAKE MICHIGAN
AND UPR 60S CLOSER TO THE LAKE. THEN FOR WED TEMPS WILL BE SLIGHTLY
WARMER AND CLOSER TO 80 DEG. IF THE SOUTH/SOUTHWEST FLOW IS SLIGHTLY
STRONGER WED IN ADVANCE OF THE FRONT...TEMPS MAY BE ABLE TO WARM
FURTHER OR 80-83 DEG.
CONFIDENCE...MEDIUM.
CONFIDENCE IN PRECIP...LOW.
THURSDAY THROUGH FRIDAY...
500MB TROUGH QUICKLY SLIDES OVERHEAD WITH ANTI-CYCLONIC FLOW
BUILDING INTO THE REGION FROM THE WEST. THIS WILL AID IN PROVIDING
DRY WEATHER FOR THUR/THUR NIGHT. SFC RIDGE PUSHES FURTHER SOUTH
ACROSS THE TENN VALLEY FRI...WHILE A LOBE OF VORTICITY IS PROGGED TO
SLIDE SOUTHEAST ACROSS THE WESTERN GREAT LAKES FRI. THIS APPEARS TO
BE ASSOCIATED WITH A FRONTAL BOUNDARY...WHICH MAY HAVE SOME PRECIP
ACCOMPANYING FROPA FRI/FRI EVE. ALTHOUGH THE SETUP LOOKS MORE
FAVORABLE FOR A DRY FROPA AS ANTI-CYCLONIC FLOW WILL BE DEPARTING
WITH YET ANOTHER ANTI-CYCLONIC FLOW SLIDING SOUTHEAST ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST FRI NIGHT.
TEMPS CONTINUE TO BE UNSEASONABLY COOL...WITH AFTN HIGHS STRUGGLING
TO WARM BEYOND THE UPR 70S IN MANY LOCATIONS. A FEW SITES MAY TOUCH
80 DEG FRI AFTN.
CONFIDENCE...MEDIUM.
SATURDAY THROUGH MONDAY...
EXTENDED PERIODS CONTINUE TO FEATURE A COOL NORTHWEST SETUP WITH
ENSEMBLES DEMONSTRATING MINIMAL NOISE OR DIFFERENCES. THE STRENGTH
OF THE DOWNSTREAM RIDGE OVER THE CANADIAN MARITIME DOES EXHIBIT SOME
WEAKENING SUN...WHICH SHOULD ALLOW THE GREAT LAKES TROUGH TO WEAKEN
AND PUSH EAST. HOWEVER PROGRESSING TOWARDS THE FINAL FEW
PERIODS...HIGH LATITUDE RIDGING IS PROGGED TO DEVELOP OVER THE NORTH
ATLANTIC AND STRETCH WEST ACROSS WESTERN CANADA. IF THIS SOLUTION
VERIFIES...FLOW ACROSS THE GREAT LAKES REGION WILL LIKELY REMAIN IN
A UNSEASONABLY COOL SETUP.
OPERATIONAL SOLUTIONS HAVE SFC RIDGING BUILDING IN FOR SAT AND
LINGERING THRU SUN NGT...WHICH WILL PROVIDE DRY WEATHER. THEN THE
500MB FLOW BEGINS TO FLATTEN AND BECOME MORE FLUID...WITH A FRONTAL
BOUNDARY AND A WEAK SYSTEM APPROACHING THE REGION TOWARDS THE FINAL
PERIODS WITH A CHANCE OF PRECIP FOR EARLY NEXT WEEK.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CHANCE OF LIGHT SHOWERS LATE MORNING THROUGH AFTERNOON...
SOMEWHAT BETTER CHANCE THIS EVENING.
* POTENTIAL FOR MVFR CIGS OVERNIGHT INTO WED MORNING...SMALL
POTENTIAL FOR IFR CIGS.
TRS
//DISCUSSION...UPDATED 12Z...
AN AREA OF SHOWERS/RAIN OVER WESTERN IL CONTINUES TO SPREAD NORTH
AND NORTHEAST THIS MORNING AND IS SLOWLY ERODING ON THE NORTHERN
EDGE AS IT ENCOUNTERS DRIER AIR. SHORT TERM/HI RES GUIDANCE IS IN
FAIR AGREEMENT THAT THIS ERODING TREND WILL CONTINUE THIS MORNING.
BUT DO EXPECT THIS ACTIVITY TO REACH A RFD/DKB/ARR LINE...AT LEAST
IN THE FORM OF SPRINKLES. ADDITIONAL SHOWERS MAY DEVELOP LATER
THIS AFTERNOON AND CONTINUE INTO THIS EVENING BUT CONFIDENCE
REGARDING COVERAGE IS FAIRLY LOW AND INCLUDED VICINITY MENTION BUT
STILL EXPECT MANY DRY HOURS.
WINDS WILL REMAIN SOUTHEASTERLY INTO THIS EVENING WITH SPEEDS
INCREASING INTO THE 7-10KT RANGE. ITS POSSIBLE A MORE TRADITIONAL
LAKE BREEZE MAY DEVELOP THIS AFTERNOON...ESPECIALLY FROM CHICAGO
NORTH INTO LAKE COUNTY IL. HOW FAR INLAND IT MOVES IS UNCERTAIN
AND TRENDS WILL NEED TO BE MONITORED INTO THIS AFTERNOON. SPEEDS
WILL DIMINISH THIS EVENING WITH LIGHT AND VARIABLE OR CALM WINDS
EXPECTED TONIGHT.
THE LOW LEVELS CONTINUE TO MOISTEN THROUGH THE EVENING AND INTO
THE OVERNIGHT HOURS. THERE IS A FAIRLY EXTENSIVE AREA OF LIFR/IFR
CIGS ACROSS THE CENTRAL PLAINS AND SOME OF THIS WILL LIKELY SHIFT
EAST TONIGHT. MOST CONFIDENT OF THIS REACHING RFD BUT FOR THE REST
OF THE TAFS...HAVE JUST INCLUDED SCATTERED IFR MENTION FOR NOW. CMS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH FOR SOME -RA/-SHRA ACROSS LOCAL AREA LATE MORNING THOUGH
EVENING.
* MODERATE THAT ANY PCPN WILL BE OPERATIONALLY INSIGNIFICANT
THOUGH LOCALIZED SPOTS MAY SEE ENOUGH TO WET THE GROUND.
* MEDIUM FOR MVFR CIGS OVERNIGHT/WEDNESDAY MORNING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...CHANCE OF TSRA.
* THURSDAY...DRY/VFR.
* FRIDAY...CHANCE OF TSRA.
* SATURDAY AND SUNDAY...DRY/VFR.
* MONDAY...CHANCE OF TSRA.
&&
.MARINE...
305 AM...BROAD HIGH PRESSURE OVER THE LAKES REGION AND EXTENDING
INTO THE MID ATLANTIC WILL SLOWLY MOVE EAST TODAY AND TONIGHT AS
LOW PRESSURE OF NORTHERN MANITOBA MOVES EAST TO NEAR JAMES BAY BY
THURSDAY MORNING. SOUTHERLY WINDS WILL CONTINUE INTO WEDNESDAY
AFTERNOON WHEN A TRAILING COLD FRONT FROM THE LOW MOVES ACROSS THE
LAKE SHIFTING WINDS NORTHWEST. AS HIGH PRESSURE MOVES FROM THE
NORTHERN PLAINS WEDNESDAY NIGHT TO THE OHIO VALLEY THURSDAY
NIGHT...THE GRADIENT TIGHTENS SOME WEDNESDAY NIGHT INTO THURSDAY
MORNING ACROSS THE SOUTHERN HALF OR SO OF THE LAKE AND WHILE A
PERIOD OF 15-20 KTS LOOKS POSSIBLE...COULD BE SOME HIGHER GUSTS
INTO THE MID 20KT RANGE TOWARD THURSDAY MORNING. SPEEDS DIMINISH
THURSDAY NIGHT BUT WINDS REMAIN GENERALLY WESTERLY UNTIL ANOTHER
COLD FRONT MOVES ACROSS THE LAKES REGION FRIDAY AND FRIDAY NIGHT.
CMS
&&
.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 GOODLAND KS
918 PM MDT WED JUL 31 2013
.UPDATE...
ISSUED AT 915 PM MDT WED JUL 31 2013
DUE TO SEVERE CONVECTION COMING TO AN END HAVE CANCELLED THE WATCH
EARLY. ADJUSTED PREICP. CHANCES TO ACCOUNT FOR THE AREA OF
CONVECTION THAT WILL MOVE INTO EAST CENTRAL CO AROUND MIDNIGHT.
OTHERWISE THOUGHTS FROM THE PREVIOUS UPDATE REMAIN UNCHANGED.
UPDATE ISSUED AT 809 PM MDT WED JUL 31 2013
STRONG/SEVERE THUNDERSTORMS HAVE DEVELOPED OVER YUMA COUNTY EAST
INTO CHEYENNE COUNTY KS. INITIALLY STORMS WERE TRIGGERED BY AN
OUTFLOW BOUNDARY FROM EARLIER CONVECTION TO THE SOUTH. THE STORMS
SEEM TO BE SUSTAINED BY THE STRENGTHENING LOW LEVEL JET AND A
SHORT WAVE TROUGH AT 500MB. FURTHER WEST AN AREA OF CONVECTION IS
MOVING TOWARD THE AREA WITH THE UPPER LEVEL TROUGH. AS THE NIGHT
PROGRESSES AM ANTICIPATING THE STORM GROUPS TO POSSIBLY MERGE AS
THEY MOVE TO THE EAST. AS A RESULT HAVE INCREASED PRECIP. CHANCES
FOR THE NIGHT AND SPEED UP THE TIME OF THE BEST CHANCES. STILL
WENT ON THE CONSERVATIVE SIDE LATE IN THE EVENING AND OVERNIGHT SINCE
THERE IS SOME UNCERTAINTY AS TO WHERE EXACTLY THE STORMS WILL
TRACK...BUT IN GENERAL THE NORTHERN HALF OF THE AREA LOOKS TO HAVE
THE BEST SHOT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 116 PM MDT WED JUL 31 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS AMPLIFIED RIDGE ACROSS
THE INTER-MOUNTAIN WEST WITH NW FLOW IN PLACE ACROSS THE HIGH
PLAINS. AT THE SURFACE A COLD FRONT IS CURRENTLY IN PLACE ACROSS
CENTRAL NEBRASKA WITH SEVERAL AREAS OF WEAK CONVERGENCE ALONG A PRE
FRONTAL TROUGH THROUGH THE CENTRAL PART OF OUR CWA...AND POSSIBLY
SEVERAL OTHER WEAK SURFACE FEATURES ASSOCIATED WITH OLD OUTFLOW FROM
OVERNIGHT CONVECTION IN THE EAST.
LATEST RAP ANALYSIS INDICATES SBCAPE IN EXCESS OF 3000 J/KG...AND
PWAT VALUES 1-1.5 INCHES ACROSS OUR CWA. THIS VERY MOIST AND
UNSTABLE AIR MASS HAS COMBINED WITH PREVIOUSLY MENTIONED SURFACE
FEATURES TO DEVELOPMENT OF SEVERAL ISOLATED THUNDERSTORMS ACROSS
THE SOUTHERN PART OF OUR CWA. WITH CU FIELD IN PLACE AND
FORCING INCREASING AHEAD OF APPROACHING COLD FRONT I WOULD
ANTICIPATE THUNDERSTORM COVERAGE TO INCREASE THROUGH THIS
AFTERNOON. RAP ALSO INDICATES 0-6KM BULK SHEER IN EXCESS OF 40KT
ACROSS THE SOUTHEASTERN HALF OF OUR CWA...AND WITH LLJ INCREASING
AROUND 00Z I WOULD EXPECT SHEER TO ONLY INCREASE. WHILE I AM
MAINLY ANTICIPATING HAIL/WIND/MULTI-CELL THREAT THROUGH
TONIGHT...TORNADOES COULDNT BE RULED OUT WITH SUPERCELLS THAT
DEVELOP CONSIDERING THE LARGE SCALE SHEER PROFILES. A SEVERE
THUNDERSTORM WATCH HAS ALREADY BEEN ISSUED FOR THE SOUTHERN HALF
OF OUR CWA...AND IF ADDITIONAL ACTIVITY DEVELOPS FURTHER NORTH OF
WATCH WE MAY NEED TO DO A LOCAL EXPANSION CONSIDERING THE
ENVIRONMENT.
WITH 0-6KM STORM MOTION GENERALLY TO THE SOUTHEAST MOST ACTIVITY
SHOULD BE TRANSITIONING OUT OF OUR CWA THIS EVENING...THOUGH WITH
GOOD THETA-E CONVERGENCE AHEAD OF LLJ WE SHOULD SEE ADDITIONAL
DEVELOPMENT TONIGHT ESPECIALLY ACROSS THE NORTHEAST.
.LONG TERM...(TOMORROW THROUGH WEDNESDAY)
ISSUED AT 1244 PM MDT WED JUL 31 2013
THE UPPER PATTERN THIS PERIOD WILL FEATURE A RIDGE CENTERED OVER
TEXAS AND OCCASIONAL SHORTWAVE TROUGHS MOVING OUT OF THE CENTRAL
AND NORTHERN ROCKIES ACROSS THE PLAINS. THIS MEANS THE SAME OLD
STORY THAT HAS BEEN RUNNING A FEW WEEKS NOW: DAILY CHANCES FOR
SHOWERS AND THUNDERSTORMS AND TEMPERATURES NEAR NORMAL. MESOSCALE
DETAILS WILL ULTIMATELY PLAY A LARGE ROLE IN DETERMINING WHERE
BETTER THUNDERSTORM CHANCES WILL BE ON ANY GIVEN DAY...BUT THEY
ARE DIFFICULT TO PREDICT BEYOND A DAY OR TWO AT BEST. AS A
RESULT...POPS WILL BE RATHER BROADBRUSHED ACROSS THE AREA. ON
THURSDAY...SEVERE STORMS WILL BE POSSIBLE GIVEN SUFFICIENT
INSTABILITY AND FAVORABLE SHEAR PROFILES. SEVERE POTENTIAL FOR THE
REMAINDER OF THE PERIOD WILL BE TIED TO SHORTWAVE IMPULSES WITH
LOW PREDICTABILITY AT THIS TIME RANGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 540 PM MDT WED JUL 31 2013
VFR CONDITIONS FORECAST FOR THE 0Z TAFS. DIFFICULT TO NAIL DOWN AN
EXACT TIME FOR STORMS TO MOVE OVER THE TAF SITES THIS
EVENING/OVERNIGHT DUE TO DIFFERENCES IN THE PLACEMENT OF THE
RATHER BENIGN UPPER LEVEL LIFT. IN GENERAL THE BEST SHOT FOR
STORMS NEAR KGLD WILL BE DURING THE EVENING AS OUTFLOW BOUNDARIES
MOVE THROUGH AND SOME UPPER LEVEL LIFT OVER THE WEST MOVES IN. FOR
KMCK STORMS CURRENTLY OVER NORTHERN COLORADO AND SOUTHERN WYOMING SHOULD
BE NEAR THE SITE DURING THE LATE EVENING THROUGH THE OVERNIGHT
HOURS AS AN UPPER LEVEL TROUGH BEHIND THEM MOVES OVER THE
SITE...SIMILAR TO LAST NIGHT. STORM CHANCES RETURN TO THE AREA MID
TO LATE AFTERNOON THURSDAY AS AN UPPER LEVEL TROUGH MOVES OVER THE
AREA BEHIND A WARM FRONT TO THE EAST AND NORTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
815 PM MDT WED JUL 31 2013
.UPDATE...
ISSUED AT 809 PM MDT WED JUL 31 2013
STRONG/SEVERE THUNDERSTORMS HAVE DEVELOPED OVER YUMA COUNTY EAST
INTO CHEYENNE COUNTY KS. INITIALLY STORMS WERE TRIGGERED BY AN
OUTFLOW BOUNDARY FROM EARLIER CONVECTION TO THE SOUTH. THE STORMS
SEEM TO BE SUSTAINED BY THE STRENGTHENING LOW LEVEL JET AND A
SHORT WAVE TROUGH AT 500MB. FURTHER WEST AN AREA OF CONVECTION IS
MOVING TOWARD THE AREA WITH THE UPPER LEVEL TROUGH. AS THE NIGHT
PROGRESSES AM ANTICIPATING THE STORM GROUPS TO POSSIBLY MERGE AS
THEY MOVE TO THE EAST. AS A RESULT HAVE INCREASED PRECIP. CHANCES
FOR THE NIGHT AND SPEED UP THE TIME OF THE BEST CHANCES. STILL
WENT ON THE CONSERVATIVE SIDE LATE IN THE EVENING AND OVERNIGHT SINCE
THERE IS SOME UNCERTAINTY AS TO WHERE EXACTLY THE STORMS WILL
TRACK...BUT IN GENERAL THE NORTHERN HALF OF THE AREA LOOKS TO HAVE
THE BEST SHOT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 116 PM MDT WED JUL 31 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS AMPLIFIED RIDGE ACROSS
THE INTER-MOUNTAIN WEST WITH NW FLOW IN PLACE ACROSS THE HIGH
PLAINS. AT THE SURFACE A COLD FRONT IS CURRENTLY IN PLACE ACROSS
CENTRAL NEBRASKA WITH SEVERAL AREAS OF WEAK CONVERGENCE ALONG A PRE
FRONTAL TROUGH THROUGH THE CENTRAL PART OF OUR CWA...AND POSSIBLY
SEVERAL OTHER WEAK SURFACE FEATURES ASSOCIATED WITH OLD OUTFLOW FROM
OVERNIGHT CONVECTION IN THE EAST.
LATEST RAP ANALYSIS INDICATES SBCAPE IN EXCESS OF 3000 J/KG...AND
PWAT VALUES 1-1.5 INCHES ACROSS OUR CWA. THIS VERY MOIST AND
UNSTABLE AIR MASS HAS COMBINED WITH PREVIOUSLY MENTIONED SURFACE
FEATURES TO DEVELOPMENT OF SEVERAL ISOLATED THUNDERSTORMS ACROSS
THE SOUTHERN PART OF OUR CWA. WITH CU FIELD IN PLACE AND
FORCING INCREASING AHEAD OF APPROACHING COLD FRONT I WOULD
ANTICIPATE THUNDERSTORM COVERAGE TO INCREASE THROUGH THIS
AFTERNOON. RAP ALSO INDICATES 0-6KM BULK SHEER IN EXCESS OF 40KT
ACROSS THE SOUTHEASTERN HALF OF OUR CWA...AND WITH LLJ INCREASING
AROUND 00Z I WOULD EXPECT SHEER TO ONLY INCREASE. WHILE I AM
MAINLY ANTICIPATING HAIL/WIND/MULTI-CELL THREAT THROUGH
TONIGHT...TORNADOES COULDNT BE RULED OUT WITH SUPERCELLS THAT
DEVELOP CONSIDERING THE LARGE SCALE SHEER PROFILES. A SEVERE
THUNDERSTORM WATCH HAS ALREADY BEEN ISSUED FOR THE SOUTHERN HALF
OF OUR CWA...AND IF ADDITIONAL ACTIVITY DEVELOPS FURTHER NORTH OF
WATCH WE MAY NEED TO DO A LOCAL EXPANSION CONSIDERING THE
ENVIRONMENT.
WITH 0-6KM STORM MOTION GENERALLY TO THE SOUTHEAST MOST ACTIVITY
SHOULD BE TRANSITIONING OUT OF OUR CWA THIS EVENING...THOUGH WITH
GOOD THETA-E CONVERGENCE AHEAD OF LLJ WE SHOULD SEE ADDITIONAL
DEVELOPMENT TONIGHT ESPECIALLY ACROSS THE NORTHEAST.
.LONG TERM...(TOMORROW THROUGH WEDNESDAY)
ISSUED AT 1244 PM MDT WED JUL 31 2013
THE UPPER PATTERN THIS PERIOD WILL FEATURE A RIDGE CENTERED OVER
TEXAS AND OCCASIONAL SHORTWAVE TROUGHS MOVING OUT OF THE CENTRAL
AND NORTHERN ROCKIES ACROSS THE PLAINS. THIS MEANS THE SAME OLD
STORY THAT HAS BEEN RUNNING A FEW WEEKS NOW: DAILY CHANCES FOR
SHOWERS AND THUNDERSTORMS AND TEMPERATURES NEAR NORMAL. MESOSCALE
DETAILS WILL ULTIMATELY PLAY A LARGE ROLE IN DETERMINING WHERE
BETTER THUNDERSTORM CHANCES WILL BE ON ANY GIVEN DAY...BUT THEY
ARE DIFFICULT TO PREDICT BEYOND A DAY OR TWO AT BEST. AS A
RESULT...POPS WILL BE RATHER BROADBRUSHED ACROSS THE AREA. ON
THURSDAY...SEVERE STORMS WILL BE POSSIBLE GIVEN SUFFICIENT
INSTABILITY AND FAVORABLE SHEAR PROFILES. SEVERE POTENTIAL FOR THE
REMAINDER OF THE PERIOD WILL BE TIED TO SHORTWAVE IMPULSES WITH
LOW PREDICTABILITY AT THIS TIME RANGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 540 PM MDT WED JUL 31 2013
VFR CONDITIONS FORECAST FOR THE 0Z TAFS. DIFFICULT TO NAIL DOWN AN
EXACT TIME FOR STORMS TO MOVE OVER THE TAF SITES THIS
EVENING/OVERNIGHT DUE TO DIFFERENCES IN THE PLACEMENT OF THE
RATHER BENIGN UPPER LEVEL LIFT. IN GENERAL THE BEST SHOT FOR
STORMS NEAR KGLD WILL BE DURING THE EVENING AS OUTFLOW BOUNDARIES
MOVE THROUGH AND SOME UPPER LEVEL LIFT OVER THE WEST MOVES IN. FOR
KMCK STORMS CURRENTLY OVER NORTHERN COLORADO AND SOUTHERN WYOMING SHOULD
BE NEAR THE SITE DURING THE LATE EVENING THROUGH THE OVERNIGHT
HOURS AS AN UPPER LEVEL TROUGH BEHIND THEM MOVES OVER THE
SITE...SIMILAR TO LAST NIGHT. STORM CHANCES RETURN TO THE AREA MID
TO LATE AFTERNOON THURSDAY AS AN UPPER LEVEL TROUGH MOVES OVER THE
AREA BEHIND A WARM FRONT TO THE EAST AND NORTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
548 PM MDT WED JUL 31 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 116 PM MDT WED JUL 31 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS AMPLIFIED RIDGE ACROSS
THE INTER-MOUNTAIN WEST WITH NW FLOW IN PLACE ACROSS THE HIGH
PLAINS. AT THE SURFACE A COLD FRONT IS CURRENTLY IN PLACE ACROSS
CENTRAL NEBRASKA WITH SEVERAL AREAS OF WEAK CONVERGENCE ALONG A PRE
FRONTAL TROUGH THROUGH THE CENTRAL PART OF OUR CWA...AND POSSIBLY
SEVERAL OTHER WEAK SURFACE FEATURES ASSOCIATED WITH OLD OUTFLOW FROM
OVERNIGHT CONVECTION IN THE EAST.
LATEST RAP ANALYSIS INDICATES SBCAPE IN EXCESS OF 3000 J/KG...AND
PWAT VALUES 1-1.5 INCHES ACROSS OUR CWA. THIS VERY MOIST AND
UNSTABLE AIR MASS HAS COMBINED WITH PREVIOUSLY MENTIONED SURFACE
FEATURES TO DEVELOPMENT OF SEVERAL ISOLATED THUNDERSTORMS ACROSS
THE SOUTHERN PART OF OUR CWA. WITH CU FIELD IN PLACE AND
FORCING INCREASING AHEAD OF APPROACHING COLD FRONT I WOULD
ANTICIPATE THUNDERSTORM COVERAGE TO INCREASE THROUGH THIS
AFTERNOON. RAP ALSO INDICATES 0-6KM BULK SHEER IN EXCESS OF 40KT
ACROSS THE SOUTHEASTERN HALF OF OUR CWA...AND WITH LLJ INCREASING
AROUND 00Z I WOULD EXPECT SHEER TO ONLY INCREASE. WHILE I AM
MAINLY ANTICIPATING HAIL/WIND/MULTI-CELL THREAT THROUGH
TONIGHT...TORNADOES COULDNT BE RULED OUT WITH SUPERCELLS THAT
DEVELOP CONSIDERING THE LARGE SCALE SHEER PROFILES. A SEVERE
THUNDERSTORM WATCH HAS ALREADY BEEN ISSUED FOR THE SOUTHERN HALF
OF OUR CWA...AND IF ADDITIONAL ACTIVITY DEVELOPS FURTHER NORTH OF
WATCH WE MAY NEED TO DO A LOCAL EXPANSION CONSIDERING THE
ENVIRONMENT.
WITH 0-6KM STORM MOTION GENERALLY TO THE SOUTHEAST MOST ACTIVITY
SHOULD BE TRANSITIONING OUT OF OUR CWA THIS EVENING...THOUGH WITH
GOOD THETA-E CONVERGENCE AHEAD OF LLJ WE SHOULD SEE ADDITIONAL
DEVELOPMENT TONIGHT ESPECIALLY ACROSS THE NORTHEAST.
.LONG TERM...(TOMORROW THROUGH WEDNESDAY)
ISSUED AT 1244 PM MDT WED JUL 31 2013
THE UPPER PATTERN THIS PERIOD WILL FEATURE A RIDGE CENTERED OVER
TEXAS AND OCCASIONAL SHORTWAVE TROUGHS MOVING OUT OF THE CENTRAL
AND NORTHERN ROCKIES ACROSS THE PLAINS. THIS MEANS THE SAME OLD
STORY THAT HAS BEEN RUNNING A FEW WEEKS NOW: DAILY CHANCES FOR
SHOWERS AND THUNDERSTORMS AND TEMPERATURES NEAR NORMAL. MESOSCALE
DETAILS WILL ULTIMATELY PLAY A LARGE ROLE IN DETERMINING WHERE
BETTER THUNDERSTORM CHANCES WILL BE ON ANY GIVEN DAY...BUT THEY
ARE DIFFICULT TO PREDICT BEYOND A DAY OR TWO AT BEST. AS A
RESULT...POPS WILL BE RATHER BROADBRUSHED ACROSS THE AREA. ON
THURSDAY...SEVERE STORMS WILL BE POSSIBLE GIVEN SUFFICIENT
INSTABILITY AND FAVORABLE SHEAR PROFILES. SEVERE POTENTIAL FOR THE
REMAINDER OF THE PERIOD WILL BE TIED TO SHORTWAVE IMPULSES WITH
LOW PREDICTABILITY AT THIS TIME RANGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 540 PM MDT WED JUL 31 2013
VFR CONDITIONS FORECAST FOR THE 0Z TAFS. DIFFICULT TO NAIL DOWN AN
EXACT TIME FOR STORMS TO MOVE OVER THE TAF SITES THIS
EVENING/OVERNIGHT DUE TO DIFFERENCES IN THE PLACEMENT OF THE
RATHER BENIGN UPPER LEVEL LIFT. IN GENERAL THE BEST SHOT FOR
STORMS NEAR KGLD WILL BE DURING THE EVENING AS OUTFLOW BOUNDARIES
MOVE THROUGH AND SOME UPPER LEVEL LIFT OVER THE WEST MOVES IN. FOR
KMCK STORMS CURRENTLY OVER NORTHERN COLORADO AND SOUTHERN WYOMING SHOULD
BE NEAR THE SITE DURING THE LATE EVENING THROUGH THE OVERNIGHT
HOURS AS AN UPPER LEVEL TROUGH BEHIND THEM MOVES OVER THE
SITE...SIMILAR TO LAST NIGHT. STORM CHANCES RETURN TO THE AREA MID
TO LATE AFTERNOON THURSDAY AS AN UPPER LEVEL TROUGH MOVES OVER THE
AREA BEHIND A WARM FRONT TO THE EAST AND NORTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
458 PM CDT TUE JUL 30 2013
...CORRECTED LONG TERM SECTION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 156 PM CDT TUE JUL 30 2013
TODAY IS SEEING A VERY SLOW CLEARING PATTERN IN THE CLOUDS FROM
WEST TO EAST. THIS SLOWNESS IN CLEARING IS PARTIALLY DUE TO THE
NORTH TO NORTHEAST LOW LEVEL FLOW, WHICH IS A SLIGHT UPSLOPE
PATTERN. THE OTHER REASON THE EAST IS SO SLOW TO CLEAR OUT IS THE
ABUNDANT SURFACE MOISTURE ACROSS OUR EASTERN ZONES, WITH PLENTY OF
LEFTOVER RAINFALL STILL ACROSS MUCH OF THE EASTERN FORECAST AREA,
ESPECIALLY SOUTHEAST OF A LINE FROM LA CROSSE TO ASHLAND. SOME OF
THESE COUNTIES RECEIVED OVER 3 INCHES OF RAINFALL MONDAY EVENING,
ESPECIALLY ACROSS PRATT AND BARBER COUNTIES. FOR THIS REASON, ALONG
WITH EXPECTED CLEAR SKIES AND LIGHT WINDS EXPECTED, THERE SHOULD
BE SOME MORE FOG FORM TOWARD 09Z TO 10Z. I HAVE DECIDED TO PUT IN
PATCHY FOG WORDING FOR NOW ACROSS OUR SOUTHEASTERN SECTIONS, AND
LATER SHIFTS CAN UPDATE TO DENSE FOG IF IT FORMS. BOTH THE NAM
AND THE HRRR MODELS ARE INDICATED AROUND 1SM VISIBILITIES IN FOG.
AS FOR LOW TEMPERATURES, NO CHANGES WERE MADE TO THE PREVIOUS
FORECAST. CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO
DROP TO THE MID 60S IN OUR WEST AND THE UPPER 60S IN OUR
SOUTHEAST.
MOSTLY SUNNY SKIES AREA EXPECTED WEDNESDAY, AFTER SOME SCATTERED
MORNING FOG. WINDS WILL BE LIGHT AND VARIABLE EARLY, THEN SHIFT TO
THE SOUTHEAST IN THE AFTERNOON AT 10 TO 20 MPH. A COLD FRONT
WILL APPROACH WESTERN KANSAS BY AFTERNOON. THE NAM MODEL BRINGS IN
THUNDERSTORMS WEDNESDAY AFTERNOON AS EARLY AS 19Z IN OUR NORTHWEST
ZONES OF SCOTT AND LANE COUNTIES, AND ADVANCES THE RAIN TOWARD
DODGE CITY AS EARLY AS 22Z. THE ECMWF AND GFS MODELS ARE A LITTLE
SLOWER, BRINGING RAIN TO SCOTT AND LANE COUNTIES AFTER 22Z AND NOT
NEAR DODGE CITY UNTIL AFTER 02Z. HAVE STARTED SLIGHT 20 PERCENT
CHANCES IN OUR FAR NORTHWEST, SUCH AS SCOTT AND LANE COUNTIES, AND
DELAYED THE ONSET OF CHANCE POP CATEGORIES IN THE DODGE CITY AREA
UNTIL 03Z. SOME OF THE LATE AFTERNOON AND EVENING STORMS COULD
CONTAIN DAMAGING WINDS AND HAIL AS LARGE AS GOLFBALLS. THE FRONT
WILL MOVE THROUGH WESTERN AND INTO CENTRAL KANSAS BY WEDNESDAY
EVENING, BRINGING RAIN CHANCES FOR SHOWERS AND THUNDERSTORMS TO
THE PRATT AND COLDWATER AREAS AFTER 00Z THURSDAY. WITH SKIES
STARTING OUT WEDNESDAY MORNING AS MOSTLY SUNNY, THEN BECOMING
PARTLY CLOUDY BY MID TO LATE AFTERNOON, AND POSSIBLY EVEN MOSTLY
CLOUDY BY EVENING, MAXIMUM TEMPERATURES COULD BE A LITTLE TRICKY.
STAYED WITH THE PREVIOUS FORECAST OF MID 90S IN THE WEST AND NEAR
90F IN THE EAST. HOW MUCH RAIN WILL FALL IS ALWAYS A LITTLE
CHALLENGING, BUT I THINK THE QPF_FM_POP PROCEDURE DID A FAIRLY
GOOD JOB WITH FORECAST RAINFALL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 PM CDT TUE JUL 30 2013
AN UPPER LEVEL LONGWAVE TROUGH WILL GENERALLY RESIDE OVER THE EASTERN
UNITED STATES THROUGH TUESDAY AUGUST 6TH, WITH UPPER LEVEL RIDGING
WAFFLING BACK AND FORTH BETWEEN NEW MEXICO AND TEXAS. ALONG THE
NORTHERN PERIPHERY OF THE RIDGE OVER THE CENTRAL HIGH PLAINS, A
QUASI-STATIONARY SURFACE FRONTAL BOUNDARY WILL EXIST, WITH LOW
LEVEL MOISTURE CONVERGING ALONG AND NORTH OF THE BOUNDARY.
ADDITIONALLY, EVAPOTRANSPIRATION FROM THE PREVIOUS HEAVY RAINS
ACROSS THE SOUTHERN AND CENTRAL PLAINS AND SUBSEQUENT TRANSPORT OF
THIS MOISTURE TO THE NORTHWEST WITH THE LOW LEVEL FLOW, WILL
ENHANCE MIXING RATIOS EVEN FURTHER. CONVECTIVE CLUSTERS WILL
ORIGINATE OFF OF THE VARIOUS TERRAIN FEATURES IN THE LEE OF THE
ROCKIES JUST ABOUT EVERY DAY, AND A FEW OF THESE COULD GROW
UPSCALE INTO LARGER CONVECTIVE CLUSTERS AND AFFECT WESTERN KANSAS
THROUGH AUGUST 6TH. THE TIMING OF THE INDIVIDUAL STORM CLUSTERS
CANNOT BE PREDICTED WITH MUCH ACCURACY IN THIS REGIME. THEREFORE,
20 TO 40% STORM CHANCES WERE GENERALLY MAINTAINED THROUGH AUGUST
6TH. ALSO, GIVEN THE UNCERTAINTY IN ANY CONVECTION AND RESULTANT
COOL OUTFLOW, HIGH TEMPERATURES WILL BE TRICKY AS WELL. OUR BEST
ESTIMATE IS THAT HIGH AND LOW TEMPERATURES WILL BE WITHIN A FEW
DEGREES OF CLIMATOLOGICAL VALUES (HIGHS 86-97F AT DODGE CITY, WITH
COOLER READINGS THAN THIS NEAR INTERSTATE 70 AND WARMER READINGS
NEAR THE OKLAHOMA STATE LINE). KEEP IN MIND THAT ANY WIDESPREAD
CLOUD COVER OR RAINFALL COULD LEAD TO MUCH COOLER TEMPERATURES ON
ANY GIVEN DAY.
AFTER AUGUST 6TH, THE VARIOUS MODELS ARE ADVERTISING A STRONG UPPER
LEVEL LOW TO DROP SOUTHWARD OUT OF CANADA INTO THE GREAT LAKES
REGION. THE ASSOCIATED COLD FRONT COULD BRING MUCH COOLER AIR INTO THE
CENTRAL PLAINS BY LATE NEXT WEEK, WITH HIGHS POSSIBLY FALLING INTO
THE 70S DEPENDING ON THE AMOUNT OF ACCOMPANYING CLOUD COVER AND
PRECIPITATION BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1145 AM CDT TUE JUL 30 2013
IN THE NEAR TERM, EXPECT MVFR CIGS AND GOOD VSBYS. WINDS WILL BE
FROM THE NORTHEAST TODAY IN THE 8 KNOT RANGE. SKIES WILL CLEAR
FROM WEST TO EAST GRADUALLY, BECOMING SCATTERED AT 250 THIS
EVENING. LIGHT WINDS AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO
SOME FOG DEVELOPING AFTER 09Z. FOR NOW, I AM EXPECTING SOME 2SM
IFR FOG POSSIBLE, WITH A CHANCE FOR ISOLATED VSBYS LESS THAN 1
MILE IN FOG.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 93 68 93 / 10 20 30 30
GCK 66 94 68 94 / 20 30 40 30
EHA 67 95 67 95 / 20 30 40 30
LBL 68 95 69 95 / 20 30 40 30
HYS 65 89 68 92 / 10 30 30 40
P28 69 89 70 94 / 10 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...FINCH
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
353 PM CDT TUE JUL 30 2013
...UPDATED FOR LONG TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 156 PM CDT TUE JUL 30 2013
TODAY IS SEEING A VERY SLOW CLEARING PATTERN IN THE CLOUDS FROM
WEST TO EAST. THIS SLOWNESS IN CLEARING IS PARTIALLY DUE TO THE
NORTH TO NORTHEAST LOW LEVEL FLOW, WHICH IS A SLIGHT UPSLOPE
PATTERN. THE OTHER REASON THE EAST IS SO SLOW TO CLEAR OUT IS THE
ABUNDANT SURFACE MOISTURE ACROSS OUR EASTERN ZONES, WITH PLENTY OF
LEFTOVER RAINFALL STILL ACROSS MUCH OF THE EASTERN FORECAST AREA,
ESPECIALLY SOUTHEAST OF A LINE FROM LA CROSSE TO ASHLAND. SOME OF
THESE COUNTIES RECEIVED OVER 3 INCHES OF RAINFALL MONDAY EVENING,
ESPECIALLY ACROSS PRATT AND BARBER COUNTIES. FOR THIS REASON, ALONG
WITH EXPECTED CLEAR SKIES AND LIGHT WINDS EXPECTED, THERE SHOULD
BE SOME MORE FOG FORM TOWARD 09Z TO 10Z. I HAVE DECIDED TO PUT IN
PATCHY FOG WORDING FOR NOW ACROSS OUR SOUTHEASTERN SECTIONS, AND
LATER SHIFTS CAN UPDATE TO DENSE FOG IF IT FORMS. BOTH THE NAM
AND THE HRRR MODELS ARE INDICATED AROUND 1SM VISIBILITIES IN FOG.
AS FOR LOW TEMPERATURES, NO CHANGES WERE MADE TO THE PREVIOUS
FORECAST. CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO
DROP TO THE MID 60S IN OUR WEST AND THE UPPER 60S IN OUR
SOUTHEAST.
MOSTLY SUNNY SKIES AREA EXPECTED WEDNESDAY, AFTER SOME SCATTERED
MORNING FOG. WINDS WILL BE LIGHT AND VARIABLE EARLY, THEN SHIFT TO
THE SOUTHEAST IN THE AFTERNOON AT 10 TO 20 MPH. A COLD FRONT
WILL APPROACH WESTERN KANSAS BY AFTERNOON. THE NAM MODEL BRINGS IN
THUNDERSTORMS WEDNESDAY AFTERNOON AS EARLY AS 19Z IN OUR NORTHWEST
ZONES OF SCOTT AND LANE COUNTIES, AND ADVANCES THE RAIN TOWARD
DODGE CITY AS EARLY AS 22Z. THE ECMWF AND GFS MODELS ARE A LITTLE
SLOWER, BRINGING RAIN TO SCOTT AND LANE COUNTIES AFTER 22Z AND NOT
NEAR DODGE CITY UNTIL AFTER 02Z. HAVE STARTED SLIGHT 20 PERCENT
CHANCES IN OUR FAR NORTHWEST, SUCH AS SCOTT AND LANE COUNTIES, AND
DELAYED THE ONSET OF CHANCE POP CATEGORIES IN THE DODGE CITY AREA
UNTIL 03Z. SOME OF THE LATE AFTERNOON AND EVENING STORMS COULD
CONTAIN DAMAGING WINDS AND HAIL AS LARGE AS GOLFBALLS. THE FRONT
WILL MOVE THROUGH WESTERN AND INTO CENTRAL KANSAS BY WEDNESDAY
EVENING, BRINGING RAIN CHANCES FOR SHOWERS AND THUNDERSTORMS TO
THE PRATT AND COLDWATER AREAS AFTER 00Z THURSDAY. WITH SKIES
STARTING OUT WEDNESDAY MORNING AS MOSTLY SUNNY, THEN BECOMING
PARTLY CLOUDY BY MID TO LATE AFTERNOON, AND POSSIBLY EVEN MOSTLY
CLOUDY BY EVENING, MAXIMUM TEMPERATURES COULD BE A LITTLE TRICKY.
STAYED WITH THE PREVIOUS FORECAST OF MID 90S IN THE WEST AND NEAR
90F IN THE EAST. HOW MUCH RAIN WILL FALL IS ALWAYS A LITTLE
CHALLENGING, BUT I THINK THE QPF_FM_POP PROCEDURE DID A FAIRLY
GOOD JOB WITH FORECAST RAINFALL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 PM CDT TUE JUL 30 2013
AN UPPER LEVEL LONGWAVE TROUGH WILL GENERALLY RESIDE OVER THE EASTERN
UNITED STATES THROUGH WEDNESDAY JULY 6TH, WITH UPPER LEVEL RIDGING
WAFFLING BACK AND FORTH BETWEEN NEW MEXICO AND TEXAS. ALONG THE
NORTHERN PERIPHERY OF THE RIDGE OVER THE CENTRAL HIGH PLAINS, A
QUASI-STATIONARY SURFACE FRONTAL BOUNDARY WILL EXIST, WITH LOW
LEVEL MOISTURE CONVERGING ALONG AND NORTH OF THE BOUNDARY.
ADDITIONALLY, EVAPOTRANSPIRATION FROM THE PREVIOUS HEAVY RAINS
ACROSS THE SOUTHERN AND CENTRAL PLAINS AND SUBSEQUENT TRANSPORT OF
THIS MOISTURE TO THE NORTHWEST WITH THE LOW LEVEL FLOW, WILL
ENHANCE MIXING RATIOS EVEN FURTHER. CONVECTIVE CLUSTERS WILL
ORIGINATE OFF OF THE VARIOUS TERRAIN FEATURES IN THE LEE OF THE
ROCKIES JUST ABOUT EVERY DAY, AND A FEW OF THESE COULD GROW UPSCALE
INTO LARGER CONVECTIVE CLUSTERS AND AFFECT WESTERN KANSAS THROUGH
JULY 6TH. THE TIMING OF THE INDIVIDUAL STORM CLUSTERS CANNOT BE
PREDICTED WITH MUCH ACCURACY IN THIS REGIME. THEREFORE, 20 TO 40%
STORM CHANCES WERE GENERALLY MAINTAINED THROUGH JULY 6TH. ALSO,
GIVEN THE UNCERTAINTY IN ANY CONVECTION AND RESULTANT COOL
OUTFLOW, HIGH TEMPERATURES WILL BE TRICKY AS WELL. OUR BEST
ESTIMATE IS THAT HIGH AND LOW TEMPERATURES WILL BE WITHIN A FEW
DEGREES OF CLIMATOLOGICAL VALUES (HIGHS 86-97F AT DODGE CITY, WITH
COOLER READINGS THAN THIS NEAR INTERSTATE 70 AND WARMER READINGS
NEAR THE OKLAHOMA STATE LINE). KEEP IN MIND THAT ANY WIDESPREAD
CLOUD COVER OR RAINFALL COULD LEAD TO MUCH COOLER TEMPERATURES
ON ANY GIVEN DAY.
AFTER JULY 6TH, THE VARIOUS MODELS ARE ADVERTISING A STRONG UPPER
LEVEL LOW TO DROP SOUTHWARD OUT OF CANADA INTO THE GREAT LAKES
REGION. THE ASSOCIATED COLD FRONT COULD BRING MUCH COOLER AIR INTO THE
CENTRAL PLAINS BY LATE NEXT WEEK, WITH HIGHS POSSIBLY FALLING INTO
THE 70S DEPENDING ON THE AMOUNT OF ACCOMPANYING CLOUD COVER AND
PRECIPITATION BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1145 AM CDT TUE JUL 30 2013
IN THE NEAR TERM, EXPECT MVFR CIGS AND GOOD VSBYS. WINDS WILL BE
FROM THE NORTHEAST TODAY IN THE 8 KNOT RANGE. SKIES WILL CLEAR
FROM WEST TO EAST GRADUALLY, BECOMING SCATTERED AT 250 THIS
EVENING. LIGHT WINDS AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO
SOME FOG DEVELOPING AFTER 09Z. FOR NOW, I AM EXPECTING SOME 2SM
IFR FOG POSSIBLE, WITH A CHANCE FOR ISOLATED VSBYS LESS THAN 1
MILE IN FOG.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 93 68 93 / 10 20 30 30
GCK 66 94 68 94 / 20 30 40 30
EHA 67 95 67 95 / 20 30 40 30
LBL 68 95 69 95 / 20 30 40 30
HYS 65 89 68 92 / 10 30 30 40
P28 69 89 70 94 / 10 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...FINCH
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
253 PM MDT TUE JUL 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 PM MDT TUE JUL 30 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS ELONGATED RIDGE ACROSS
THE SOUTHERN PLAINS WITH WESTERLY FLOW IN PLACE ACROSS THE
CENTRAL/HIGH PLAINS. A WEAK LEE TROUGH IS CURRENTLY IN PLACE ACROSS
EASTERN COLORADO WITH A WEAK CONVERGENCE REGION EXTENDING INTO OUR
WESTERN CWA.
THIS WILL ACT AS THE FOCUS FOR ISOLATED THUNDERSTORM DEVELOPMENT
THIS AFTERNOON...WITH CU FIELD ALREADY IN PLACE AND RADAR INDICATING
SEVERAL DEVELOPING UPDRAFTS JUST NW OF OUR CWA NEAR YUMA COUNTY. WITH
STORM MOTIONS OUT OF THE EAST 10-20KT MOST STORMS WILL BE SLOW
MOVERS...THOUGH WE COULD STILL SEE THIS ACTIVITY MOVE FURTHER EAST
IN OUR CWA THROUGH THE AFTERNOON BEFORE FALLING APART AFTER SUNSET
WITH LOSS OF DAYTIME HEATING AND INCREASING LOW LEVEL CINH. LATEST
RAP ANALYSIS SHOWS SB/ML CAPE VALUES RANGING FROM 1000-1500
J/KG...AND WITH ADJUSTED SOUNDINGS SUPPORTING POSSIBLE CAPE VALUES
IN THE 2000-2500J/KG RANGE LATER THIS AFTERNOON. WITH HIGH TD
DEPRESSIONS TO ABOUT 700MB THROUGH A DRY ADIABATIC AIRMASS AND HIGH
LFC/LCL IN THE 10-13KFT RANGE WE COULD SEE STRONG THUNDERSTORM GUST
POTENTIAL. IF WE REALIZE THE HIGHER CAPE VALUES I COULDNT RULE OUT
LARGE HAIL POTENTIAL...HOWEVER AT THIS POINT STRONG WINDS ARE
PROBABLY THE GREATER THREAT WITH ANY THUNDERSTORMS THAT DEVELOP.
MET/MAV GUIDANCE ARE INDICATING FOG DEVELOPMENT TONIGHT...HOWEVER
WITH W-SW WINDS TO 10KT AT THE SURFACE AND BL WINDS IN EXCESS OF
20KT...I AM NOT AS CONFIDENT WE WILL SEE A REPEAT OF LAST NIGHT.
WITH TROUGH AXIS SHIFTING EAST WE COULD STILL SEE LIGHT SURFACE
WINDS IN THE EAST WHERE FOG WOULD BE MORE LIKELY TO OCCUR...AND
WHERE I KEPT PATCHY FOG MENTION.
A WEAK COLD FRONT WILL DROP SOUTH LATE TONIGHT AND STALL ALONG THE
NE/KS STATE LINE BY MIDDAY WEDNESDAY WITH A PRE FRONTAL TROUGH
SETTLING TO OUR SOUTHEAST. AHEAD OF THE TROUGH AXIS CAPE VALUES IN
EXCESS OF 2500 J/KG ARE ADVERTISED. THIS TROUGH AXIS WILL BE THE
MAIN FOCUS WITH GOOD SURFACE CONVERGENCE IN PLACE...AND I KEPT 30/40
POPS TIED TO THIS FEATURE...AND LOWER POPS TO THE NORTH. WITH BETTER
CAPE AND MARGINALLY BETTER SHEER WE WILL SEE A CHANCE FOR
THUNDERSTORMS TO BECOME BETTER ORGANIZED WITH SEVERE WIND/HAIL A
POSSIBILITY IN OUR SOUTHEAST DURING THE AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 250 PM MDT TUE JUL 30 2013
NO MAJOR CHANGES SEEN TO THE UPPER PATTERN ACROSS THE SOUTHERN AND
CENTRAL PLAINS DURING THIS PERIOD. UPPER HIGH NOW CENTERED OVER
NEW MEXICO AND WAFFLE BACK AND FORTH OVER TO WEST TEXAS AND BACK DURING
PERIOD. ALTHOUGH THE UPPER RIDGE IS FORECAST TO ASSERT ITSELF SLIGHTLY
NORTH OVER THE MOUNTAINS...A SERIES OF WEAK UPPER IMPULSES WILL
CONTINUE TO MOVE OVER THE TOP OF THE RIDGE KEEPING IT FAIRLY
FLAT OVERALL.
THIS MAKES IT DIFFICULT TO ASSESS TIMING OF PRECIPITATION. ALL
GUIDANCE IS SUGGESTING AN ACTIVE FLOW REGIME WILL CONTINUE WITH
SLIGHT CHANCE TO CHANCE POPS EVERY DAY. RIGHT NOW THE MOST ACTIVE
PERIODS FOR PRECIPITATION LOOK TO BE THURSDAY NIGHT AND AGAIN
SATURDAY NIGHT. TEMPERATURES WILL CONTINUE SEASONAL WITH HIGHS
MOSTLY IN THE UPPER 80S TO LOWER 90S AND LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1146 AM MDT TUE JUL 30 2013
VFR CONDITIONS SHOULD PERSIST THROUGH THIS EVENING AT BOTH KGLD
AND KMCK THROUGH THE VALID TAF PERIOD. WITH SURFACE TROUGH AXIS
NEAR BOTH TERMINALS WINDS WILL BE SOMEWHAT ERRATIC...THOUGH THEY
SHOULD REMAIN BELOW 12KT AT THE SURFACE GENERALLY OUT OF THE EAST-
SOUTHEAST. THUNDERSTORMS MAY DEVELOP THIS AFTERNOON AHEAD OF
TROUGH AXIS ALONG KS/CO STATE LINE...HOWEVER WITH COVERAGE
ISOLATED I DECIDED AGAINST MENTION AT EITHER TAF SITE.
FOG WILL ONCE AGAIN BE POSSIBLE TONIGHT AFTER 09Z WITH MOIST
SURFACE LAYER STILL IN PLACE. MET/MAV GUIDANCE SHOWING CONDITIONS
DROPPING TO IFR/LIFR...HOWEVER WITH BL WINDS INCREASING TONIGHT
(ESPECIALLY OVER KGLD) I AM SKEPTICAL OF CONDITIONS MUCH LOWER THAN
MVFR. AT THIS TIME IF WE SAW LOWER CONDITIONS I THINK IT WOULD BE
AT KMCK WHERE SURFACE WINDS MAY REMAIN VARIABLE ALONG REPUBLICAN
RIVER VALLEY. A W-SW DRAINAGE WIND AROUND 10KT MAY HELP KEEP
CONDITIONS VFR AT KGLD. ANY FOG SHOULD DISSIPATE BY 15Z AS DIURNAL
HEATING MIXES OUT OF THE LOWER LEVELS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...DR
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
204 PM CDT TUE JUL 30 2013
...UPDATED FOR THE SHORT TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 156 PM CDT TUE JUL 30 2013
TODAY IS SEEING A VERY SLOW CLEARING PATTERN IN THE CLOUDS, FROM
WEST TO EAST. THIS SLOWNESS IN CLEARING IS PARTIALLY DUE TO THE
NORTH TO NORTHEAST LOW LEVEL FLOW, WHICH IS A SLIGHT UPSLOPE
PATTERN. THE OTHER REASON THE EAST IS SO SLOW TO CLEAR OUT IS THE
ABUNDANT SURFACE MOISTURE ACROSS OUR EASTERN ZONES, WITH PLENTY OF
LEFTOVER RAINFALL STILL ACROSS MUCH OF THE EASTERN FORECAST AREA,
ESPECIALLY SOUTHEAST OF A LINE FROM LA CROSSE TO ASHLAND. SOME OF
THESE COUNTIES RECEIVED OVER 3 INCHES OF RAINFALL MONDAY EVENING,
ESPECIALLY ACROSS PRATT AND BARBER COUNTIES. FOR THIS REASON, ALONG
WITH EXPECTED CLEAR SKIES AND LIGHT WINDS EXPECTED, THERE SHOULD
BE SOME MORE FOG FORM TOWARD 09Z TO 10Z. I HAVE DECIDED TO PUT IN
PATCHY FOG WORDING FOR NOW ACROSS OUR SOUTHEASTERN SECTIONS, AND
LATER SHIFTS CAN UPDATE TO DENSE FOG IF IT FORMS. BOTH THE NAM
AND THE HRRR MODELS ARE INDICATED AROUND 1SM VISIBILITIES IN FOG.
AS FOR LOW TEMPERATURES, NO CHANGES WERE MADE TO THE PREVIOUS
FORECAST. CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO
DROP TO THE MID 60S IN OUR WEST AND THE UPPER 60S IN OUR
SOUTHEAST.
MOSTLY SUNNY SKIES AREA EXPECTED WEDNESDAY, AFTER SOME SCATTERED
MORNING FOG. WINDS WILL BE LIGHT AND VARIABLE EARLY, THEN SHIFT TO
THE SOUTHEAST IN THE AFTERNOON AT 10 TO 20 MPH. THE SOUTHEASTERN
FLOW WILL BE AN UPSLOPE PATTERN, WITH THE MOISTURE RIDING UP HILL
WHICH MAY COLLIDE WITH THE LATE AFTERNOON TROUGH MOVING EAST FROM
COLORADO. HOW FAST THIS UPSLOPE AND TROUGH INTERACTION WILL
DEVELOP INTO CONVECTION IS HANDLED DIFFERENTLY BY THE MODELS. THE
NAM MODEL BRINGS IN THUNDERSTORMS WEDNESDAY AFTERNOON AS EARLY AS
19Z IN OUR NORTHWEST ZONES OF SCOTT AND LANE COUNTIES, AND
ADVANCES THE RAIN TOWARD DODGE CITY AS EARLY AS 22Z. THE ECMWF AND
GFS MODELS ARE A LITTLE SLOWER, BRINGING RAIN TO SCOTT AND LANE
COUNTIES AFTER 22Z AND NOT NEAR DODGE CITY UNTIL AFTER 02Z. HAVE
STARTED SLIGHT 20 PERCENT CHANCES IN OUR FAR NORTHWEST, SUCH AS
SCOTT AND LANE COUNTIES, AND DELAYED THE ONSET OF CHANCE POP
CATEGORIES IN THE DODGE CITY AREA UNTIL 03Z. SOME OF THE LATE
AFTERNOON AND EVENING STORMS COULD BE STRONG TO SEVERE
SUPPER CELLS, CAPABLE OF STRONG DOWNBURST WINDS AND MARGINAL HAIL
IN THE GOLF BALL SIZE. THE TROUGH BOUNDARY WILL MOVE THROUGH
WESTERN AND INTO CENTRAL KANSAS BY WEDNESDAY EVENING, BRINGING
RAIN CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE PRATT AND
COLDWATER AREAS AFTER 00Z THURSDAY. WITH SKIES STARTING OUT
WEDNESDAY MORNING AS MOSTLY SUNNY, THEN BECOMING PARTLY CLOUDY BY
MID TO LATE AFTERNOON, AND POSSIBLY EVEN MOSTLY CLOUDY BY EVENING,
MAXIMUM TEMPERATURES COULD BE A LITTLE TRICKY. STAYED WITH THE
PREVIOUS FORECAST OF MID 90S IN THE WEST AND NEAR 90F IN THE EAST.
HOW MUCH RAIN WILL FALL IS ALWAYS A LITTLE CHALLENGING, BUT I
THINK THE QPF_FM_POP PROCEDURE DID A FAIRLY GOOD JOB WITH FORECAST
RAINFALL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 348 AM CDT TUE JUL 30 2013
MEDIUM RANGE MODELS INDICATE A NORTHWESTERLY FLOW ALOFT DEVELOPING
ACROSS THE WESTERN HIGH PLAINS AS UPPER LEVEL RIDGING BUILDS ACROSS
THE INTERMOUNTAIN WEST WEDNESDAY. MEANWHILE, AN UPPER LEVEL
SHORTWAVE TROUGH WILL DROP SOUTHEAST OUT OF THE NORTHERN PLAINS INTO
THE UPPER MIDWEST DURING THE DAY. A WEAK COLD FRONT ASSOCIATED WITH
THE SHORTWAVE IS PROJECTED TO MOVE SLOWLY SOUTHEAST INTO WESTERN
KANSAS BEFORE STALLING OUT BY WEDNESDAY AFTERNOON. ALONG WITH
FAVORABLE DYNAMIC SUPPORT ALOFT, AMPLE LOW LEVEL MOISTURE AND THE
INCREASED LOW LEVEL FORCING ASSOCIATED WITH THE BOUNDARY WILL SET
THE STAGE FOR THUNDERSTORM DEVELOPMENT ACROSS PORTIONS OF CENTRAL
AND SOUTHWEST KANSAS WEDNESDAY AFTERNOON AND EVENING.
FOR THURSDAY, THE UPPER LEVEL RIDGE IS PROGGED TO DRIFT EASTWARD
ACROSS THE DESERT SOUTHWEST WHILE H5 VORT MAXES CONTINUE TO TOP
THE RIDGE AXIS THEN DROP SOUTHEAST INTO THE WESTERN HIGH PLAINS.
MEANWHILE, LEE SIDE TROUGHING IS EXPECTED TO DEVELOP IN EASTERN
COLORADO AS SURFACE HIGH PRESSURE SETS UP ACROSS THE MISSISSIPPI
RIVER VALLEY PROVIDING INCREASED SURFACE CONVERGENCE ACROSS
WESTERN KANSAS, NOT TO MENTION SURFACE DEWPOINTS WELL UP INTO THE
60S(F) TO NEAR 70F. WITH PLENTY OF INSTABILITY PRESENT,
THUNDERSTORMS WILL BE POSSIBLE LATE THURSDAY AFTERNOON AND
EVENING, ESPECIALLY ACROSS WEST CENTRAL AND CENTRAL KANSAS WHERE
BETTER LOW LEVEL FORCING IS LIKELY TO BE PRESENT. CHANCES FOR
THUNDERSTORMS WILL CONTINUE FRIDAY GOING INTO THE WEEKEND WITH
LITTLE CHANGE EXPECTED TO THE OVERALL PATTERN AND A FRONTAL
BOUNDARY LINGERING GENERALLY ACROSS WESTERN KANSAS.
TEMPERATURES WILL BE NEAR NORMAL WEDNESDAY AS A GRADUAL WARMING
TREND CONTINUES ACROSS WESTERN KANSAS. WARMER H85 TEMPERATURES WILL
SLOWLY ADVECT NORTHWARD INTO THE AREA WITH VALUES RANGING FROM THE
MID 20S(C) ACROSS CENTRAL KANSAS TO NEAR 30C NEAR THE COLORADO
BORDER. WITH STEEP LAPSE RATES DEVELOPING IN THE LOWER LEVELS
IN THE AFTERNOON, EXPECT HIGHS WELL UP INTO THE 90S(F). WIDESPREAD
90S(F) ARE LIKELY THURSDAY AFTERNOON WITH NEAR 100F POSSIBLE IN
EXTREME SOUTHWEST KANSAS AS A MODEST LOW LEVEL FLOW CONTINUES TO
ADVECT WARMER AIR INTO WESTERN KANSAS. THE MORE SEASONAL
TEMPERATURES ARE EXPECTED TO CONTINUE INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1145 AM CDT TUE JUL 30 2013
IN THE NEAR TERM, EXPECT MVFR CIGS AND GOOD VSBYS. WINDS WILL BE
FROM THE NORTHEAST TODAY IN THE 8 KNOT RANGE. SKIES WILL CLEAR
FROM WEST TO EAST GRADUALLY, BECOMING SCATTERED AT 250 THIS
EVENING. LIGHT WINDS AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO
SOME FOG DEVELOPING AFTER 09Z. FOR NOW, I AM EXPECTING SOME 2SM
IFR FOG POSSIBLE, WITH A CHANCE FOR ISOLATED VSBYS LESS THAN 1
MILE IN FOG.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 93 68 93 / 10 20 30 20
GCK 66 94 68 94 / 20 30 40 30
EHA 67 95 67 95 / 20 30 40 20
LBL 68 95 69 95 / 20 30 40 20
HYS 65 89 68 92 / 10 30 30 40
P28 69 89 70 94 / 10 10 30 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...JJOHNSON
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1001 PM EDT WED JUL 31 2013
.FORECAST UPDATE...
Issued at 1000 PM EDT Wed Jul 31 2013
Did an update to align near-term forecast with trends in obs. The
first frontal boundary is pushing southeast out of our forecast area
and taking with it the broken line of showers across the Lake
Cumberland region. Behind that line, there are areas of drizzle
associated with the low stratus that hung around for much of the
day. This drizzle should drift southeast and diminish within the
next few hours. The stratus is breaking up, with mostly clear skies
across our west and northwest counties. Have updated the forecast to
cover all these trends in the near-term.
Another feature of note is a surface trough stretching southwest
through central IN into southern IL. There are a few isolated
showers along this boundary and it is edging our way. Some hi-res
models bring those into our northern CWA. Have added isolated
showers across our north through about 2 AM EDT.
All of the latest guidance indicates low stratus will build across
the region, mainly after midnight. So, even though some areas are
experiencing mostly clear skies, believe that will change as the
night progresses. Have bumped up the cloud cover from around
midnight through sunrise, with clouds beginning to dissipate mid to
late morning. Cannot rule out some patchy fog/mist/haze with this
stratus that will build in overnight, reducing visibilities just a
bit. All updates will be out shortly.
&&
.SHORT TERM (Tonight through Thursday night)...
Issued at 310 PM EDT Tue Jul 31 2013
Weak surface trof sits just this side of US 41, with light NNE winds
in southern Illinois and western Kentucky, while we are still
southerly here in central Kentucky and southern Indiana. Extensive
low cloud deck maintains its hold on the Ohio Valley as soundings
are pretty well saturated up to about 700mb. A few showers have
tried to pop in south central Kentucky, but any instability to
support thunder is suppressed well down into Tennessee.
Still can`t rule out a shower through early evening, as is evident
by that weak activity in the south. More likely scenario is probably
sprinkles, but the main theme of the night will be low clouds. Could
also be some light fog, but because of the stratus we do not expect
visibilities to drop enough to have any impacts other than aviation.
Otherwise expect a muggy night with temps near or just a couple
degrees below normal.
Deep NW flow on Thursday will finally dry out the column, so morning
stratus will give way to a partly sunny afternoon. Temps will run
below normal, as 850mb temps at 14C will only allow for lower 80s,
even in fairly deep mixing. Decent radiational cooling conditions
Thursday night will provide more free air conditioning, with temps
dipping into the lower 60s in most locations, with even a few 50s
possible in the traditionally cooler spots.
.LONG TERM (Friday through Wednesday)...
Issued at 232 PM EDT Wed Jul 31 2013
Surface high pressure to start off this forecast period will begin
to lose its hold over the Ohio Valley by early Saturday as a frontal
boundary sags southward across Indiana. Latest GFS run (12Z) shows
the front clearing south of the forecast area by Sunday, allowing
for the next surface high to move on through. Once again, however,
the two major long-term deterministic models disagree and diverge by
Monday on the pattern. The GFS has the high shunting off of the East
Coast by Monday evening, allowing for some possible convection to
fire up, especially in southern Kentucky where GFS PW values run
close to 2 inches. The focus for precip relies on a series of
shortwaves rotating through early next week. The 00Z ECMWF,
meanwhile, has the high washing out somewhere over the East Coast,
leaving the region in a messy pattern with two weak surface lows to
our NE and SE. By Wednesday, the models are drastically different
with the GFS trying to bring a cold front associated with a surface
low through the region while the ECMWF has us dry and already under
northerly flow. The two models are spatially displaced on a Canadian
upper low that should ultimately be the determining factor in our
local weather for Monday through Wednesday. Therefore, once again,
confidence in the forecast for the latter half of this period
remains low at best. Given that yesterday`s 12Z ECMWF came in at a
bit of a closer agreement to the 12Z GFS for the same forecast time
frame, am leaning more toward the GFS in tweaking today`s forecast
for the upcoming work week.
To summarize the precip forecast, showers and thunderstorms should
begin to approach southern Indiana by Friday afternoon, eventually
overspreading the area by Saturday. Instability looks decent enough
to warrant good thunderstorm potential with the slight chance of
some storms becoming strong, but only if a break in the cloud cover
allows for decent daytime heating. Any stronger storm would contain
gusty winds. By the end of the weekend, any remaining activity
should be contained primarily in southern KY and clear of the
forecast area by Sunday night. Again, confidence beyond this point
is low, but should it pan out, we`ll see this brief lull in precip
chances overnight Sunday before at least a slight chance of
thunderstorms creeps back in on Monday. Currently, have depicted the
"best" (relatively speaking) precip chances Tuesday, waning after
sunset and potentially re-emerging on Wednesday.
Temperatures continue to look like they`ll remain near or slightly
below normal for this time of year, with the warmest two days during
this period occurring on Friday and Wednesday. Cloud cover and
precip will, of course, throw a wrench into the mix for temperature
forecasts. Highs on Friday will be in the mid 80s with lows in the
upper 60s. Have bumped up Saturday highs slightly, giving the area
low to mid 80s as highs. From Sunday onward, look for fluctuating
highs ranging from the low to mid (and possibly upper) 80s and lows
in the 60s to near 70.
&&
.AVIATION (00Z TAF Update)...
Issued at 725 PM EDT Wed Jul 31 2013
Rain potential is slim to none at all sites, so the main concern
will be cigs and vis overnight. Back edge of low stratus is
approaching SDF from the northwest and should arrive shortly before
02Z, with VFR conditions to follow for a few hours. This will take a
little longer to reach LEX if it can make it there. BWG broke out
earlier this afternoon, but there remains a chance to drop back to
MVFR until that back edge finally moves through, around 02-03Z. This
VFR window is in response to slight ridging ahead of our next
shortwave, which is slated to move across the Ohio Valley overnight.
The second band of low stratus across central IL is associated with
the shortwave for tonight. Latest guidance either builds lower
stratus or advects it in from the west around 05-06Z. The RAP and
WRF simulated GOES-R show the low stratus developing a little later,
closer to 07-09Z, particularly for BWG and SDF. So, confidence in
timing remains low, but it certainly appears fuel-alternate cigs are
a sure bet for all sites, with some bases approaching alternate
minimums at BWG and LEX. Expect vis to drop generally into the MVFR
range with the low stratus. Conditions should begin to improve
around or shortly after 15Z, with VFR conditions expected by the
afternoon hours. Winds will remain light and variable overnight and
pick up out of the northwest around mid morning Thursday, with
speeds in the 6-9 knot range expected through the afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........MJP
Short Term.......RAS
Long Term........lg
Aviation.........MJP
AREA FORECAST DISCUSSION
NWS PADUCAH KY
849 PM CDT Wed Jul 31 2013
.UPDATE...
ISSUED AT 849 PM CDT WED JUL 31 2013
A very weak surface convergence zone has developed along the
Wabash River this evening, and some isolated showers have
resulted. The most recent HRRR indicates that the convergence zone
and showers will slowly shift southeast through midnight. Decided
to add a slight chance/isolated pop over areas east of the Lakes
and Wabash through midnight.
All guidance shows a minor push of northwest winds and drier air
into the region overnight behind this convergence zone. Given some
variable cloud cover expected, the light northwest wind, and drier
air moving in, fog should not be a widespread problem overnight.
Made some adjustments to T/Td through the night to match these
overall trends and the current observations.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 245 PM CDT Wed Jul 31 2013
Early this afternoon, a few showers and storms continue to flare
up near the KY/TN MO/AR borders in best instability axis per LAPS
surface data. Otherwise considerable clouds persist given ample
low level moisture, though minor improvement has been noted with
daytime heating and weak mixing. Not seeing much up north into
Missouri and Illinois. May leave pops out starting at 00z. We have
slight chances even north of the Ohio River through 00z just in
case there is a little development in an expanding zone of
instability. It may take the weak wave moving southeast across
MO/CNTRL IL to kick something off, if at all. Will monitor.
Otherwise tonight in the wake of the weak surface low, light NNW
winds below 5 kts are anticipated. Low level moisture will remain.
So there may be some fog. Not sure how much at this time,
especially if lower clouds remain a factor. May have to include
patchy fog in the forecast. Weak high pressure and overall drying
means dry Thursday through Thursday night. Then our attention
turns to the next impulse and a frontal boundary that will
approach Friday through Friday night. We have increasing pops from
north to south for convection. The oveall model agreement is good
enough to use a compromise. Temperatures and humidity will be a
bit more summer like, but still tolerable as we head into early
August.
.LONG TERM...(Saturday Through Wednesday)
Issued at 245 PM CDT Wed Jul 31 2013
The northeast U.S. / southeast Canadian cold core vortex will
continue to dominate the medium range weather pattern from
Saturday through the middle of next week. The North American
Oscillation (NAO) ensembles indicate slightly negative values
through at least August 6th, suggesting that the vortex will
remain dominate in holding the base of the westerlies either over
the WFO PAH forecast area, or just to the southwest.
With this in mind, adjusted the probability of precipitation (PoP)
gradient further to the southwest over parts of southeast
Missouri, as well as southwest Illinois and Kentucky. Given the
thickness and moisture gradient, combined with subtle forcing from
passing upper level jetlets and low level insolation/differential
heating, kept the highest PoPs to the south and west of the
forecast area.
In all of the medium range forecast period, the time period of
mixed/lowest confidence is from after midnight Monday through the
daytime hours on Tuesday. The latest run (12z Wednesday) of the
operational ECMWF supports much lower PoPs compared to the 00z
run, indicating the lower PoPs may be the way to go over
Kentucky, Indiana, and most of southern Illinois. Unfortunately,
this scenario places our office with lower PoPs versus surrounding
NWS offices, with the possible exception of Nashville and Little
Rock NWS offices.
The negative NAO scenario will also keep maximum temperature 3 to 7
degrees below normal highs for this time of year.
&&
.AVIATION...
Issued at 1055 AM CDT Wed Jul 31 2013
Will monitor convective chances the rest of the day. Gradual
improvement in cloud base heights and vsbys expected with
weak mixing, heat of the day. Lower clouds may linger tonight
across part of the area, with some light fog possible as well.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...Noles
LONG TERM... Smith
AVIATION...Noles
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
727 PM EDT WED JUL 31 2013
...Updated Aviation Discussion...
.SHORT TERM (Tonight through Thursday night)...
Issued at 310 PM EDT Tue Jul 31 2013
Weak surface trof sits just this side of US 41, with light NNE winds
in southern Illinois and western Kentucky, while we are still
southerly here in central Kentucky and southern Indiana. Extensive
low cloud deck maintains its hold on the Ohio Valley as soundings
are pretty well saturated up to about 700mb. A few showers have
tried to pop in south central Kentucky, but any instability to
support thunder is suppressed well down into Tennessee.
Still can`t rule out a shower through early evening, as is evident
by that weak activity in the south. More likely scenario is probably
sprinkles, but the main theme of the night will be low clouds. Could
also be some light fog, but because of the stratus we do not expect
visibilities to drop enough to have any impacts other than aviation.
Otherwise expect a muggy night with temps near or just a couple
degrees below normal.
Deep NW flow on Thursday will finally dry out the column, so morning
stratus will give way to a partly sunny afternoon. Temps will run
below normal, as 850mb temps at 14C will only allow for lower 80s,
even in fairly deep mixing. Decent radiational cooling conditions
Thursday night will provide more free air conditioning, with temps
dipping into the lower 60s in most locations, with even a few 50s
possible in the traditionally cooler spots.
.LONG TERM (Friday through Wednesday)...
Issued at 232 PM EDT Wed Jul 31 2013
Surface high pressure to start off this forecast period will begin
to lose its hold over the Ohio Valley by early Saturday as a frontal
boundary sags southward across Indiana. Latest GFS run (12Z) shows
the front clearing south of the forecast area by Sunday, allowing
for the next surface high to move on through. Once again, however,
the two major long-term deterministic models disagree and diverge by
Monday on the pattern. The GFS has the high shunting off of the East
Coast by Monday evening, allowing for some possible convection to
fire up, especially in southern Kentucky where GFS PW values run
close to 2 inches. The focus for precip relies on a series of
shortwaves rotating through early next week. The 00Z ECMWF,
meanwhile, has the high washing out somewhere over the East Coast,
leaving the region in a messy pattern with two weak surface lows to
our NE and SE. By Wednesday, the models are drastically different
with the GFS trying to bring a cold front associated with a surface
low through the region while the ECMWF has us dry and already under
northerly flow. The two models are spatially displaced on a Canadian
upper low that should ultimately be the determining factor in our
local weather for Monday through Wednesday. Therefore, once again,
confidence in the forecast for the latter half of this period
remains low at best. Given that yesterday`s 12Z ECMWF came in at a
bit of a closer agreement to the 12Z GFS for the same forecast time
frame, am leaning more toward the GFS in tweaking today`s forecast
for the upcoming work week.
To summarize the precip forecast, showers and thunderstorms should
begin to approach southern Indiana by Friday afternoon, eventually
overspreading the area by Saturday. Instability looks decent enough
to warrant good thunderstorm potential with the slight chance of
some storms becoming strong, but only if a break in the cloud cover
allows for decent daytime heating. Any stronger storm would contain
gusty winds. By the end of the weekend, any remaining activity
should be contained primarily in southern KY and clear of the
forecast area by Sunday night. Again, confidence beyond this point
is low, but should it pan out, we`ll see this brief lull in precip
chances overnight Sunday before at least a slight chance of
thunderstorms creeps back in on Monday. Currently, have depicted the
"best" (relatively speaking) precip chances Tuesday, waning after
sunset and potentially re-emerging on Wednesday.
Temperatures continue to look like they`ll remain near or slightly
below normal for this time of year, with the warmest two days during
this period occurring on Friday and Wednesday. Cloud cover and
precip will, of course, throw a wrench into the mix for temperature
forecasts. Highs on Friday will be in the mid 80s with lows in the
upper 60s. Have bumped up Saturday highs slightly, giving the area
low to mid 80s as highs. From Sunday onward, look for fluctuating
highs ranging from the low to mid (and possibly upper) 80s and lows
in the 60s to near 70.
&&
.AVIATION (00Z TAF Update)...
Issued at 725 PM EDT Wed Jul 31 2013
Rain potential is slim to none at all sites, so the main concern
will be cigs and vis overnight. Back edge of low stratus is
approaching SDF from the northwest and should arrive shortly before
02Z, with VFR conditions to follow for a few hours. This will take a
little longer to reach LEX if it can make it there. BWG broke out
earlier this afternoon, but there remains a chance to drop back to
MVFR until that back edge finally moves through, around 02-03Z. This
VFR window is in response to slight ridging ahead of our next
shortwave, which is slated to move across the Ohio Valley overnight.
The second band of low stratus across central IL is associated with
the shortwave for tonight. Latest guidance either builds lower
stratus or advects it in from the west around 05-06Z. The RAP and
WRF simulated GOES-R show the low stratus developing a little later,
closer to 07-09Z, particularly for BWG and SDF. So, confidence in
timing remains low, but it certainly appears fuel-alternate cigs are
a sure bet for all sites, with some bases approaching alternate
minimums at BWG and LEX. Expect vis to drop generally into the MVFR
range with the low stratus. Conditions should begin to improve
around or shortly after 15Z, with VFR conditions expected by the
afternoon hours. Winds will remain light and variable overnight and
pick up out of the northwest around mid morning Thursday, with
speeds in the 6-9 knot range expected through the afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......RAS
Long Term........lg
Aviation.........MJP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
645 PM EDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 645 PM EDT TUE JUL 30 2013
22Z SFC ANALYSIS SHOWS THAT OUR COOL HIGH PRESSURE IS NOW RETREATING
TO THE EAST IN THE FACE OF A DEVELOPING AREA OF LOW PRESSURE LIFTING
INTO THE MID MISSISSIPPI VALLEY. AHEAD OF THIS LOW...AN MCV IN THE
MID LEVELS OF THE ATMOSPHERE IS PUSHING EAST INTO KENTUCKY THIS
EVENING. THIS IS HELPING TO SUSTAIN A LARGE AREA OF LIGHT TO MODERATE
RAIN SLOWLY CROSSING THE BLUEGRASS STATE. FOR EAST KENTUCKY...SO
FAR...THIS HAS MEANT LITTLE MORE THAN SOME VIRGA OVER THE CUMBERLAND
VALLEY BUT MORE SUBSTANTIAL SHOWERS ARE NOT FAR OUT. EXPECT THE RAIN
TO OVERTAKE THE CWA THROUGH THE LATE EVENING AND EARLY MORNING HOURS
FROM WEST TO EAST. A STRAY BOLT OF LIGHTNING WILL BE POSSIBLE THROUGH
THE NIGHT ALONG WITH HEAVIER AMOUNTS OF RAIN FOR THE SOUTHEAST PARTS
OF THE AREA PER THE LATEST NAM12 AND HRRR GUIDANCE. HAVE UPDATED THE
FIRST TWO PERIODS OF THE FORECAST TO REFLECT THIS. ALSO ADJUSTED
TEMPERATURES AND DEWPOINTS THROUGH THE NIGHT IN LINE WITH THE LATEST
THOUGHTS ON PCPN CHANCES AND QPF. UPDATES HAVE BEEN SENT TO THE NDFD
AND WEB SERVERS...ALONG WITH A FRESHENED SET OF ZONES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 250 PM EDT TUE JUL 30 2013
SFC WARM FRONT FROM SRN ILL TO MIDDLE TENN AND SLOWLY CREEPING TO THE
NE. CURRENT PCPN APPEARS TO BE EDGING INTO MIDDLE KY. CURRENT CLOUD
COVER OVER ERN KY IS HIGH CI WITH SOME MID LEVEL CLOUDS AND VIRGA
EDGING INTO OUR SWRN COUNTIES. SKEW-T INDICATES A WEAK SPEED MAX AT
50H COINCIDENT WITH A VERY MOIST LAYER ABOVE AND VERY DRY BELOW THAT
MAX. SHOULD SEE A GRADUAL MOISTENING OF THE LOWER LAYERS AND A
LOWERING OF THE CEILING HEIGHTS THIS EVENING INTO TONIGHT.
MODELS INDICATE THE PCPN ENTERING THE I-75 CORRIDOR AROUND MIDNIGHT
TONIGHT AS A COLD FRONT SWEEPS ACROSS THE OHIO VALLEY OVERNIGHT. THE
COLD FRONT WILL PROVIDE THE BEST RAINFALL EARLY THU BEFORE BECOMING
NEARLY STATIONARY JUST EAST OF THE APPALACHIAN MTNS WITH SEVERAL
SHORT WAVES DROPPING FROM THE GREAT LAKES TO REINFORCE THE ERN TROF.
EACH SHORT WAVE WILL BRING ANOTHER QUICK SHOT OF PCPN BUT THE
RAINFALL ON WED NITE AND THU WILL NOT BE AS HEAVY OR WIDESPREAD WITH
THE FRONTAL BNDRY HAVING WRUNG MUCH OF THE AVAILABLE MOISTURE FROM
THE AIR. THE LAST OF THE SHRA SHOULD EASE OUT OF THE STATE ON THU
MORNING WITH THE SKY BEGINNING TO CLEAR THU AFTERNOON.
CLOUD COVER AND AN INCREASE IN DEW POINTS WILL HOLD TEMPS TONIGHT IN
THE LOWER 60S. WITH THE INFLUX OF RAIN ON WED BEFORE DROPPING TO THE
MID 60S WED NITE. THEN WITH AN END TO THE RAIN AND SOME HELP FROM
BREAKS IN THE CLOUD COVER ON THU AFTERNOON...TEMPS COULD SHOOT UP TO
THE LOWER 80S. THU HIGHS ARE PREDICATED ON SOME CLEARING...SO IF THE
CLOUDS REMAIN THE HIGHS WILL NECESSARILY NEED TO BE LOWERED SOME.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 251 PM EDT TUE JUL 30 2013
THE MODELS START OFF IN VERY GOOD AGREEMENT WITH UPPER TROUGHS OVER
BOTH COASTS AND AN UPPER RIDGE OVER THE ROCKIES. WITH THIS TYPE OF
PATTERN...SYSTEMS FROM THE WEST COAST ARE BEING BLOCKED BY THE RIDGE
FROM MOVING ACROSS THE AREA. ALL THE SYSTEMS THAT COME THROUGH THE
AREA COME FROM ARES FAR TO THE NORTH AND THEN MOVE DOWN THE BACK OF
THE UPPER TROUGH. THIS SHOULD RESULT IN CONTINUED COOL WEATHER FOR
THIS TIME OF YEAR. BY SUNDAY...THE TIMING OF THE SYSTEMS STARTS TO
BECOME LESS CERTAIN AS THE MODELS DIFFER IN THE TIMING OF THE SHORT
WAVES MOVING DOWN THE BACK SIDE OF THE TROUGH. THE GFS HAS A FRONT
MOVING THROUGH THE AREA ON SATURDAY AND HAS THE LAST OF THE
PRECIPITATION MOVING OUT OF THE AREA SUNDAY MORNING. THE 00Z ECMWF
IS A LITTLE SLOWER WITH MOVING THE RAIN OUT. THE GFS BRINGS THE NEXT
SYSTEM THROUGH ON TUESDAY WHILE THE THE 00Z ECMWF THEN DOES NOT MOVE
THE NEXT SYSTEM INTO THE AREA UNTIL WEDNESDAY. WILL STAY WITH A
MODEL BLEND FOR TIMING AND THEN NUDGE IT TOWARD THE NEW ECMWF
FORECAST WHEN IT COMES IN AT 3 PM. FOR TEMPERATURES STAYED CLOSE
STAYED A BIT COOLER THAN MOS...BUT DID NOT MAKE ANY LARGE CHANGES
FROM THE CONSENSUS MODEL BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 119 PM EDT TUE JUL 30 2013
AN AREA OF SURFACE HIGH PRESSURE WILL GRADUALLY SHIFT EAST OF THE OH
VALLEY TODAY. THIS WILL KEEP VFR CONDITIONS ACROSS THE AREA THROUGH
THE MAJORITY OF THE TIME...ALTHOUGH CLOUDS WILL THICKEN AND LOWER
OUT AHEAD OF AN APPROACHING UPPER LEVEL DISTURBANCE. SOME CONVECTION
SHOULD THREATEN THE INTERSTATE 75 CORRIDOR BETWEEN 0Z AND 6Z AND
OVERSPREAD MOST OF THE AREA BY 9Z. AS THE RA MOISTENS THE AIR MASS...
LOOK FOR VSBY AND CIGS TO LOWER TO MVFR TO IFR VALUES. HAVE NOT YET
BROUGHT IN TSRA/VCTS ALTHOUGH THIS IS A POSSIBILITY BY LATE MORNING
AND A GOOD CHANCE BY EARLY WED AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DUSTY
LONG TERM...JJ
AVIATION...DUSTY
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
942 PM EDT WED JUL 31 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE OFF THE COAST TONIGHT WHILE A
COLD FRONT APPROACHES FROM THE MIDWEST. THE COLD FRONT WILL PASS
THROUGH THE AREA LATE THURSDAY INTO THURSDAY NIGHT. HIGH PRESSURE RETURN
FRIDAY. THE HIGH WILL MOVE OFF THE COAST SATURDAY BEFORE THE NEXT COLD
FRONT IS EXPECTED TO IMPACT THE AREA LATE SATURDAY INTO SUNDAY.
&&
.NEAR TERM /TONIGHT/...
00Z SFC ANALYSIS REVEALS A WEAK SFC LOW NEAR DTW WHILE ITS ATTENDANT
SFC TROUGH EXTENDS SWWD FROM THE LOW INTO THE MIDWEST. HIPRES HAS
MOVED OFF THE MID-ATLANTIC COAST. THE PWAT MEASURED ON THE 00Z IAD
RAOB SOUNDING HAS INCREASED ONE-HALF INCH IN THE PAST 12H IN
RESPONSE TO LLVL SLY FLOW AHEAD OF THE TROUGH ADVECTING A MOIST
AIRMASS OVER THE SE STATES NWD INTO THE MID-ATLANTIC REGION. A BAND
OF SHOWERS THAT DEVELOPED ALONG THE LEADING EDGE OF MID-LVL DPVA AND
ISENTROPIC LIFT WILL LIFT NORTH OF THE POTOMAC RIVER THIS EVE...
PROVIDING A BRIEF LGT TO MODERATE SHOWER. ADDITIONAL LGT SHOWERS
WILL CONTINUE OVER CENTRAL VA AND LWR SRN MD THIS EVE.
18Z MODEL GUIDANCE AND LATEST RAP SHOWS PWATS CONTINUING TO INCREASE
TO NEAR 2 INCHES EAST OF BLUE RIDGE OVNGT. DURING THIS TIME...SLY
LLVL JET AHEAD OF THE APPROACHING TROUGH IS EXPECTED TO STRENGTHEN.
LLVL CONV AT THE NOSE OF THE JET AND WEAK ISENTROPIC LIFT WILL
PROVIDE THE FOCUS FOR ADDITIONAL SHOWER DEVELOPMENT LATE TNGT. THERE
ARE NOTICEABLE DIFFERENCES WITH BOTH TIMING AND LOCATION OF OVNGT
PRECIP...WHICH RESULTED IN LIMITED FCST CONFIDENCE IN ANY ONE
SOLUTION. BASED ON LOCATION OF THE DEVELOPING LLVL JET...FAVORED
HIGHER POPS IN CENTRAL VA WITH PRECIP EXPANDING N-EWD INTO NRN VA
AND SRN/CNTRL MD LATE IN THE PERIOD.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
COLD FRONT WILL APPROACH FROM THE OH VLY BUT REMAIN WEST OF THE
AREA DURING THE MRNG. SHOWERS WILL BE ONGOING DURING THE MRNG IN
SHARPENING THETA-E RIDGE. UPPER-JET DYNAMICS AND MID-LVL DPVA
WILL PROVIDE NECESSARY FORCING FOR ASCENT ON THU. ADDITIONAL
SHOWERS AND SCT STORMS ARE EXPECTED TO DEVELOP DURING THE PEAK
HEATING HRS WITH CONVECTION ENHANCED NEAR PRE-FRONTAL SFC TROUGH
THAT WILL BE MOVING EWD THRU THE REGION. A VERY MOIST AIRMASS WITH
PWATS NEAR 1.75 IN WILL RESIDE OVER THE AREA...PARTICULARLY EAST OF
THE BLUE RIDGE. WITH A SLOW-MOVING SFC BOUNDARY AND LOCALLY HVY
DOWNPOURS...THERE IS A POTENTIAL FOR LOCALIZED FLASH FLOODING.
WITH RELATIVELY HIGH FFG AND A RATHER PROGRESSIVE SYSTEM ALOFT...
OPTED NOT TO ISSUE A FLASH FLOOD WATCH.
PREVIOUS DISCUSSION...
THURSDAY NIGHT...QUICK CUTOFF FROM PRECIP AS THE SFC
TROUGH MOVES EAST FROM THE CWA THURSDAY EVENING. CD FROPAS ARE
RARE FOR SUMMER... BUT CONSENSUS HAS THE TROUGH REACHING THE MID-
ATLANTIC COASTLINE THROUGH THE OVERNIGHT. MAV/MET/SREF BLEND MAKES
FOR MIN TEMPS LOW TO MID 60S INLAND...AROUND 70F FOR URBAN AND
NEARSHORE LOCALES. THE RAIN ON THURSDAY SHOULD LOWER THE WATER
TEMPS A BIT...BUT THEY ARE CURRENTLY AROUND 80F.
FRIDAY...DOWNSLOPING FLOW...SUNSHINE...AND LESS HUMIDITY LEAD TO
HIGHER TEMPS THAN RAINY THURSDAY. MID 80S MAX TEMPS...NEAR NORMAL.
DRY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
UPR TROUGH PERSISTS OVER THE ERN CONUS THROUGH THE FORECAST PERIOD.
SFC TROUGH CROSSES THE MID-ATLANTIC SATURDAY INTO SUNDAY WITH CHANCE
POPS. MORE CANADIAN HIGH PRESSURE SUNDAY AND MONDAY.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
LGT SHRA CONTINUE TO SPREAD NWD IN ADVANCE OF A TROUGH TO OUR
WEST. MAINLY VFR CONDITIONS THIS EVE...ALTHOUGH A BRIEF PERIOD OF
MVFR CIGS/VSBYS POSSIBLE IN HEAVIER SHOWERS. CIGS LOWER OVNGT AS
TOP OF NOCTURNAL BOUNDARY LAYER MOISTENS AND LOWERS. EXPECT MVFR
CIGS AT MOST TERMINALS BETWEEN 06Z-12Z WITH SOME PLACES BECOMING
MVFR A COUPLE OF HRS EARLIER. WHILE IFR CIGS POSSIBLE...CONFIDENCE
NOT HIGH ENOUGH TO FCST IN 00Z TAFS...ESPECIALLY SINCE SLY WINDS
MAY KEEP STRATUS DECK AOA 1 KFT.
HEAVY SHOWERS/THUNDERSTORMS THURSDAY AHEAD OF A WEAK COLD FRONT. IFR
CONDS LIKELY IN HEAVIER ACTIVITY. SLY FLOW GUSTS UP TO 20 KT
DURING THE DAY. WLY/NWLY FLOW THURSDAY NIGHT THROUGH FRIDAY IN VFR
CONDS. SFC TROUGH SATURDAY INTO SUNDAY WITH SCATTERED
THUNDERSTORMS.
&&
.MARINE...
SLY WINDS HAVE INCREASED THIS EVE AROUND HIPRES THAT HAS MOVED
OFFSHORE. AREAS THAT ARE EXPOSED TO SLY CHANNELING...HAVE BEEN
GUSTING AROUND 20 KT. HAVE EXPANDED SCA FOR TNGT TO INCLUDE ALL MD
CHSPK BAY ZONES AS WELL AS THE MOUTH OF THE TIDAL POTOMAC.
SCA CONTINUES ON THU WITH 15-25 KT SLY WINDS EXPECTED AHEAD OF AN
APPROACHING COLD FRONT. SHOWERS AND THUNDERSTORMS MAY PRODUCE
LOCALLY HIGHER GUSTS THU AFTN.
WLY/NWLY FLOW AROUND 15 KT THURSDAY NIGHT INTO FRIDAY. WEAK
DISTURBANCE SATURDAY INTO SUNDAY BRINGS SCATTERED THUNDERSTORMS.
&&
.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES HAVE INCREASED TO AROUND A TWO-THIRDS OF
A FOOT THIS EVE ALONG THE WRN SHORE OF THE MD CHSPK BAY. EXPECT
POSITIVE ANOMALIES TO INCREASE FURTHER TNGT AS S-SE WINDS AT THE
MOUTH OF THE CHSPK BAY BLOCK WATER FROM EXITING THE BAY. HAVE
ISSUED A COASTAL FLOOD ADVISORY OVNGT FOR ANNE ARUNDEL COUNTY AS
THREE- QUARTER FOOT DEPARTURES WILL BE ENOUGH TO PRODUCE MINOR
COASTAL FLOODING AT ANNAPOLIS. ELSEWHERE...WATER LVLS WILL REMAIN
BELOW THRESHOLD.
CANNOT RULE OUT ADDITIONAL MINOR COASTAL FLOODING AT SENSITIVE
LOCATIONS /PRIMARILY ANNAPOLIS/ DURING HIGH TIDE THURSDAY WITH SLY
FLOW CONTINUING AHEAD OF A COLD FRONT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 4 AM EDT
THURSDAY FOR MDZ014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ530>534-
537>541-543.
SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT THURSDAY FOR ANZ536-
542.
&&
$$
SYNOPSIS...JRK/HAS
NEAR TERM...JRK
SHORT TERM...BAJ/JRK
LONG TERM...BAJ
AVIATION...BAJ/JRK
MARINE...BAJ/JRK
TIDES/COASTAL FLOODING...JRK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1141 PM EDT WED JUL 31 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 311 PM EDT WED JUL 31 2013
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THIS EVENING AS
A WEAK COLD FRONT PASSES THROUGH. CONDITIONS DRY OUT ON THURSDAY
BEFORE RAIN CHANCES RETURN FRIDAY MORNING WITH A WEAK UPPER AIR
WAVE. TEMPERATURES WILL REMAIN A LITTLE COOL WITH HIGHS IN THE
MID TO UPPER 70S THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 833 PM EDT WED JUL 31 2013
RADAR TRENDS SHOW ONE AREA OF SHOWERS MOVING IN FROM THE WEST.
THIS PRECIPITATION HAS BEEN WEAKENING. HOWEVER...MOST LOCATIONS ON
THE LAKESHORE SHOULD SEE RAIN. A GROWING AREA OF R-/L- WAS
LOCATED ROUGHLY SOUTHEAST OF A LANSING TO KALAMAZOO LINE...MOVING
EAST. THIS PRECIPITATION WILL IMPACT MUCH OF SOUTH CENTRAL LOWER
MI OVER THE NEXT COUPLE OF HRS. ALSO...THE INSTABILITY IS
DIMINISHING AND THE LIGHTNING ACTIVITY HAS DECREASED WITH THE
PRECIPITATION OVER LAKE MI. SO THE UPDATED REFLECTED LESS
LIGHTNING...BUT MORE RAIN THAN FORECASTED. BY MIDNIGHT
06Z...LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 311 PM EDT WED JUL 31 2013
EXPECT SHOWERS AND ANY POSSIBLE THUNDERSTORMS TO END BY THIS
EVENING WITH ONLY A SLIGHT CHANCE FOR SHOWERS AND STORMS TO THE
EAST TOMORROW AFTERNOON. SOLID CHANCE FOR RAIN RETURNS FRIDAY
MORNING WITH THE NEXT SHORTWAVE ROTATING THROUGH THE NORTHWEST
FLOW.
WE COULD CERTAINLY SEE SOME STORMS IMPACT SOUTHWEST LOWER MICHIGAN
AS THEY MOVE IN FROM WISCONSIN. STORMS ARE CURRENTLY DEVELOPING IN
CENTRAL WISCONSIN ALONG THE COLD FRONT. NOT OVERLY IMPRESSED...THE
BEST CHANCE FOR THUNDERSTORMS IS CERTAIN TO THE NORTHEAST. CLOUD
COVER HAS LIMITED INSTABILITY AND THE UPPER AIR DIVERGENCE IS MORE
FAVORABLE IN NORTHER LOWER MICHIGAN. THE HRRR SUGGESTS A WEAKENING
BAND OF SHOWERS WILL ENTER WEST MICHIGAN EARLY THIS EVENING...SO
WE BUMPED UP POPS SLIGHTLY.
AREAS OF FOG ARE LIKELY OVERNIGHT WITH THE RAIN COMING TO AN END BY
MIDNIGHT OR SO AND DRIER AIR FILTERING IN BEHIND THE FRONT. CLOUDS
DURING THE DAY HAVE LIMITED HIGH TEMPS AND CLOUDS CLEARING
OVERNIGHT AS WELL AS LIGHT WINDS ALL SUGGEST FAVORABLE CONDITIONS
FOR FOG DEVELOPMENT.
DUE TO THE POSITIONING OF THE UPPER LEVEL JET AND LIMITED
INSTABILITY...WE FEEL THE BEST AREA FOR SHOWERS AND STORMS ON
THURSDAY AFTERNOON IS EASTERN LWR MICHIGAN. THE UPPER JET FLOWS
DIRECTLY OVER US ON FRIDAY BRINGING THE POTENTIAL FOR ADDITIONAL
SHOWERS...HOWEVER THE ENTRANCE AND EXIT REGION DYNAMICS PASS TO
THE NORTHEAST AND SOUTHWEST. THE HEAVIER QPF AMOUNTS ARE RESERVED
TO THESE AREAS FOR THESE REASONS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 311 PM EDT WED JUL 31 2013
SEASONABLY COOL TEMPERATURES ARE EXPECTED THROUGH THE LONG RANGE
FORECAST PERIOD WITH A PERSISTENT UPPER LEVEL TROUGH IN PLACE OVER
THE NORTHERN GREAT LAKES REGION THAT WILL AMPLIFY OVER OUR REGION
TOWARD THE MIDDLE PORTION OF NEXT WEEK.
A HIGH PRESSURE RIDGE SHOULD BRING FAIR AND DRY BUT SEASONABLY COOL
WEATHER SATURDAY THROUGH SUNDAY. THE FORECAST FOR THE EARLY TO
MIDDLE PORTION OF NEXT WEEK BECOMES A LITTLE MORE UNCERTAIN SINCE THE
UPPER LEVEL TROUGH WILL AMPLIFY OVER THE NORTHERN GREAT LAKES REGION
AND SEVERAL SHORTWAVES WILL DROP DOWN FROM THE NW. THIS TYPE OF
PATTERN COULD BRING SOME SCATTERED SHOWERS AND A FEW STORMS MONDAY
THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1136 PM EDT WED JUL 31 2013
SKIES WERE CLEARING OUT FROM THE NORTHWEST WITH KLDM SHOWING CLR.
GIVEN THE HUMID CONDITIONS IN PLACE AND THE FACT THAT MANY SITES
WERE ALREADY IFR...ANY CLEARING WILL LIKELY LEAD TO IFR OR LOWER
FOG CONDITIONS. I HAVE TRENDED THE FORECAST IN THIS DIRECTION.
CONDITIONS SHOULD IMPROVE STEADILY THU AM...AND VFR WEATHER SHOULD
BE DOMINATING BY NOON. INSTABILITY SHOWERS AND THUNDERSTORMS ARE
EXPECTED...BUT THE COVERAGE SHOULD BE WIDELY SCATTERED.
&&
.MARINE...
ISSUED AT 311 PM EDT WED JUL 31 2013
WINDS WILL PICK UP ON THURSDAY BEHIND THE COLD FRONT OUT OF THE
NORTHWEST. WINDS WILL BE IN THE 10 TO 15 KT RANGE...KEEPING WINDS
AND WAVES BELOW SMALL CRAFT ADVISORY CRITERIA.
&&
.HYDROLOGY...
ISSUED AT 311 PM EDT WED JUL 31 2013
LIMITED QPF WILL RESULT IN FEW HYDRO CONCERNS THROUGH THE WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MJS
SYNOPSIS...EBW
SHORT TERM...WDM/EBW
LONG TERM...LAURENS
AVIATION...MJS
HYDROLOGY...WDM/EBW
MARINE...WDM/EBW
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1022 PM EDT WED JUL 31 2013
.SYNOPSIS...
ISSUED AT 355 PM EDT WED JUL 31 2013
A WEAK COLD FRONT WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS
TO NORTHERN MICHIGAN TONIGHT...WITH THE BEST CHANCES FOR EASTERN
UPPER AND NORTHWEST LOWER. A WEAK DISTURBANCE WILL BRING LOW CHANCES
OF SHOWERS TO NORTHEAST LOWER AND THE EASTERN U.P. FOR
THURSDAY...WITH A SLIGHTLY BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS FOR ALL OF NORTHERN MICHIGAN AGAIN ON FRIDAY...AS
ANOTHER WEAK COLD FRONT MOVES THROUGH THE AREA. HIGH PRESSURE WILL
BRING FAIR WEATHER FOR THIS WEEKEND.
&&
.UPDATE...
ISSUED AT 1022 PM EDT WED JUL 31 2013
UPSTREAM COLD FRONT HAS REACHED NRN LAKE MICHIGAN LATE THIS
EVENING...AS THE NEXT WEAK MID LEVEL WAVE SWINGS INTO NRN MICHIGAN
ALONG THE 500 MB TROUGH AXIS. CONVECTIVE LINE THAT IMPACTED ERN
UPR MICHIGAN EARLIER THIS EVENING HAS PUSHED SE INTO FAR NRN LWR
MICHIGAN...AND HAS BUILT FURTHER SOUTHWARD TRYING TO MERGE WITH AN
AREA OF WEAKER CONVECTION GRAZING OUR SRN COUNTIES ATTM. INTENSITY
OF EMBEDDED STORMS HAS FURTHER DIMINISH WITH LOSS OF DIURNAL
INSTABILITY...BUT WITH LOW LEVEL CONVERGENCE AHEAD OF THE FRONT
COMBINED WITH OUR NEXT SHORT WAVE NOW ARRIVING...THUNDERSTORMS DO
CONTINUE TO DEVELOP. EASTWARD PROGRESSION HAS BEEN A BIT SLOWER
THAN PREVIOUSLY EXPECTED...AND HAVE MODIFIED TIMING OF WX/POPS TO
ACCOUNT FOR THIS. CONVECTION WILL CONTINUE ITS SLOW EASTWARD PUSH
INTO THE OVERNIGHT HOURS...WITH PRECIP FINALLY CLEARING OUR CWA
VERY LATE TONIGHT. SVR WX IS STILL NOT EXPECTED FOR THE REST OF
THE NIGHT...BUT DO EXPECT A FEW STORMS WILL PRODUCE WIND GUSTS OF
30 TO 40 MPH AND MAYBE SOME SMALL HAIL.
UPDATE ISSUED AT 720 PM EDT WED JUL 31 2013
WELL-ESTABLISHED LINE OF CONVECTION CONTINUES TO IMPACT THE ERN
HALF OF UPPER MICHIGAN AHEAD OF AN APPROACHING COLD FRONT...AND
ENHANCED BY A MODEST SHORT WAVE AND LOCALIZED LAKE BREEZE
CONVERGENCE. OVERALL INTENSITY OF THIS CONVECTION HAS WEAKENED
OVER THE PAST HOUR OR SO AS THE GUST FRONT AHEAD OF THE MAIN LINE
LIMITED THE INFLOW. MAIN LINE HAS ALSO MOVED OUT OF THE AREA OF
BEST LAKE BREEZE CONVERGENCE. LATEST NAM AND 3KM HRRR SHOWS THIS
AREA OF CONVECTION WILL TRY TO MERGE (TO A DEGREE) WITH ANOTHER
AREA OF WEAKER CONVECTION NOW MOVING INTO OUR FAR SW CWA OUT OF
CENTRAL LAKE MICHIGAN...AND WILL THEN SWEEP EASTWARD THRU NRN LWR
MICHIGAN DURING THE BALANCE OF THE EVENING. OVERALL INTENSITY...AND
LIKELY AREAL COVERAGE AS WELL...SHOULD CONTINUE TO DIMINISH WITH
LOSS OF DIURNAL INSTABILITY THIS EVENING. WILL CERTAINLY CONTINUE
TO KEEP A CLOSE EYE ON THE CONVECTIVE LINE MOVING OUT OF ERN UPR
MICHIGAN AND INTO THE STRAITS FOR ANY FURTHER STRENGTHENING...BUT
DO NOT EXPECT ANY SIGNIFICANT THREAT FOR SEVERE STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM EDT WED JUL 31 2013
FAST FLOW PATTERN CONTINUES ACROSS THE NORTHERN LAKES THIS
AFTERNOON...WITH LEAD SHORTWAVE TROUGH DAMPENING OUT AND MOVING OFF
TO THE EAST...WITH SECONDARY STRONGER SHORTWAVE AND ATTENDANT COLD
FRONT CUTTING INTO THE NORTHWEST LAKES. TOOK A WHILE...BUT
CONVECTION IS STARTING TO FIRE WITH THE LATTER FEATURES...MOST
NOTABLY ACROSS CENTRAL/EASTERN UPPER MICHIGAN WHERE A BROKEN LINE OF
THUNDERSTORMS HAS DEVELOPED IN THE LAST FEW HOURS. NOT MUCH TAKING
PLACE SOUTH OF THE BIG BRIDGE...WITH CLOUD COVER AND LACK OF
DYNAMICS IN WAKE OF FIRST WAVE PREVENTING ANY SHOWER/STORM
DEVELOPMENT. FORECAST CONCERNS CENTER ON SHOWER/STORM POTENTIAL THIS
EVENING...WITH ADDITIONAL LIGHT SHOWER CHANCES NEEDING ADDRESSING
FOR THURSDAY.
UPSTREAM COLD FRONT AND MID LEVEL SUPPORT EXPECTED TO CROSS NORTHERN
MICHIGAN THIS EVENING. JUST ENOUGH FORCING/LOW LEVEL CONVERGENCE TO
CONTINUE TO SUPPORT SHOWER AND STORM DEVELOPMENT ALONG THESE
FEATURES...AND WOULD EXPECT UPSTREAM ACTIVITY TO CONTINUE TO SLOWLY
CONGEAL THIS AFTERNOON. LACK OF PRE-FRONTAL DESTABILIZATION SHOULD
KEEP BOTH COVERAGE AND INTENSITY IN CHECK...AND WILL SIMPLY SPREAD A
BROKEN LINE OF SHOWERS/EMBEDDED STORMS FROM NORTHWEST TO SOUTHEAST
ACROSS THE REGION TONIGHT. ORGANIZED SEVERE WEATHER DEFINITELY NOT
EXPECTED...BUT SUPPOSE AN ISOLATED STRONGER STORM IS POSSIBLE
THROUGH THE REMAINDER OF THIS AFTERNOON...ESPECIALLY ACROSS EASTERN
UPPER MICHIGAN. SHOWER THREAT EXPECTED TO END DURING THE EARLY
MORNING HOURS. POST-FRONTAL DRYING NOT OVERLY AGGRESSIVE...AND WITH
EXPECTED RAINS...FEEL PATCHY/AREAS OF FOG A GOOD BET DURING THE
EARLY MORNING HOURS.
THURSDAY EXPECTED TO START OFF DRY...WITH NEXT LOW AMPLITUDE FAST
MOVING WAVE SPREADING ACROSS OUR AREA DURING THE LATE MORNING AND
EARLY AFTERNOON. MOISTURE PROFILES LIMITED...AS IS ANY SPECIFIC LOW
LEVEL CONVERGENCE BOUNDARY (PERHAPS WEAK LAKE INFLUENCED BOUNDARY
SOUTH SIDE OF EASTERN UPPER). THAT SAID...MODEL DERIVED SOUNDINGS
NOT TOO TERRIBLE FOR SHOWER DEVELOPMENT...WITH STEEP LOW LEVEL LAPSE
RATES AND PROJECTED ML CAPE NEAR 500 J/KG. ABOVE PROBABLY A TOUCH
AGGRESSIVE...AND WITH NO WELL DEFINED LOW LEVEL CONVERGENCE
BOUNDARIES...WILL TEMPER INHERITED POPS SOME...FEATURING JUST LOW
CHANCE IN CLIMATOLOGICALLY FAVORED AREAS OF EASTERN UPPER AND
NORTHEAST LOWER MICHIGAN. WILL KEEP THUNDER OUT OF THE EQUATION FOR
NOW. TEMPERATURES REMAINING BELOW NORMAL...WITH HIGHS IN THE LOWER
AND MIDDLE 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED JUL 31 2013
THURSDAY NIGHT AND FRIDAY...A COLD FRONT ASSOCIATED WITH A STORM
SYSTEM OVER HUDSON BAY...WILL PUSH INTO THE WRN LAKES THURSDAY
EVENING BEFORE SLOWLY SWEEPING OVER THE STATE FRIDAY. HIGH PRESSURE
WILL THEN QUICKLY BUILD BACK INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES FRIDAY NIGHT...AS THE COLD FRONT EXITS EAST OF THE
REGION. MODEL SOUNDINGS AND MSTR PROGS SHOWING LIMITED MSTR WILL
HINDER PCPN AMOUNTS AND CHC`S OVR NRN MI THURSDAY NIGHT. HOWEVER
THERE WILL BE SOME MSTR INCREASE OVER THE CWA FRIDAY JUST IN ADVANCE
OF THE COLD APPROACHING FRONT. 850/500MB RH WILL INCREASE FROM
AROUND 40PCT THURSDAY NIGHT TO 80PCT FRIDAY...WHILE MODEL SOUNDINGS
SHOW PWAT VALUES INCREASING TO 90PCT FRIDAY. 850/500MB QVECTORS
SHOWING LIMITED CONVERGENCE WITH APPROACHING COLD FRONT...CONFINED
MAINLY TO RIGHT ALONG THE BOUNDARY. OVERALL WILL KEEP MOST OF THE
FCST AREA DRY THURSDAY NIGHT...WITH BETTER CHANCES OF RAIN FRIDAY AS
BOUNDARY MOVES ACRS LAKE MICHIGAN. WILL MENTION HIGH TEMPS IN THE
MID 70S OVR THE CWA AIDED IN PART BY SOME SUN AND SOUTHWEST FLOW.
FOR THE WEEKEND...COOL UNSEASONAL CONDITIONS ARE EXPECTED ACRS THE
GREAT LAKES FOR THE FIRST WEEKEND IN AUGUST. AT UPPER LEVELS...
WHICH WILL RESEMBLE MORE THAT OF MID WINTER INSTEAD OF MID
SUMMER...A 500MB LOW WILL BECOME CENTERED OVER HUDSON BAY THROUGH
THE WEEKEND. WHILE AT THE SURFACE...AN AREA OF CANADIAN HIGH
PRESSURE WILL BUILD INTO THE NRN PLAINS AND GREAT LAKES THRU THE
WEEKEND. TEMPS WILL TREND BELOW NORMAL THRU SUNDAY...AS THE HUDSON
BAY 500MB LOW FORCES COLD 850MB TEMPS INTO THE REGION. 850MB TEMPS
WILL COOL FROM AROUND 11C FRIDAY TO BTWN 6C AND 8C BY SUNDAY.
CURRENT TRENDS CONT TO INDICATE DRY CONDS OVER NRN MI THIS WEEKEND
THOUGH SOME LAKE INFLUENCES ARE POSSIBLE. SUSPECT THE DRY AIR MOVING
INTO THE GREAT LAKES WILL LIMIT LAKE EFFECTS TO MAINLY CLOUDS...AS
850/500MB RH DIMINISHES TO UNDER 40 PCT. WILL KEEP AFTN TEMPS COOL
THROUGH THE WEEKEND...IN THE UPPER 60S TO LOWER 70S ACRS NRN MI...
AS 850MB TEMPS FALL TO AROUND 6C.
MONDAY THROUGH WEDNESDAY...UNSEASONABLY COOL TREND TO LINGER ACRS
THE NORTHERN GREAT LAKES REGION THRU MID WEEK...AS BROAD UPPER
TROUGH FROM THE WEEKEND LINGERS ACRS THE GREAT LAKES. 850MB TEMPS
LINGER AROUND 6C TO BEGIN THE UPCOMING WORK WEEK...KEEPING AFTN HIGHS
IN THE LOWER 70S. SMALL CHANCES OF SHOWERS WILL EXIST THROUGH THE
PERIOD...AS HIGH PRESSURE FROM THE WEEKEND EXITS EAST AND A WEAK
SYSTEM TRIES TO ORGANIZE OVER THE NRN PLAINS AND UPPER MIDWEST.
PCPN AMOUNTS AND CHC WILL BE HINDERED GREATLY BY LIMITED MOISTURE
AS 850/500MB RH REMAINS AROUND 60PCT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 720 PM EDT WED JUL 31 2013
SCATTERED SHOWERS AND THUNDERSTORMS WILL IMPACT ALL NRN LWR
MICHIGAN TAF SITES THIS EVENING ALONG AND AHEAD OF A COLD FRONT
PASSING THRU THE REGION. CONDITIONS WILL DROP TO MVFR AND POSSIBLY
IFR WITHIN ANY CONVECTION THAT ROLLS THRU THE AREA. PRECIP CHANCES
WILL END OVERNIGHT...BUT LINGERING LOW LEVEL MOISTURE WILL RESULT
IN FOG DEVELOPMENT AND MVFR/IFR CONDITIONS. FOG WILL MIX OUT BY
MID THURSDAY MORNING...WITH VFR CONDITIONS EXPECTED FOR THE REST
OF THE DAY. LIGHT WINDS TONIGHT WILL INCREASE TO NEAR 10 KTS ON
THURSDAY AND SHIFT TO THE NW BEHIND THE FRONT.
&&
.MARINE...
ISSUED AT 355 PM EDT WED JUL 31 2013
LIGHT TO MODERATE SOUTHWEST FLOW WILL VEER WEST OVERNIGHT
BEHIND COLD FRONT PASSAGE. SOME SHOWERS/STORMS POSSIBLE ALONG THIS
FRONT...PERHAPS PRODUCING SOME LOCALIZED GUSTY WINDS. SUB ADVISORY
WINDS EXPECTED TO CONTINUE INTO THIS WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MR
SYNOPSIS...NS
SHORT TERM...MB
LONG TERM...SR
AVIATION...MR
MARINE...MB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
838 PM EDT WED JUL 31 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 311 PM EDT WED JUL 31 2013
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THIS EVENING AS
A WEAK COLD FRONT PASSES THROUGH. CONDITIONS DRY OUT ON THURSDAY
BEFORE RAIN CHANCES RETURN FRIDAY MORNING WITH A WEAK UPPER AIR
WAVE. TEMPERATURES WILL REMAIN A LITTLE COOL WITH HIGHS IN THE
MID TO UPPER 70S THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 833 PM EDT WED JUL 31 2013
RADAR TRENDS SHOW ONE AREA OF SHOWERS MOVING IN FROM THE WEST.
THIS PRECIPITATION HAS BEEN WEAKENING. HOWEVER...MOST LOCATIONS ON
THE LAKESHORE SHOULD SEE RAIN. A GROWING AREA OF R-/L- WAS
LOCATED ROUGHLY SOUTHEAST OF A LANSING TO KALAMAZOO LINE...MOVING
EAST. THIS PRECIPITATION WILL IMPACT MUCH OF SOUTH CENTRAL LOWER
MI OVER THE NEXT COUPLE OF HRS. ALSO...THE INSTABILITY IS
DIMINISHING AND THE LIGHTNING ACTIVITY HAS DECREASED WITH THE
PRECIPITATION OVER LAKE MI. SO THE UPDATED REFLECTED LESS
LIGHTNING...BUT MORE RAIN THAN FORECASTED. BY MIDNIGHT
06Z...LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 311 PM EDT WED JUL 31 2013
EXPECT SHOWERS AND ANY POSSIBLE THUNDERSTORMS TO END BY THIS
EVENING WITH ONLY A SLIGHT CHANCE FOR SHOWERS AND STORMS TO THE
EAST TOMORROW AFTERNOON. SOLID CHANCE FOR RAIN RETURNS FRIDAY
MORNING WITH THE NEXT SHORTWAVE ROTATING THROUGH THE NORTHWEST
FLOW.
WE COULD CERTAINLY SEE SOME STORMS IMPACT SOUTHWEST LOWER MICHIGAN
AS THEY MOVE IN FROM WISCONSIN. STORMS ARE CURRENTLY DEVELOPING IN
CENTRAL WISCONSIN ALONG THE COLD FRONT. NOT OVERLY IMPRESSED...THE
BEST CHANCE FOR THUNDERSTORMS IS CERTAIN TO THE NORTHEAST. CLOUD
COVER HAS LIMITED INSTABILITY AND THE UPPER AIR DIVERGENCE IS MORE
FAVORABLE IN NORTHER LOWER MICHIGAN. THE HRRR SUGGESTS A WEAKENING
BAND OF SHOWERS WILL ENTER WEST MICHIGAN EARLY THIS EVENING...SO
WE BUMPED UP POPS SLIGHTLY.
AREAS OF FOG ARE LIKELY OVERNIGHT WITH THE RAIN COMING TO AN END BY
MIDNIGHT OR SO AND DRIER AIR FILTERING IN BEHIND THE FRONT. CLOUDS
DURING THE DAY HAVE LIMITED HIGH TEMPS AND CLOUDS CLEARING
OVERNIGHT AS WELL AS LIGHT WINDS ALL SUGGEST FAVORABLE CONDITIONS
FOR FOG DEVELOPMENT.
DUE TO THE POSITIONING OF THE UPPER LEVEL JET AND LIMITED
INSTABILITY...WE FEEL THE BEST AREA FOR SHOWERS AND STORMS ON
THURSDAY AFTERNOON IS EASTERN LWR MICHIGAN. THE UPPER JET FLOWS
DIRECTLY OVER US ON FRIDAY BRINGING THE POTENTIAL FOR ADDITIONAL
SHOWERS...HOWEVER THE ENTRANCE AND EXIT REGION DYNAMICS PASS TO
THE NORTHEAST AND SOUTHWEST. THE HEAVIER QPF AMOUNTS ARE RESERVED
TO THESE AREAS FOR THESE REASONS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 311 PM EDT WED JUL 31 2013
SEASONABLY COOL TEMPERATURES ARE EXPECTED THROUGH THE LONG RANGE
FORECAST PERIOD WITH A PERSISTENT UPPER LEVEL TROUGH IN PLACE OVER
THE NORTHERN GREAT LAKES REGION THAT WILL AMPLIFY OVER OUR REGION
TOWARD THE MIDDLE PORTION OF NEXT WEEK.
A HIGH PRESSURE RIDGE SHOULD BRING FAIR AND DRY BUT SEASONABLY COOL
WEATHER SATURDAY THROUGH SUNDAY. THE FORECAST FOR THE EARLY TO
MIDDLE PORTION OF NEXT WEEK BECOMES A LITTLE MORE UNCERTAIN SINCE THE
UPPER LEVEL TROUGH WILL AMPLIFY OVER THE NORTHERN GREAT LAKES REGION
AND SEVERAL SHORTWAVES WILL DROP DOWN FROM THE NW. THIS TYPE OF
PATTERN COULD BRING SOME SCATTERED SHOWERS AND A FEW STORMS MONDAY
THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 743 PM EDT WED JUL 31 2013
THE MAIN CHALLENGE IN THE AVIATION FORECAST DEALS WITH THE IFR
POTENTIAL. OVERALL THE FORECAST REFLECTS LOWER CONDITIONS TONIGHT.
LOW CLOUDS HAVE REMAINED OVER SOUTHERN LOWER MI THIS AFTERNOON.
WITH THE COLD FRONT STILL WEST OF KLDM...THE CEILINGS AND
VISIBILITIES WILL BE DELAYED IN IMPROVING...ESPECIALLY
KLAN...KJXN...KAZO AND KBTL. GUIDANCE IS NOW SHOWING THE LOW
CLOUDS REDEVELOPING BEHIND THE FRONT. AS A RESULT...WHILE A WINDOW
OF BETTER THAN IFR CONDITIONS EXISTS FOR MOST SITE TONIGHT...THE
IFR SHOULD RETURN. CONDITIONS WILL IMPROVE THU AM AS MIXING
DEVELOPS.
A BRIEF SHOWER OR THUNDERSTORM WILL BE POSSIBLE LATER
THURSDAY...BUT DUE TO THE EXPECTED LIMITED COVERAGE...I AM NOT
CONFIDENT ENOUGH TO ADD THEM TO THE TAFS AT THIS TIME.
&&
.MARINE...
ISSUED AT 311 PM EDT WED JUL 31 2013
WINDS WILL PICK UP ON THURSDAY BEHIND THE COLD FRONT OUT OF THE
NORTHWEST. WINDS WILL BE IN THE 10 TO 15 KT RANGE...KEEPING WINDS
AND WAVES BELOW SMALL CRAFT ADVISORY CRITERIA.
&&
.HYDROLOGY...
ISSUED AT 311 PM EDT WED JUL 31 2013
LIMITED QPF WILL RESULT IN FEW HYDRO CONCERNS THROUGH THE WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MJS
SYNOPSIS...EBW
SHORT TERM...WDM/EBW
LONG TERM...LAURENS
AVIATION...MJS
HYDROLOGY...WDM/EBW
MARINE...WDM/EBW
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
751 PM EDT WED JUL 31 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 311 PM EDT WED JUL 31 2013
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THIS EVENING AS
A WEAK COLD FRONT PASSES THROUGH. CONDITIONS DRY OUT ON THURSDAY
BEFORE RAIN CHANCES RETURN FRIDAY MORNING WITH A WEAK UPPER AIR
WAVE. TEMPERATURES WILL REMAIN A LITTLE COOL WITH HIGHS IN THE
MID TO UPPER 70S THROUGH THE WEEKEND.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 311 PM EDT WED JUL 31 2013
EXPECT SHOWERS AND ANY POSSIBLE THUNDERSTORMS TO END BY THIS
EVENING WITH ONLY A SLIGHT CHANCE FOR SHOWERS AND STORMS TO THE
EAST TOMORROW AFTERNOON. SOLID CHANCE FOR RAIN RETURNS FRIDAY
MORNING WITH THE NEXT SHORTWAVE ROTATING THROUGH THE NORTHWEST
FLOW.
WE COULD CERTAINLY SEE SOME STORMS IMPACT SOUTHWEST LOWER MICHIGAN
AS THEY MOVE IN FROM WISCONSIN. STORMS ARE CURRENTLY DEVELOPING IN
CENTRAL WISCONSIN ALONG THE COLD FRONT. NOT OVERLY IMPRESSED...THE
BEST CHANCE FOR THUNDERSTORMS IS CERTAIN TO THE NORTHEAST. CLOUD
COVER HAS LIMITED INSTABILITY AND THE UPPER AIR DIVERGENCE IS MORE
FAVORABLE IN NORTHER LOWER MICHIGAN. THE HRRR SUGGESTS A WEAKENING
BAND OF SHOWERS WILL ENTER WEST MICHIGAN EARLY THIS EVENING...SO
WE BUMPED UP POPS SLIGHTLY.
AREAS OF FOG ARE LIKELY OVERNIGHT WITH THE RAIN COMING TO AN END BY
MIDNIGHT OR SO AND DRIER AIR FILTERING IN BEHIND THE FRONT. CLOUDS
DURING THE DAY HAVE LIMITED HIGH TEMPS AND CLOUDS CLEARING
OVERNIGHT AS WELL AS LIGHT WINDS ALL SUGGEST FAVORABLE CONDITIONS
FOR FOG DEVELOPMENT.
DUE TO THE POSITIONING OF THE UPPER LEVEL JET AND LIMITED
INSTABILITY...WE FEEL THE BEST AREA FOR SHOWERS AND STORMS ON
THURSDAY AFTERNOON IS EASTERN LWR MICHIGAN. THE UPPER JET FLOWS
DIRECTLY OVER US ON FRIDAY BRINGING THE POTENTIAL FOR ADDITIONAL
SHOWERS...HOWEVER THE ENTRANCE AND EXIT REGION DYNAMICS PASS TO
THE NORTHEAST AND SOUTHWEST. THE HEAVIER QPF AMOUNTS ARE RESERVED
TO THESE AREAS FOR THESE REASONS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 311 PM EDT WED JUL 31 2013
SEASONABLY COOL TEMPERATURES ARE EXPECTED THROUGH THE LONG RANGE
FORECAST PERIOD WITH A PERSISTENT UPPER LEVEL TROUGH IN PLACE OVER
THE NORTHERN GREAT LAKES REGION THAT WILL AMPLIFY OVER OUR REGION
TOWARD THE MIDDLE PORTION OF NEXT WEEK.
A HIGH PRESSURE RIDGE SHOULD BRING FAIR AND DRY BUT SEASONABLY COOL
WEATHER SATURDAY THROUGH SUNDAY. THE FORECAST FOR THE EARLY TO
MIDDLE PORTION OF NEXT WEEK BECOMES A LITTLE MORE UNCERTAIN SINCE THE
UPPER LEVEL TROUGH WILL AMPLIFY OVER THE NORTHERN GREAT LAKES REGION
AND SEVERAL SHORTWAVES WILL DROP DOWN FROM THE NW. THIS TYPE OF
PATTERN COULD BRING SOME SCATTERED SHOWERS AND A FEW STORMS MONDAY
THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 743 PM EDT WED JUL 31 2013
THE MAIN CHALLENGE IN THE AVIATION FORECAST DEALS WITH THE IFR
POTENTIAL. OVERALL THE FORECAST REFLECTS LOWER CONDITIONS TONIGHT.
LOW CLOUDS HAVE REMAINED OVER SOUTHERN LOWER MI THIS AFTERNOON.
WITH THE COLD FRONT STILL WEST OF KLDM...THE CEILINGS AND
VISIBILITIES WILL BE DELAYED IN IMPROVING...ESPECIALLY
KLAN...KJXN...KAZO AND KBTL. GUIDANCE IS NOW SHOWING THE LOW
CLOUDS REDEVELOPING BEHIND THE FRONT. AS A RESULT...WHILE A WINDOW
OF BETTER THAN IFR CONDITIONS EXISTS FOR MOST SITE TONIGHT...THE
IFR SHOULD RETURN. CONDITIONS WILL IMPROVE THU AM AS MIXING
DEVELOPS.
A BRIEF SHOWER OR THUNDERSTORM WILL BE POSSIBLE LATER
THURSDAY...BUT DUE TO THE EXPECTED LIMITED COVERAGE...I AM NOT
CONFIDENT ENOUGH TO ADD THEM TO THE TAFS AT THIS TIME.
&&
.MARINE...
ISSUED AT 311 PM EDT WED JUL 31 2013
WINDS WILL PICK UP ON THURSDAY BEHIND THE COLD FRONT OUT OF THE
NORTHWEST. WINDS WILL BE IN THE 10 TO 15 KT RANGE...KEEPING WINDS
AND WAVES BELOW SMALL CRAFT ADVISORY CRITERIA.
&&
.HYDROLOGY...
ISSUED AT 311 PM EDT WED JUL 31 2013
LIMITED QPF WILL RESULT IN FEW HYDRO CONCERNS THROUGH THE WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...EBW
SHORT TERM...WDM/EBW
LONG TERM...LAURENS
AVIATION...MJS
HYDROLOGY...WDM/EBW
MARINE...WDM/EBW
AREA FORECAST DISCUSSION
NWS GAYLORD MI
720 PM EDT WED JUL 31 2013
.SYNOPSIS...
ISSUED AT 355 PM EDT WED JUL 31 2013
A WEAK COLD FRONT WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS
TO NORTHERN MICHIGAN TONIGHT...WITH THE BEST CHANCES FOR EASTERN
UPPER AND NORTHWEST LOWER. A WEAK DISTURBANCE WILL BRING LOW CHANCES
OF SHOWERS TO NORTHEAST LOWER AND THE EASTERN U.P. FOR
THURSDAY...WITH A SLIGHTLY BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS FOR ALL OF NORTHERN MICHIGAN AGAIN ON FRIDAY...AS
ANOTHER WEAK COLD FRONT MOVES THROUGH THE AREA. HIGH PRESSURE WILL
BRING FAIR WEATHER FOR THIS WEEKEND.
&&
.UPDATE...
ISSUED AT 720 PM EDT WED JUL 31 2013
WELL-ESTABLISHED LINE OF CONVECTION CONTINUES TO IMPACT THE ERN
HALF OF UPPER MICHIGAN AHEAD OF AN APPROACHING COLD FRONT...AND
ENHANCED BY A MODEST SHORT WAVE AND LOCALIZED LAKE BREEZE
CONVERGENCE. OVERALL INTENSITY OF THIS CONVECTION HAS WEAKENED
OVER THE PAST HOUR OR SO AS THE GUST FRONT AHEAD OF THE MAIN LINE
LIMITED THE INFLOW. MAIN LINE HAS ALSO MOVED OUT OF THE AREA OF
BEST LAKE BREEZE CONVERGENCE. LATEST NAM AND 3KM HRRR SHOWS THIS
AREA OF CONVECTION WILL TRY TO MERGE (TO A DEGREE) WITH ANOTHER
AREA OF WEAKER CONVECTION NOW MOVING INTO OUR FAR SW CWA OUT OF
CENTRAL LAKE MICHIGAN...AND WILL THEN SWEEP EASTWARD THRU NRN LWR
MICHIGAN DURING THE BALANCE OF THE EVENING. OVERALL INTENSITY...AND
LIKELY AREAL COVERAGE AS WELL...SHOULD CONTINUE TO DIMINISH WITH
LOSS OF DIURNAL INSTABILITY THIS EVENING. WILL CERTAINLY CONTINUE
TO KEEP A CLOSE EYE ON THE CONVECTIVE LINE MOVING OUT OF ERN UPR
MICHIGAN AND INTO THE STRAITS FOR ANY FURTHER STRENGTHENING...BUT
DO NOT EXPECT ANY SIGNIFICANT THREAT FOR SEVERE STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM EDT WED JUL 31 2013
FAST FLOW PATTERN CONTINUES ACROSS THE NORTHERN LAKES THIS
AFTERNOON...WITH LEAD SHORTWAVE TROUGH DAMPENING OUT AND MOVING OFF
TO THE EAST...WITH SECONDARY STRONGER SHORTWAVE AND ATTENDANT COLD
FRONT CUTTING INTO THE NORTHWEST LAKES. TOOK A WHILE...BUT
CONVECTION IS STARTING TO FIRE WITH THE LATTER FEATURES...MOST
NOTABLY ACROSS CENTRAL/EASTERN UPPER MICHIGAN WHERE A BROKEN LINE OF
THUNDERSTORMS HAS DEVELOPED IN THE LAST FEW HOURS. NOT MUCH TAKING
PLACE SOUTH OF THE BIG BRIDGE...WITH CLOUD COVER AND LACK OF
DYNAMICS IN WAKE OF FIRST WAVE PREVENTING ANY SHOWER/STORM
DEVELOPMENT. FORECAST CONCERNS CENTER ON SHOWER/STORM POTENTIAL THIS
EVENING...WITH ADDITIONAL LIGHT SHOWER CHANCES NEEDING ADDRESSING
FOR THURSDAY.
UPSTREAM COLD FRONT AND MID LEVEL SUPPORT EXPECTED TO CROSS NORTHERN
MICHIGAN THIS EVENING. JUST ENOUGH FORCING/LOW LEVEL CONVERGENCE TO
CONTINUE TO SUPPORT SHOWER AND STORM DEVELOPMENT ALONG THESE
FEATURES...AND WOULD EXPECT UPSTREAM ACTIVITY TO CONTINUE TO SLOWLY
CONGEAL THIS AFTERNOON. LACK OF PRE-FRONTAL DESTABILIZATION SHOULD
KEEP BOTH COVERAGE AND INTENSITY IN CHECK...AND WILL SIMPLY SPREAD A
BROKEN LINE OF SHOWERS/EMBEDDED STORMS FROM NORTHWEST TO SOUTHEAST
ACROSS THE REGION TONIGHT. ORGANIZED SEVERE WEATHER DEFINITELY NOT
EXPECTED...BUT SUPPOSE AN ISOLATED STRONGER STORM IS POSSIBLE
THROUGH THE REMAINDER OF THIS AFTERNOON...ESPECIALLY ACROSS EASTERN
UPPER MICHIGAN. SHOWER THREAT EXPECTED TO END DURING THE EARLY
MORNING HOURS. POST-FRONTAL DRYING NOT OVERLY AGGRESSIVE...AND WITH
EXPECTED RAINS...FEEL PATCHY/AREAS OF FOG A GOOD BET DURING THE
EARLY MORNING HOURS.
THURSDAY EXPECTED TO START OFF DRY...WITH NEXT LOW AMPLITUDE FAST
MOVING WAVE SPREADING ACROSS OUR AREA DURING THE LATE MORNING AND
EARLY AFTERNOON. MOISTURE PROFILES LIMITED...AS IS ANY SPECIFIC LOW
LEVEL CONVERGENCE BOUNDARY (PERHAPS WEAK LAKE INFLUENCED BOUNDARY
SOUTH SIDE OF EASTERN UPPER). THAT SAID...MODEL DERIVED SOUNDINGS
NOT TOO TERRIBLE FOR SHOWER DEVELOPMENT...WITH STEEP LOW LEVEL LAPSE
RATES AND PROJECTED ML CAPE NEAR 500 J/KG. ABOVE PROBABLY A TOUCH
AGGRESSIVE...AND WITH NO WELL DEFINED LOW LEVEL CONVERGENCE
BOUNDARIES...WILL TEMPER INHERITED POPS SOME...FEATURING JUST LOW
CHANCE IN CLIMATOLOGICALLY FAVORED AREAS OF EASTERN UPPER AND
NORTHEAST LOWER MICHIGAN. WILL KEEP THUNDER OUT OF THE EQUATION FOR
NOW. TEMPERATURES REMAINING BELOW NORMAL...WITH HIGHS IN THE LOWER
AND MIDDLE 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED JUL 31 2013
THURSDAY NIGHT AND FRIDAY...A COLD FRONT ASSOCIATED WITH A STORM
SYSTEM OVER HUDSON BAY...WILL PUSH INTO THE WRN LAKES THURSDAY
EVENING BEFORE SLOWLY SWEEPING OVER THE STATE FRIDAY. HIGH PRESSURE
WILL THEN QUICKLY BUILD BACK INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES FRIDAY NIGHT...AS THE COLD FRONT EXITS EAST OF THE
REGION. MODEL SOUNDINGS AND MSTR PROGS SHOWING LIMITED MSTR WILL
HINDER PCPN AMOUNTS AND CHC`S OVR NRN MI THURSDAY NIGHT. HOWEVER
THERE WILL BE SOME MSTR INCREASE OVER THE CWA FRIDAY JUST IN ADVANCE
OF THE COLD APPROACHING FRONT. 850/500MB RH WILL INCREASE FROM
AROUND 40PCT THURSDAY NIGHT TO 80PCT FRIDAY...WHILE MODEL SOUNDINGS
SHOW PWAT VALUES INCREASING TO 90PCT FRIDAY. 850/500MB QVECTORS
SHOWING LIMITED CONVERGENCE WITH APPROACHING COLD FRONT...CONFINED
MAINLY TO RIGHT ALONG THE BOUNDARY. OVERALL WILL KEEP MOST OF THE
FCST AREA DRY THURSDAY NIGHT...WITH BETTER CHANCES OF RAIN FRIDAY AS
BOUNDARY MOVES ACRS LAKE MICHIGAN. WILL MENTION HIGH TEMPS IN THE
MID 70S OVR THE CWA AIDED IN PART BY SOME SUN AND SOUTHWEST FLOW.
FOR THE WEEKEND...COOL UNSEASONAL CONDITIONS ARE EXPECTED ACRS THE
GREAT LAKES FOR THE FIRST WEEKEND IN AUGUST. AT UPPER LEVELS...
WHICH WILL RESEMBLE MORE THAT OF MID WINTER INSTEAD OF MID
SUMMER...A 500MB LOW WILL BECOME CENTERED OVER HUDSON BAY THROUGH
THE WEEKEND. WHILE AT THE SURFACE...AN AREA OF CANADIAN HIGH
PRESSURE WILL BUILD INTO THE NRN PLAINS AND GREAT LAKES THRU THE
WEEKEND. TEMPS WILL TREND BELOW NORMAL THRU SUNDAY...AS THE HUDSON
BAY 500MB LOW FORCES COLD 850MB TEMPS INTO THE REGION. 850MB TEMPS
WILL COOL FROM AROUND 11C FRIDAY TO BTWN 6C AND 8C BY SUNDAY.
CURRENT TRENDS CONT TO INDICATE DRY CONDS OVER NRN MI THIS WEEKEND
THOUGH SOME LAKE INFLUENCES ARE POSSIBLE. SUSPECT THE DRY AIR MOVING
INTO THE GREAT LAKES WILL LIMIT LAKE EFFECTS TO MAINLY CLOUDS...AS
850/500MB RH DIMINISHES TO UNDER 40 PCT. WILL KEEP AFTN TEMPS COOL
THROUGH THE WEEKEND...IN THE UPPER 60S TO LOWER 70S ACRS NRN MI...
AS 850MB TEMPS FALL TO AROUND 6C.
MONDAY THROUGH WEDNESDAY...UNSEASONABLY COOL TREND TO LINGER ACRS
THE NORTHERN GREAT LAKES REGION THRU MID WEEK...AS BROAD UPPER
TROUGH FROM THE WEEKEND LINGERS ACRS THE GREAT LAKES. 850MB TEMPS
LINGER AROUND 6C TO BEGIN THE UPCOMING WORK WEEK...KEEPING AFTN HIGHS
IN THE LOWER 70S. SMALL CHANCES OF SHOWERS WILL EXIST THROUGH THE
PERIOD...AS HIGH PRESSURE FROM THE WEEKEND EXITS EAST AND A WEAK
SYSTEM TRIES TO ORGANIZE OVER THE NRN PLAINS AND UPPER MIDWEST.
PCPN AMOUNTS AND CHC WILL BE HINDERED GREATLY BY LIMITED MOISTURE
AS 850/500MB RH REMAINS AROUND 60PCT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 720 PM EDT WED JUL 31 2013
SCATTERED SHOWERS AND THUNDERSTORMS WILL IMPACT ALL NRN LWR
MICHIGAN TAF SITES THIS EVENING ALONG AND AHEAD OF A COLD FRONT
PASSING THRU THE REGION. CONDITIONS WILL DROP TO MVFR AND POSSIBLY
IFR WITHIN ANY CONVECTION THAT ROLLS THRU THE AREA. PRECIP CHANCES
WILL END OVERNIGHT...BUT LINGERING LOW LEVEL MOISTURE WILL RESULT
IN FOG DEVELOPMENT AND MVFR/IFR CONDITIONS. FOG WILL MIX OUT BY
MID THURSDAY MORNING...WITH VFR CONDITIONS EXPECTED FOR THE REST
OF THE DAY. LIGHT WINDS TONIGHT WILL INCREASE TO NEAR 10 KTS ON
THURSDAY AND SHIFT TO THE NW BEHIND THE FRONT.
&&
.MARINE...
ISSUED AT 355 PM EDT WED JUL 31 2013
LIGHT TO MODERATE SOUTHWEST FLOW WILL VEER WEST OVERNIGHT
BEHIND COLD FRONT PASSAGE. SOME SHOWERS/STORMS POSSIBLE ALONG THIS
FRONT...PERHAPS PRODUCING SOME LOCALIZED GUSTY WINDS. SUB ADVISORY
WINDS EXPECTED TO CONTINUE INTO THIS WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MR
SYNOPSIS...NS
SHORT TERM...MB
LONG TERM...SR
AVIATION...MR
MARINE...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
314 PM EDT TUE JUL 30 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 314 PM EDT TUE JUL 30 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALF
OVER THE NRN TIER CONUS AND OVER THE UPR LKS BTWN A SPRAWLING RDG
OVER THE S AND A TROF OVER CNTRL CANADA. SOME SCT -SHRA ASSOCIATED
WITH A DISTURBANCE THRU ONTARIO JUST N OF LK SUP IMPACTED UPR MI
EARLIER IN THE DAY...BUT THE ARRIVAL OF MUCH DRIER AIR ALF SHOWN
BEST ON THE 12Z MPX...ABERDEEN SDAKOTA...AND BISMARCK RAOBS IS
CAUSING THE SHRA TO DIMINISH THIS AFTN. STRONG CAPPING DEPICTED ON
THE LOCAL AND THOSE UPSTREAM RAOBS HAS PREVENTED ANY TS. THE CLDS
ARE A BIT MORE RESILIENT ESPECIALLY OVER THE W WITH LINGERING LLVL
MSTR SHOWN ON THOSE UPSTREAM RAOBS. FARTHER TO THE W...ANOTHER
SHRTWV MOVING FM THE NRN ROCKIES INTO THE NRN PLAINS IS INTERACTING
WITH THE MUCH MOISTER ENVIRONMENT SHOWN ON THE 12Z GLASGOW MT RAOB
AND CAUSING MORE SHRA/TS TO EXPAND INTO THE NRN PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS/IMPACT ON TEMPS
TNGT AND THEN SHRA/TS CHCS LATE TNGT THRU WED ASSOCIATED WITH
DISTURBANCE NOW ROLLING INTO THE NRN PLAINS.
TNGT...WITH DRYING ALF AND LOSS OF DAYTIME HEATING...ANY LINGERING
DIURNAL -SHRA SHOULD DIMINISH ANRD 00Z...WITH THE MORE PERSISTENT
ACTIVITY ALONG DECAYING LK BREEZE BNDRY OVER THE NCENTRAL. SUPRISED
SEVERAL OF THE MODELS GENERATE PCPN THRU MUCH OF THE NGT. BUT
CONSIDERING THE MAGNITUDE OF THE DRYING SHOWN ON THE UPSTREAM RAOBS
AND LACK OF ANY SGNFT H85 THETA E ADVCTN...SUSPECT THE REST OF THE
EVNG WL FEATURE DRY WX WITH THIS MID LVL DRY AIR DOMINATING. MORE
SHRA MAY ARRIVE OVER THE W LATER TNGT AS DPVA/HGT FALLS IN ADVANCE
OF NEXT SHRTWV PUSH INTO THE AREA AND ERODE MID LVL CAPPING AND
MOISTEN THE MID LVLS. BUMPED UP POPS OVER THE W TO ACCOUNT FOR MODEL
TRENDS TOWARD FASTER ARRIVAL OF THIS DYNAMIC FORCING.
WED...SHRA/EMBEDDED TS OVER THE W IN THE MRNG IN ADVANCE OF INCOMING
SHRTWV/ATTENDANT COLD FNT WL MOVE E THRU THE DAY WITH FAIRLY POTENT
DPVA/DEEP LYR QVECTOR CNVGC. A GOOD AMOUNT OF CLD COVER/FCST NEUTRAL
TO NEGATIVE H85 THETA E ADVCTN WL LIMIT HOW MUCH DEEPER LAPSE RATES
CAN DESTABILIZE...AND MODEL FCST SDNGS SHOW NARROW/SKINNY CAPE
DESPITE MUCAPE AS HI AS 1000J/KG. SO SUSPECT SEVERE WX THREAT WL BE
QUITE LIMITED DESPITE STRENGTH OF SHRTWV/12HR HGT FALLS UP TO 60M
DURING DIURNAL HEATING TIME/DEEP LYR SHEAR 30-35KTS...ESPECIALLY
SINCE MODELS HAVE TRENDED FASTER WITH THE SHRTWV PASSAGE/COLD FROPA.
THE BETTER CHC FOR MORE WDSPRD AND STRONGER SHRA/TS WOULD BE OVER
THE E...WHERE LATER ARRIVAL OF THE FNT MIGHT ALLOW FOR MORE DIURNAL
ENHANCEMENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 241 PM EDT TUE JUL 30 2013
MUCH OF THIS TIME PERIOD WILL BE PLAGUED BY AFTERNOON SHOWERS OR
POSSIBLE THUNDERSTORMS ACROSS MAINLY CENTRAL UPPER MICHIGAN...THANKS
TO PERSISTENT NW FLOW ALOFT USHERING IN NEARLY DAILY DISTURBANCES
THAT WILL BE ENHANCED BY DAYTIME HEATING AND POTENTIAL LAKE BREEZES.
EXPECT A NEARLY STEADY FORECAST OF THROUGH TUESDAY OF LOWS IN THE
50S /WITH A FEW UPPER 40S/ AND HIGHS IN THE 60S TO LOW 70S /WARMEST
SOUTH CENTRAL/.
BY WEDNESDAY EVENING THE MAIN SYSTEM WILL BE ON ITS WAY OUT...WITH
THE 500MB LOW SET UP ACROSS NORTHERN ONTARIO AND A BROAD TROUGH
EXTENDING FROM ALBERTA AND SASKATCHEWAN THROUGH WI AND MI. THE SLOW
MOVING SFC LOW SHOULD BE OVER N ONTARIO...WITH A COLD FRONT
EXTENDING ACROSS E UPPER MI. BEHIND THE FRONT...LIGHT W TO WNW FLOW
WILL BE THE RULE NEAR THE SFC...WITH THE SFC TROUGH SLOWLY EXITING
EASTWARD BY THE END OF THE WORK WEEK. A SECONDARY COLD FRONT/TROUGH
WILL CROSS THE REGION LATE THURSDAY AFTERNOON...WITH ANOTHER GOOD
CHANCE OF SHOWERS OR THUNDERSTORMS MAINLY INLAND FROM LAKE SUPERIOR.
HIGH PRESSURE WILL ENCOMPASS UPPER MI AND LAKE SUPERIOR LATE FRIDAY
THROUGH SUNDAY. THE GFS AND ECMWF ARE IN A SLIGHT DISAGREEMENT BY
SUNDAY NIGHT...WHICH CONTINUES THROUGH THE REMAINDER OF THE FCST
PERIOD. IT ALL STEMS FROM TIMING OF THE NEXT WAVES SWINGING IN FROM
THE NW...WITH THE GFS BUILDING IN A MORE ROBUST RIDGE AT THE SFC AND
ALOFT SUNDAY NIGHT. EXPECT WAA TO BEGIN OVER THE W LATE
SUNDAY...WITH HIGH CLOUDS ENCROACHING IN ADVANCE OF LOW PRESSURE
ORGANIZING ACROSS THE PLAINS STATES. WE MAY END UP DRY ON
MONDAY...AS THE 30/00Z IS MUCH WEAKER AND SLOWER WITH THE LOW WHEN
COMPARED TO THE 30/12Z GFS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 126 PM EDT TUE JUL 30 2013
EXPECT DRY WX/VFR CONDITIONS TO PREVAIL AT ALL 3 TAF SITES UNTIL
LATE TNGT DESPITE SOME MID CLDS AS DRY LLVL AIR LINGERS. SOME SHRA
WL ARRIVE LATER TNGT/WED MRNG W-E IN ADVANCE OF AN APRCHG COLD FNT.
ALTHOUGH SOME MVFR CONDITIONS COULD OCCUR UNDER ANY HEAVIER SHRA...
LINGERING DRY LLVL AIR SHOULD BRING PREDOMINANT VFR WX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 314 PM EDT TUE JUL 30 2013
EXPECT WINDS NO HIGHER THAN 20 KTS THIS FORECAST PERIOD WITH A WEAK
PRESSURE GRADIENT DOMINATING THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
111 AM EDT TUE JUL 30 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 251 PM EDT MON JUL 29 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CONFLUENT NW FLOW
ALF OVER THE WRN GRT LKS BTWN SLOWLY DEPARTING CUTOFF LO JUST S OF
JAMES BAY AND AN UPR RDG OVER MN. THE ARRIVAL OF SFC HI PRES/ACYC
FLOW AND DRIER AIRMASS SHOWN ON THE 12Z INL RAOB ARE BRINGING A
MOSUNNY DAY TO THE CWA. LOOKING UPSTREAM...A SHRTWV IS MOVING INTO
THE NRN PLAINS IN THE WSW FLOW ALF BTWN THE UPR RDG OVER MN AND A
TROF OVER SW CANADA. THERE ARE SOME SHRA/TS ASSOCIATED WITH THIS
FEATURE...AND SOME CLDS WELL IN ADVANCE OF THE SHRA ARE SPILLING
INTO MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE MIN TEMPS TNGT AND THE CHC
FOR SOME SHRA ON TUE.
TNGT...UPR RDG AXIS IS PROGGED TO DRIFT W-E OVER UPR MI TNGT.
FOLLOWING THE PASSAGE OF THE UPR RDG...SOME MSTR IN ADVANCE OF
SHRTWV MOVING INTO MN IS FCST TO SPREAD INTO THE WRN CWA. IN CONCERT
WITH INCRSG WSW FLOW AT H925 ON THE BACK SIDE OF RETREATING SFC HI
PRES TO THE E...THE FALL OF TEMP OVER THE NW PORTIONS OF THE CWA
SHOULD BE HELD IN CHECK A BIT. THE BEST CHC FOR MIN TEMPS FALLING
FARTHER INTO THE 40S WL BE OVER THE INTERIOR SCENTRAL AND E...WHERE
THE CLDS WL ARRIVE LATEST CLOSER TO THE RETREATING HI.
TUE...A NUMBER OF MODELS GENERATE SOME MAINLY LGT PCPN OVER UPR MI
AS SHRTWV DRIFTS TO THE E AND INTERACTS WITH MODEST RETURN OF
SOMEWHAT HIER H85 THETA E. SUSPECT THE BEST CHC FOR SOME SHRA WL BE
IN THE AFTN WITH DAYTIME HEATING AND SOME LLVL CNVGC ON LK BREEZE
BNDRYS. SYNOPTIC SCALE SW FLOW SHOULD LIMIT INLAND PENETRATION OF
BREEZE OFF LK SUP. SINCE MODEL FCST SDNGS CONTINUE TO EXHIBIT
RELATIVELY WARM MID LVLS TEMPS/SOME CAPPING AOA H7/MARGINAL MID LVL
LAPSE RATES...WENT NO HIER THAN SCHC POPS AND KEPT OUT THE MENTION
OF TS FOR NOW WITH LIMITED INSTABILITY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 344 PM EDT MON JUL 29 2013
WE WILL START THIS LONG TERM PERIOD OUT WITH WESTERLY FLOW AT
500MB...WITH A RIDGE STUCK ACROSS THE SOUTHERN U.S. AND THE NEXT OF
A SERIES OF LOWS SET UP ACROSS MANITOBA.
THE 500MB LOW OVER MANITOBA WILL SHIFT ACROSS WESTERN AND CENTRAL
ONTARIO WEDNESDAY AS THE SFC RIDGE OVERHEAD EXITS TO THE SE. 850MB
TEMPS IN DECENT WAA BEHIND THE RIDGE SHOULD RISE TO AROUND 13C
BEFORE COLD FRONT SWEEPS IN FROM THE WNW DURING THE AFTERNOON AND
EARLY EVENING HOURS. TIMING LOOKS TO BE SIMILAR WITH THE AVAILABLE
MODEL GUIDANCE...WITH SHOWERS AND THUNDERSTORMS REMAINING MAINLY TO
OUR W OR OVER LAKE SUPERIOR THROUGH 12Z WEDNESDAY...AROUND 0.25IN
OVER THE W TIER OF COUNTIES BY 18Z...AND CENTRAL AND E DURING THE
MID TO LATE AFTERNOON HOURS. THERE ARE A COUPLE OF OUTLIERS. THE
29/12Z REGIONAL WRF AND CANADIAN RUNS WERE EITHER TOO STRONG OR TOO
WEAK WITH THE SHORTWAVES ROTATING THROUGH...AS THE 500MB TROUGH
BEGINS TO SWING INTO UPPER MI ON WEDNESDAY. VARIABLE PRECIPITATION
OUTPUTS OF NEARLY NOTHING TO AROUND AN INCH WERE THE RESULT. THE WRF
AND CANADIAN RUNS WERE EXCLUDED FROM MUCH OF THIS FCST...GIVEN THE
LOWER CONFIDENCE IN EITHER SOLUTION.
EXPECT THE COLD FRONT TO BE OVER FAR EASTERN UPPER MI BY 06Z
THURSDAY...WITH COOLER AIR FILTERING IN FROM THE NW ONCE AGAIN.
850MB TEMPS SHOULD FALL TO AROUND 8C BY DAYBREAK THURSDAY...WITH
LOWS NEAR 50F OVER THE W HALF OF UPPER MI WITH W WINDS HOVERING NEAR
10KTS.
NO REAL WARM UP IS EXPECTED FOR THURSDAY THROUGH THE UPCOMING
WEEKEND AS A SERIES OF DISTURBANCES SWINGING IN FROM THE NW HELP
KEEP THEM IN CHECK. THERE COULD BE SOME POP UP AFTERNOON SHOWERS OR
EVEN A THUNDERSTORM THURSDAY AFTERNOON INLAND FROM LAKE
SUPERIOR...AS ANOTHER SHORTWAVE ROTATES AROUND THE MAIN 500MB LOW
STUCK NEAR AND ACROSS HUDSON BAY. A SLIGHTLY MORE SIGNIFICANT SFC
TROUGH/500MB SHORTWAVE WILL SLIDE ACROSS FRIDAY AFTERNOON...WITH
ADDITIONAL CLOUD COVER...SHOWERS...AND INLAND POP UP THUNDERSTORMS.
YET ANOTHER ROUND OF SHOWERS WILL BE POSSIBLE SATURDAY...ALTHOUGH
LIKELY FARTHER EAST AS THE ENTIRE SYSTEM SHIFTS EASTWARD AND THE SFC
RIDGE BEGINS TO SHIFT IN. EXPECT DRY WEATHER SUNDAY AS THE SFC HIGH
PUSHES OVERHEAD...EVEN THROUGH NW FLOW LINGERS ALOFT. WITH THE
29/12Z ECMWF SHOWING 850MB TEMPS ON AROUND 7C AND LIGHT N
WINDS...60S AND LOW 70S STILL LOOK REASONABLE FOR HIGH TEMPS. AS FOR
DAY 7/MONDAY...THE SFC HIGH DOES NOT LOOK TO MOVE MUCH...BUT A WAVE
SLIDING THROUGH THE NW FLOW COULD BRING A PARTLY CLOUDY SKY TO THE W
WITH A FEW SHOWERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 110 AM EDT TUE JUL 30 2013
VFR CONDITIONS WILL PREVAIL THRU THE FCST PERIOD AT KIWD/KCMX/KSAW.
A DISTURBANCE CURRENTLY OVER THE NRN PLAINS WILL PASS ACROSS THE
UPPER GREAT LAKES TODAY...BRINGING LOWER CLOUDS DOWN TO AROUND 5KFT
ALONG WITH THE POSSIBILITY OF A FEW -SHRA. INCLUDED VCSH DURING THE
MORNING/EARLY AFTN AT KIWD AS THERE IS SOME MODEL AGREEMENT FOR
ISOLD/SCT -SHRA TO REACH WRN UPPER MI. AT KCMX/KSAW...CONFIDENCE IS
LOWER THAT ANY SHRA WILL OCCUR AT OR IN THE VCNTY AS DISTURBANCE
WILL BE WEAKENING. SO...NO PCPN WAS MENTIONED FOR NOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 251 PM EDT MON JUL 29 2013
EXPECT WINDS NO HIER THAN 20 KTS THIS FORECAST PERIOD WITH WEAK PRES
GRADIENT DOMINATING THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1225 AM CDT TUE JUL 30 2013
.AVIATION.../06Z TAF ISSUANCE/
AN APPROACHING AREA OF LOW PRESSURE IN THE CENTRAL/EASTERN DAKOTAS
WILL BRING INCREASING LOW/MID LEVEL CLOUD COVER AND -SHRA ACROSS
NE MINNESOTA AND NW WISCONSIN EARLY THIS MORNING WHICH MAY
RESULT IN ISOLATED MVFR CIGS. THE CLOUD COVER WILL BEGIN TO SCATTER
AND/OR MOVE OUT OF THE REGION LATE THIS MORNING.
WHILE VFR CONDITIONS ARE IN THE FORECAST FOR THIS AFTERNOON AND
EVENING...A COLD FRONT WILL SET UP ACROSS NE MINNESOTA AND COULD
RESULT IN SOME -TSRA FOR THE KINL/KHIB/KBRD AREAS LATE IN THE
AFTERNOON AND/OR THE EVENING. ANY -TSRA COULD RESULT IN BRIEF MVFR
CIGS/VSBYS.
.PREV DISCUSSION... /ISSUED 848 PM CDT MON JUL 29 2013/
UPDATE...
AT 845PM/145Z...SURFACE HIGH PRESSURE WAS CENTERED NEAR THE
SOUTHERN GREAT LAKES. A TROUGH OF LOW PRESSURE WAS ORIENTATED FROM
NORTH TO SOUTH THROUGH CENTRAL MANITOBA THROUGH THE CENTRAL
DAKOTAS. THERE WERE SPRINKLES & LIGHT RAIN SHOWERS SOUTH OF THE
BRAINERD LAKES REGION AND HINCKLEY AREAS...WHICH WAS ASSOCIATED
WITH MID LEVEL CLOUDS WITH A PASSING WEAK SHORTWAVE. THERE WAS A
MUCH STRONGER SHORTWAVE IN NORTH CENTRAL NORTH DAKOTA HEADING
EAST. SHOWERS AND STORMS WERE MOVING THROUGH SOUTHERN MANITOBA AND
EASTERN NORTH DAKOTA AHEAD OF THE APPROACHING TROUGH. MUCH OF THE
NORTHLAND HAD PARTLY TO MOSTLY CLEAR SKIES...EXCEPT FOR MOSTLY
CLOUDY SKIES ACROSS THE SOUTHERN FRINGE OF THE FORECAST AREA NEAR
THE SHOWERS WITH THE WEAK SHORTWAVE. MOSTLY TO FULLY CLOUDY SKIES
COVERED MUCH OF EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA...AND
THOSE CLOUDS WERE HEADING EAST TOWARDS THE NORTHLAND. THE
NORTHLAND HAD TEMPERATURES RANGING FROM THE MID 50S TO UPPER 60S.
BASED ON THE LATEST TRENDS AND HIGH RESOLUTION MODELS...IT APPEARS
THE PREVIOUS FORECAST NEEDED SIGNIFICANT TWEAKS TO INCREASE CLOUD
COVER AND PCPN CHANCES FOR LATER TONIGHT AND INTO TUESDAY MORNING.
THE RAP13 AND HRRR ARE INDICATING THAT THERE WILL BE A LOT OF
INCREASING LOW/MID LEVEL HUMIDITY WITH THE LIGHT SOUTHERLY FLOW AS
THE TROUGH APPROACHES TONIGHT. THIS SHOULD RESULT IN INCREASING
CLOUD COVER. THOSE MODELS ARE ALSO INDICATING SCATTERED SHOWERS
WILL DEVELOP OVER MUCH OF THE NORTHLAND BY LATE TONIGHT AND THEN
BEGIN TO TAPER OFF AND/OR MOVE OUT OF THE NORTHLAND LATER TUESDAY
MORNING. THERE SEEMS TO BE LITTLE SUPPORT IN CAPE AND SHEAR IN THE
MODELS TO CONTINUE CARRYING ISOLATED THUNDER THROUGH THE
NIGHT...SO I ONLY FORECAST RAIN SHOWERS.
I ALSO INCREASED THE LOW TEMPERATURES A BIT BECAUSE OF THE
EXPECTED INCREASE IN CLOUD COVER.
PREV DISCUSSION... /ISSUED 626 PM CDT MON JUL 29 2013/
AVIATION.../00Z TAF ISSUANCE/
THERE WILL BE INCREASING LOW/MID LEVEL MOISTURE THIS EVENING AND
OVERNIGHT ACROSS NE MINNESOTA AND NW WISCONSIN WITH THE LIGHT
SOUTHERLY FLOW AHEAD OF AN APPROACHING TROUGH OF LOW PRESSURE
CURRENTLY IN THE DAKOTAS. THIS INCREASING MOISTURE WILL LIKELY
RESULT IN A PERIOD OF MVFR CIGS FOR KINL/KBRD/KHIB/KDLH/KHYR LATER
TONIGHT AND THROUGH PART OF TUESDAY MORNING BEFORE SCATTERING OR
MOVING OUT OF THE REGION LATE TUESDAY MORNING OR BY NOON. THERE
COULD BE SOME LIGHT RAIN SHOWERS DURING THIS PERIOD TOO. THE MVFR
CIGS SHOULD DEVELOP AT KINL/KBRD LATE THIS EVENING...AND THEN
SPREAD EAST TO KHIB/KDLH/KHYR LATE TONIGHT. VFR CONDITIONS ARE
LIKELY ACROSS THE REGION TUESDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 322 PM CDT MON JUL 29 2013/
SHORT TERM...TONIGHT...
HIGH PRESSURE OVER THE GREAT LAKES WILL CONTINUE TO MOVE TO THE EAST
TONIGHT BRINGING SOUTHERLY WINDS AND MILDER CONDITIONS TO THE
NORTHLAND TONIGHT. TEMPERATURES WILL BE MAINLY IN THE LOWER 50S
OVERNIGHT. A SHORTWAVE WILL APPROACH FROM THE NORTHERN GREAT PLAINS
LATE TONIGHT AND BRING A CHANCE OF SHOWERS AND SOME THUNDERSTORMS TO
THE WESTERN PART OF THE FORECAST AREA...MAINLY AROUND MIDNIGHT. HIGH
RESOLUTION MODELS TRENDING A LITTLE FASTER BRINGING IN THE
PRECIPITATION AFTER 4Z FROM THE BRAINERD LAKES REGION TO THE
BORDERLAND. RAINFALL AMOUNTS LOOK TO BE UNDER A TENTH OF AN INCH BY
TUESDAY MORNING.
LONG TERM...TUESDAY THROUGH SATURDAY...
WESTERLY FLOW ALOFT TUESDAY WILL CARRY A WEAK MID LVL SHORTWAVE TROF
ACROSS THE REGION WITH SCTD LIGHT PRECIP. THE UPPER SHORTWAVE TROF
WILL OUTRUN THE LOW LVL FRONTAL SYSTEM. THE ASSOCIATED LOW LVL
FRONTAL SYSTEM WILL ENTER THE REGION TUESDAY NIGHT AS REFLECTED IN
THE LOW LVL THETAE FIELDS AND A DISTINCT SHIFT TO NW BDRY LAYER
FLOW. THIS FRONTAL PASSAGE WILL BE ACCOMPANIED BY A HIGHER PROB OF
PRECIP AS FRONTAL CONVERGENCE COMBINES WITH A STRONGER SHORTWAVE
ALOFT AND A SECONDARY PWAT AXIS. THIS FROPA WILL HERALD THE
AMPLIFICATION OF THE UPPER FLOW WEDNESDAY AFTN WHICH WILL CONTINUE
INTO THE WEEKEND. AS UPPER FLOW DEEPENS AND MEAN LAYER RH INCREASES
THUR/FRI AN OPPORTUNITY FOR SHOWERS WILL ARISE. NOT CONFIDENT ON HOW
FAR SOUTH THE POPS WILL OCCUR. HAVE STARTED WITH ARROWHEAD AND NRN
WISC..SPREADING INTO SERN CWA FRIDAY. LOW LVL THERMAL FIELDS SUGGEST
ANOTHER COLD FRONT WILL SWEEP ACROSS THE REGION FRIDAY. LARGE SFC
HIGH WILL MOVE FROM MANITOBA INTO NORTHLAND SATURDAY AND EARLY
SUNDAY. THE SFC HIGH IS FCST TO SHIFT EAST OF THE REGION SUNDAY
EVENING. A SLIGHT CHC THAT SOME PRECIP AMY ARRIVE LATE SUNDAY OVER
SWRN CORNER OF CWA IN RESPONSE TO WARM ADVECTION REGIME FROM NRN
PLAINS SYSTEM. TEMPS WILL RUN BLO CLIMO FOR MOST OF THIS PERIOD.
&&
.POINT TEMPS/POPS...
DLH 58 72 56 73 / 50 60 10 10
INL 55 71 53 71 / 50 10 10 20
BRD 59 76 56 76 / 60 40 0 10
HYR 59 75 54 75 / 30 60 10 10
ASX 59 73 56 73 / 30 60 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM....CLC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
250 PM CDT TUE JUL 30 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 246 PM CDT TUE JUL 30 2013
MAIN UPPER LEVEL SCENARIO INCLUDES A PERSISTENT SUBTROPICAL RIDGE
OVER THE SOUTHERN UNITED STATES. SPLIT JET WITHIN QUASI-ZONAL FLOW
IN THE NORTH CONTAINS A SHORTWAVE TROUGH SKIRTING ACROSS THE
NORTHERN PLAINS WHICH SHOULD DEVELOP A LONG ADVERTISED MCS OVER
SOUTH DAKOTA THAT SHOULD MAKE ITS WAY SOUTHEAST...AND COULD JUST
SWIPE THE CWA IN THE NORTH BY LATE TONIGHT. THERE COULD BE ENOUGH
SHEAR TO GET SOME STRONG TO SEVERE WEATHER FROM THE REMNANTS OF THE
EXPECTED MCS. CONVERGENCE ALONG AN APPROACHING COLD FRONT WILL ALSO
INCREASE PRECIPITATION AND SEVERE THUNDERSTORM CHANCES. AS A SIDE
NOTE...SKY COVER IS DIFFICULT TO FORECAST FOR THIS EVENING...AND I
HAVE CURBED THE ENTHUSIASM OF MOST MODELS FOR CLEARING...AS EVEN
THE HRRR HAS SHOWN TOO MUCH OPTIMISM FOR THE CLEARING.
ALSO...MODELS HAVE CONTINUED TO ADVERTISE A FAIRLY STRONG SIGNAL FOR
FOG AND HAVE BEEN PRETTY CONSISTENT AS STRATUS IS FORECAST TO
LOWER UNTIL WE GET DENSE FOG IN OUR EAST. CONFIDENCE IS HIGHER WITH
THE RECENT CONSISTENCY...AND A FAIRLY STRONG SIGNAL IN THE
EASTERN THIRD OF THE CWA PERSISTS...PROMPTING ME TO ISSUE A DENS
FOG ADVISORY FOR LATE TONIGHT INTO WEDNESDAY MORNING.
A COLD FRONT WILL MAKE ITS WAY ACROSS THE CWA FOR WEDNESDAY AND WILL
BE THE FOCUS FOR MORE POSSIBLE SEVERE WEATHER. DEWPOINTS ARE
EXPECTED TO POOL NEAR THE BOUNDARY WITH INCREASED INSTABILITY ALONG
THE FRONT...AND CONTINUED LOW-LEVEL CONVERGENCE. BULK SHEAR WILL
ALSO BE SUFFICIENT ENOUGH FOR SEVERE WEATHER...EVEN IF THERE ARE
LIMITED BREAKS IN SKY COVER. THIS COULD WIND UP BEING A POTENTIALLY
INTERESTING DAY DEPENDING ON THE TIMING OF THE COLD FRONT. KEPT A
CHANCE OF PRECIPITATION NEAR THE FRONT...SIMILAR TO THE PREVIOUS
FORECAST.
BASED TEMPERATURES AND DEWPOINTS ON RECENT MODEL PERFORMANCE AND NOT
MUCH HAS CHANGED FOR THESE FIELDS COMPARED TO THE PREVIOUS
FORECAST...EXCEPT PERHAPS HIGHER DEWPOINTS NEAR THE PROJECTED TIMING
AND PLACEMENT OF THE COLD FRONT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 246 PM CDT TUE JUL 30 2013
GUIDANCE SUGGESTS NORTHWESTERLY MID TO UPPER LEVEL FLOW WILL PERSIST
OVER THE CENTRAL PLAINS THROUGH MUCH OF THE LONG TERM FORECAST
PERIOD. WITH MULTIPLE MID LEVEL PERTURBATIONS PERHAPS MOVING OVER
THE AREA WITHIN THE MEAN MID LEVEL FLOW...POPS REMAIN LITTERED
THROUGHOUT MOST ALL OF THE LONG TERM FORECAST PERIOD. OUT OF ALL THE
LONG TERM FORECAST PERIODS...THE HIGHEST CONFIDENCE WITH RESPECT TO
POPS EXISTS DURING THURSDAY AND THURSDAY NIGHT. THESE ARE TIME
PERIODS IN WHICH GUIDANCE SUGGESTS LOW LEVEL THERMAL ADVECTION AND
RESULTANT ISENTROPIC UPGLIDE AND SATURATION...PRIMARILY ALONG THE
315-320K SURFACES...WILL PERSIST. THIS THERMAL ADVECTION...WORKING IN
CONCERT WITH OMEGA FROM MID LEVEL PERTURBATIONS PUSHING
OVERHEAD...SHOULD BE STRONG ENOUGH TO PROMOTE PRECIPITATION
PRODUCTION ACROSS MUCH OF OUR AREA. TAKING A AVERAGE OF THE
NAM...OPERATIONAL GFS...EC...AND SREF-MEAN PROVIDES BETWEEN A
QUARTER INCH AND A HALF INCH OF RAIN ACROSS MUCH OF OUR CWA DURING
THE DAY THURSDAY...AND MUCH OF THE SAME ACROSS OUR EAST THURSDAY
NIGHT. WENT AHEAD AND INCREASED POPS ACROSS MUCH OF OUR CWA THURSDAY
INTO THURSDAY NIGHT AS A RESULT. POPS ALSO CONTINUE ACROSS OUR AREA
FOR THE MOST PART HEADING INTO FRIDAY BEFORE THE PRIMARY AXIS OF
THERMAL ADVECTION FINALLY EXITS THE AREA TO THE EAST. AS MENTIONED
ALREADY...THE POTENTIAL FOR MID LEVEL PERTURBATIONS MOVING OVER THE
AREA SUGGESTS POPS REMAIN WARRANTED ACROSS OUR AREA THROUGH THE
REMAINDER OF THE EXTENDED FORECAST PERIOD. ALLBLEND PROVIDED A
VARIETY OF POPS TO OUR AREA EACH DAY...GENERALLY IN THE 20-40%
RANGE...AND GIVEN THE LOW PROBABILITY OF IMPROVING THE FORECAST
THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART.
INCREASING LOW LEVEL RETURN FLOW AND RESULTANT MOISTURE FLUX INTO
THE AREA SHOULD HELP PROMOTE RESPECTABLE VALUES OF POTENTIAL
INSTABILITY ON THURSDAY...WITH GUIDANCE FROM THE NAM...OPERATIONAL
GFS...AND EC SUGGESTING MUCAPE VALUES RANGING BETWEEN 1500 AND
3500J/KG ACROSS OUR CWA. DEEP LAYER BULK SHEAR VALUES OF 35-45KTS
ARE ALSO FORECAST ACROSS THE AREA ON THURSDAY. THERE IS A CONCERN
THAT EXPANSIVE CLOUD COVER WILL KEEP LOW LEVEL TEMPERATURES ON THE
COOL SIDE WHICH WOULD HELP PRESERVE A LOW LEVEL CAPPING
INVERSION...WHICH WOULD OBVIOUSLY INHIBIT STRONG/DEEP CONVECTION
FROM BEING REALIZED. THAT BEING SAID...IF NEAR-SURFACE BASED
CONVECTION CAN BE REALIZED THURSDAY...THEN CERTAINLY SEVERE WEATHER
WILL BE POSSIBLE AND WILL INTRODUCE SUCH WORDING TO THE HWO. BEYOND
THURSDAY...GUIDANCE SUGGESTS MUCAPE VALUES IN EXCESS OF 2000J/KG
COULD BE REALIZED MOST ANY DAY...BUT AS ALREADY MENTIONED CONFIDENCE
ON WHEN AND WHERE CONVECTION WILL BE REALIZED IS VERY LOW AND AS A
RESULT...WILL MAINTAIN VAGUE SEVERE WEATHER WORDING IN THE HWO FOR
FRIDAY AND BEYOND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1256 PM CDT TUE JUL 30 2013
TRICKY CALL WITH HOW QUICKLY THE STRATUS WILL ERODE FROM THE WEST.
CEILINGS SHOULD RISE AND THEN SCATTER OUT THIS AFTERNOON. THERE IS
A CHANCE OF MORE MVFR OR LOWER STRATUS AND SOME REDUCED VISIBILITY
FOR TONIGHT...BUT THE MAJORITY OF POORER CEILINGS AND VISIBILIIY
SHOULD REMAIN JUST EAST OF THE TERMINAL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY FROM 4 AM TO 10 AM CDT WEDNESDAY FOR NEZ041-
048-049-063-064-076-077-086-087.
KS...DENSE FOG ADVISORY FROM 4 AM TO 10 AM CDT WEDNESDAY FOR KSZ007-
019.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...BRYANT
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
239 PM CDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 238 PM CDT TUE JUL 30 2013
UPDATED ZONES TO ADD WATCH REFRESHED ZONES FOR CURRENT CONDITIONS.
UPDATE ISSUED AT 1255 PM CDT TUE JUL 30 2013
HAVE UPDATED TO RAISE MAX TEMPS THIS AFTERNOON ACROSS THE WEST
WHERE STRONG INSOLATION HAS ALLOWED TEMPS TO WARM INTO THE 80S
ALREADY. HOWEVER...DID NOT CHANGE TEMPS MUCH FURTHER EAST WHERE
LOW CLOUDS REMAIN OR WERE LIMITING SUNSHINE EARLIER THIS MORNING.
ALSO ADJUSTED POPS TO BETTER REFLECT CURRENT THINKING OF
CONVECTION INITIATION. MOST CONVECTION ALLOWING MODELS SUGGEST
CONVECTIVE INITIATION ALONG SURFACE TROUGH/WIND SHIFT BOUNDARY
THAT WILL EXIST FROM NORTH CENTRAL NEBRASKA INTO THE EASTERN
PANHANDLE. COULD BE SOME ENHANCEMENT TO THE CONVERGENCE ALONG THE
BOUNDARY FROM DIFFERENTIAL HEATING DUE TO EARLIER CLOUD
COVER...DEPENDING ON HOW MUCH MIXING EVOLVES FURTHER EAST THIS
AFTERNOON. ALSO COULD BE SOME STORMS THAT MOVE SOUTH INTO THE CWA
FROM SD. OVERALL STILL THINKING BEST THUNDERSTORM CHANCES WILL BE
ACROSS THE NORTH CENTRAL INTO THE SANDHILLS. COVERAGE WILL BE
LIMITED INITIALLY BUT MAY EVOLVE INTO CONVECTIVE CLUSTERS THROUGH
THE LATE AFTERNOON EVENING. MESOANALYSIS SUGGESTS GOOD
DESTABILIZATION OCCURRING ALREADY ALONG THIS BOUNDARY AS IT
DEVELOPS...WITH MLCAPE EXCEEDING 1500 J/KG. SO SOME POTENTIAL FOR
ISOLATED SVR HAIL AND DAMAGING WIND GUSTS AS CONVECTIVE CLUSTERS
DEVELOP.
UPDATE ISSUED AT 950 AM CDT TUE JUL 30 2013
UPDATED FORECAST TO DROP DENSE FOG ADVISORY AND INCREASE CLOUD
COVER THROUGH THE MORNING WITH AREAS OF PATCHY FOG CONTINUING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE JUL 30 2013
TODAY AND TONIGHT...DENSE FOG WOULD APPEAR TO BE VERY SHALLOW
THIS MORNING WITH THE MOON VISIBLE AT KLBF AND NEDOR SHOWING IT
LIFTING AT KLXN. SO WE WOULD EXPECT A RAPID CLEARING AFTER SUNRISE
IN SOME AREAS AS SATELLITE SHOWS AREAS OF STRATUS AT THE SAME TIME
WHICH WOULD SLOW THE LIFTING PROCESS.
A WEAK AND DECAYING MCS ACROSS NWRN NEB/SWRN SD THIS MORNING IN
COMBINATION WITH A WEAK DISTURBANCE OVER ERN COLO COULD PERHAPS
SPREAD ISOLATED SHOWERS AND THUNDERSTORMS INTO WRN NEB.
THE HRRR THEN SHOWS CONVECTIVE DESTABILIZATION ACROSS SWRN NEB BY
20Z WHICH IS PROBABLY AN HOUR OR TWO TOO FAST. THE MAIN IMPULSE
WOULD APPEAR TO BE DROPPING SOUTHEAST THROUGH NERN WY/WRN SD AT
20Z...STILL HOURS AWAY FROM THE FCST AREA. A MCS IS EXPECTED TO
DEVELOP OUT OF THE STORMS FIRING ACROSS THE NRN HIGH PLAINS WHICH
SHOULD SWEEP THRU NRN NEB OVERNIGHT. THE MCS SHOULD REMAIN MOSTLY
ALONG AND NORTH OF HIGHWAY 20.
TEMPERATURES TODAY ARE EXPECTED TO RISE INTO THE LOW TO MID 80S
IN MOST AREAS GIVEN THE CONTINUED SOUTH AND SOUTHEAST WINDS
CIRCULATING AROUND HIGH PRESSURE CENTERED OVER THE MIDWEST. THE
ENSUING WARM AIR ADVECTION FUELING THE MCS TONIGHT SHOULD KEEP
SKIES MOSTLY CLEAR SOUTH OF THE CONVECTIVE COMPLEX. THE NAM12
HINTS AT A BANK OF STRATUS FILLING IN ACROSS NWRN NEB IN THE WAKE
OF THE MCS AROUND 12Z.
SEVERE WEATHER POTENTIAL WITH THE THUNDERSTORMS THIS AFTERNOON
AND TONIGHT IS LIMITED TO 5 PERCENT OR ISOLATED WITH THE BEST
INSTABILITY AND 40 TO 50 KT 1 TO 6 KM SHEAR ACROSS NRN NEB MOSTLY
ASSOCIATED WITH THE DEVELOPING MCS. MODEL INDICATIONS SUGGEST THE
BLACK HILLS COULD BE THE GENESIS FOR A CLUSTER OF STORMS FORMING
LATE IN THE AFTERNOON WHICH WOULD MOVE EAST SOUTHEAST TOWARD
KVTN-KANW-KONL DURING THE EVENING AND OVERNIGHT. THIS IN TURN
COULD CERTAINLY INCREASE THE SEVERE WEATHER POTENTIAL IN THOSE
AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE JUL 30 2013
WEDNESDAY MORNING LINGER SHOWERS WILL BE POSSIBLE ACROSS PORTIONS
OF CENTRAL/NORTH CENTRAL NEB. THEN BREAKS IN THE CLOUDS SHOULD
HELP TO PUSH HIGHS INTO THE 80S. LATE IN THE DATE MODELS IN
AGREEMENT WITH A BOUNDARY STRETCHED FROM WEST CENTRAL KS
NORTHEAST INTO CENTRAL NEB AND ON TOWARDS THE WESTERN GREAT
LAKES. THUNDERSTORMS WILL BE POSSIBLE ALONG THE SLOW MOVING
BOUNDARY...HOWEVER IMPACT TO THE CWA IN QUESTIONS. THE LATEST NAM
AND GFS HAVE PUSHED THE BOUNDARY JUST SE OF THE CWA BY PEAK
HEATING...HOWEVER THE EC AND GEM DO DEVELOP ACTIVITY IN THE SE
CWA. WILL TREND DOWN WITH POPS...ALTHOUGH STILL RETAIN SLGHT CHC
IN THE FAR SE ZONES. MORE OF A FOCUS WILL BE THE NEXT SHORT WAVE
CROSSING THE ROCKIES. THIS WAVE SHOULD ALLOW DEVELOPMENT ON THE
HIGHER TERRAIN WITH FLOW TO PUSH THIS INTO THE PANHANDLE AND
WESTERN NEBRASKA OVERNIGHT.
THURSDAY WILL SEE YET ANOTHER SHORT WAVE TO PUSH ACROSS THE AREA.
MODELS CONTINUE TO SHOW GOOD INSTABILITY WITH DECENT SHEAR...ALSO
WILL SEE A SURF LOW DEVELOP NEAR NE CO. ANY ACTIVITY DEVELOPING IN
THE EVENING FROM PEAK HEATING WILL LIKELY BE SUSTAINED BY A 30 TO
40K LL JET. LOW FREEZING LEVEL WITH STEEP LAPSE RATE SHOULD RESULT
IN A FEW STRONG TO EVEN SEVERE STORMS...WITH HAIL THE MAIN THREAT.
FRIDAY WILL SEE AN UPPER LEVEL LOW COME ONSHORE TO THE PAC
NW...THIS WILL FLATTEN THE RIDGE AND PUSH IT EASTWARD. INITIALLY
THOUGHT THERE COULD BE A WARM UP...HOWEVER MODELS CONTINUE TO
BRING GOOD MOISTURE AROUND THE RIDGE...RESULTING IN MORE CLOUDS
THAN SUN. FORECAST RESULTS IN BELOW NORMAL HIGHS...WHICH IS CLOSE
TO MOS GUIDANCE.
LITTLE CHANGES THROUGH THE WEEKEND FOR THE AREA...AS RIDGE REMAINS
TO THE SOUTH AND LOW WILL TRAVERSE ACROSS THE US/CAN BORDER. FLOW
WILL CONTINUE TO BE NORTHWESTERLY TO ZONAL...AND MODELS CONTINUE
TO BRING WAVE AFTER WAVE ACROSS THE AREA. QPF MAY NOT BE
SIGNIFICANT...HOWEVER WILL NEED TO CONTINUE TO MENTION IN NEARLY
EVERY PERIOD PENDING TIMING OF THE WAVES. TEMPS WILL GENERALLY BE
BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1255 PM CDT TUE JUL 30 2013
HAVE ADDED VCTS IN THE VTN TAF BASED ON THE IDEA OF BETTER
CONVECTIVE COVERAGE ACROSS NC NEBRASKA THIS AFTERNOON AND EVENING.
CONFIDENCE ON COVERAGE FURTHER SOUTH IS NOT AS GOOD AND THEREFORE
LEFT OUT OF THE LBF TAF.
OTHERWISE HAVE GONE WITH MAINLY IFR CONDITIONS THROUGH THE
PERIOD...THOUGH SOME CONCERN ABOUT A REDEVELOPMENT OF LOW CLOUDS
AND/OR FOG AFTER 09Z TONIGHT. THINK BETTER CHANCES FOR THIS WOULD
BE EAST OF VTN TAF SITE SINCE A SHIFT TO A NORTHERLY WIND SHOULD
OCCUR BEFORE ONSET...BUT MAY HAVE TO BE INTRODUCED INTO THE LBF
TAF WITH LATER FCSTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...POWER
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
137 PM CDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 135 PM CDT TUE JUL 30 2013
UPDATED THE FORECAST FOR THIS AFTERNOON TO LOWER TEMPERATURES IN
THE EASTERN CWA WHERE SKY COVER WILL LINGER LONGER.
UPDATE ISSUED AT 1057 AM CDT TUE JUL 30 2013
ADJUSTED SKY COVER UP FOR THE REMAINDER OF THE MORNING...AND
FOLLOWED CLOSER TO THE HRRR FOR SKY COVER FOR THE REST OF THE DAY
INTO THE NIGHT. THIS MODEL SEEMS TO BE DOING THE BEST HANDLING THE
ERODING WEST SIDE OF THE STROTOCUMULUS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CDT TUE JUL 30 2013
AREAS OF FOG HAVE DEVELOPED ACROSS THE REGION OVERNIGHT AS ELEVATED
DEW POINTS AND LIGHT WINDS HAVE AIDED IN ITS FORMATION. AFTER MAKING
A FEW PHONE CALLS AND PERUSING HIGHWAY CAMERAS THE PAST HOUR...HAVE
DECIDED TO GO AHEAD AND EXPAND THE DENSE FOG ADVISORY NORTH AND EAST
WITH THE MORNING FORECAST PACKAGE TO ACCOUNT FOR POCKETS OF DENSE
FOG THAT HAVE FORMED. WHILE MODEL GUIDANCE IS NOT HANDLING THIS FOG
VERY WELL...CANNOT SEE A REASON FOR CONDITIONS TO IMPROVE MUCH
BEFORE SUNRISE...AND WILL KEEP EXPIRATION TIME OF 14Z FOR THE TIME
BEING.
FOR TODAY...ONCE THE FOG BEGINS TO LIFT DURING THE MID MORNING
HOURS...EXPECT A FAIRLY NICE DAY ACROSS THE REGION AS TEMPERATURES
WILL BEGIN TO MODERATE CLOSER TO SEASONAL NORMS...WINDS WILL BE
LIGHT...AND SKIES WILL BEGIN TO CLEAR. WHILE CLOUDY SKIES WILL
ENVELOP THE REGION THROUGH MID MORNING HOURS...EXPECT AT LEAST A
PARTLY SUNNY AFTERNOON AS THE FRONTAL BOUNDARY TO OUR SOUTH...
RESPONSIBLE FOR THE ACTIVE WEATHER ON MONDAY...CONTINUES TO SHIFT
SOUTHEASTWARD.
THEREAFTER THE FOCUS WILL SHIFT NORTHWARD AS SHORTWAVE CROSSING THE
NORTHERN PLAINS...ALONG WITH A SURFACE COLD FRONT...BEGIN TO SAG
SOUTHWARD TOWARDS THE LOCAL AREA. THE LATEST WRF INDICATES A NICE
BAND OF CONVECTION DEVELOPING AHEAD OF THIS WAVE LATE TUESDAY
NIGHT...WHILE THE 06Z NAM/00Z GFS/EC KEEP THE BULK OF THE CONVECTION
NORTH OF THE LOCAL FORECAST AREA. HOWEVER...WITH PLENTY OF ELEVATED
INSTABILITY TO WORK WITH AND SOME SYNOPTIC SCALE FORCING...SIDED
TOWARDS THE MORE AGGRESSIVE SOLUTION OF THE WRF AND INCREASED POPS
ACROSS THE NORTH LATE TUESDAY NIGHT. THAT SAID...KEPT CONVECTION
POTENTIAL GENERALLY NORTH OF I80 DURING THE OVERNIGHT HOURS AS THE
00Z WRF SEEMS TO BE THE OUTLIER TAKING ACTIVITY MUCH FURTHER SOUTH
THAN REMAINDER OF GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 336 AM CDT TUE JUL 30 2013
PRIMARY CONCERN IN THE EXTENDED WILL BE ALMOST DAILY
CHANCES FOR PRECIPITATION. LOOKING AT THE BIG PICTURE...BY
WEDNESDAY MORNING IT APPEARS WE WILL BE IN NORTHWEST FLOW AS MODELS
IN DECENT AGREEMENT IN PLACING A MID LEVEL CUT OFF LOW JUST OFF THE
PACIFIC NORTHWEST COAST...AND ANOTHER ONE OVER WESTERN ONTARIO. IN
BETWEEN THIS IS A DIRTY RIDGE CENTERED OVER THE ROCKIES. THERE
APPEARS TO BE SOME PROGRESSION OF THESE SYSTEMS EASTWARD DURING THE
REST OF THE WORK WEEK...BUT FOR US IT LOOKS LIKE WE COULD HAVE MINOR
SHORTWAVES PASSING THROUGH THE RIDGE. SOME OF THESE MAY PACK A
LITTLE MORE PUNCH AND THE FIRST ONE OF THESE LOOKS TO BE THURSDAY
NIGHT. WILL CONTINUE TO KEEP HIGHEST POPS GOING FOR THURS NIGHT.
BACKING UP JUST A BIT AND CHECKING THE SURFACE FEATURES...IT LOOKS
LIKE THERE WILL BE A WEAK FRONTAL BOUNDARY DROPPING SOUTH ACROSS THE
CWA DURING THE DAYTIME ON WED. THIS COULD HELP TRIGGER THUNDERSTORMS
BY THE AFTERNOON. BY LATE IN THE WEEK AND INTO THE WEEKEND A
FRONTAL BOUNDARY WILL BE SOMEWHERE NEAR THE CWA AND THE INTERACTION
OF PASSING MID LEVEL DISTURBANCES WITH THE SURFACE FEATURE WILL KEEP
OUR WEATHER UNSETTLED.
AS FAR AS SEVERE CHANCES ARE CONCERNED...PROGGED DEEP LAYER SHEAR
LOOKS TO BE IMPRESSIVE...ESPECIALLY FOR THIS TIME OF YEAR...WITH
0-6 KM VALUES OF 20 TO 50 KT NOTED FOR MOST DAYS ON THE LATEST EC
AND/OR GFS RUN. INSTABILITY ALSO IMPRESSIVE WITH MU CAPE NUMBERS
QUITE HIGH. ON THE NEGATIVE SIDE...THERE COULD BE SOME CAPPING
ISSUES ESPECIALLY LATER IN THE WEEK AND INTO THE WEEKEND WITH
PROGGED 700 MB TEMPS EXPECTED TO BE BETWEEN 11 AND 15 DEGREES
CELSIUS..WITH THE GFS A LITTLE WARMER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1256 PM CDT TUE JUL 30 2013
TRICKY CALL WITH HOW QUICKLY THE STRATUS WILL ERODE FROM THE WEST.
CEILINGS SHOULD RISE AND THEN SCATTER OUT THIS AFTERNOON. THERE IS
A CHANCE OF MORE MVFR OR LOWER STRATUS AND SOME REDUCED VISIBILITY
FOR TONIGHT...BUT THE MAJORITY OF POORER CEILINGS AND VISIBILIIY
SHOULD REMAIN JUST EAST OF THE TERMINAL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...SAR
LONG TERM...EWALD
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1258 PM CDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 1057 AM CDT TUE JUL 30 2013
ADJUSTED SKY COVER UP FOR THE REMAINDER OF THE MORNING...AND
FOLLOWED CLOSER TO THE HRRR FOR SKY COVER FOR THE REST OF THE DAY
INTO THE NIGHT. THIS MODEL SEEMS TO BE DOING THE BEST HANDLING THE
ERODING WEST SIDE OF THE STROTOCUMULUS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CDT TUE JUL 30 2013
AREAS OF FOG HAVE DEVELOPED ACROSS THE REGION OVERNIGHT AS ELEVATED
DEW POINTS AND LIGHT WINDS HAVE AIDED IN ITS FORMATION. AFTER MAKING
A FEW PHONE CALLS AND PERUSING HIGHWAY CAMERAS THE PAST HOUR...HAVE
DECIDED TO GO AHEAD AND EXPAND THE DENSE FOG ADVISORY NORTH AND EAST
WITH THE MORNING FORECAST PACKAGE TO ACCOUNT FOR POCKETS OF DENSE
FOG THAT HAVE FORMED. WHILE MODEL GUIDANCE IS NOT HANDLING THIS FOG
VERY WELL...CANNOT SEE A REASON FOR CONDITIONS TO IMPROVE MUCH
BEFORE SUNRISE...AND WILL KEEP EXPIRATION TIME OF 14Z FOR THE TIME
BEING.
FOR TODAY...ONCE THE FOG BEGINS TO LIFT DURING THE MID MORNING
HOURS...EXPECT A FAIRLY NICE DAY ACROSS THE REGION AS TEMPERATURES
WILL BEGIN TO MODERATE CLOSER TO SEASONAL NORMS...WINDS WILL BE
LIGHT...AND SKIES WILL BEGIN TO CLEAR. WHILE CLOUDY SKIES WILL
ENVELOP THE REGION THROUGH MID MORNING HOURS...EXPECT AT LEAST A
PARTLY SUNNY AFTERNOON AS THE FRONTAL BOUNDARY TO OUR SOUTH...
RESPONSIBLE FOR THE ACTIVE WEATHER ON MONDAY...CONTINUES TO SHIFT
SOUTHEASTWARD.
THEREAFTER THE FOCUS WILL SHIFT NORTHWARD AS SHORTWAVE CROSSING THE
NORTHERN PLAINS...ALONG WITH A SURFACE COLD FRONT...BEGIN TO SAG
SOUTHWARD TOWARDS THE LOCAL AREA. THE LATEST WRF INDICATES A NICE
BAND OF CONVECTION DEVELOPING AHEAD OF THIS WAVE LATE TUESDAY
NIGHT...WHILE THE 06Z NAM/00Z GFS/EC KEEP THE BULK OF THE CONVECTION
NORTH OF THE LOCAL FORECAST AREA. HOWEVER...WITH PLENTY OF ELEVATED
INSTABILITY TO WORK WITH AND SOME SYNOPTIC SCALE FORCING...SIDED
TOWARDS THE MORE AGGRESSIVE SOLUTION OF THE WRF AND INCREASED POPS
ACROSS THE NORTH LATE TUESDAY NIGHT. THAT SAID...KEPT CONVECTION
POTENTIAL GENERALLY NORTH OF I80 DURING THE OVERNIGHT HOURS AS THE
00Z WRF SEEMS TO BE THE OUTLIER TAKING ACTIVITY MUCH FURTHER SOUTH
THAN REMAINDER OF GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 336 AM CDT TUE JUL 30 2013
PRIMARY CONCERN IN THE EXTENDED WILL BE ALMOST DAILY
CHANCES FOR PRECIPITATION. LOOKING AT THE BIG PICTURE...BY
WEDNESDAY MORNING IT APPEARS WE WILL BE IN NORTHWEST FLOW AS MODELS
IN DECENT AGREEMENT IN PLACING A MID LEVEL CUT OFF LOW JUST OFF THE
PACIFIC NORTHWEST COAST...AND ANOTHER ONE OVER WESTERN ONTARIO. IN
BETWEEN THIS IS A DIRTY RIDGE CENTERED OVER THE ROCKIES. THERE
APPEARS TO BE SOME PROGRESSION OF THESE SYSTEMS EASTWARD DURING THE
REST OF THE WORK WEEK...BUT FOR US IT LOOKS LIKE WE COULD HAVE MINOR
SHORTWAVES PASSING THROUGH THE RIDGE. SOME OF THESE MAY PACK A
LITTLE MORE PUNCH AND THE FIRST ONE OF THESE LOOKS TO BE THURSDAY
NIGHT. WILL CONTINUE TO KEEP HIGHEST POPS GOING FOR THURS NIGHT.
BACKING UP JUST A BIT AND CHECKING THE SURFACE FEATURES...IT LOOKS
LIKE THERE WILL BE A WEAK FRONTAL BOUNDARY DROPPING SOUTH ACROSS THE
CWA DURING THE DAYTIME ON WED. THIS COULD HELP TRIGGER THUNDERSTORMS
BY THE AFTERNOON. BY LATE IN THE WEEK AND INTO THE WEEKEND A
FRONTAL BOUNDARY WILL BE SOMEWHERE NEAR THE CWA AND THE INTERACTION
OF PASSING MID LEVEL DISTURBANCES WITH THE SURFACE FEATURE WILL KEEP
OUR WEATHER UNSETTLED.
AS FAR AS SEVERE CHANCES ARE CONCERNED...PROGGED DEEP LAYER SHEAR
LOOKS TO BE IMPRESSIVE...ESPECIALLY FOR THIS TIME OF YEAR...WITH
0-6 KM VALUES OF 20 TO 50 KT NOTED FOR MOST DAYS ON THE LATEST EC
AND/OR GFS RUN. INSTABILITY ALSO IMPRESSIVE WITH MU CAPE NUMBERS
QUITE HIGH. ON THE NEGATIVE SIDE...THERE COULD BE SOME CAPPING
ISSUES ESPECIALLY LATER IN THE WEEK AND INTO THE WEEKEND WITH
PROGGED 700 MB TEMPS EXPECTED TO BE BETWEEN 11 AND 15 DEGREES
CELSIUS..WITH THE GFS A LITTLE WARMER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1256 PM CDT TUE JUL 30 2013
TRICKY CALL WITH HOW QUICKLY THE STRATUS WILL ERODE FROM THE WEST.
CEILINGS SHOULD RISE AND THEN SCATTER OUT THIS AFTERNOON. THERE IS
A CHANCE OF MORE MVFR OR LOWER STRATUS AND SOME REDUCED VISIBILITY
FOR TONIGHT...BUT THE MAJORITY OF POORER CEILINGS AND VISIBILIIY
SHOULD REMAIN JUST EAST OF THE TERMINAL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...SAR
LONG TERM...EWALD
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1257 PM CDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 1255 PM CDT TUE JUL 30 2013
HAVE UPDATED TO RAISE MAX TEMPS THIS AFTERNOON ACROSS THE WEST
WHERE STRONG INSOLATION HAS ALLOWED TEMPS TO WARM INTO THE 80S
ALREADY. HOWEVER...DID NOT CHANGE TEMPS MUCH FURTHER EAST WHERE
LOW CLOUDS REMAIN OR WERE LIMITING SUNSHINE EARLIER THIS MORNING.
ALSO ADJUSTED POPS TO BETTER REFLECT CURRENT THINKING OF
CONVECTION INITIATION. MOST CONVECTION ALLOWING MODELS SUGGEST
CONVECTIVE INITIATION ALONG SURFACE TROUGH/WIND SHIFT BOUNDARY
THAT WILL EXIST FROM NORTH CENTRAL NEBRASKA INTO THE EASTERN
PANHANDLE. COULD BE SOME ENHANCEMENT TO THE CONVERGENCE ALONG THE
BOUNDARY FROM DIFFERENTIAL HEATING DUE TO EARLIER CLOUD
COVER...DEPENDING ON HOW MUCH MIXING EVOLVES FURTHER EAST THIS
AFTERNOON. ALOS COULD BE SOME STORMS THAT MOVE SOUTH INTO THE CWA
FROM SD. OVERAL STILL THINKING BEST THUNDERSTORM CHANCES WILL BE
ACROSS THE NORTH CENTRAL INTO THE SANDHILLS. COVERAGE WILL BE
LIMITED INITIALLY BUT MAY EVOLVE INTO CONVECTIVE CLUSTERS THROUGH
THE LATE AFTERNOON EVENING. MESOANALYSIS SUGGESTS GOOD
DESTABILIZATION OCCURRING ALREADY ALONG THIS BOUNDARY AS IT
DEVELOPS...WITH MLCAPE EXCEEDING 1500 J/KG. SO SOME POTENTIAL FOR
ISOLATED SVR HAIL AND DAMAGING WIND GUSTS AS CONVECTIVE CLUSTERS
DEVELOP.
UPDATE ISSUED AT 950 AM CDT TUE JUL 30 2013
UPDATED FORECAST TO DROP DENSE FOG ADVISORY AND INCREASE CLOUD
COVER THROUGH THE MORNING WITH AREAS OF PATCHY FOG CONTINUING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE JUL 30 2013
TODAY AND TONIGHT...DENSE FOG WOULD APPEAR TO BE VERY SHALLOW
THIS MORNING WITH THE MOON VISIBLE AT KLBF AND NEDOR SHOWING IT
LIFTING AT KLXN. SO WE WOULD EXPECT A RAPID CLEARING AFTER SUNRISE
IN SOME AREAS AS SATELLITE SHOWS AREAS OF STRATUS AT THE SAME TIME
WHICH WOULD SLOW THE LIFTING PROCESS.
A WEAK AND DECAYING MCS ACROSS NWRN NEB/SWRN SD THIS MORNING IN
COMBINATION WITH A WEAK DISTURBANCE OVER ERN COLO COULD PERHAPS
SPREAD ISOLATED SHOWERS AND THUNDERSTORMS INTO WRN NEB.
THE HRRR THEN SHOWS CONVECTIVE DESTABILIZATION ACROSS SWRN NEB BY
20Z WHICH IS PROBABLY AN HOUR OR TWO TOO FAST. THE MAIN IMPULSE
WOULD APPEAR TO BE DROPPING SOUTHEAST THROUGH NERN WY/WRN SD AT
20Z...STILL HOURS AWAY FROM THE FCST AREA. A MCS IS EXPECTED TO
DEVELOP OUT OF THE STORMS FIRING ACROSS THE NRN HIGH PLAINS WHICH
SHOULD SWEEP THRU NRN NEB OVERNIGHT. THE MCS SHOULD REMAIN MOSTLY
ALONG AND NORTH OF HIGHWAY 20.
TEMPERATURES TODAY ARE EXPECTED TO RISE INTO THE LOW TO MID 80S
IN MOST AREAS GIVEN THE CONTINUED SOUTH AND SOUTHEAST WINDS
CIRCULATING AROUND HIGH PRESSURE CENTERED OVER THE MIDWEST. THE
ENSUING WARM AIR ADVECTION FUELING THE MCS TONIGHT SHOULD KEEP
SKIES MOSTLY CLEAR SOUTH OF THE CONVECTIVE COMPLEX. THE NAM12
HINTS AT A BANK OF STRATUS FILLING IN ACROSS NWRN NEB IN THE WAKE
OF THE MCS AROUND 12Z.
SEVERE WEATHER POTENTIAL WITH THE THUNDERSTORMS THIS AFTERNOON
AND TONIGHT IS LIMITED TO 5 PERCENT OR ISOLATED WITH THE BEST
INSTABILITY AND 40 TO 50 KT 1 TO 6 KM SHEAR ACROSS NRN NEB MOSTLY
ASSOCIATED WITH THE DEVELOPING MCS. MODEL INDICATIONS SUGGEST THE
BLACK HILLS COULD BE THE GENESIS FOR A CLUSTER OF STORMS FORMING
LATE IN THE AFTERNOON WHICH WOULD MOVE EAST SOUTHEAST TOWARD
KVTN-KANW-KONL DURING THE EVENING AND OVERNIGHT. THIS IN TURN
COULD CERTAINLY INCREASE THE SEVERE WEATHER POTENTIAL IN THOSE
AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE JUL 30 2013
WEDNESDAY MORNING LINGER SHOWERS WILL BE POSSIBLE ACROSS PORTIONS
OF CENTRAL/NORTH CENTRAL NEB. THEN BREAKS IN THE CLOUDS SHOULD
HELP TO PUSH HIGHS INTO THE 80S. LATE IN THE DATE MODELS IN
AGREEMENT WITH A BOUNDARY STRETCHED FROM WEST CENTRAL KS
NORTHEAST INTO CENTRAL NEB AND ON TOWARDS THE WESTERN GREAT
LAKES. THUNDERSTORMS WILL BE POSSIBLE ALONG THE SLOW MOVING
BOUNDARY...HOWEVER IMPACT TO THE CWA IN QUESTIONS. THE LATEST NAM
AND GFS HAVE PUSHED THE BOUNDARY JUST SE OF THE CWA BY PEAK
HEATING...HOWEVER THE EC AND GEM DO DEVELOP ACTIVITY IN THE SE
CWA. WILL TREND DOWN WITH POPS...ALTHOUGH STILL RETAIN SLGHT CHC
IN THE FAR SE ZONES. MORE OF A FOCUS WILL BE THE NEXT SHORT WAVE
CROSSING THE ROCKIES. THIS WAVE SHOULD ALLOW DEVELOPMENT ON THE
HIGHER TERRAIN WITH FLOW TO PUSH THIS INTO THE PANHANDLE AND
WESTERN NEBRASKA OVERNIGHT.
THURSDAY WILL SEE YET ANOTHER SHORT WAVE TO PUSH ACROSS THE AREA.
MODELS CONTINUE TO SHOW GOOD INSTABILITY WITH DECENT SHEAR...ALSO
WILL SEE A SURF LOW DEVELOP NEAR NE CO. ANY ACTIVITY DEVELOPING IN
THE EVENING FROM PEAK HEATING WILL LIKELY BE SUSTAINED BY A 30 TO
40K LL JET. LOW FREEZING LEVEL WITH STEEP LAPSE RATE SHOULD RESULT
IN A FEW STRONG TO EVEN SEVERE STORMS...WITH HAIL THE MAIN THREAT.
FRIDAY WILL SEE AN UPPER LEVEL LOW COME ONSHORE TO THE PAC
NW...THIS WILL FLATTEN THE RIDGE AND PUSH IT EASTWARD. INITIALLY
THOUGHT THERE COULD BE A WARM UP...HOWEVER MODELS CONTINUE TO
BRING GOOD MOISTURE AROUND THE RIDGE...RESULTING IN MORE CLOUDS
THAN SUN. FORECAST RESULTS IN BELOW NORMAL HIGHS...WHICH IS CLOSE
TO MOS GUIDANCE.
LITTLE CHANGES THROUGH THE WEEKEND FOR THE AREA...AS RIDGE REMAINS
TO THE SOUTH AND LOW WILL TRAVERSE ACROSS THE US/CAN BORDER. FLOW
WILL CONTINUE TO BE NORTHWESTERLY TO ZONAL...AND MODELS CONTINUE
TO BRING WAVE AFTER WAVE ACROSS THE AREA. QPF MAY NOT BE
SIGNIFICANT...HOWEVER WILL NEED TO CONTINUE TO MENTION IN NEARLY
EVERY PERIOD PENDING TIMING OF THE WAVES. TEMPS WILL GENERALLY BE
BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1255 PM CDT TUE JUL 30 2013
HAVE ADDED VCTS IN THE VTN TAF BASED ON THE IDEA OF BETTER
CONVECTIVE COVERAGE ACROSS NC NEBRASKA THIS AFTERNOON AND EVENING.
CONFIDENCE ON COVERAGE FURTHER SOUTH IS NOT AS GOOD AND THEREFORE
LEFT OUT OF THE LBF TAF.
OTHERWISE HAVE GONE WITH MAINLY IFR CONDITIONS THROUGH THE
PERIOD...THOUGH SOME CONCERN ABOUT A REDEVELOPMENT OF LOW CLOUDS
AND/OR FOG AFTER 09Z TONIGHT. THINK BETTER CHANCES FOR THIS WOULD
BE EAST OF VTN TAF SITE SINCE A SHIFT TO A NORTHERLY WIND SHOULD
OCCUR BEFORE ONSET...BUT MAY HAVE TO BE INTRODUCED INTO THE LBF
TAF WITH LATER FCSTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1118 AM CDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 1057 AM CDT TUE JUL 30 2013
ADJUSTED SKY COVER UP FOR THE REMAINDER OF THE MORNING...AND
FOLLOWED CLOSER TO THE HRRR FOR SKY COVER FOR THE REST OF THE DAY
INTO THE NIGHT. THIS MODEL SEEMS TO BE DOING THE BEST HANDLING THE
ERODING WEST SIDE OF THE STROTOCUMULUS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CDT TUE JUL 30 2013
AREAS OF FOG HAVE DEVELOPED ACROSS THE REGION OVERNIGHT AS ELEVATED
DEW POINTS AND LIGHT WINDS HAVE AIDED IN ITS FORMATION. AFTER MAKING
A FEW PHONE CALLS AND PERUSING HIGHWAY CAMERAS THE PAST HOUR...HAVE
DECIDED TO GO AHEAD AND EXPAND THE DENSE FOG ADVISORY NORTH AND EAST
WITH THE MORNING FORECAST PACKAGE TO ACCOUNT FOR POCKETS OF DENSE
FOG THAT HAVE FORMED. WHILE MODEL GUIDANCE IS NOT HANDLING THIS FOG
VERY WELL...CANNOT SEE A REASON FOR CONDITIONS TO IMPROVE MUCH
BEFORE SUNRISE...AND WILL KEEP EXPIRATION TIME OF 14Z FOR THE TIME
BEING.
FOR TODAY...ONCE THE FOG BEGINS TO LIFT DURING THE MID MORNING
HOURS...EXPECT A FAIRLY NICE DAY ACROSS THE REGION AS TEMPERATURES
WILL BEGIN TO MODERATE CLOSER TO SEASONAL NORMS...WINDS WILL BE
LIGHT...AND SKIES WILL BEGIN TO CLEAR. WHILE CLOUDY SKIES WILL
ENVELOP THE REGION THROUGH MID MORNING HOURS...EXPECT AT LEAST A
PARTLY SUNNY AFTERNOON AS THE FRONTAL BOUNDARY TO OUR SOUTH...
RESPONSIBLE FOR THE ACTIVE WEATHER ON MONDAY...CONTINUES TO SHIFT
SOUTHEASTWARD.
THEREAFTER THE FOCUS WILL SHIFT NORTHWARD AS SHORTWAVE CROSSING THE
NORTHERN PLAINS...ALONG WITH A SURFACE COLD FRONT...BEGIN TO SAG
SOUTHWARD TOWARDS THE LOCAL AREA. THE LATEST WRF INDICATES A NICE
BAND OF CONVECTION DEVELOPING AHEAD OF THIS WAVE LATE TUESDAY
NIGHT...WHILE THE 06Z NAM/00Z GFS/EC KEEP THE BULK OF THE CONVECTION
NORTH OF THE LOCAL FORECAST AREA. HOWEVER...WITH PLENTY OF ELEVATED
INSTABILITY TO WORK WITH AND SOME SYNOPTIC SCALE FORCING...SIDED
TOWARDS THE MORE AGGRESSIVE SOLUTION OF THE WRF AND INCREASED POPS
ACROSS THE NORTH LATE TUESDAY NIGHT. THAT SAID...KEPT CONVECTION
POTENTIAL GENERALLY NORTH OF I80 DURING THE OVERNIGHT HOURS AS THE
00Z WRF SEEMS TO BE THE OUTLIER TAKING ACTIVITY MUCH FURTHER SOUTH
THAN REMAINDER OF GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 336 AM CDT TUE JUL 30 2013
PRIMARY CONCERN IN THE EXTENDED WILL BE ALMOST DAILY
CHANCES FOR PRECIPITATION. LOOKING AT THE BIG PICTURE...BY
WEDNESDAY MORNING IT APPEARS WE WILL BE IN NORTHWEST FLOW AS MODELS
IN DECENT AGREEMENT IN PLACING A MID LEVEL CUT OFF LOW JUST OFF THE
PACIFIC NORTHWEST COAST...AND ANOTHER ONE OVER WESTERN ONTARIO. IN
BETWEEN THIS IS A DIRTY RIDGE CENTERED OVER THE ROCKIES. THERE
APPEARS TO BE SOME PROGRESSION OF THESE SYSTEMS EASTWARD DURING THE
REST OF THE WORK WEEK...BUT FOR US IT LOOKS LIKE WE COULD HAVE MINOR
SHORTWAVES PASSING THROUGH THE RIDGE. SOME OF THESE MAY PACK A
LITTLE MORE PUNCH AND THE FIRST ONE OF THESE LOOKS TO BE THURSDAY
NIGHT. WILL CONTINUE TO KEEP HIGHEST POPS GOING FOR THURS NIGHT.
BACKING UP JUST A BIT AND CHECKING THE SURFACE FEATURES...IT LOOKS
LIKE THERE WILL BE A WEAK FRONTAL BOUNDARY DROPPING SOUTH ACROSS THE
CWA DURING THE DAYTIME ON WED. THIS COULD HELP TRIGGER THUNDERSTORMS
BY THE AFTERNOON. BY LATE IN THE WEEK AND INTO THE WEEKEND A
FRONTAL BOUNDARY WILL BE SOMEWHERE NEAR THE CWA AND THE INTERACTION
OF PASSING MID LEVEL DISTURBANCES WITH THE SURFACE FEATURE WILL KEEP
OUR WEATHER UNSETTLED.
AS FAR AS SEVERE CHANCES ARE CONCERNED...PROGGED DEEP LAYER SHEAR
LOOKS TO BE IMPRESSIVE...ESPECIALLY FOR THIS TIME OF YEAR...WITH
0-6 KM VALUES OF 20 TO 50 KT NOTED FOR MOST DAYS ON THE LATEST EC
AND/OR GFS RUN. INSTABILITY ALSO IMPRESSIVE WITH MU CAPE NUMBERS
QUITE HIGH. ON THE NEGATIVE SIDE...THERE COULD BE SOME CAPPING
ISSUES ESPECIALLY LATER IN THE WEEK AND INTO THE WEEKEND WITH
PROGGED 700 MB TEMPS EXPECTED TO BE BETWEEN 11 AND 15 DEGREES
CELSIUS..WITH THE GFS A LITTLE WARMER.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 550 AM CDT TUE JUL 30 2013
POOR AVIATION CONDITIONS ARE EXPECTED TO PREVAIL AT KGRI FOR THE
NEXT SEVERAL HOURS AS DENSE FOG HAS SET IN ACROSS THE TERMINAL.
PREVAILING VISIBILITIES OF 1SM OR LESS ARE EXPECTED THROUGH
30/14Z...WITH IFR/LIFR CIGS NEAR OR BELOW 500 FT. EXPECT THE
CEILINGS AND VSBYS TO SLOWLY IMPROVE DURING THE LATE MORNING
HOURS...WITH A RETURN TO VFR VSBYS AND MVFR CIGS BY 30/17Z. WINDS
WILL START OFF THE PERIOD LIGHT AND VARIABLE...AND REMAIN LIGHT
AT LESS THAN 8KTS OUT OF THE EAST THROUGH THE REMAINDER OF THE
PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...SAR
LONG TERM...EWALD
AVIATION...SAR
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
951 AM CDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 950 AM CDT TUE JUL 30 2013
UPDATED FORECAST TO DROP DENSE FOG ADVISORY AND INCREASE CLOUD
COVER THROUGH THE MORNING WITH AREAS OF PATCHY FOG CONTINUING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE JUL 30 2013
TODAY AND TONIGHT...DENSE FOG WOULD APPEAR TO BE VERY SHALLOW
THIS MORNING WITH THE MOON VISIBLE AT KLBF AND NEDOR SHOWING IT
LIFTING AT KLXN. SO WE WOULD EXPECT A RAPID CLEARING AFTER SUNRISE
IN SOME AREAS AS SATELLITE SHOWS AREAS OF STRATUS AT THE SAME TIME
WHICH WOULD SLOW THE LIFTING PROCESS.
A WEAK AND DECAYING MCS ACROSS NWRN NEB/SWRN SD THIS MORNING IN
COMBINATION WITH A WEAK DISTURBANCE OVER ERN COLO COULD PERHAPS
SPREAD ISOLATED SHOWERS AND THUNDERSTORMS INTO WRN NEB.
THE HRRR THEN SHOWS CONVECTIVE DESTABILIZATION ACROSS SWRN NEB BY
20Z WHICH IS PROBABLY AN HOUR OR TWO TOO FAST. THE MAIN IMPULSE
WOULD APPEAR TO BE DROPPING SOUTHEAST THROUGH NERN WY/WRN SD AT
20Z...STILL HOURS AWAY FROM THE FCST AREA. A MCS IS EXPECTED TO
DEVELOP OUT OF THE STORMS FIRING ACROSS THE NRN HIGH PLAINS WHICH
SHOULD SWEEP THRU NRN NEB OVERNIGHT. THE MCS SHOULD REMAIN MOSTLY
ALONG AND NORTH OF HIGHWAY 20.
TEMPERATURES TODAY ARE EXPECTED TO RISE INTO THE LOW TO MID 80S
IN MOST AREAS GIVEN THE CONTINUED SOUTH AND SOUTHEAST WINDS
CIRCULATING AROUND HIGH PRESSURE CENTERED OVER THE MIDWEST. THE
ENSUING WARM AIR ADVECTION FUELING THE MCS TONIGHT SHOULD KEEP
SKIES MOSTLY CLEAR SOUTH OF THE CONVECTIVE COMPLEX. THE NAM12
HINTS AT A BANK OF STRATUS FILLING IN ACROSS NWRN NEB IN THE WAKE
OF THE MCS AROUND 12Z.
SEVERE WEATHER POTENTIAL WITH THE THUNDERSTORMS THIS AFTERNOON
AND TONIGHT IS LIMITED TO 5 PERCENT OR ISOLATED WITH THE BEST
INSTABILITY AND 40 TO 50 KT 1 TO 6 KM SHEAR ACROSS NRN NEB MOSTLY
ASSOCIATED WITH THE DEVELOPING MCS. MODEL INDICATIONS SUGGEST THE
BLACK HILLS COULD BE THE GENESIS FOR A CLUSTER OF STORMS FORMING
LATE IN THE AFTERNOON WHICH WOULD MOVE EAST SOUTHEAST TOWARD
KVTN-KANW-KONL DURING THE EVENING AND OVERNIGHT. THIS IN TURN
COULD CERTAINLY INCREASE THE SEVERE WEATHER POTENTIAL IN THOSE
AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE JUL 30 2013
WEDNESDAY MORNING LINGER SHOWERS WILL BE POSSIBLE ACROSS PORTIONS
OF CENTRAL/NORTH CENTRAL NEB. THEN BREAKS IN THE CLOUDS SHOULD
HELP TO PUSH HIGHS INTO THE 80S. LATE IN THE DATE MODELS IN
AGREEMENT WITH A BOUNDARY STRETCHED FROM WEST CENTRAL KS
NORTHEAST INTO CENTRAL NEB AND ON TOWARDS THE WESTERN GREAT
LAKES. THUNDERSTORMS WILL BE POSSIBLE ALONG THE SLOW MOVING
BOUNDARY...HOWEVER IMPACT TO THE CWA IN QUESTIONS. THE LATEST NAM
AND GFS HAVE PUSHED THE BOUNDARY JUST SE OF THE CWA BY PEAK
HEATING...HOWEVER THE EC AND GEM DO DEVELOP ACTIVITY IN THE SE
CWA. WILL TREND DOWN WITH POPS...ALTHOUGH STILL RETAIN SLGHT CHC
IN THE FAR SE ZONES. MORE OF A FOCUS WILL BE THE NEXT SHORT WAVE
CROSSING THE ROCKIES. THIS WAVE SHOULD ALLOW DEVELOPMENT ON THE
HIGHER TERRAIN WITH FLOW TO PUSH THIS INTO THE PANHANDLE AND
WESTERN NEBRASKA OVERNIGHT.
THURSDAY WILL SEE YET ANOTHER SHORT WAVE TO PUSH ACROSS THE AREA.
MODELS CONTINUE TO SHOW GOOD INSTABILITY WITH DECENT SHEAR...ALSO
WILL SEE A SURF LOW DEVELOP NEAR NE CO. ANY ACTIVITY DEVELOPING IN
THE EVENING FROM PEAK HEATING WILL LIKELY BE SUSTAINED BY A 30 TO
40K LL JET. LOW FREEZING LEVEL WITH STEEP LAPSE RATE SHOULD RESULT
IN A FEW STRONG TO EVEN SEVERE STORMS...WITH HAIL THE MAIN THREAT.
FRIDAY WILL SEE AN UPPER LEVEL LOW COME ONSHORE TO THE PAC
NW...THIS WILL FLATTEN THE RIDGE AND PUSH IT EASTWARD. INITIALLY
THOUGHT THERE COULD BE A WARM UP...HOWEVER MODELS CONTINUE TO
BRING GOOD MOISTURE AROUND THE RIDGE...RESULTING IN MORE CLOUDS
THAN SUN. FORECAST RESULTS IN BELOW NORMAL HIGHS...WHICH IS CLOSE
TO MOS GUIDANCE.
LITTLE CHANGES THROUGH THE WEEKEND FOR THE AREA...AS RIDGE REMAINS
TO THE SOUTH AND LOW WILL TRAVERSE ACROSS THE US/CAN BORDER. FLOW
WILL CONTINUE TO BE NORTHWESTERLY TO ZONAL...AND MODELS CONTINUE
TO BRING WAVE AFTER WAVE ACROSS THE AREA. QPF MAY NOT BE
SIGNIFICANT...HOWEVER WILL NEED TO CONTINUE TO MENTION IN NEARLY
EVERY PERIOD PENDING TIMING OF THE WAVES. TEMPS WILL GENERALLY BE
BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 617 AM CDT TUE JUL 30 2013
LIFR CIGS SHOULD IMPROVE TO IFR/MVFR/VFR FROM WEST TO EAST THIS
MORNING. BOTH THE NAM AND RAP MODELS SHOW THIS AREA OF CLOUDS
EXITING BETWEEN 18Z-20Z. THEREAFTER...A TSTM COMPLEX SHOULD BEGIN
ORGANIZING ACROSS NERN WY/WRN SD WHICH SHOULD MOVE EAST AND
SOUTHEAST AFFECTING NRN NEBRASKA...MAINLY AFTER 00Z. NOTE THAT A
FEW STORMS COULD FORM ACROSS THE NEBRASKA PANHANDLE THIS AFTERNOON
AND MOVE EAST BUT THE MAIN COMPLEX FORMS ACROSS SD AND TSTMS ARE
NOT EXPECTED SOUTH OF NEBRASKA HIGHWAY 2 TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...POWER
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
622 AM CDT TUE JUL 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE JUL 30 2013
TODAY AND TONIGHT...DENSE FOG WOULD APPEAR TO BE VERY SHALLOW
THIS MORNING WITH THE MOON VISIBLE AT KLBF AND NEDOR SHOWING IT
LIFTING AT KLXN. SO WE WOULD EXPECT A RAPID CLEARING AFTER SUNRISE
IN SOME AREAS AS SATELLITE SHOWS AREAS OF STRATUS AT THE SAME TIME
WHICH WOULD SLOW THE LIFTING PROCESS.
A WEAK AND DECAYING MCS ACROSS NWRN NEB/SWRN SD THIS MORNING IN
COMBINATION WITH A WEAK DISTURBANCE OVER ERN COLO COULD PERHAPS
SPREAD ISOLATED SHOWERS AND THUNDERSTORMS INTO WRN NEB.
THE HRRR THEN SHOWS CONVECTIVE DESTABILIZATION ACROSS SWRN NEB BY
20Z WHICH IS PROBABLY AN HOUR OR TWO TOO FAST. THE MAIN IMPULSE
WOULD APPEAR TO BE DROPPING SOUTHEAST THROUGH NERN WY/WRN SD AT
20Z...STILL HOURS AWAY FROM THE FCST AREA. A MCS IS EXPECTED TO
DEVELOP OUT OF THE STORMS FIRING ACROSS THE NRN HIGH PLAINS WHICH
SHOULD SWEEP THRU NRN NEB OVERNIGHT. THE MCS SHOULD REMAIN MOSTLY
ALONG AND NORTH OF HIGHWAY 20.
TEMPERATURES TODAY ARE EXPECTED TO RISE INTO THE LOW TO MID 80S
IN MOST AREAS GIVEN THE CONTINUED SOUTH AND SOUTHEAST WINDS
CIRCULATING AROUND HIGH PRESSURE CENTERED OVER THE MIDWEST. THE
ENSUING WARM AIR ADVECTION FUELING THE MCS TONIGHT SHOULD KEEP
SKIES MOSTLY CLEAR SOUTH OF THE CONVECTIVE COMPLEX. THE NAM12
HINTS AT A BANK OF STRATUS FILLING IN ACROSS NWRN NEB IN THE WAKE
OF THE MCS AROUND 12Z.
SEVERE WEATHER POTENTIAL WITH THE THUNDERSTORMS THIS AFTERNOON
AND TONIGHT IS LIMITED TO 5 PERCENT OR ISOLATED WITH THE BEST
INSTABILITY AND 40 TO 50 KT 1 TO 6 KM SHEAR ACROSS NRN NEB MOSTLY
ASSOCIATED WITH THE DEVELOPING MCS. MODEL INDICATIONS SUGGEST THE
BLACK HILLS COULD BE THE GENESIS FOR A CLUSTER OF STORMS FORMING
LATE IN THE AFTERNOON WHICH WOULD MOVE EAST SOUTHEAST TOWARD
KVTN-KANW-KONL DURING THE EVENING AND OVERNIGHT. THIS IN TURN
COULD CERTAINLY INCREASE THE SEVERE WEATHER POTENTIAL IN THOSE
AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE JUL 30 2013
WEDNESDAY MORNING LINGER SHOWERS WILL BE POSSIBLE ACROSS PORTIONS
OF CENTRAL/NORTH CENTRAL NEB. THEN BREAKS IN THE CLOUDS SHOULD
HELP TO PUSH HIGHS INTO THE 80S. LATE IN THE DATE MODELS IN
AGREEMENT WITH A BOUNDARY STRETCHED FROM WEST CENTRAL KS
NORTHEAST INTO CENTRAL NEB AND ON TOWARDS THE WESTERN GREAT
LAKES. THUNDERSTORMS WILL BE POSSIBLE ALONG THE SLOW MOVING
BOUNDARY...HOWEVER IMPACT TO THE CWA IN QUESTIONS. THE LATEST NAM
AND GFS HAVE PUSHED THE BOUNDARY JUST SE OF THE CWA BY PEAK
HEATING...HOWEVER THE EC AND GEM DO DEVELOP ACTIVITY IN THE SE
CWA. WILL TREND DOWN WITH POPS...ALTHOUGH STILL RETAIN SLGHT CHC
IN THE FAR SE ZONES. MORE OF A FOCUS WILL BE THE NEXT SHORT WAVE
CROSSING THE ROCKIES. THIS WAVE SHOULD ALLOW DEVELOPMENT ON THE
HIGHER TERRAIN WITH FLOW TO PUSH THIS INTO THE PANHANDLE AND
WESTERN NEBRASKA OVERNIGHT.
THURSDAY WILL SEE YET ANOTHER SHORT WAVE TO PUSH ACROSS THE AREA.
MODELS CONTINUE TO SHOW GOOD INSTABILITY WITH DECENT SHEAR...ALSO
WILL SEE A SURF LOW DEVELOP NEAR NE CO. ANY ACTIVITY DEVELOPING IN
THE EVENING FROM PEAK HEATING WILL LIKELY BE SUSTAINED BY A 30 TO
40K LL JET. LOW FREEZING LEVEL WITH STEEP LAPSE RATE SHOULD RESULT
IN A FEW STRONG TO EVEN SEVERE STORMS...WITH HAIL THE MAIN THREAT.
FRIDAY WILL SEE AN UPPER LEVEL LOW COME ONSHORE TO THE PAC
NW...THIS WILL FLATTEN THE RIDGE AND PUSH IT EASTWARD. INITIALLY
THOUGHT THERE COULD BE A WARM UP...HOWEVER MODELS CONTINUE TO
BRING GOOD MOISTURE AROUND THE RIDGE...RESULTING IN MORE CLOUDS
THAN SUN. FORECAST RESULTS IN BELOW NORMAL HIGHS...WHICH IS CLOSE
TO MOS GUIDANCE.
LITTLE CHANGES THROUGH THE WEEKEND FOR THE AREA...AS RIDGE REMAINS
TO THE SOUTH AND LOW WILL TRAVERSE ACROSS THE US/CAN BORDER. FLOW
WILL CONTINUE TO BE NORTHWESTERLY TO ZONAL...AND MODELS CONTINUE
TO BRING WAVE AFTER WAVE ACROSS THE AREA. QPF MAY NOT BE
SIGNIFICANT...HOWEVER WILL NEED TO CONTINUE TO MENTION IN NEARLY
EVERY PERIOD PENDING TIMING OF THE WAVES. TEMPS WILL GENERALLY BE
BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 617 AM CDT TUE JUL 30 2013
LIFR CIGS SHOULD IMPROVE TO IFR/MVFR/VFR FROM WEST TO EAST THIS
MORNING. BOTH THE NAM AND RAP MODELS SHOW THIS AREA OF CLOUDS
EXITING BETWEEN 18Z-20Z. THEREAFTER...A TSTM COMPLEX SHOULD BEGIN
ORGANIZING ACROSS NERN WY/WRN SD WHICH SHOULD MOVE EAST AND
SOUTHEAST AFFECTING NRN NEBRASKA...MAINLY AFTER 00Z. NOTE THAT A
FEW STORMS COULD FORM ACROSS THE NEBRASKA PANHANDLE THIS AFTERNOON
AND MOVE EAST BUT THE MAIN COMPLEX FORMS ACROSS SD AND TSTMS ARE
NOT EXPECTED SOUTH OF NEBRASKA HIGHWAY 2 TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING FOR
NEZ038-059-069>071.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
401 AM CDT TUE JUL 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE JUL 30 2013
TODAY AND TONIGHT...DENSE FOG WOULD APPEAR TO BE VERY SHALLOW
THIS MORNING WITH THE MOON VISIBLE AT KLBF AND NEDOR SHOWING IT
LIFTING AT KLXN. SO WE WOULD EXPECT A RAPID CLEARING AFTER SUNRISE
IN SOME AREAS AS SATELLITE SHOWS AREAS OF STRATUS AT THE SAME TIME
WHICH WOULD SLOW THE LIFTING PROCESS.
A WEAK AND DECAYING MCS ACROSS NWRN NEB/SWRN SD THIS MORNING IN
COMBINATION WITH A WEAK DISTURBANCE OVER ERN COLO COULD PERHAPS
SPREAD ISOLATED SHOWERS AND THUNDERSTORMS INTO WRN NEB.
THE HRRR THEN SHOWS CONVECTIVE DESTABILIZATION ACROSS SWRN NEB BY
20Z WHICH IS PROBABLY AN HOUR OR TWO TOO FAST. THE MAIN IMPULSE
WOULD APPEAR TO BE DROPPING SOUTHEAST THROUGH NERN WY/WRN SD AT
20Z...STILL HOURS AWAY FROM THE FCST AREA. A MCS IS EXPECTED TO
DEVELOP OUT OF THE STORMS FIRING ACROSS THE NRN HIGH PLAINS WHICH
SHOULD SWEEP THRU NRN NEB OVERNIGHT. THE MCS SHOULD REMAIN MOSTLY
ALONG AND NORTH OF HIGHWAY 20.
TEMPERATURES TODAY ARE EXPECTED TO RISE INTO THE LOW TO MID 80S
IN MOST AREAS GIVEN THE CONTINUED SOUTH AND SOUTHEAST WINDS
CIRCULATING AROUND HIGH PRESSURE CENTERED OVER THE MIDWEST. THE
ENSUING WARM AIR ADVECTION FUELING THE MCS TONIGHT SHOULD KEEP
SKIES MOSTLY CLEAR SOUTH OF THE CONVECTIVE COMPLEX. THE NAM12
HINTS AT A BANK OF STRATUS FILLING IN ACROSS NWRN NEB IN THE WAKE
OF THE MCS AROUND 12Z.
SEVERE WEATHER POTENTIAL WITH THE THUNDERSTORMS THIS AFTERNOON
AND TONIGHT IS LIMITED TO 5 PERCENT OR ISOLATED WITH THE BEST
INSTABILITY AND 40 TO 50 KT 1 TO 6 KM SHEAR ACROSS NRN NEB MOSTLY
ASSOCIATED WITH THE DEVELOPING MCS. MODEL INDICATIONS SUGGEST THE
BLACK HILLS COULD BE THE GENESIS FOR A CLUSTER OF STORMS FORMING
LATE IN THE AFTERNOON WHICH WOULD MOVE EAST SOUTHEAST TOWARD
KVTN-KANW-KONL DURING THE EVENING AND OVERNIGHT. THIS IN TURN
COULD CERTAINLY INCREASE THE SEVERE WEATHER POTENTIAL IN THOSE
AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE JUL 30 2013
WEDNESDAY MORNING LINGER SHOWERS WILL BE POSSIBLE ACROSS PORTIONS
OF CENTRAL/NORTH CENTRAL NEB. THEN BREAKS IN THE CLOUDS SHOULD
HELP TO PUSH HIGHS INTO THE 80S. LATE IN THE DATE MODELS IN
AGREEMENT WITH A BOUNDARY STRETCHED FROM WEST CENTRAL KS
NORTHEAST INTO CENTRAL NEB AND ON TOWARDS THE WESTERN GREAT
LAKES. THUNDERSTORMS WILL BE POSSIBLE ALONG THE SLOW MOVING
BOUNDARY...HOWEVER IMPACT TO THE CWA IN QUESTIONS. THE LATEST NAM
AND GFS HAVE PUSHED THE BOUNDARY JUST SE OF THE CWA BY PEAK
HEATING...HOWEVER THE EC AND GEM DO DEVELOP ACTIVITY IN THE SE
CWA. WILL TREND DOWN WITH POPS...ALTHOUGH STILL RETAIN SLGHT CHC
IN THE FAR SE ZONES. MORE OF A FOCUS WILL BE THE NEXT SHORT WAVE
CROSSING THE ROCKIES. THIS WAVE SHOULD ALLOW DEVELOPMENT ON THE
HIGHER TERRAIN WITH FLOW TO PUSH THIS INTO THE PANHANDLE AND
WESTERN NEBRASKA OVERNIGHT.
THURSDAY WILL SEE YET ANOTHER SHORT WAVE TO PUSH ACROSS THE AREA.
MODELS CONTINUE TO SHOW GOOD INSTABILITY WITH DECENT SHEAR...ALSO
WILL SEE A SURF LOW DEVELOP NEAR NE CO. ANY ACTIVITY DEVELOPING IN
THE EVENING FROM PEAK HEATING WILL LIKELY BE SUSTAINED BY A 30 TO
40K LL JET. LOW FREEZING LEVEL WITH STEEP LAPSE RATE SHOULD RESULT
IN A FEW STRONG TO EVEN SEVERE STORMS...WITH HAIL THE MAIN THREAT.
FRIDAY WILL SEE AN UPPER LEVEL LOW COME ONSHORE TO THE PAC
NW...THIS WILL FLATTEN THE RIDGE AND PUSH IT EASTWARD. INITIALLY
THOUGHT THERE COULD BE A WARM UP...HOWEVER MODELS CONTINUE TO
BRING GOOD MOISTURE AROUND THE RIDGE...RESULTING IN MORE CLOUDS
THAN SUN. FORECAST RESULTS IN BELOW NORMAL HIGHS...WHICH IS CLOSE
TO MOS GUIDANCE.
LITTLE CHANGES THROUGH THE WEEKEND FOR THE AREA...AS RIDGE REMAINS
TO THE SOUTH AND LOW WILL TRAVERSE ACROSS THE US/CAN BORDER. FLOW
WILL CONTINUE TO BE NORTHWESTERLY TO ZONAL...AND MODELS CONTINUE
TO BRING WAVE AFTER WAVE ACROSS THE AREA. QPF MAY NOT BE
SIGNIFICANT...HOWEVER WILL NEED TO CONTINUE TO MENTION IN NEARLY
EVERY PERIOD PENDING TIMING OF THE WAVES. TEMPS WILL GENERALLY BE
BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM CDT MON JUL 29 2013
THE 06Z TAF ISSUANCE FOR KLBF AND KVTN. IFR CONDITIONS ARE
FORECAST FOR KLBF UNTIL 14Z. LOWEST CIGS AND VSBYS FAVORED TO
OCCUR FROM 09Z-13Z. IFR WITH SOME DEVELOPING LIFR CONDITIONS IN
CENTRAL AND SOUTH CENTRAL NEBRASKA WILL AFFECT PORTIONS OF WESTERN
NEBRASKA OVERNIGHT INTO EARLY TUESDAY. CIGS AND VSBY TO QUICKLY
LIFT/IMPROVE AFTER 14Z TO VFR. CURRENT VFR CONDITIONS AT KVTN
SHOULD REMAIN PREVAILING OVERNIGHT. HAVE CONTINUED A TEMPO FOR 5SM
BR 09Z-13Z. LOW STRATUS LIFTING NORTHWEST TOWARD KANW MAY BE ABLE
TO REACH KVTN AND WILL NEED TO MONITOR OVERNIGHT. ISOLATED/SCATTERED
STORM DEVELOPMENT POSSIBLE TUES AFTERNOON/EVENING...BUT WILL NOT
INCLUDE ATTM WITH MODEL DIFFERENCES IN TIMING LEADING TO LOW
CONFIDENCE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING FOR
NEZ038-059-069>071.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1028 PM EDT WED JUL 31 2013
.SYNOPSIS...
SHOWERS AND SCATTERED THUNDERSTORMS WILL OVERSPREAD THE REGION VERY
LATE TONIGHT AND THURSDAY AS A COLD FRONT APPROACHES THEN CROSSES
THE REGION. LINGERING MOISTURE AND SOMEWHAT UNSTABLE AIR BEHIND THE
FRONT MAY BRING A FEW MORE WIDELY SCATTERED SHOWERS ON FRIDAY. BELOW
AVERAGE TEMPERATURES WILL LAST THROUGH THE WEEKEND AND INTO AT LEAST
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
RADAR IMAGERY THIS EVENING SHOWING AN AREA OF STEADY SHOWERS OVER
SOUTHERN ONTARIO...BUT THESE ARE GENERALLY MOVING TO THE ENE AND ARE
STRUGGLING TO MAKE MUCH HEADWAY TOWARDS WESTERN NY AS THE NEWLY
LAUNCHED 00Z KBUF RAOB STILL SHOWS PLENTY OF DRY AIR IN THE LOW
LEVELS. RECENT RADAR TRENDS SUGGEST A FEW SPRINKLES OR LIGHT SHOWERS
MAY CLIP PORTIONS OF NIAGARA COUNTY NEAR YOUNGSTOWN OVER THE NEXT
FEW HOURS. SHORT TERM MESOSCALE MODEL GUIDANCE SUCH AS THE HRRR AND
THE 18Z NAM HAVE A REASONABLE HANDLE ON THIS FIRST BATCH OF RAIN AND
KEEP IT TO OUR NORTH AND WEST THROUGH MUCH OF THE NIGHT UNTIL
UPSTREAM SHOWERS OVER LOWER MICHIGAN APPROACH.
LATE TONIGHT INTO THURSDAY A SHORTWAVE EVIDENT IN WATER VAPOR
IMAGERY CROSSING LAKE MICHIGAN THIS EVENING WILL MOVE EAST AND GAIN
AMPLITUDE WITH TIME AS ADDITIONAL SHORTWAVE ENERGY DIGS INTO A
DEVELOPING GREAT LAKES TROUGH. LARGE SCALE ASCENT WILL INCREASE AS
DPVA SPREADS ACROSS THE LOWER LAKES LATE TONIGHT IN ADVANCE OF THE
DIGGING MID LEVEL SHORTWAVE. AN UPPER LEVEL JET WILL ALSO STRENGTHEN
ACROSS SOUTHERN QUEBEC...WITH THE FAVORED RIGHT ENTRANCE REGION AND
ASSOCIATED UPPER LEVEL DIVERGENCE PLACED OVER THE LOWER LAKES. THE
MID LEVEL SHORTWAVE WILL CATCH UP TO A SURFACE COLD FRONT ACROSS
LOWER MICHIGAN LATER THIS EVENING...WITH LOW LEVEL CONVERGENCE
BECOMING ENHANCED ALONG THE FRONTAL BOUNDARY. PWAT RISES TO A
RESPECTABLE 1.5 INCHES OR SO OVERNIGHT...AND THE QUALITY OF DYNAMICS
AND MOISTURE COMING TOGETHER STILL SUPPORT A HIGH PROBABILITY OF
RAIN.
MOST OF THE RAIN SHOULD FALL IN A 3-5 HOUR WINDOW FROM VERY LATE
TONIGHT THROUGH THURSDAY MORNING IN THE WEST...AND HOUR OR TWO LATER
IN THE GENESEE VALLEY...AND FROM MID MORNING THROUGH MID AFTERNOON
THURSDAY ACROSS THE NORTH COUNTRY AND CENTRAL NY. MODEST INSTABILITY
MAY SUPPORT A FEW EMBEDDED THUNDERSTORMS ALTHOUGH EXPECT COVERAGE TO
REMAIN WIDELY SCATTERED IN NATURE. EXPECT OVERALL RAIN AMOUNTS TO
RANGE FROM A QUARTER TO THIRD OF AN INCH IN MOST LOCATIONS...
ALTHOUGH ANY EMBEDDED CONVECTION WILL PRODUCE LOCALLY HIGHER AMOUNTS.
FOLLOWING THE END OF THE SHOWERS LATER THURSDAY MORNING IN THE
WEST...EXPECT A FEW BREAKS OF SUNSHINE ALTHOUGH LINGERING LOW LEVEL
MOISTURE AND COOLING TEMPS ALOFT WILL LIKELY PRODUCE PLENTY OF
CUMULUS DURING THE AFTERNOON.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
THURSDAY NIGHT A COLD FRONT WILL CONTINUE TO SLICE ACROSS THE
REMAINDER OF THE CWA...WITH A NARROW LINE OF SHOWERS LIKELY ALONG
THE IMMEDIATE FRONTAL BOUNDARY. THE DEEPEST MOISTURE WILL RUN OUT
AHEAD OF THE COLD FRONT...LEAVING A MORE STABLE ATMOSPHERE FOR THE
COLD FRONT TO SHIFT ACROSS...WITH SHOWERS LIKELY BUT NO THUNDER.
TEMPERATURES THURSDAY NIGHT WILL DROP BACK INTO THE 50S...WITH A
SPOT 40S NOT OUT OF THE QUESTION ACROSS THE VALLEYS OF THE INTERIOR
SOUTHERN TIER.
FOR FRIDAY AND INTO SATURDAY A -1SD UPPER LEVEL TROUGH WILL BE
ANCHORED ACROSS THE NORTHEAST AND SOUTHERN CANADA. MULTIPLE
SHORTWAVES WILL RIDE THROUGH THIS TROUGH SPARKING SHOWERS ON BOTH
FRIDAY AND SATURDAY. WILL COVER THIS WITH A BROAD BRUSH CHANCE POP
THROUGH THE TIME PERIOD...WITH GREATEST CHANCES DURING THE AFTERNOON
AND EARLY EVENING WHEN DAYTIME INSTABILITY SHOWERS WILL BE GREAT
CHANCES FOR OCCURRENCE.
ALSO OF NOTE FOR BOTH FRIDAY MORNING AND SATURDAY MORNING WILL BE A
MARGINAL SETUP FOR LAKE EFFECT RAIN. TEMPERATURES ALOFT BOTH
MORNINGS WILL DROP TO ABOUT +9 TO +10...WHICH WILL JUST TOUCH THE
DELTA 13C FROM 850 HPA DOWN TO THE SURFACE...WITH LIMITED LAKE
INSTABILITY. A LAKE EFFECT RAIN SHOWER IS POSSIBLE BOTH MORNINGS.
TEMPERATURES BOTH DAYS WILL AVERAGE JUST BELOW NORMAL WITH HIGHS IN
THE LOW TO MID 70S...AND NIGHTTIME LOWS DROPPING BACK INTO THE
50S...WITH AROUND 60 ALONG THE LAKESHORE PLAINS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THIS TIME
PERIOD...WITH AN AMPLIFIED PATTERN CONSISTING OF A RIDGE ACROSS THE
WEST AND TROUGH ACROSS THE EAST. VARIOUS SHORTWAVES RIDING THROUGH
THIS TROUGH WILL BRING CHANCES OF PRECIPITATION.
ON SUNDAY MODEL CONSENSUS IS NOW TO BRING A SHORTWAVE TROUGH
DROPPING FROM NEAR THE NORTHERN GREAT LAKES AND ACROSS OUR REGION.
THE CORE OF THE SHORTWAVE...MINUS 2 SD AT 500 HPA ACCORDING TO THE
06Z/31 GEFS WILL RIDE ACROSS THE NORTH COUNTRY. WITH ANOTHER SHOT OF
COLD AIR WITH THIS SHORT WAVE...AROUND 6 TO 7C AT 850 HPA...CREATING
STEEP LOW LEVEL LAPSE RATES...COMBINED WITH THE PASSAGE OF THE
SHORTWAVE A CHANCE OF SHOWERS WILL BE POSSIBLE SUNDAY. WILL HAVE THE
GREATEST CHANCE ACROSS LAKE ONTARIO AND THE NORTH COUNTRY WHERE THE
STEEPER LAPSE RATES AND GREATER HEIGHT FALLS WILL BE FOUND.
THE COOL POOL OF AIR ALOFT WILL ALSO CREATE A MOSTLY CLOUDY DAY WITH
COOL AFTERNOON TEMPERATURES. WITH NOT MUCH SUNSHINE SUNDAY HIGHS
WILL ONLY CLIMB INTO THE UPPER 60S TO LOWER 70S ACROSS THE REGION.
HIGH PRESSURE WILL START TO BUILD INTO THE REGION SUNDAY NIGHT AND
PUSH DRIER AIR ACROSS THE REGION. THIS DRIER AIR COUPLED WITH THE
LOSS OF DAYTIME HEATING AND THE SUBSIDENCE BEHIND THE SHORTWAVE WILL
BRING AN END TO THE SHOWERS AND ALLOW FOR SOME CLEARING
SKIES....ESPECIALLY ACROSS WNY. WINDS WILL VEER TO NORTHWEST WHICH
WITH THE UPSLOPE FLOW MAY LINGER LOW CLOUDS ACROSS THE WNY...AND
THIS WILL MAKE FOR A LITTLE BIT OF UNCERTAINTY TO OVERNIGHT LOWS.
TOTAL CLEARING WILL ALLOW FOR A VERY CHILLY NIGHT WITH MANY AREAS
DROPPING DOWN INTO THE 40S...WITH ONLY AROUND 50 NEAR THE
LAKESHORES. FOR NOW LEAVE SOME LOW CLOUDS IN THE GRIDS OVERNIGHT AND
NOT GO QUITE AS COLD AS WHAT A COMPLETE CLEARING NIGHT WOULD GIVE
US. THE OTHER CONCERN FOR SUNDAY NIGHT WILL BE LAKE EFFECT CLOUDS
AND POSSIBLE LIGHT SHOWERS SOUTHEAST OF LAKE ONTARIO. WITH A CHILLY
8C 850 HPA AIR CROSSING THE LAKE SOME LAKE EFFECT CLOUDS AND PERHAPS
EVEN A LIGHT SHOWER IS POSSIBLE...THOUGH SYNOPTIC MOISTURE IS
LACKING AND WILL HOLD POPS SOUTHEAST OF LAKE ONTARIO TO LOW
CHANCE.
ON MONDAY SOME BACKING TO THE WINDS AS HIGH PRESSURE DROPS JUST TO
THE SOUTH OF THE REGION WILL ALLOW FOR CLEARING SKIES. CLOUDS WILL
BE MOST PLENTIFUL ACROSS THE NORTH COUNTRY CLOSER TO THE UPPER LEVEL
LOW...AND IN FACT THERE MAY EVEN STILL BE A SHOWER THIS DAY...SO
WILL HAVE A LOW CHANCE POP ACROSS THIS REGION.
HIGHS MONDAY WILL LIKELY BE A COUPLE DEGREES WARMER THAN SUNDAY WITH
THE ADDITIONAL SUNSHINE...AND NOT AS COOL TEMPERATURES ALOFT. HIGHS
WILL REACH BACK INTO THE 70S ACROSS THE REGION...COOLEST ACROSS THE
NORTH COUNTRY WHERE SOME CLOUDINESS MAY LINGER.
ANOTHER SHORTWAVE WILL RIDE ALONG THE WESTERN PERIPHERY OF THIS
UPPER LEVEL TROUGH AND DROP ACROSS THE GREAT LAKES REGION TUESDAY
AND WEDNESDAY. THIS WILL BRING ADDITIONAL CHANCES FOR SHOWERS...WITH
TEMPERATURES REMAINING COOL.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL PREVAIL FOR MUCH OF TONIGHT AS THE FIRST AREA OF
RAIN OVER SOUTHERN ONTARIO WILL REMAIN TO THE NORTH AND WEST OF THE
AREA THROUGH AT LEAST 08Z-09Z. THIS WILL LEAVE THICKENING AND
LOWERING MID LEVEL CLOUDS SPREADING FROM WEST TO EAST ACROSS THE
AREA. EXPECT A 3-5 HOUR PERIOD OF SHOWERS TO CROSS THE REGION FROM
WEST TO EAST LATE TONIGHT THROUGH THE FIRST HALF OF THURSDAY AS A
COLD FRONT AND STRENGTHENING MID LEVEL TROUGH CROSS THE AREA. THE
HEAVIER SHOWERS MAY PRODUCE PERIODS OF MVFR CIGS/VSBY AND POSSIBLY
EVEN A BRIEF PERIOD OF IFR. BEHIND THE COLD FRONT EXPECT RAIN TO
TAPER OFF...ALTHOUGH MVFR CIGS MAY LINGER FOR A FEW HOURS BEFORE
IMPROVING TO VFR DURING THE AFTERNOON.
FARTHER EAST AT KART...EXPECT THE SAME TREND JUST A FEW HOURS
LATER...WITH THE BULK OF THE RAIN AND POTENTIAL FOR LOWER CIGS/VSBY
COMING FROM MID MORNING THROUGH MID AFTERNOON THURSDAY.
OUTLOOK...
FRIDAY AND SATURDAY...MAINLY VFR WITH A SMALL CHANCE OF SHOWERS.
SUNDAY AND MONDAY...VFR.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE ACROSS THE
LOWER LAKES TONIGHT. AFTER A FRONT CROSSES THE LAKES ON
THURSDAY...THE WINDS WILL SWITCH TO THE SOUTHWEST AND PICK UP A
BIT...BUT CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. MORE IMPORTANTLY...THE FRONT WILL BRING A GOOD
CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS LATE TONIGHT AND
THURSDAY...WITH LOCAL INCREASES IN WIND AND WAVES POSSIBLE.
THE PRESSURE GRADIENT BETWEEN BETWEEN A SURFACE HIGH OVER THE MIDDLE
ATLANTIC STATES AND LOW PRESSURE PUSHING ACROSS HUDSON BAY WILL
CAUSE WESTERLY WINDS TO PICK UP A LITTLE MORE ON FRIDAY. WATERSPOUTS
WILL BECOME POSSIBLE AGAIN AT TIMES FRIDAY INTO THE WEEKEND AS TEMPS
COOL ALOFT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LEVAN
NEAR TERM...HITCHCOCK
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...HITCHCOCK
MARINE...HITCHCOCK/LEVAN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1023 AM EDT TUE JUL 30 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE ACROSS SOUTHERN QUEBEC WILL DEPART
NORTHEASTWARD THIS MORNING ALLOWING HIGH PRESSURE TO BUILD INTO THE
NORTH COUNTRY THIS AFTERNOON THROUGH WEDNESDAY. AN ISOLATED RAIN
SHOWER IS POSSIBLE THIS MORNING...FOLLOWED BY MOSTLY CLEAR AND
PLEASANT WEATHER CONDITIONS TONIGHT AND WEDNESDAY. THE NEXT UPPER
TROUGH APPROACHING FROM THE GREAT LAKES REGION WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO THE REGION THURSDAY AFTERNOON AND
EVENING. ADDITIONAL SHOWERS ARE POSSIBLE FRIDAY AND SATURDAY AS A
BROAD UPPER LEVEL TROUGH BECOMES ESTABLISHED OVER NEW YORK AND NEW
ENGLAND. TEMPERATURES WILL REACH THE UPPER 70S TODAY...LOW 80S ON
WEDNESDAY...AND THEN GENERALLY IN THE MID TO UPPER 70S THROUGH THE
REMAINDER OF THE WEEK...WHICH IS SLIGHTLY BELOW AVERAGE FOR THE
START OF AUGUST.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1019 AM EDT TUESDAY...MINOR ADJUSTMENTS TO SKY COVER AND
TEMPS AS WE PROGRESS INTO THE LATE MORNING HOURS. OTW INHERITED
FORECAST REMAINS IN GOOD SHAPE. MAINTAINED PRIOR IDEA OF AN
OUTSIDE SHOT OF A FEW LIGHT SHOWERS OR SPRINKLES ACROSS NERN VT
TODAY...BUT LATEST PROXY RAP SOUNDINGS SHOW A DRY AND DEEPLY MIXED
PBL TO NEARLY 700 MB TODAY SO ANY ACTIVITY WOULD BE LIGHT AT BEST
WITH MOST AREAS...EVEN IN THESE LOCALES REMAINING DRY. HAVE A
GREAT DAY.
PREVIOUS DISCUSSION: EARLY MORNING WATER VAPOR IMAGERY REVEALS
COMPACT MID-LEVEL VORT CENTERED ACROSS SWRN QUEBEC ABOUT 100 MI
NORTH OF KMSS AT 07Z. THIS SYSTEM WILL CONTINUE TO TRANSLATE ENEWD
TODAY AND GENERALLY AWAY FROM THE NORTH COUNTRY. LINGERING/ISOLD
-SHRA NEAR THE INTL BORDER PER CXX 88-D SHOULD GENERALLY END BY
15-16Z AS DRIER AIR WORKS IN ON DEVELOPING NW FLOW BEHIND THE VORT
MAX /MID-LEVEL TROUGH. ALSO ANTICIPATING PRONOUNCED MID-LEVEL
HEIGHT RISES THIS AFTN. INSOLATIONAL EFFECTS AND SUBSIDENCE ALOFT
SHOULD ALLOW SKIES TO TREND MOSTLY SUNNY THIS AFTN. IT APPEARS
AFTN VALLEY HIGHS WILL REACH THE UPR 70S. LIGHT AND VARIABLE WINDS
EARLY THIS MORNING WILL BECOME W-NW AT 5-10 MPH LATE MORNING THRU
AFTN. NOT MUCH FOG AROUND EARLY THIS MORNING DUE TO CLOUD
COVER...AND ANY PATCHY FOG DEVELOPMENT BETWEEN NOW AND SUNRISE
WILL DISSIPATE BY 12Z.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY/...
AS OF 329 AM EDT TUESDAY...A QUIET AND DRY STRETCH OF WEATHER IS EXPECTED
TONIGHT...WEDNESDAY...AND WEDNESDAY NIGHT. SHORTWAVE RIDGING
TRANSLATES FROM W-E ACROSS THE REGION AND WEAK SFC RIDGE WILL BRING
TRANQUIL WEATHER AND LIGHT WIND CONDITIONS. LOW TEMPERATURES
TONIGHT WILL GENERALLY BE IN THE 50S. A FEW THIN MID-UPR CLOUDS ARE
POSSIBLE...BUT RADIATIONAL COOLING SHOULD BE SUFFICIENT FOR PATCHY
FOG DEVELOPMENT IN THE FAVORED SPOTS WITHIN THE NRN ADIRONDACK
REGION AND ACROSS THE RIVER VALLEYS OF CENTRAL/ERN VT 06-12Z WED.
WEDNESDAY WILL BE OUR WARMEST DAY THIS WEEK WITH AFTN HIGHS IN THE
LOW 80S MOST SECTIONS. HUMIDITY LEVELS WILL REMAIN MODEST WITH
DEWPOINTS IN THE MID-UPR 50S. A FEW PASSING HIGH CLOUDS
ANTICIPATED BUT GENERALLY MOSTLY SUNNY WITH S-SW WINDS 5-10 MPH.
CHANGES ARRIVE ON THURSDAY AS MID-UPPER TROPOSPHERIC FLOW BECOMES
INCREASINGLY CYCLONIC IN RESPONSE TO SHORTWAVE TROUGH TRANSLATING
EWD FROM THE GREAT LAKES REGION. BANDS OF SHOWERS WILL PRECEDE THE
TROUGH AXIS...LIKELY REACHING NRN NY DURING THE MID-LATE MORNING
AND DEVELOPING ACROSS VT IN THE AFTN. CAPE VALUES OF 500-1000 J/KG
ARE ANTICIPATED...AND WILL CONTRIBUTE TO POTENTIAL FOR EMBEDDED
TSTMS THURSDAY AFTN/EVE. CAPE PROFILES ARE NARROW AND DON/T SUGGEST
A SVR THREAT AT THIS TIME. A FEW STORMS MAY CONTAIN BRIEF HEAVY
RAINFALL AND CG LIGHTNING AND WILL PUT MENTION OF THIS IN THE
HAZARDOUS WEATHER OUTLOOK. POPS THURSDAY AFTN/EVE REACH 70-80
PERCENT AND CONTINUE INTO THURSDAY NIGHT. HIGH TEMPERATURES ON
THURSDAY WILL BE AROUND 80F IN VERMONT WITH PARTIAL SUNSHINE EARLY.
ACROSS NY...EARLIER ARRIVAL OF SHOWERS LIKELY KEEPS TEMPS IN THE
MID 70S FOR DAYTIME HIGHS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 350 AM EDT TUESDAY...OVERALL MODELS IN GOOD AGREEMENT WITH
LARGE SCALE PATTERN FOR DAYS 4 THRU 7...WHICH SUPPORTS MID/UPPER
LVL TROF ACRS THE NE CONUS. THIS SYNOPTIC SETUP WL RESULT IN BLW NORMAL
TEMPS AND SEVERAL CHCS FOR PRECIP THRU THE PERIOD. WL CONT TO
MENTION LIKELY POPS ON THURS NIGHT ASSOCIATED WITH SFC BOUNDARY
AND 5H VORT INTERACTING WITH FAVORABLE 850 TO 500MB RH PROFILES.
ON FRIDAY INTO SATURDAY...SEVERAL EMBEDDED VORTS IN FLW ALOFT WL
MOVE ACRS OUR CENTRAL/NORTHERN CWA...WITH ADDITIONAL CHCS FOR
PRECIP. WL MENTION HIGHEST CHC POPS ACRS THE MTNS OF NNY AND VT ON
FRIDAY/SATURDAY. ECMWF SHOWS A PROGRESSIVE NW FLW WITH ADDITIONAL ENERGY
IMPACTING OUR CWA ON SUNDAY INTO MONDAY...WHILE THE GFS SHOWS SOME
DRYING. WL TREND TWD A DRIER FCST FOR EARLY NEXT WEEK...AS WEAK
RIDGE BUILDS INTO OUR FA. PROGGED 85H TEMPS START AROUND 10C...BUT
COOL BTWN 4C AND 6C BY EARLY NEXT WEEK...SUPPORTING HIGHS MAINLY
IN THE U60S MTNS TO UPPER 70S VALLEYS.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...VFR CONDITIONS AT ALL TAF SITES EXCEPT
IFR/MVFR AT SLK...WHICH WL LIFT TO VFR BY 13Z THIS MORNING. RAP13
SOUNDINGS SHOWS RH BTWN 925MB AND 700MB TODAY...WHICH WL HLEP IN
THE DEVELOPMENT OF A STRATOCUMULUS DECK...ESPECIALLY AT MPV/SLK.
WL MENTION A BROKEN DECK AT 4500 FEET. SOUTHWEST WINDS WL SLOWLY
SHIFT TO THE NORTHWEST BY MID MORNING AT 5 TO 10 KNOTS. CLOUDS WL
DECREASE THIS EVENING WITH LIGHT AND VARIABLE WINDS. SOME FOG/BR
WL BE POSSIBLE AT SLK/MPV AFT 06Z...WITH OCCASIONAL IFR
CONDITIONS.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...VFR CONDITIONS WL
PREVAIL FOR WEDS INTO THURSDAY WITH SFC HIGH PRES. CLOUDS WL
THICKEN WITH RAIN SHOWERS DEVELOPING BY THURSDAY MIDDAY...ALONG
WITH THE POTENTIAL FOR MVFR/IFR IN THE HEAVIER SHOWERS. SYSTEM
SHIFTS EAST OF TAF SITES BY FRIDAY...WITH VFR CONDITIONS EXPECTED
INTO SATURDAY.
&&
.EQUIPMENT...
AS OF 1230 AM EDT TUESDAY...THE WSR-88D DOPPLER RADAR AT FORT DRUM NY
(KTYX) REMAINS INOPERABLE AS TECHS AWAIT NECESSARY REPLACEMENT
PARTS. THE PARTS ARE NOT EXPECTED TO BE ON SITE UNTIL WEDNESDAY OR
THURSDAY. WE APOLOGIZE FOR THE RADAR OUTAGE AND WILL PROVIDED
AN UPDATED REPAIR TIMELINE AS IT BECOMES AVAILABLE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...JMG/BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS RALEIGH NC
941 PM EDT WED JUL 31 2013
.SYNOPSIS...
A SERIES OF RATHER WEAK UPPER DISTURBANCES WILL CROSS THE REGION
FROM THE WEST THROUGH TONIGHT. A WEAK COLD FRONT WILL APPROACH FROM
THE NORTHWEST ON THURSDAY...THEN STALL OUT OVER THE EASTERN
CAROLINAS ON FRIDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 940 PM WEDNESDAY...
CURRENT BAND OF SHOWERS AND STORMS MOVING SLOWLY ACROSS WESTERN
PORTIONS OF THE AREA IS EXPECTED TO CONTINUE SLOWLY MOVING ACROSS
MOST OF THE AREA OVER THE NEXT 3-6 HOURS (LOWEST PROBABILITIES IN
THE SE/E)... WITH ADDITIONAL WEAK S/W ENERGY POSSIBLE LATER TONIGHT
MOVING THROUGH THE BROAD MID LEVEL CYCLONIC FLOW. HOWEVER... WITH
MLCAPE VALUES GENERALLY IN THE 500 TO 1000 J/KG OR LESS (ALONG WITH
NOCTURNAL STABILIZATION EXPECTED/UNDERWAY) DONT EXPECT ANY SEVERE
STORMS... THOUGH ISOLATED URBAN FLOODING WILL BE POSSIBLE AS PW`S
HAVE INCREASE INTO THE 1.8 TO 2.0" RANGE. WILL GO WITH POPS IN THE
LIKELY/CATEGORICAL RANGE FOR THE REST OF THE EVENING AND CHANCE POPS
AFTERWARD GIVEN THE MOIST AIRMASS AND ADDITIONAL S/W ENERGY (WITH
THE 850 MB TROUGH MOVING INTO THE AREA NEAR 12Z THURSDAY).
HOWEVER... THE LATEST HRRR GUIDANCE DOES NOT ADVERTISE MUCH AFTER
THIS CURRENT BAND MOVES THROUGH THE AREA... BUT THINK THE MOIST ATMO
AND POSSIBLE ADDITIONAL S/W ENERGY WARRANTS AT LEAST CHANCE POPS IN
THE WAKE OF THE CURRENT ACTIVITY. GIVEN THE EXPECTED CONSIDERABLE
CLOUD COVER... EXPECT LOW TEMPS WILL GENERALLY RANGE FROM UPPER
60S/NEAR 70 TO THE LOWER TO MAYBE EVEN MID 70S (MID 70S IN THE SE IF
THEY REMAIN DRY).
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 230 PM WEDNESDAY...
LOOKING AT A CONTINUATION OF SHORTWAVE PERTURBATIONS MOVING EAST
ACROSS THE AREA INITIALLY ON THURSDAY. THESE WILL NUDGE THE SURFACE
FRONT EASTWARD INTO CENTRAL NC TOWARDS MID DAY. ENSUING DEEP LAYER
FORCING WILL BE WELL PHASED WITH ABUNDANT DEEP MOISTURE TO ASSIST
THE CONVECTIVE PROCESS DURING DIURNAL DESTABILIZATION. AS
SUCH...POPS WILL REMAIN IN THE LIKELY CATEGORY THROUGH LATE
AFTERNOON...WITH A BETTER CHANCE OF THUNDERSTORMS WITH DRY AIR
PUSHING IN BEHIND THE TROF PRODUCING MLCAPES >1500J AND MID LEVEL
LAPSE RATES STEEPENING TO 6.5K/KM. HIGHS WILL BE SIMILAR TO TODAY
GIVEN LACK OF INSOLATION AND SIMILAR AIRMASS...LOW 80S NORTHWEST TO
MID 80S IN THE SOUTHEAST.
WILL COMMENCE TAPERING THE POPS OFF IN THE WEST BY EVENING AS FLOW
FLATTENS AND BECOMES MORE WESTERLY BEHIND THE TROF. WILL KEEP SMALL
CHANCES IN THE EAST THROUGH AROUND MIDNIGHT. MINS WILL BE A LITTLE
COOLER GIVEN DRIER AIR AND GRADUAL CLEARING OVERNIGHT...65-70.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 258 PM WEDNESDAY...
CONTINUED GOOD MODEL AGREEMENT ON THE OVERALL PATTERN THROUGH EARLY
NEXT WEEK WITH AN UPPER LEVEL RIDGE REMAINING OVER THE ROCKIES...
AND UPPER LEVEL TROUGHING OVER THE EAST US... ALLOWING TEMPS A FEW
DEGREES BELOW NORMAL AND ABOVE NORMAL PRECIP CHANCES. DRIER AIR WILL
BRIEFLY MOVE IN TO THE AREA ON FRIDAY AFTER THE FRONT PASSES WITH
PWS PROGGED TO FALL TO NEAR AN INCH. MOISTURE WILL BEGIN TO REBOUND
OVER THE WEEKEND... AHEAD OF ANOTHER FRONT THAT LOOKS LIKELY TO PUSH
IN TO THE AREA FROM THE NORTH... POTENTIALLY MORE BACKDOOR IN
CHARACTER... SUNDAY INTO EARLY MONDAY. ANOTHER FRONT LOOKS TO
APPROACH THE AREA ON WEDNESDAY... ALTHOUGH UNCERTAINTY INCREASES AT
THIS TIME. THE MOST RECENT GFS RUN KEEPS THIS BOUNDARY WELL NORTH OF
THE AREA... AS IT FLATTENS THE EAST COAST TROUGH INTO A MORE ZONAL
FLOW. THIS OUTCOME IS NOT SUPPORTED BY ENSEMBLE MEANS... AND WILL
THEREFORE DISCOUNT AT THIS TIME. HIGHS WILL GENERALLY BE IN THE MID
TO UPPER 80S... LOWS MID 60S TO LOWER 70S.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 750 PM WEDNESDAY...
24-HR TAF PERIOD:
SHOWERS HAVE BEEN HARD TO COME BY THIS EVENING...ESPECIALLY ACROSS
THE EASTERN HALF OF THE CWA. RADAR TRENDS HAVE INCREASED SLIGHTLY IN
THE WEST AND KGSO COULD SEE SOME HEAVIER SHOWERS IN THE NEXT COUPLE
OF HOURS ALTHOUGH IT LOOKS LIKE KINT MAY JUST CATCH SOME LIGHT RAIN
ON THE FRINGES OF THE HEAVIER CONVECTION. THE ATMOSPHERE WILL
CONTINUE TO MOISTEN TONIGHT AND VFR CONDITIONS WILL SLOWLY
DETERIORATE TO MVFR AND BELOW...POSSIBLY DOWN TO LIFR IN THE EARLY
MORNING HOURS. AFTER SUNRISE CONDITIONS WILL IMPROVE SLIGHTLY BUT
SHOWERS AND THUNDERSTORMS WILL STILL BE A CONCERN ON THURSDAY
AFTERNOON. WINDS WILL REMAIN SOUTH OR SOUTHWESTERLY TONIGHT AND THEN
FINALLY BECOME WESTERLY IN THE TRIAD AS THE FRONTAL PASSAGE OCCURS
NEAR THE END OF THE TAF PERIOD. SITES TO THE EAST WILL REMAIN
SOUTHWESTERLY THROUGH THE TAF PERIOD. SOME HIGHER WINDS OF 10-15
KNOTS CAN BE EXPECTED TOMORROW AFTERNOON AT KFAY AND POSSIBLY KRWI.
LOOKING AHEAD:
AS THE FRONT PUSHES TOWARDS THE COAST ON FRIDAY CONDITIONS SHOULD
REMAIN VFR. ANOTHER FRONTAL SYSTEM WILL APPROACH SATURDAY NIGHT INTO
SUNDAY...POTENTIALLY CAUSING ADVERSE AVIATION CONDITIONS. HIGH
PRESSURE ON MONDAY SHOULD KEEP WEATHER SETTLED WITH VFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MLM
NEAR TERM...BSD
SHORT TERM...MLM
LONG TERM...SEC
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
259 AM EDT TUE JUL 30 2013
.SYNOPSIS...
A STATIONARY FRONT WILL LINGER OVER SOUTHEAST NORTH CAROLINA TODAY
AS WEAK HIGH PRESSURE BUILDS INTO THE MID ATLANTIC FROM THE WEST. A
MORE AMPLIFIED PATTERN OF CYCLONIC FLOW ALOFT WILL PREVAIL ON
WEDNESDAY AND THURSDAY...WITH ANOTHER WEAK COLD FRONT PROGRESSING
INTO THE CAROLINAS FROM THE NORTHWEST THURSDAY NIGHT.
&&
.NEAR TERM /TONIGHT/...
AS OF 945 PM MONDAY...
THE LATEST SURFACE ANALYSIS SHOWED A SURFACE FRONT NEARLY STATIONARY
OVER THE SOUTHEAST PART OF CENTRAL NORTH CAROLINA. AS OUTFLOW FROM
DEEP CONVECTION ALONG THE COAST MOVED NORTHWEST...THIS SUPPORTED
SOME SHORT-LIVED STRENGTHENING OF SHOWERS AND THUNDERSTORMS THAT
DEVELOPED IN VICINITY OF KFAY AND KMEB. THESE SHOWERS AND STORMS
HAVE CERTAINLY WANED DURING THE MID-EVENING HOURS...AND BUFR
SOUNDINGS FROM BOTH THE NAM AND THE GFS...ALONG WITH OUTPUT FROM THE
RUC AND MOST RECENT HRRR WRF...SHOW THAT THE POTENTIAL FOR DEEP
CONVECTION OVERNIGHT SHOULD BE LIMITED. 850MB SUBSIDENCE IS FORECAST
BY THE RUC OVERNIGHT...AND THOSE BUFR SOUNDINGS INDICATE SLIGHT
WARMING AND RELAXING OF LAPSE RATES ALOFT OVERNIGHT. FOR THE REST OF
THE EVENING...MAINTAINED A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM
SOUTH OF A LINE FROM ABOUT GOLDSBORO TO ROCKINGHAM...WITH A CHANCE
IN VICINITY OF KCTZ. OVERNIGHT...IN THE DEEPER MOISTURE SOUTH OF THE
FRONT...MAINTAINED A SLIGHT CHANCE OF A SHOWER ONLY OVER THE LATTER.
THE IR SATELLITE IMAGES SHOW PATCHES OF CI AND AC IN THE NORTHWEST
FLOW ALOFT BEHIND THE TROUGH AXIS. WHILE THE GFS BUFR SOUNDINGS ARE
VERY DRY ALOFT...THE NAM SHOWS A NARROW VOLUME OF MOISTURE ALOFT AT
MOST SITES THROUGH THE OVERNIGHT HOURS. BASED ON THE SATELLITE
IMAGES...THE NAM MAY BE VERIFYING BEST...AND PARTLY CLOUDY
CONDITIONS ARE FORECAST ON AVERAGE FOR THE OVERNIGHT. ANTICIPATE THE
DEVELOPMENT OF SOME LOW CLOUDS AND PATCHY FOG ESPECIALLY OVER THE
SOUTHEAST PART OF CENTRAL NORTH CAROLINA OVERNIGHT...IN THE BETTER
MOISTURE AND WHERE SCATTERED SHOWERS OCCURRED DURING THE DAY AND
EARLY EVENING. LOWERED MINS A BIT ESPECIALLY TOWARD KTDF...AND
KHNZ...WHERE TEMPERATURES DURING THE EVENING WERE FALLING QUICKLY
AND READINGS NEAR 60 APPEARED LIKELY. IN FACT...A COUPLE OF UPPER
50S ARE POSSIBLE TOWARD THE VIRGINIA BORDER. OVERNIGHT LOWS IN THE
60S.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 225 PM MONDAY...
WITH ZONAL FLOW ALOFT AND HIGH PRESSURE TO OUR NORTH MOST OF THE
DAY...THE AFOREMENTIONED FRONT WILL REMAIN POSITIONED NEAR OR
PERHAPS A BIT FURTHER SOUTH THAN ITS CURRENT POSITION. WITH MOST OF
OUR CWA ON THE DRIER MORE STABLE SIDE OF THE BOUNDARY...FOR NOW THE
ONLY PLACE WE`LL CARRY SLIGHT CHANCE POPS DURING THE DAY WILL BE
ACROSS OUR FAR S/SE ZONES. HIGHS WILL ONCE AGAIN RANGE FROM THE MID
80S NW TO UPPER 80S SE...WHICH IS A DEGREE OR TWO BELOW NORMAL.
CLOUDS WILL BE ON THE INCREASE TUESDAY NIGHT AS THE SHORT WAVE
THAT`S CURRENTLY OVER THE CENTRAL PLAINS MOVES EAST AND APPROACHES
THE CAROLINAS. IF THIS SYSTEM SPEEDS UP...SOME LIGHT SHOWER ACTIVITY
MAY MOVE INTO OUR WESTERN ZONES BEFORE SUNRISE. WILL INCLUDE SLIGHT
CHANCE POPS ACROSS OUR WESTERN ZONES TUESDAY NIGHT TO ACCOUNT FOR
THIS POSSIBILITY. SLIGHTLY WARMER LOWS CAN BE EXPECTED DUE TO THE
ADDITIONAL CLOUD COVER...UPPER 60S NW TO LOWER 70S SE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 259 AM TUESDAY...
THE PATTERN OF THE PAST 30-60 DAYS CONTINUES TO BE VERY PERSISTENT
AND WILL REMAIN SO THROUGH THE NEXT WEEK OR TWO.
A BROAD MID/UPPER TROUGH IS EXPECTED TO CONTINUE TO DIG SE ACROSS
FROM THE OHIO VALLEY INTO OUR REGION THURSDAY AND THURSDAY NIGHT.
THE MAIN COLD FRONT AGAIN SHOULD LAG WELL BEHIND THE PRE-FRONTAL
TROUGH THAT IS FORECAST TO BE IN THE LEE OF THE BLUE RIDGE BY
12Z/THU. IN ADDITION... THERE SHOULD BE RESIDUAL OUTFLOWS FROM THE
PREVIOUS NIGHTS CONVECTION IN OR NEAR THIS REGION TO BEGIN THURSDAY
AS WELL. STRONG SURFACE HEATING THURSDAY MAY BE HARD TO COME BY
GIVEN THE INCREASE OF PRECIPITABLE WATER VALUES TO AROUND 2 INCHES
LEADING TO PLENTY OF CLOUDINESS. HOWEVER... DIFFERENTIAL HEATING
WITHIN THE BREAKS OF THE CLOUDS SHOULD LEAD TO RAPID DESTABILIZATION
WITH DAYTIME HEATING. MIXED LAYER CAPES BETWEEN 1000 AND 1500 J/KG
ARE GENERALLY FORECAST OVER OUR REGION DURING THE AFTERNOON AND
EVENING... HIGHEST IN THE SOUTH AND EAST. SHOWERS AND THUNDERSTORMS
ARE LIKELY ANYTIME DURING THE DAY... BUT SHOULD BECOME MOST LIKELY
DURING THE AFTERNOON AND EVENING HOURS ALONG AND EAST OF THE
PRE-FRONTAL TROUGH AS IT SLOWLY PROGRESS SE INTO THE PIEDMONT...
THEN COASTAL PLAIN AND SANDHILLS IN THE EVENING. WHILE A WIDESPREAD
SEVERE THREAT IS NOT EXPECTED... ISOLATED STORMS MAY APPROACH SEVERE
CRITERIA GIVEN THE LIMITED SHEAR EXPECTED. LOCALLY HEAVY RAIN MAY BE
THE MAIN WEATHER HAZARD... ALONG WITH FREQUENTLY CG LIGHTNING
STRIKES. WE WILL CONTINUE THE LIKELY POP THURSDAY... FOCUSING ON THE
NW EARLY TO MID DAY... THEN ELSEWHERE BETWEEN 18Z AND 06Z/FRIDAY.
HIGHS THURSDAY SHOULD TOP OUT IN THE MID TO UPPER 80S EXCEPT LOWER
80S IN THE NW. LOWS THURSDAY NIGHT SHOULD BE IN THE MID 60S NW...
AND 70-73 ELSEWHERE UNDER MOSTLY CLOUDY SKIES AND DECREASING STORM
CHANCES BY 12Z/FRI.
FRIDAY THROUGH SATURDAY... THE AFOREMENTIONED COLD FRONT SHOULD
FINALLY OVERTAKE THE PRE-FRONTAL TROUGH OVER SOUTHEASTERN SECTIONS
OF NC BY EARLY FRIDAY. THIS IS WHERE A CHANCE OF SHOWERS AND
THUNDERSTORMS WILL LINGER FRIDAY. MOST OF OUR REGION SHOULD BE
DRIER... AND BECOMING LESS HUMID WITH THE NNE LOW LEVEL FLOW AND
DECREASE IN CLOUDINESS. HIGHS FRIDAY SHOULD BE IN THE MID TO UPPER
80S (MUCH LIKE THE TEMPERATURES WE EXPERIENCED SUNDAY). MOSTLY CLEAR
SKIES FRIDAY NIGHT WILL LEAD TO COMFORTABLE LOWS FOR EARLY AUGUST.
MOST GUIDANCE SUGGESTS LOWER TO MID 60S EXCEPT NEAR 70 IN THE SE
(ABOUT 4-8 DEG BELOW NORMAL). SATURDAY SHOULD BE LARGELY DRY AS THE
FRONT WASHES OUT ALONG THE COAST AND WEAK HIGH PRESSURE REMAINS
INLAND. MOSTLY SUNNY TO PARTLY CLOUDY WITH HIGHS IN THE MID 80S.
SUNDAY AND MONDAY... THE PATTERN REPEATS AGAIN. ANOTHER MID/UPPER
TROUGH IS FORECAST TO DIG SE INTO THE CENTRAL APPALACHIANS AND
EVENTUALLY OUR REGION BY MONDAY. THIS WILL ALLOW ANOTHER COLD FRONT
AND PRE-FRONTAL TROUGH/OUTFLOWS TO DRIVE CONVECTION CHANCES UP AGAIN
SUNDAY AFTERNOON THROUGH MONDAY. LOWS WILL CREEP BY UP TO 70+. HIGHS
SHOULD BE IN THE MID TO UPPER 80S BOTH DAYS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 115 AM TUESDAY...
24-HR TAF PERIOD:
SUB-VFR VISBYS ASSOCIATED WITH FOG WILL BE POSSIBLE BETWEEN 07-12Z
THIS MORNING...PRIMARILY AT THE RDU/FAY/RWI TERMINALS ALONG AND
SOUTH OF A STALLED FRONT. OTHERWISE...EXPECT VFR CONDITIONS TO
PREVAIL THROUGH THE TAF PERIOD WITH LITTLE CHANCE FOR AFTERNOON
CONVECTION ASIDE FROM A SMALL PROBABILITY FOR AN ISOLD SHOWER OR
STORM AT THE FAY TERMINAL BETWEEN 20-00Z.
LOOKING AHEAD:
EXPECT AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS
CENTRAL NC WED AFT/EVE AS UPPER LEVEL DISTURBANCES PROGRESS INTO THE
REGION FROM THE WEST...WITH A CONTINUED POTENTIAL FOR MORNING
FOG/STRATUS. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED
THU AND PERHAPS INTO THU NIGHT AS A WEAK COLD FRONT APPROACHES FROM
THE WEST IN CYCLONIC FLOW ALOFT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF
SHORT TERM...NP
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
123 AM EDT TUE JUL 30 2013
.SYNOPSIS...
A STATIONARY FRONT WILL LINGER OVER SOUTHEAST NORTH CAROLINA TODAY
AS WEAK HIGH PRESSURE BUILDS INTO THE MID ATLANTIC FROM THE WEST. A
MORE AMPLIFIED PATTERN OF CYCLONIC FLOW ALOFT WILL PREVAIL ON
WEDNESDAY AND THURSDAY...WITH ANOTHER WEAK COLD FRONT PROGRESSING
INTO THE CAROLINAS FROM THE NORTHWEST THURSDAY NIGHT.
&&
.NEAR TERM /TONIGHT/...
AS OF 945 PM MONDAY...
THE LATEST SURFACE ANALYSIS SHOWED A SURFACE FRONT NEARLY STATIONARY
OVER THE SOUTHEAST PART OF CENTRAL NORTH CAROLINA. AS OUTFLOW FROM
DEEP CONVECTION ALONG THE COAST MOVED NORTHWEST...THIS SUPPORTED
SOME SHORT-LIVED STRENGTHENING OF SHOWERS AND THUNDERSTORMS THAT
DEVELOPED IN VICINITY OF KFAY AND KMEB. THESE SHOWERS AND STORMS
HAVE CERTAINLY WANED DURING THE MID-EVENING HOURS...AND BUFR
SOUNDINGS FROM BOTH THE NAM AND THE GFS...ALONG WITH OUTPUT FROM THE
RUC AND MOST RECENT HRRR WRF...SHOW THAT THE POTENTIAL FOR DEEP
CONVECTION OVERNIGHT SHOULD BE LIMITED. 850MB SUBSIDENCE IS FORECAST
BY THE RUC OVERNIGHT...AND THOSE BUFR SOUNDINGS INDICATE SLIGHT
WARMING AND RELAXING OF LAPSE RATES ALOFT OVERNIGHT. FOR THE REST OF
THE EVENING...MAINTAINED A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM
SOUTH OF A LINE FROM ABOUT GOLDSBORO TO ROCKINGHAM...WITH A CHANCE
IN VICINITY OF KCTZ. OVERNIGHT...IN THE DEEPER MOISTURE SOUTH OF THE
FRONT...MAINTAINED A SLIGHT CHANCE OF A SHOWER ONLY OVER THE LATTER.
THE IR SATELLITE IMAGES SHOW PATCHES OF CI AND AC IN THE NORTHWEST
FLOW ALOFT BEHIND THE TROUGH AXIS. WHILE THE GFS BUFR SOUNDINGS ARE
VERY DRY ALOFT...THE NAM SHOWS A NARROW VOLUME OF MOISTURE ALOFT AT
MOST SITES THROUGH THE OVERNIGHT HOURS. BASED ON THE SATELLITE
IMAGES...THE NAM MAY BE VERIFYING BEST...AND PARTLY CLOUDY
CONDITIONS ARE FORECAST ON AVERAGE FOR THE OVERNIGHT. ANTICIPATE THE
DEVELOPMENT OF SOME LOW CLOUDS AND PATCHY FOG ESPECIALLY OVER THE
SOUTHEAST PART OF CENTRAL NORTH CAROLINA OVERNIGHT...IN THE BETTER
MOISTURE AND WHERE SCATTERED SHOWERS OCCURRED DURING THE DAY AND
EARLY EVENING. LOWERED MINS A BIT ESPECIALLY TOWARD KTDF...AND
KHNZ...WHERE TEMPERATURES DURING THE EVENING WERE FALLING QUICKLY
AND READINGS NEAR 60 APPEARED LIKELY. IN FACT...A COUPLE OF UPPER
50S ARE POSSIBLE TOWARD THE VIRGINIA BORDER. OVERNIGHT LOWS IN THE
60S.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 225 PM MONDAY...
WITH ZONAL FLOW ALOFT AND HIGH PRESSURE TO OUR NORTH MOST OF THE
DAY...THE AFOREMENTIONED FRONT WILL REMAIN POSITIONED NEAR OR
PERHAPS A BIT FURTHER SOUTH THAN ITS CURRENT POSITION. WITH MOST OF
OUR CWA ON THE DRIER MORE STABLE SIDE OF THE BOUNDARY...FOR NOW THE
ONLY PLACE WE`LL CARRY SLIGHT CHANCE POPS DURING THE DAY WILL BE
ACROSS OUR FAR S/SE ZONES. HIGHS WILL ONCE AGAIN RANGE FROM THE MID
80S NW TO UPPER 80S SE...WHICH IS A DEGREE OR TWO BELOW NORMAL.
CLOUDS WILL BE ON THE INCREASE TUESDAY NIGHT AS THE SHORT WAVE
THAT`S CURRENTLY OVER THE CENTRAL PLAINS MOVES EAST AND APPROACHES
THE CAROLINAS. IF THIS SYSTEM SPEEDS UP...SOME LIGHT SHOWER ACTIVITY
MAY MOVE INTO OUR WESTERN ZONES BEFORE SUNRISE. WILL INCLUDE SLIGHT
CHANCE POPS ACROSS OUR WESTERN ZONES TUESDAY NIGHT TO ACCOUNT FOR
THIS POSSIBILITY. SLIGHTLY WARMER LOWS CAN BE EXPECTED DUE TO THE
ADDITIONAL CLOUD COVER...UPPER 60S NW TO LOWER 70S SE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 250 PM MONDAY...
OVERALL THE LONG TERM PERIOD WILL FEATURE A MEAN TROUGH ACROSS THE
EASTERN CONUS WITH A SERIES OF SHORTWAVES/WEAK FRONTS PROGRESSING
THROUGH THE AREA. THIS SET-UP WILL KEEP THE SUMMER HEAT AT BAY WHILE
PROVIDING PERIODS OF INCREASED SHOWER AND THUNDERSTORM ACTIVITY.
THIS NEXT UPPER TROUGH/SURFACE COLD FRONT IS PROGGED TO APPROACH AND
SLOWLY CROSS THE REGION WEDNESDAY INTO THURSDAY. MODELS HAVE SHOWN
SOMEWHAT OF A SLOWING TREND THE PAST COUPLE OF DAYS (ESPECIALLY THE
GFS)...BUT FOR NOW IT STILL APPEARS THAT THE BEST CHANCE OF RAIN
WILL OCCUR LATE WEDNESDAY INTO THURSDAY (ALTHOUGH CURRENT GFS SHOWS
THE SIGNIFICANT PRECIP ASSOCIATED WITH THE FRONT HOLDING OFF UNTIL
THURSDAY AND PERSISTING MORE INTO FRIDAY). NEVERTHELESS...WILL STILL
SHOW POPS INCREASING FROM WEST TO EAST ON WEDNESDAY AND THEN
GRADUALLY DECREASING IN THE SAME FASHION LATE THURSDAY.
BY FRIDAY...THE FRONT SHOULD STALL/WASH OUT SOMEWHERE NEAR THE
REGION. OVERALL...THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH PUSHING
IT SOUTH/EAST OF THE FORECAST AREA WHICH WOULD RESULT IN MOSTLY DRY
CONDITIONS FOR CENTRAL NC...WHILE THE GFS IS SLOWER WITH THE
EASTWARD PROGRESSION (SEE ABOVE PARAGRAPH). HOWEVER...GIVEN THE TIME
OF THE YEAR AND RECENT EVENTS...WILL MAINTAIN AT LEAST A MENTION OF
PRECIP FOR FRIDAY AND SATURDAY...ESPECIALLY ON FRIDAY AND MOSTLY
ACROSS THE EASTERN/SOUTHERN PORTIONS OF THE FORECAST AREA...WITH ANY
ACTIVITY BEING MOSTLY DIURNAL IN NATURE. YET ANOTHER NEXT SYSTEM
WILL APPROACH THE AREA LATE IN THE WEEKEND/EARLY NEXT WEEK (ALTHOUGH
TIMING IS IN QUESTION AT THIS TIME).
TEMPS WILL ULTIMATELY BE DEPENDENT ON THE EXACT TIMING/EXTENT OF ANY
PRECIP THAT OCCURS...BUT SHOULD LARGELY BE NEAR TO SLIGHTLY BELOW
NORMAL THROUGH THE PERIOD.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 115 AM TUESDAY...
24-HR TAF PERIOD:
SUB-VFR VISBYS ASSOCIATED WITH FOG WILL BE POSSIBLE BETWEEN 07-12Z
THIS MORNING...PRIMARILY AT THE RDU/FAY/RWI TERMINALS ALONG AND
SOUTH OF A STALLED FRONT. OTHERWISE...EXPECT VFR CONDITIONS TO
PREVAIL THROUGH THE TAF PERIOD WITH LITTLE CHANCE FOR AFTERNOON
CONVECTION ASIDE FROM A SMALL PROBABILITY FOR AN ISOLD SHOWER OR
STORM AT THE FAY TERMINAL BETWEEN 20-00Z.
LOOKING AHEAD:
EXPECT AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS
CENTRAL NC WED AFT/EVE AS UPPER LEVEL DISTURBANCES PROGRESS INTO THE
REGION FROM THE WEST...WITH A CONTINUED POTENTIAL FOR MORNING
FOG/STRATUS. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED
THU AND PERHAPS INTO THU NIGHT AS A WEAK COLD FRONT APPROACHES FROM
THE WEST IN CYCLONIC FLOW ALOFT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF
SHORT TERM...NP
LONG TERM...KRR
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
933 PM CDT WED JUL 31 2013
.UPDATE...
ISSUED AT 927 PM CDT WED JUL 31 2013
AT 9 PM CDT...LATEST RUC MODEL DEPICTS A RIDGE OF SURFACE HIGH
PRESSURE FROM EASTERN SOUTH DAKOTA NORTHWEST THROUGH SOUTHERN
SASKATCHEWAN. THE AREA OF HIGH PRESSURE WILL CONTINUE TO SLIDE
SOUTHEAST OVER THE REGION THROUGH THURSDAY. THIS WILL KEEP SKIES
MOSTLY CLEAR AND WINDS LIGHT NORTHWEST. COOL OVERNIGHT TEMPERATURES
WILL AGAIN BE IN THE OFFING WITH OVERNIGHT READINGS FROM THE UPPER
40S NORTHWEST AND CENTRAL TO THE LOWER 50S WESTERN DEVILS LAKE
BASIN. CURRENT FORECAST TENDING WELL.
UPDATE ISSUED AT 628 PM CDT WED JUL 31 2013
LATEST WATER VAPOR IMAGE SHOWS UPSTREAM SHORT WAVE MOVING THROUGH
EAST CENTRAL SASKATCHEWAN INTO MANITOBA NEAR LAKE WINNIPEG.
IMMEDIATELY UPSTREAM OF NORTH DAKOTA WEAK CHANNELED VORTICITY IN
NORTHWEST FLOW WILL BRING NO SIGNIFICANT FORCING THIS EVENING.
EXPECT NORTHWEST SURFACE FLOW TO DIMINISH OVERNIGHT AS REMAINING
CUMULUS FIELD DIMINISHES. CURRENT FORECAST LOOKS GOOD.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 304 PM CDT WED JUL 31 2013
MAIN HIGHLIGHTS IN THE SHORT TERM WILL BE THE POSSIBILITY OF A
SHOWER/SPRINKLES IN THE FAR NORTHEAST/TURTLE MOUNTAINS THURSDAY.
OTHERWISE EXPECT MOSTLY SUNNY...DRY...AND WARMER CONDITIONS.
THE LATEST SATELLITE IMAGERY SHOWS A SCATTERED TO AT TIMES A
BROKEN CUMULUS DECK ACROSS WESTERN AND CENTRAL NORTH DAKOTA. FOR
THE MOST PART EXPECT THE CUMULUS TO DISSIPATE TOWARD SUNSET.
WATER VAPOR IMAGERY SHOWS THE NEXT SHORTWAVE SLIDING SOUTHEAST
INTO CENTRAL SASKATCHEWAN THIS AFTERNOON. VISIBLE IMAGERY SHOWS
THICKER CLOUDS ACROSS SOUTH CENTRAL SASKATCHEWAN WITH SURFACE
OBSERVATIONS CLOSER TO THE SHORTWAVE REVEALING LIGHT RAIN AT
PRINCE ALBERT AND IN LA RONGE SASKATCHEWAN. HIGH RESOLUTION MODELS
ALONG WITH THE NAM/GFS/SREF KEEP THE PRECIPITATION ACROSS MANITOBA
THIS EVENING INTO TONIGHT...SO WILL NOT MENTION ANY POPS IN THE
TURTLE MOUNTAINS. THERE IS A REFLECTION OF A WEAK COLD FRONT AT
THE SURFACE...WHICH IS FORECAST TO REACH THE NORTHERN BORDER
BETWEEN 12Z AND 15Z THURSDAY. THE NAM SUGGESTS AN ISOLATED SHOWER
POSSIBLE NEAR THE INTERNATIONAL PEACE GARDEN PRIOR TO 18Z THURSDAY
ASSOCIATED WITH THE COLD FRONT...WHILE THE 09Z SREF ADVERTISES
SOME PRECIPITATION BETWEEN 18Z AND 21Z THURSDAY IN THE SAME AREA.
THE GFS/ECMWF ARE BOTH DRY. AFTER COORDINATING WITH GRAND
FORKS...WE AGREE THAT WE ARE NOT REAL CONFIDENT WITH MEASURABLE
PRECIPITATION AT THIS TIME. WILL LET THE EVENING AND NIGHT SHIFT
WATCH THE TRENDS AND ADJUST. ELSEWHERE...THE NAM/GFS SOUNDING
PROFILES SHOW A STRONG CAP IN PLACE ACROSS THE SOUTHWEST
THURSDAY AFTERNOON AND HAVE REMOVED THE SLIGHT CHC MENTION OF A
THUNDERSTORM. HIGHS THURSDAY WILL BE WARMER WITH AFTERNOON HIGHS
IN THE UPPER 70S TO LOWER 80S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 304 PM CDT WED JUL 31 2013
ACTIVE NORTHWEST FLOW AND BELOW NORMAL TEMPERATURES WILL HIGHLIGHT
THE EXTENDED FORECAST.
OVERALL...THE 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT ON
NORTHWEST FLOW ACROSS THE NORTHERN PLAINS THROUGH NEARLY THE
ENTIRE EXTENDED FORECAST PERIOD. THIS IS FORECAST TO RESULT IN
CONTINUED BELOW NORMAL TEMPERATURES WITH HIGHS IN THE 70S...WITH THE
COOLER EDGE OF GUIDANCE PREFERRED BASED UPON VERIFICATION OVER THE
PAST WEEK. WHILE IT IS HARD TO RULE OUT ISOLATED CONVECTION ANY
DAY IN A NORTHWEST FLOW REGIME...THE FAVORED TIME FRAME FOR
THUNDERSTORMS IS SATURDAY NIGHT THROUGH SUNDAY AS ENERGY FROM THE
PACIFIC NORTHWEST PROPAGATES ALONG THE CREST OF THE RIDGE INTO THE
NORTHERN PLAINS. AN EARLY LOOK AT SHEAR AND INSTABILITY PROFILES
SUGGESTS SEVERE STORMS MAY BE POSSIBLE DURING THIS TIME FRAME. THE
12 UTC GFS/ECMWF CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL
LOW ACROSS SOUTH CANADA AND POSSIBLY INTO THE FAR NORTH CENTRAL
CONUS NEXT WEDNESDAY THROUGH FRIDAY. WILL CONTINUE TO MONITOR AS
THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 927 PM CDT WED JUL 31 2013
AT 9 PM CDT...HIGH PRESSURE EXTENDED FROM EASTERN SOUTH DAKOTA
THROUGH SASKATCHEWAN. VFR CONDITIONS FORECAST AT ALL TAF SITES
THROUGH THE 00Z TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...KS
LONG TERM...AYD
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1211 PM CDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 1211 PM CDT TUE JUL 30 2013
LATEST TRENDS PER SATELLITE/RADAR/SPC DATA SHOW THAT THE AREAL
COVERAGE FOR POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT CONTINUES
TO SHRINK...NOW COVERING ONLY FAR SOUTH CENTRAL NORTH DAKOTA.
CURRENT CLOUD CANOPY COVERING MOST OF WESTERN AND CENTRAL NORTH
DAKOTA IS LIMITING LOW LEVEL INSTABILITY TO NIL...AND WHILE UPSTREAM
IMAGERY DOES SHOW SOME BREAKS IN THE CLOUD COVER...IT APPEARS
THAT THE STRONGEST DIVERGENCE FIELD WILL LAY ACROSS SOUTH DAKOTA
THIS AFTERNOON AND EVENING. AT THE SURFACE...PRESSURE RISES ARE
MAXIMIZED IN SOUTHWEST NORTH DAKOTA ALONG WITH A WEAK LOW LEVEL
EAST TO NORTHEAST WIND FIELD. THE LATEST HIGH RESOLUTION MODELS OF
THE RAP AND HRRR CONTINUE TO TREND WITH SEVERE WEATHER THREAT
MAINLY SOUTH OF THE BORDER THIS AFTERNOON...WITH MORE OF A
SCATTERED SHOWER/THUNDERSTORM EVENT WITH AN ISOLATED STRONG TO
POSSIBLY SEVERE THUNDERSTORM EMBEDDED WITHIN THIS AREA ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. WILL CONTINUE TO MONITOR FOR ANY
CHANGES. 12Z NAM/GFS SOUNDINGS CONTINUE TO INDICATE A SKINNY CAPE
FIELD THIS AFTERNOON. ADJUSTED POPS THIS AFTERNOON AND LIMITED THE
SEVERE WEATHER WORDING FAR SOUTH CENTRAL. ALSO LOWERED MAX TEMPS A
COUPLE OF DEGREES...ALLOWING FOR A QUICK RISE WITH ANY BREAKS
FOLLOWED BY CLOUDS QUICKLY FILLING BACK IN AGAIN.
UPDATE ISSUED AT 839 AM CDT TUE JUL 30 2013
LATEST REGIONAL LOCAL/RADAR SHOWS SCATTERED SHOWERS AND
THUNDERSTORMS INTO SOUTHWEST AND PORTIONS OF WESTERN NORTH DAKOTA.
VISIBLE IMAGERY SHOWS A LARGE CLOUD CANOPY ASSOCIATED WITH THE
SOUTHWEST AREA OF THUNDERSTORMS EXTENDING EAST TO NEAR THE
MANDAN/BISMARCK AREA.
STILL NOT REAL CLEAR ON WHAT SCENARIO WILL PLAY OUT TODAY. HIGH
RESOLUTION MODELS HINTING AT THE CURRENT PRECIPITATION IN THE WEST TO
EXPAND AND BECOME THE MAIN SHOW THROUGH MOST OF THE AFTERNOON WITH
LITTLE FURTHER ACTIVITY BY LATE AFTERNOON AND EARLY EVENING. THE
LARGER SCALE MODELS AND WATER VAPOR IMAGERY DEPICT A KEY SHORTWAVE
NOW OVER SOUTHWEST MONTANA TO EJECT EAST INTO WESTERN AND SOUTHWESTERN
NORTH DAKOTA LATER THIS AFTERNOON AND EVENING. THIS SHORTWAVE
COMBINED WITH A JET STREAK IN SOUTHERN CANADA AND A WEAKER ONE IN
SOUTH DAKOTA WOULD BECOME THE MAIN CATALYSTS TO HELP INITIATE
STRONG TO SEVERE THUNDERSTORMS. THE NAM/GFS 06Z SOUNDINGS SHOW
MINIMAL TO NIL CAPE THIS AFTERNOON. AS MENTIONED ABOVE...LARGE
CLOUD SHIELD WILL INHIBIT SURFACE HEATING AND OVERALL LOW LEVEL
DESTABILIZATION. IF THIS CONTINUES WILL HAVE TO AWAIT FOR STRONGER
DYNAMICS WITH THE AFOREMENTIONED SHORTWAVE AND JET STREAKS TO
ENHANCE LIFT AND INITIATE STRONGER CONVECTION TO FORM.
UPDATES TO HOURLY SKY GRIDS PER LATEST VISIBLE IMAGERY. WILL
ADJUST POPS TO MATCH THIS MORNINGS RADAR...BUT UNTIL THE 12Z DATA
COMES IN...WILL LEAVE CURRENT POP/WEATHER SCENARIO ALONE FOR NOW
OTHER THAN CHANGING THE WORDING FROM UNCERTAINTY TO AREAL COVERAGE.
UPDATE ISSUED AT 637 AM CDT TUE JUL 30 2013
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG OVER PIERCE AND
WELLS COUNTIES BASED ON SURFACE OBS. THINK THESE REDUCED
VISIBILITIES SHOULD IMPROVE DURING THE NEXT FEW HOURS AS VERTICAL
MIXING COMMENCES WITH THE ONSET OF DAYTIME HEATING.
OTHERWISE...THE SEVERE THREAT STILL APPEARS VALID PRIMARILY FOR
AREAS ALONG AND SOUTH OF I-94 THIS AFTERNOON AND EVENING. LARGE
HAIL AND DAMAGING WINDS STILL LOOK TO BE THE PRIMARY THREATS.
THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT TUE JUL 30 2013
HAVE NOWCASTED THUNDERSTORMS OUT OF THE FORECAST THROUGH 7 AM CDT
BASED ON AREA DOPPLER RADAR RETURNS. A FEW LOCATIONS...BISMARCK
EARLIER AND HARVEY AND RUGBY AS OF THIS WRITING...HAVE HAD PATCHY
FOG SO WILL KEEP THAT IN THE FORECAST THROUGH 9 AM CDT.
TEMPERATURES WERE IN THE 50S.
FOR TODAY...THE MAIN FORECAST ISSUE IS THUNDERSTORMS AND THE RISK
FOR SEVERE WEATHER. MODELS ARE COMING INTO AGREEMENT THAT THE
RISK OF SEVERE THUNDERSTORMS WILL BE CONFINED TO THE SOUTHWEST AND
SOUTHCENTRAL PARTS OF NORTH DAKOTA. DEW POINTS INTO THE LOWER AND
MID 50S WILL BE INCREASING INTO THE 55 TO 60 DEGREE RANGE ACROSS
THE SOUTH AS MORE MOIST AIR IS ADVECTING IN FROM SOUTH DAKOTA. A
TROUGH AT THE SURFACE...ORIENTED NORTHEAST TO SOUTHWEST THROUGH
THE AREA...WILL BE THE FOCUS FOR LOW PRESSURE IN SOUTHEAST MONTANA
TO RIDE NORTHEAST ON. AT THE SAME TIME A SHORT WAVE TROUGH IN THE
MID ATMOSPHERE WILL BE ADVANCING TOWARD THE STATE AND PROVIDE
LIFTING THROUGH THE MID LEVELS. THE MOISTURE ADVECTION WILL
INCREASE INSTABILITY AND SET THE STAGE FOR STORM DEVELOPMENT.
ADDING TO THIS WILL BE SUFFICIENT SHEAR (BOTH SPEED AND DIRECTION)
TO SUPPORT SUPER CELL FORMATION. STEEP MID LEVEL LAPSE RATES WILL
ADD TO THE STORMS ABILITY TO GROW VERTICALLY INTO THE ATMOSPHERE.
HAVE HIGHLIGHTED THE RISK IN SERVICES FOR TODAY...INCLUDING ON THE
WEB PAGE AND LATER TO SOCIAL MEDIA.
STORMS DECREASE FROM WEST TO EAST THIS EVENING.
HIGH TEMPERATURES TODAY WILL BE CLOSER TO SEASON NORMALS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE JUL 30 2013
DRY CONDITIONS AND BELOW NORMAL TEMPERATURES ARE EXPECTED TO DEVELOP
AREAWIDE WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDS INTO THE
REGION.
PRECIP CHANCES ARE PROGGED TO INCREASE WEST FRIDAY AHEAD OF A
SHORTWAVE OVER THE PACIFIC NORTHWEST. PRECIP CHANCES ARE THEN
EXPECTED TO GRADUALLY SPREAD INTO CENTRAL NORTH DAKOTA LATE SATURDAY
AND CONTINUE THROUGH MONDAY AS THE SHORTWAVE LIFTS INTO THE CANADIAN
PRAIRIES. THE PERSISTENT NORTHWESTERLY FLOW ALOFT SHOULD KEEP
TEMPERATURES BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1211 PM CDT TUE JUL 30 2013
A VCTS COVERS ALL AERODROMES THROUGH THE EVENING AS SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP...BUT TIMING
AND COVERAGE OF THE PRECIPITATION IS NOT EXACT. WILL MONITOR RADAR AND
AMEND AS NECESSARY TO CAPTURE ANY CRITICAL CIG/VSBY REDUCTION DUE
TO THE SHOWERS/THUNDERSTORMS. EXPECT VFR CIGS/VSBYS OUTSIDE ANY
THUNDERSTORMS WITH A BRIEF PERIOD OF MVFR/IFR CIGS/VSBYS POSSIBLE
WITH ANY OF THE STRONGER THUNDERSTORMS. THE PRECIPITATION WILL
DIMINISH BY 06Z WITH CLEARING SKIES AND VFR CIGS FORECAST FOR
WEDNESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...JPM
LONG TERM...TM
AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1130 PM CDT MON JUL 29 2013
.UPDATE...
ISSUED AT 1130 PM CDT MON JUL 29 2013
CURRENT RADAR SHOWS LINE OF RAIN SHOWERS JUST EAST OF THE RRV AND
ALONG THE INTERNATIONAL BORDER STRETCHING SOUTHWARD TO SOUTHERN
CASS COUNTY. LINE IS MOVING AROUND 25 KTS AND EXPECT IT TO CLEAR
CWA BY AROUND 13Z. UPDATED TIMING OF SCATTERED SHOWERS ACROSS CWA.
WATER VAPOR SHOWING DECENT DRYING BEHIND WAVE AND SKIES MOSTLY
CLEAR ACROSS CNTRL AND WRN ND. WILL MENTION MIST IN TAFS BUT DO
NOT THINK VSBYS WILL BE LOW ENOUGH FOR A MENTION OF FOG IN GRIDS
WITH LACK OF SFC HIGH BRINGING CALM WINDS.
UPDATE ISSUED AT 930 PM CDT MON JUL 29 2013
CURRENT RADAR SHOWING LINE OF SHOWERS PARALLEL AND JUST WEST OF
RRV. CTG LIGHTNING HAS DECREASED AND ONLY STRIKE ON NLDN IS NOW IN
VICINITY OF VALLEY CITY. EXPECT THIS WILL DIE OFF IN THE NEXT 30
MIN OR SO AND HAVE WENT TO ALL SHOWERS FOR REMAINDER OF THE NIGHT.
MAIN FORECAST CHANGE IS SLOWING DOWN EASTWARD PROGRESSION AND ALSO
BEGINNING TO REMOVE POPS FROM SOUTHERN END OF LINE AS SHOWERS
PROGRESS EASTWARD. DO NOT LOOK FOR ANY SHOWERS ALONG SOUTHERN TIER
OF ZONES. ALSO PULLING POPS BEHIND LINE IN THE DVL BASIN UP
THROUGH TOWNER COUNTY. NO SIG CHANGES TO TEMPS ANTICIPATED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 338 PM CDT MON JUL 29 2013
FORECAST CHALLENGES INCLUDE CONVECTIVE CHANCES TONIGHT THROUGH
TOMORROW NIGHT. GFS/NAM/ECMWF/GEM SYNOPTIC FIELDS IN GOOD OVERALL
AGREEMENT...BUT DIFFER SOMEWHAT WITH THE MESOSCALE DETAILS. WILL
USE THE RAP FOR THE ONGOING CONVECTION ACROSS CENTRAL ND THIS
EVENING AND TONIGHT...SHIFTING TO A MODEL BLEND FOR THE REMAINDER
OF THE SHORT-TERM.
20 UTC REGIONAL RADARS SHOW THE SHOWERS ACROSS NORTHEAST SD HAVE
BARELY MOVED INTO THE SOUTHERN VALLEY WITH PERHAPS A FEW SPRINKLES
FALLING ACROSS THE LAKES COUNTRY OF WEST CENTRAL MN. WILL KEEP 20
TO 30 POPS IN THESE AREAS THROUGH THE EARLY EVENING AFTER WHICH ANY
REMAINING ACTIVITY SHOULD DISSIPATE. IN ADDITION...THE ORIGINAL
LINE OF CONVECTION AHEAD OF THE SURFACE TROUGH THIS MORNING HAS
DISSIPATED AND GIVEN WAY TO A STRONGER LINE NOW STRETCHING FROM
NORTHWEST OF MINOT TO SOUTHWEST OF BISMARCK...MOVING TO THE EAST
AROUND 25 KTS. THESE THUNDERSTORMS ARE ALIGNED ALONG THE SURFACE
BOUNDARY NEAR THE AXIS OF GREATEST INSTABILITY. AS THE SHORT-WAVE
ALOFT PROPAGATES ACROSS EASTERN ND AND NORTHWEST MN THIS EVENING
AND OVERNIGHT...THESE STORMS WILL CONTINUE TO MOVE ACROSS ND/MN.
HOWEVER...INSTABILITY IS WEAK ALONG AND EAST OF THE VALLEY...SO
THE EXTENT TO WHICH THEY HOLD TOGETHER IS IN QUESTION. THE RAP
WITH SUPPORT FROM THE GFS/NAM DISSIPATE THESE STORMS EAST OF THE
VALLEY AND IF THIS VERIFIES...CURRENT POPS MAY BE TOO HIGH. GIVEN
HIGHER INSTABILITY TO THE WEST...SOME THUNDERSTORMS COULD BE STRONG
AND EVEN SEVERE ACROSS THE DEVILS LAKE BASIN. HOWEVER...NO SEVERE
CONVECTION IS EXPECTED ALONG AND EAST OF THE VALLEY.
MUCH OF TUESDAY SHOULD BE DRY AS THE REGION IS BETWEEN WEATHER
SYSTEMS...BUT SHOWER AND THUNDERSTORM CHANCES INCREASE AGAIN LATE
IN THE DAY AND OVERNIGHT AS A STRONG CANADIAN SHORT-WAVE AND
ASSOCIATED COLD FRONT MOVE ACROSS THE FORECAST AREA. THE HIGHEST
INSTABILITY WILL REMAIN ACROSS SD INTO SOUTHWEST MN...BUT MODELS
INDICATE MLCAPE UP TO 1500 J/KG MAINLY ALONG AND SOUTH OF THE I-94
CORRIDOR BY TUESDAY AFTERNOON. WITH THE APPROACHING COLD FRONT AND
50+ KTS OF 0 TO 6 KM BULK SHEAR ASSOCIATED WITH A 60 TO 80 KT 300
HPA JET STREAK...MODELS HINT AT A CONVECTIVE COMPLEX DEVELOPING
SOMEWHERE NEAR THE ND/SD BORDER. SPC DAY 2 CONVECTIVE OUTLOOK
SHOWS A SLIGHT RISK FOR SEVERE CONVECTION IN THIS AREA AND THIS
SEEMS REASONABLE. EXACT PLACEMENT OF ANY COMPLEX THAT DOES DEVELOP
IS UNCERTAIN AS IS THE EASTWARD EXTENT TO THE SEVERE POTENTIAL...
SO SOMETHING TO FINE-TUNE IN THE NEXT FORECAST PACKAGE IF POSSIBLE.
THERMAL RIDGE AXIS MOVES OVERHEAD IN FRONT OF THE COLD FRONT...SO
HIGHS TUESDAY WILL REACH THE UPPER 70S TO NEAR 80 DEGREES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 338 PM CDT MON JUL 29 2013
WEDNESDAY AND THURSDAY WILL BE DRY WITH SURFACE HIGH PRESSURE
BUILDING ACROSS THE FORECAST AREA. TEMPERATURES WILL BE A BIT
COOLER WITH HIGHS IN THE 70S AND LOWS IN THE 50S. WINDS WILL BE
BREEZY FROM THE NORTHWEST WEDNESDAY BEFORE BECOMING LIGHT ON
THURSDAY AS THE PRESSURE GRADIENT RELAXES.
HIGH PRESSURE WILL REMAIN FROM MANITOBA INTO EASTERN NORTH DAKOTA
FRIDAY INTO SATURDAY KEEPING US DRY WITH TEMPERATURES REMAINING
NEARLY 10 DEGREES BELOW AVERAGE. HIGH PRESSURE MOVES EAST INTO THE
WESTERN GREAT LAKES REGION BY LATE SUNDAY ALLOWING NEXT SHORT WAVE
AND SURFACE LOW TO MOVE INTO THE NORTHERN PLAINS. THIS SYSTEM WILL
GIVE THE RISK OF SHOWERS AND THUNDERSTORMS SUNDAY TO EASTERN NORTH
DAKOTA AND PARTS OF WESTERN MINNESOTA...WHILE EASTERN FCST AREA WILL
REMAIN DRY. WILL GO WITH MOSTLY 30-40 POPS MONDAY AS SYSTEM MOVES
THROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM CDT MON JUL 29 2013
SAT SHOWING CLEARING BEHIND LINE OF SHOWERS. WITH AROUND ONE
QUARTER TO ONE HALF INCH OF RAIN AND CLEARING BY EARLY
MORNING...WILL MENTION MVFR MIST AT DVL...GFK AND FAR. DO NOT
THINK CLOUDS WILL CLEAR IN TIME TO GET CLEARING SUFFICIENT FOR
MIST AT TVF AND BJI. FOR TOMORROW EVENING...WITH MODELS BACKING
OFF ON TIMING OF PRECIP INTO THE WEST...NOT ENOUGH CONFIDENCE TO
PUT TSTMS IN THE LAST SIX HOURS OF 06Z TAFS. DVL OR FAR WOULD HAVE
BEST CHANCE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...ROGERS
LONG TERM...ROGERS/RIDDLE
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1010 PM EDT WED JUL 31 2013
.SYNOPSIS...
A WEAK COLD FRONT CROSSES LATE TONIGHT AND EARLY THURSDAY. HIGH
PRESSURE PASSES THURSDAY NIGHT/FRIDAY MORNING. A COLD FRONT CROSSES
THIS WEEKEND...FOLLOWED BY BELOW NORMAL TEMPERATURES EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
10 PM UPDATE...NO SIGNIFICANT CHANGE.
PREVIOUS DISCUSSION...
DISTURBANCE MOVING THRU CWA WITH MAINLY SCT -SHRA AND EVEN SOME
-DZ ABOUT THE AREA. WEAKENING VORT MAX HANGING OUT ACROSS SE OH CO
WITH LOBE APPENDAGE MOVING NE INTO N WV SERVING AS MAIN FOCUS FOR
LIFT. RUC AND HRRR SEEMS TO HAVE A MUCH BETTER HANDLE ON THINGS VS
OTHER MDLS AND HAVE USED THESE AS GUIDANCE. OTHERWISE LOOKING AT
AN ABUNDANCE OF LLVL MOISTURE REMAINDER OF AFTN.
FRONT POISED TO MOVE THRU LATE TONIGHT INTO EARLY THU MORNING WITH
A BAND OF SHRA WITH IT. THERE COULD BE AN AREA OF -RA OR DZ ALONG
AND E OF I79 TONIGHT BEFORE AFOREMENTIONED SHRA ARRIVE WITH
IMPRESSIVE DRYING SHOWING UP IN MID LVLS. THINK LOW STRATUS AND
FG WILL SETUP REGARDLESS THIS EVE...TRYING TO LIFT SOME AS FRONTAL
SHRA MOVE IN PREDAWN.
ALL OF THIS PUSHES E ON THU WITH AMPLIFYING UPR TROF ACROSS OH
VALLEY. HOWEVER...LLVL MOISTURE WILL BE VERY SLOW TO GIVE UP THE
GHOST. EVEN THOUGH LOW STRATUS LIFTS BY MIDDAY...SUSPECT THIS WILL
GIVE WAY TO AN ABUNDANCE OF CU GIVEN H85 MOISTURE UNDERNEATH A
DEVELOPING STOUT INVERSION ARND H7. AS FOR POPS DRY THINGS OUT FOR
MOST PART. DID LEAVE SOME LOW POPS FOR A FEW EARLY AFTN DEVELOPMENT
ACROSS THE MTNS.
FOR TEMPS...INHERITED NUMBERS LOOKED GOOD TONIGHT. ELECTED TO GO
CLOSER TO COOLER MET ON THU WITH EXPECTATION THAT EXTENT OF CLDS
HOLDS NUMBERS DOWN A BIT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
A FEW OF THE MESO MODELS ARE SHOWING SOME LINGERING SHOWERS BEHIND
THE COLD FRONT THURSDAY NIGHT. DUE TO THE TIME OF DAY AND DRY AIR
PUSH...DO NOT THINK THAT THIS IS REALISTIC. WILL LEAVE DRY FOR NOW.
HIGH PRESSURE THEN PROVIDES A BRIEF PERIOD OF DRY WEATHER FRIDAY
MORNING. ALL MODELS ARE SHOWING SOME MOISTURE PUSHING BACK IN LATE
FRIDAY...ALTHOUGH TIMING DIFFERENCES EXIST. WILL INCLUDE A CHANCE OF
SHOWERS...AND POSSIBLY THUNDERSTORMS...BUT NOT BE TOO DEFINITIVE. WILL
INCREASE POPS INTO SATURDAY AS FRONT APPROACHES AND MOISTURE
DEEPENS. FRONT THEN PUSHES THROUGH LATE SATURDAY/SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LOTS OF MODEL DIFFERENCES IN HOW FAR SOUTH THE FRONT AND MOISTURE
PUSH FOR THE END OF THE WEEKEND AND BEGINNING OF NEXT WEEK. USED A
BLEND OF THE ECMWF MEAN AND THE GEFS...WHICH WOULD PUT THE FRONT
JUST SOUTH OF THE FORECAST AREA. WITH SOME WAVES POSSIBLE ALONG THE
FRONT...SOME PRECIPITATION COULD MAKE IT INTO THE FORECAST
AREA...WITH THE BEST CHANCES IN THE SOUTH.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
02Z WEDNESDAY THRU 00Z THURSDAY...
GENERALLY MVFR CIGS WILL LWR TONIGHT INTO MAINLY IFR CIGS. HAVE SOME
IFR VSBY COMBO FG. KEKN AND KBKW WILL SEE CIGS LWR INTO LIFR.
SLOW MOVING COLD FRONT APPROACHES AFTER 10Z WITH SOME SHRA. FRONT
MOVES E OF AREA THU MORNING. LLVL MOISTURE WILL LINGER
THOUGH...BENEATH A DEVELOPING INVERSION...WHICH WILL DELAY
IMPROVEMENT OF CIGS. THINK LOW STRATUS LIFTS INTO MVFR TO LOW VFR
ABUNDANCE OF CU BY AFTN. ANY LINGERING SHRA ACROSS THE MTNS SHOULD
END IN AFTN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: DEVELOPMENT OF LOW STRATUS/FOG OVERNIGHT MAY
VARY FROM CURRENT FORECAST. TIMING OF FRONT AND SHRA TONIGHT 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 THU 08/01/13
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H M M H H H H H H
HTS CONSISTENCY M M M M H H L L M M H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H M M M M H H M M M H H
CKB CONSISTENCY H M M M M H H M M M H M
AFTER 00Z FRIDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS LATE FRIDAY THROUGH
SATURDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...JMV/30
SHORT TERM...RPY
LONG TERM...RPY
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
742 PM EDT WED JUL 31 2013
.SYNOPSIS...
A WEAK COLD FRONT CROSSES LATE TONIGHT AND EARLY THURSDAY. HIGH
PRESSURE PASSES THURSDAY NIGHT/FRIDAY MORNING. A COLD FRONT CROSSES
THIS WEEKEND...FOLLOWED BY BELOW NORMAL TEMPERATURES EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
DISTURBANCE MOVING THRU CWA WITH MAINLY SCT -SHRA AND EVEN SOME
-DZ ABOUT THE AREA. WEAKENING VORT MAX HANGING OUT ACROSS SE OH CO
WITH LOBE APPENDAGE MOVING NE INTO N WV SERVING AS MAIN FOCUS FOR
LIFT. RUC AND HRRR SEEMS TO HAVE A MUCH BETTER HANDLE ON THINGS VS
OTHER MDLS AND HAVE USED THESE AS GUIDANCE. OTHERWISE LOOKING AT
AN ABUNDANCE OF LLVL MOISTURE REMAINDER OF AFTN.
FRONT POISED TO MOVE THRU LATE TONIGHT INTO EARLY THU MORNING WITH
A BAND OF SHRA WITH IT. THERE COULD BE AN AREA OF -RA OR DZ ALONG
AND E OF I79 TONIGHT BEFORE AFOREMENTIONED SHRA ARRIVE WITH
IMPRESSIVE DRYING SHOWING UP IN MID LVLS. THINK LOW STRATUS AND
FG WILL SETUP REGARDLESS THIS EVE...TRYING TO LIFT SOME AS FRONTAL
SHRA MOVE IN PREDAWN.
ALL OF THIS PUSHES E ON THU WITH AMPLIFYING UPR TROF ACROSS OH
VALLEY. HOWEVER...LLVL MOISTURE WILL BE VERY SLOW TO GIVE UP THE
GHOST. EVEN THOUGH LOW STRATUS LIFTS BY MIDDAY...SUSPECT THIS WILL
GIVE WAY TO AN ABUNDANCE OF CU GIVEN H85 MOISTURE UNDERNEATH A
DEVELOPING STOUT INVERSION ARND H7. AS FOR POPS DRY THINGS OUT FOR
MOST PART. DID LEAVE SOME LOW POPS FOR A FEW EARLY AFTN DEVELOPMENT
ACROSS THE MTNS.
FOR TEMPS...INHERITED NUMBERS LOOKED GOOD TONIGHT. ELECTED TO GO
CLOSER TO COOLER MET ON THU WITH EXPECTATION THAT EXTENT OF CLDS
HOLDS NUMBERS DOWN A BIT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
A FEW OF THE MESO MODELS ARE SHOWING SOME LINGERING SHOWERS BEHIND
THE COLD FRONT THURSDAY NIGHT. DUE TO THE TIME OF DAY AND DRY AIR
PUSH...DO NOT THINK THAT THIS IS REALISTIC. WILL LEAVE DRY FOR NOW.
HIGH PRESSURE THEN PROVIDES A BRIEF PERIOD OF DRY WEATHER FRIDAY
MORNING. ALL MODELS ARE SHOWING SOME MOISTURE PUSHING BACK IN LATE
FRIDAY...ALTHOUGH TIMING DIFFERENCES EXIST. WILL INCLUDE A CHANCE OF
SHOWERS...AND POSSIBLY THUNDERSTORMS...BUT NOT BE TOO DEFINITIVE. WILL
INCREASE POPS INTO SATURDAY AS FRONT APPROACHES AND MOISTURE
DEEPENS. FRONT THEN PUSHES THROUGH LATE SATURDAY/SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LOTS OF MODEL DIFFERENCES IN HOW FAR SOUTH THE FRONT AND MOISTURE
PUSH FOR THE END OF THE WEEKEND AND BEGINNING OF NEXT WEEK. USED A
BLEND OF THE ECMWF MEAN AND THE GEFS...WHICH WOULD PUT THE FRONT
JUST SOUTH OF THE FORECAST AREA. WITH SOME WAVES POSSIBLE ALONG THE
FRONT...SOME PRECIPITATION COULD MAKE IT INTO THE FORECAST
AREA...WITH THE BEST CHANCES IN THE SOUTH.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
00Z WEDNESDAY THRU 00Z THURSDAY...
GENERALLY MVFR CIGS WILL LWR TONIGHT INTO MAINLY IFR CIGS. HAVE SOME
IFR VSBY COMBO FG. KEKN AND KBKW WILL SEE CIGS LWR INTO LIFR.
SLOW MOVING COLD FRONT APPROACHES AFTER 10Z WITH SOME SHRA. FRONT
MOVES E OF AREA THU MORNING. LLVL MOISTURE WILL LINGER
THOUGH...BENEATH A DEVELOPING INVERSION...WHICH WILL DELAY
IMPROVEMENT OF CIGS. THINK LOW STRATUS LIFTS INTO MVFR TO LOW VFR
ABUNDANCE OF CU BY AFTN. ANY LINGERING SHRA ACROSS THE MTNS SHOULD
END IN AFTN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: DEVELOPMENT OF LOW STRATUS/FOG AFTER 00Z MAY
VARY FROM CURRENT FORECAST. TIMING OF FRONT AND SHRA TONIGHT 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 THU 08/01/13
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 H H H H H H M M H H H H
HTS CONSISTENCY M M M M H H H H L L M H
BKW CONSISTENCY H H H H H M H H H H H H
EKN CONSISTENCY M M M M H H H H H H H H
PKB CONSISTENCY H H H M M M M H H M M M
CKB CONSISTENCY H H H M M M H H H H H H
AFTER 00Z FRIDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS LATE FRIDAY THROUGH
SATURDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...RPY
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS TULSA OK
1155 PM CDT MON JUL 29 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 6Z TAFS... A LARGE AREA OF RAIN SHOWERS WITH EMBEDDED
THUNDERSTORMS IS CURRENTLY OVERSPREADING THE REGION FROM THE NORTHWEST.
THIS ACTIVITY WILL INTERMITTENTLY AFFECT ALL TAF SITES OVERNIGHT
AND INTO THE DAY TUESDAY. TEMPORARY MVFR CONDITIONS WILL OCCUR
WITH ANY CONVECTIVE ACTIVITY... ALONG WITH ERRATIC GUSTY WINDS AND
BRIEF HEAVY RAINFALL.
&&
.PREV DISCUSSION... /ISSUED 800 PM CDT MON JUL 29 2013/
DISCUSSION...
STORMS THAT DEVELOPED NEAR THE BORDER OVER SOUTHWEST KS AND
NORTHWEST OK ARE MOVING SOUTHEAST THIS EVENING INTO NORTHWEST AND
NORTH CENTRAL OK. SEVERAL RUNS OF THE HRRR MODEL HAVE BEEN
FORECASTING THE CONVECTION TO BUILD SOUTH INTO OKLAHOMA.
CONSOLIDATING COLD POOLS WILL PUSH INTO THE STRENGTHENING
SOUTHWESTERLY LLJ THIS EVENING...AND SHOULD HELP TO KEEP THE
STORMS GOING FOR SEVERAL MORE HOURS. DAMAGING WINDS 60-70 MPH AND
MARGINALLY SEVERE HAIL WILL BE THE MAIN THREATS...AND THIS THREAT
WILL BE GREATEST BEFORE MIDNIGHT AND TO THE WEST OF TULSA. THE
CURRENT FORECAST HAS HIGH POPS NEAR THE KS BORDER AND SEE NO
REASON TO CHANGE AT THIS POINT GIVEN LATEST HRRR DATA.
LACY
PREV DISCUSSION... /ISSUED 605 PM CDT MON JUL 29 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 0Z TAFS... SCATTERED THUNDERSTORMS MAY AFFECT NORTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS SITES THIS EVENING. LATER IN THE
EVENING AND OVERNIGHT PRESENTS THE GREATEST CHANCE FOR WIDESPREAD
CONVECTIVE ACTIVITY AT THESE SITES. ANY SITE EXPERIENCING A STORM
CELL WILL LIKELY SEE TEMPORARY MVFR CONDITIONS WITH STRONG GUSTY
WINDS AND HEAVY RAINFALL.
PREV DISCUSSION... /ISSUED 407 PM CDT MON JUL 29 2013/
DISCUSSION...
PRECIPITABLE WATER VALUES IN EXCESS OF TWO BUCKS
COUPLED WITH IMPENDING THUNDER WILL DEPOSIT LOTS
OF RAIN TONIGHT... ESPECIALLY FROM ABOUT HIGHWAY
412 NORTH. THUNDER THROUGH THE EVENING HOURS MAY
BE SEVERE WITH BIG HAIL & WIND. HIGH RES MODELS
BULLISH ON QPF AND PUSHING MCS CLUSTER SOUTHEAST
WHILE LOW RES MODELS LESS SO. LOCAL 3 INCH RAIN
NOT OUT OF THE QUESTION TONIGHT..ESPECIALLY NEAR
THE KANSAS BORDER. FLOOD WATCH AREA MAY NEED TO
BE STRETCHED SOUTHEAST... IF SHORT RANGE MODELS
VERIFY. CARRIED HIGHER POPS INTO TUESDAY MORNING
GIVEN MODEL BIAS OF LESS RAIN BEHIND MCS ACTION.
ALSO LOWERED MAX TEMPS TUESDAY NORTH. LESSER POP
TUESDAY AFTERNOON AND NIGHT WITH COOL FRONT.
DRY WEDNESDAY/THURSDAY EAST OF H5 RIDGE ANCHORED
SOUTHWEST. NEXT WAVE IN NORTHWEST FLOW OVER THE
RIDGE BRINGS RAIN CHANCES AGAIN FRIDAY/SATURDAY.
GW
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH UNTIL 1 PM TUESDAY FOR OKZ054-OKZ055-OKZ056-
OKZ057-OKZ059.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS PORTLAND OR
715 PM PDT WED JUL 31 2013
.SYNOPSIS...AN UPPER LEVEL LOW OFF THE COAST WILL SLOWLY MOVE INLAND
ACROSS THE PACIFIC NW THIS WEEK. THIS WILL BRING A CHANCE OF
THUNDERSTORMS TO THE CASCADES THROUGH THURSDAY. A COOLING TREND
WILL BEGIN THURSDAY AS THE UPPER LEVEL LOW MOVES OVER THE AREA AND
COOLER MARINE AIR MOVES INTO THE VALLEYS. AN UPPER RIDGE WILL BUILD
OVER THE WEEKEND...RESULTING IN WARMER WEATHER.
&&
.MESOSCALE UPDATE...BEST CO-LOCATION OF INSTABILITY AND SHEAR IS
RIGHT ALONG THE LANE COUNTY CASCADE CREST AND THEN SOUTH INTO
KLAMATH AND LAKE COUNTIES. DIME SIZED HAIL WAS REPORTED IN
CHEMULT...EAST OF THE MAIN CORE OF AN EARLIER STORM. SPC MESOSCALE
ANALYSIS SUGGESTS THAT THERE IS A SMALL CORRIDOR IN FAR EASTERN LANE
COUNTY WHERE STRONGER STORMS MAY SNEAK BACK INTO THIS
EVENING...WHICH INCLUDES HIGHWAY 58 NEAR WILLAMETTE PASS.
ADDITIONALLY...THE RAP MODEL HANGS ONTO DECENT INSTABILITY IN THE
LANE COUNTY AND NORTH OREGON CASCADES/EASTERN FOOTHILLS AT LEAST
THROUGH MIDNIGHT IF NOT LONGER... COUPLED WITH A SERIES OF
SHORTWAVES ROTATING AROUND THE UPPER LOW. WE ARE SEEING NEW
DEVELOPMENT IN THIS AREA INITIATING ON THE WEST SIDE OF THE CREST
THIS EVENING.
MEANWHILE...WE ARE STARTING TO SEE SOME ECHOES ON
RADAR MOVING NORTH THROUGH THE CENTRAL VALLEY AND FOOTHILLS. THESE
CELLS ARE FIGHTING A STOUT CAP AND ARE LOWER TOPPED..BUT ARE SHOWING
SIGNS OF BREAKING THE CAP ENOUGH TO PRODUCE THUNDER...AS IS
OCCURRING NEAR MILL CITY AND SILVER FALLS STATE PARK. EXPANDED THE
SHOWER WORDING THIS EVENING TO INCLUDE THE CENTRAL VALLEY INTO THE
EASTERN PORTION OF THE NORTH VALLEY...AND KEPT THE THUNDER WORDING
IN THE FOOTHILLS FOR NOW GIVEN THE STRONGER CAP IN THE
VALLEY...THOUGH THIS WILL BEAR WATCHING. KMD
.SHORT TERM...AN UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE UPPER
LEVEL LOW CONTINUES TO MOVE THROUGH THE AREA THIS AFTERNOON.
SATELLITE IMAGERY SHOWS LOTS OF MID AND HIGH LEVEL CLOUDS STREAMING
ACROSS THE INLAND AREAS WHILE THE COAST REMAINS UNDER MARINE
STRATUS. RADAR AND CAMERA IMAGERY INDICATES MOST OF THE MOISTURE
FALLING AS VIRGA THIS AFTERNOON AS THE ATMOSPHERE MOISTENS. AS OF
230 PM THIS AFTERNOON...THUNDERSTORMS WERE MAINLY SOUTH OF MT
JEFFERSON...BUT MOVING NORTHWARD IN SOUTHERLY FLOW ALOFT. EXPECT
THESE THUNDERSTORMS TO CONTINUE TO MOVE NORTHWARD THIS AFTERNOON
INTO THE OVERNIGHT HOURS. THE LIGHTNING ACTIVITY ASSOCIATED WITH THE
THUNDERSTORMS COMBINED WITH DRY FUELS PRESENT A VERY DANGEROUS
WILDFIRE SITUATION.
ON THURSDAY...UPPER LEVEL INSTABILITY REMAINS OVER THE CASCADES AS
THE UPPER LOW SHIFTS MORE OVER THE AREA. THUS...THE THUNDERSTORM
POTENTIAL FOR THE CASCADES WILL CONTINUE INTO THURSDAY...BUT IT
LOOKS LIKE THE GREATEST THREAT WILL BE EAST OF THE CASCADES. THERE
WILL ALSO BE A STRONG MARINE PUSH INTO THE VALLEYS THURSDAY. MODEL
CROSS SECTIONS INDICATE MARINE LAYER MAY NOT BURN OFF THURSDAY...SO
TEMPERATURES WILL BE QUITE A BIT LOWER TOMORROW AND FRIDAY THAN THE
PAST FEW DAYS. INLAND TEMPERATURES ON THURSDAY WILL ONLY BE IN THE
70S...WHICH IS ABOUT 10 DEGREES BELOW NORMAL. INLAND TEMPS ON FRIDAY
WILL BE A FEW DEGREES WARMER...BUT STILL BELOW NORMAL AND MARINE AIR
WILL STRUGGLE TO BURN OFF. THE UPPER LEVEL LOW HANGS AROUND THE
REGION ON SAT...ALTHOUGH TEMPS REBOUND TO NEAR NORMAL.
.LONG TERM...THERE WILL BE SOME FORM OF A WEAK UPPER LEVEL LOW OR
BAGGY TROUGH OVER THE AREA AS WE BEGIN NEXT WEEK...WITH SOME
DIFFERENCES IN THE VARIOUS MODELS. TW
&&
.AVIATION...UPPER LOW OFFSHORE...WITH S FLOW ALOFT. THIS WILL
KEEP VARIABLE MID AND HIGH CLOUDS OVER THE REGION TONIGHT. MARINE
STRATUS WILL CONTINUE TO AFFECT THE COAST TONIGHT...AND WILL
EXPAND INLAND OVERNIGHT...PROBABLY AFTER 08Z...AND CONTINUE DEEP
INTO THURSDAY AFTERNOON.
KPDX AND APPROACHES...EXPECT VFR CONDITIONS THROUGH 08-10Z. MVFR
STRATUS WILL MOVE IN AFTER 10Z AND CONTINUE INTO THURSDAY
AFTERNOON.
&&
.MARINE...LITTLE CHANGE THROUGH FRI AS WEAK UPPER LOW PUSHES
ACROSS THE REGION. WEAK PRES GRADIENTS WILL KEEP WINDS BELOW 15
KT...WITH SEAS 2 TO 4 FT. RETURN TO MORE TYPICAL NW WINDS THIS
WEEKEND AS HIGH BUILDS...BUT STILL 20 KT OR LESS.
&&
.FIRE WEATHER...AFTER A LONG WAIT TODAY...THUNDERSTORMS ARE STARTING
TO FIRE ALONG THE CASCADES THIS AFTERNOON. SO FAR THE ACTIVITY HAS
BEEN MAINLY SOUTH OF MOUNT JEFFERSON...NEAR THE CENTER OF AN UPPER
LEVEL DISTURBANCE LIFTING NORTH FROM SW OREGON. AS THIS DISTURBANCE
LIFTS NORTHWARD THROUGH OUR DISTRICT...SCATTERED THUNDERSTORMS WILL
DEVELOP THROUGHOUT OUR CASCADES AND FOOTHILLS. THERE ARE GOOD JET
DYNAMICS AND EVEN SOME SHEAR...SO SOME OF THESE THUNDERSTORMS COULD
BECOME STRONG AND PRODUCE VERY GUSTY AND ERRATIC SURFACE WINDS. ALSO
THE THUNDERSTORMS HAVE HIGH BASES SO IT WILL BE DIFFICULT FOR MUCH
RAIN TO REACH THE GROUND. WITH ALL OF THIS IN MIND...THE RED FLAG
WARNING LOOKS GOOD FOR THIS AFTERNOON AND EVENING FOR OUR CASCADE
AND FOOTHILL ZONES.
AS TONIGHT PROGRESSES...THE BEST JET DYNAMICS BEGIN TO SHIFT EAST OF
THE CASCADE CREST. THIS WILL LIKELY PUSH THE STRONGEST THUNDERSTORMS
EAST OF OUR DISTRICT. ALSO THE AIR MASS WILL BE MOISTENING UP
SIGNIFICANTLY AS THE UPPER LOW BEGINS TO DRIFT ONSHORE...RESULTING
IN A RAPIDLY DEEPENING MARINE LAYER. THERE MAY STILL BE A COUPLE
THUNDERSTORMS OVER THE CASCADES INTO THURSDAY...BUT MAINLY JUST
SHOWERS IN THE DEEP MARINE LAYER. THERE COULD ALSO BE A COUPLE
SHOWERS OVER THE LOWLANDS DUE TO THE UPPER LOW...BUT THE BEST CHANCE
FOR WETTING RAIN APPEARS TO BE NORTH AND EAST OF OUR DISTRICT.
WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR ZONE 605-ZONE
606-ZONE 607-ZONE 608.
WA...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR ZONE 660.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
509 AM EDT TUE JUL 30 2013
.SYNOPSIS...
HIGH PRESSURE AND SLIGHTLY DRIER AIR WILL REMAIN ACROSS THE REGION TODAY.
WEDNESDAY AND THURSDAY WILL SEE AN UPPER LEVEL DISTURBANCE MOVE
THROUGH FOLLOWED BY A COLD FRONT...WHICH TOGETHER WILL BRING
NUMEROUS SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS BACK IN
ON FRIDAY AND WILL LINGER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
430 AM UPDATE...CONTINUING TO EVALUATE DENSE FOG SITUATION IN OUR
LOWER SC PIEDMONT ZONES. SEVERAL OBS SITES NEAR THE SE BORDER OF THE
CWFA HAVE DIPPED TO 1/4SM OR LOWER. RUC HAS PICKED UP ON THE FOG AND
ITS SOUNDINGS INDICATE A CLASSIC FOG PROFILE WITH INCREASING
MOISTURE CONTENT WITH ALTITUDE. THE RUC DOES SUGGEST SOME DRYING IN
THE LLVLS...POSSIBLY DUE TO SETTLING OF DROPLETS. CIRRUS MOVING
OVERHEAD MAY ACCELERATE THAT. HOWEVER...IF OBS DO NOT SHOW SOME
IMPROVEMENT OVER NEXT 30-60 MIN...A DENSE FOG ADVY SEEMS LIKE A GOOD
IDEA AS TRAFFIC PICKS UP FOR THE MORNING RUSH.
TODAY...HIGH PRESSURE CENTERED OVER THE UPPER OHIO VALLEY WILL HOLD
STRONG MAINTAINING LIGHT EASTERLY WINDS ACROSS THE REGION AND
SOMEWHAT SETTLED WEATHER...WITH MOISTURE INSUFFICIENT TO EXPECT MUCH
PRECIP FROM UPSLOPING. LOW LEVEL RIDGING WILL PRODUCE POOR MIDLEVEL
LAPSE RATES AND THUS LIMIT INSTABILITY...ESPECIALLY IN THE NORTHERN
PORTION OF THE CWFA AWAY FROM THE BLUE RIDGE. HOWEVER BOTH NAM/GFS
HAVE A SMALL VORT MAX MOVING THRU...AND THE NAM KICKS OFF SOME
SHOWERS WITH IT. THOUGH INSTABILITY REMAINS WELL BELOW CLIMO...0-6KM
BULK SHEAR HIGH ENOUGH TO SUPPORT SOME SEVERE WX IF A GOOD UPDRAFT
GOES UP. NONETHELESS GIVEN THE LACK OF GOOD MOISTURE MOSTLY SCHC POPS
SOUND GOOD. HIGHS WILL RECOVER SLIGHTLY FROM YESTERDAY BUT REMAIN 3-5
DEGREES BELOW NORMAL.
TONIGHT...SYNOPTIC SCALE SHORTWAVE AND WEAK SFC LOW CROSS THE TENN
VALLEY WITH THE SHORTWAVE IN PLACE TO PROVIDE INCREASING FORCING AS
THE NIGHT GOES ON. STATIONARY FRONT TO OUR SOUTH WILL PUSH BACK NORTH
WITH MODEST ISENTROPIC LIFT IN ADDITION TO THE DYNAMIC LIFT FROM THE
SHORTWAVE. WITH THE BEST FORCING ARRIVING LATER...POPS DO LOOK TO BE
ABLE TO DROP OFF IN THE EVENING BRIEFLY BEFORE RAMPING UP THRU DAWN.
ENOUGH ELEVATED INSTABILITY IS PRESENT TO EXPECT A FEW
THUNDERSTORMS...WITH EFFECTIVE BULK SHEAR OF 20-30 KT STILL
INDICATIVE OF AT LEAST AN OUTSIDE CHANCE OF SEVERE. PWAT VALUES AGAIN
RISE ABOVE NORMAL BUT FOR THE MOST PART STAY BELOW 2 INCHES. THE LLJ
ASSOCIATED WITH THE SYSTEM IS SHOWN TO STAY TO OUR WEST...WHICH DOES
MITIGATE THE HEAVY RAIN THREAT THOUGH. ON THE OTHER HAND WINDS
REMAIN PRETTY LIGHT BELOW THE UPPER LEVELS SO STORM MOTION MAY BE
SLOW ENOUGH TO ALLOW SOME SIGNIFICANT ACCUMULATIONS. LOW TEMPS WILL
BE NEAR NORMAL.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 235 AM TUE...AN ACTIVE PATTERN WILL DEVELOP ON WED AS A SERIES
OF ULVL DISTURBANCES TRAVERSE THE BROAD SCALE TROF AXIS OVER THE ERN
CONUS. THE ECMWF IS A BIT OF AN OUTLIER WITH KEEPING THE BEST
FORCING OFF TO THE NW...WHILE THE GFS AND THE NAM BOTH BRING A GOOD
AMOUNT OF ULVL FORCING DIRECTLY OVER THE FA. PWAT VALUES WILL BE
HIGH ON WED...ABOUT 1.75 IN...BUT THERE IS NO GOOD EVIDENCE OF A
LLVL FOCUSING MECHANISM FOR CELLS TO GET HUNG UP ON AND CREATING A
SIGNFT QPF THREAT. THUS WILL COUNT ON THE OPEN UPPER WAVE TO
TRAVERSE THE AREA DURING THE DAY AND PRODUCE LESS THAN AN INCH OF
RAINFALL AT ANY GIVEN LOCATION.
SOUNDINGS LOOK RATHER INTERESTING ON THU WITH MLVL DRY AIR WORKING
IN AND STEEP LLVL LAPSE RATES SETTING UP. WITH A WEAK YET CONVERGENT
SFC FRONT PUSHING IN...THE ATMOS WILL BE SET FOR SCT TO NUMEROUS
STRONG TO SEVERE STORMS DEVELOPING IN THE AFTERNOON. THE FRONT WILL
PUSH INTO THE NC MTNS BEFORE NOON AND LOW END INSTABILITY SHOULD
KEEP DEEP CONVECTION IN CHECK...LEAVING THE FHILLS AND PIEDMONT WITH
THE BEST CHANCES FOR SEVERE ACTIVITY. SOME COLD POOL ORGANIZATION IS
POSSIBLE WITH 0-3 KM SHEAR INCREASING THROUGHOUT THE DAY. CONVECTIVE
ACTIVITY SHOULD LINGER INTO THE LATE EVENING THU AS THE FRONT SLOWS.
BUT BY 06Z FRI...A LOWER THETA/E AIRMASS AND NW/LY FLOW WILL REACH
THE FAR ERN ZONES. MAX TEMPS WILL BE A FEW DEGREES BELOW NORMAL WITH
ALL THE CLOUD COVER AND PRECIP...WHILE HIGH LLVL RH WILL KEEP MINS A
FEW DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 250 AM TUE...NOT MUCH CHANGE WAS NEEDED TO THE GOING FCST. FRI
AND THE WEEKEND STILL LOOKS MOSTLY QUIET AS RELATIVELY TIGHT H5
GRADIENT AND AN OVERALL SUBS ZONE TRAVERSES THE AREA. FRI LOOKS THE
DRIEST WITH ISOL POPS MAINTAINED SAT AND SUN ACROSS THE HIGHER
TERRAIN. THE UPPER PATTERN BECOMES MORE DIFFLUENT LATE SUN AND POPS
WERE BUMPED UP A BIT TO ACCOUNT FOR POCKETS OF S/W ENERGY
INTERACTING WITH MECH LIFT MON. WITH A DRIER COLUMN AND DEEP
SUBS...SFC TEMPS SHOULD REBOUND TO AROUND NORMAL FRI AND PERSIST
THROUGH THE WEEKEND. A LITTLE COOLER ON MON DUE TO INCREASED CLOUD
COVER.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
AT KCLT /09Z UPDATE/...LOW STRATUS HAVE MOVED IN AND BROUGHT CIGS AS
LOW AS 005. DENSE FOG WILL CONTINUE IN AREAS JUST SOUTH OF THE FIELD
BUT THIS DOES NOT APPEAR TO BE EXPANDING...WITH WEAK FLOW AT THE
SFC. HEAT ISLAND EXPECTED TO KEEP DRIER CONDITIONS AT THE FIELD AND
VFR VSBY. MODELS REFLECTING THE CIG INDICATE LOW CLOUDS WILL HANG
AROUND THRU DAWN. CIRRUS ABOVE THE LAYER MAY ALLOW IT TO REMAIN SCT
THOUGH IT MAY BRIEFLY GO OVC. ONCE THE LOW DECK BURNS OFF...CU WILL
DEVELOP AND FORM A CIG BY AFTERNOON...PERHAPS BRIEFLY FORMING FIRST
AT MVFR BEFORE MIXING TO VFR. CIGS AFTER SUNSET MAINLY WILL COME
FROM MID-HIGH CLOUDS ASSOCIATED WITH INCOMING SHORTWAVE TROUGH.
PRECIP CHANCES REMAIN TOO LOW TO MENTION THRU 06Z. LIGHT NELY WINDS
WILL VEER TO SE TUE EVENING AHEAD OF THE TROUGH.
ELSEWHERE...PATCHY MVFR FOG WILL AFFECT SOME OF THE TAF SITES MAINLY
AROUND DAYBREAK TUE THOUGH GUIDANCE AND OBS SUGGEST SOME POSSIBILITY
PRIOR TO THEN...WITH DENSE FOG REMAINING ACRS THE LOWER SC PIEDMONT.
SOME SCT-BKN MVFR CLOUDS WILL LINGER OVER THE NC FOOTHILLS AND
PIEDMONT THRU DAWN. VFR CUMULUS WILL DEVELOP TODAY ALONG WITH
ISOLATED SHOWERS...THOUGH SHRA/TSRA CHANCES TOO SMALL TO MENTION.
CIGS WILL GRADUALLY LOWER AND PRECIP CHANCES INCREASE WEST TO EAST
AFTER SUNSET WITH INCOMING SHORTWAVE TROUGH...BUT PRIOR TO 06Z ONLY
A PROB30 OR VC MENTION IS WARRANTED.
OUTLOOK...A RETURN TO AN ACTIVE/WET PATTERN IS EXPECTED BY MID-WEEK.
ANOTHER PERIOD OF DRYING IS POSSIBLE BY NEXT WEEKEND.
CONFIDENCE TABLE...
09-15Z 15-21Z 21-03Z 03-09Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 97% MED 78% HIGH 85%
KAVL HIGH 100% HIGH 100% HIGH 100% MED 79%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 99% MED 78% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...WIMBERLEY
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
442 AM EDT TUE JUL 30 2013
.SYNOPSIS...
HIGH PRESSURE AND SLIGHTLY DRIER AIR WILL REMAIN ACROSS THE REGION TODAY.
WEDNESDAY AND THURSDAY WILL SEE AN UPPER LEVEL DISTURBANCE MOVE
THROUGH FOLLOWED BY A COLD FRONT...WHICH TOGETHER WILL BRING
NUMEROUS SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS BACK IN
ON FRIDAY AND WILL LINGER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
430 AM UPDATE...CONTINUING TO EVALUATE DENSE FOG SITUATION IN OUR
LOWER SC PIEDMONT ZONES. SEVERAL OBS SITES NEAR THE SE BORDER OF THE
CWFA HAVE DIPPED TO 1/4SM OR LOWER. RUC HAS PICKED UP ON THE FOG AND
ITS SOUNDINGS INDICATE A CLASSIC FOG PROFILE WITH INCREASING
MOISTURE CONTENT WITH ALTITUDE. THE RUC DOES SUGGEST SOME DRYING IN
THE LLVLS...POSSIBLY DUE TO SETTLING OF DROPLETS. CIRRUS MOVING
OVERHEAD MAY ACCELERATE THAT. HOWEVER...IF OBS DO NOT SHOW SOME
IMPROVEMENT OVER NEXT 30-60 MIN...A DENSE FOG ADVY SEEMS LIKE A GOOD
IDEA AS TRAFFIC PICKS UP FOR THE MORNING RUSH.
TODAY...HIGH PRESSURE CENTERED OVER THE UPPER OHIO VALLEY WILL HOLD
STRONG MAINTAINING LIGHT EASTERLY WINDS ACROSS THE REGION AND
SOMEWHAT SETTLED WEATHER...WITH MOISTURE INSUFFICIENT TO EXPECT MUCH
PRECIP FROM UPSLOPING. LOW LEVEL RIDGING WILL PRODUCE POOR MIDLEVEL
LAPSE RATES AND THUS LIMIT INSTABILITY...ESPECIALLY IN THE NORTHERN
PORTION OF THE CWFA AWAY FROM THE BLUE RIDGE. HOWEVER BOTH NAM/GFS
HAVE A SMALL VORT MAX MOVING THRU...AND THE NAM KICKS OFF SOME
SHOWERS WITH IT. THOUGH INSTABILITY REMAINS WELL BELOW CLIMO...0-6KM
BULK SHEAR HIGH ENOUGH TO SUPPORT SOME SEVERE WX IF A GOOD UPDRAFT
GOES UP. NONETHELESS GIVEN THE LACK OF GOOD MOISTURE MOSTLY SCHC POPS
SOUND GOOD. HIGHS WILL RECOVER SLIGHTLY FROM YESTERDAY BUT REMAIN 3-5
DEGREES BELOW NORMAL.
TONIGHT...SYNOPTIC SCALE SHORTWAVE AND WEAK SFC LOW CROSS THE TENN
VALLEY WITH THE SHORTWAVE IN PLACE TO PROVIDE INCREASING FORCING AS
THE NIGHT GOES ON. STATIONARY FRONT TO OUR SOUTH WILL PUSH BACK NORTH
WITH MODEST ISENTROPIC LIFT IN ADDITION TO THE DYNAMIC LIFT FROM THE
SHORTWAVE. WITH THE BEST FORCING ARRIVING LATER...POPS DO LOOK TO BE
ABLE TO DROP OFF IN THE EVENING BRIEFLY BEFORE RAMPING UP THRU DAWN.
ENOUGH ELEVATED INSTABILITY IS PRESENT TO EXPECT A FEW
THUNDERSTORMS...WITH EFFECTIVE BULK SHEAR OF 20-30 KT STILL
INDICATIVE OF AT LEAST AN OUTSIDE CHANCE OF SEVERE. PWAT VALUES AGAIN
RISE ABOVE NORMAL BUT FOR THE MOST PART STAY BELOW 2 INCHES. THE LLJ
ASSOCIATED WITH THE SYSTEM IS SHOWN TO STAY TO OUR WEST...WHICH DOES
MITIGATE THE HEAVY RAIN THREAT THOUGH. ON THE OTHER HAND WINDS
REMAIN PRETTY LIGHT BELOW THE UPPER LEVELS SO STORM MOTION MAY BE
SLOW ENOUGH TO ALLOW SOME SIGNIFICANT ACCUMULATIONS. LOW TEMPS WILL
BE NEAR NORMAL.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 235 AM TUE...AN ACTIVE PATTERN WILL DEVELOP ON WED AS A SERIES
OF ULVL DISTURBANCES TRAVERSE THE BROAD SCALE TROF AXIS OVER THE ERN
CONUS. THE ECMWF IS A BIT OF AN OUTLIER WITH KEEPING THE BEST
FORCING OFF TO THE NW...WHILE THE GFS AND THE NAM BOTH BRING A GOOD
AMOUNT OF ULVL FORCING DIRECTLY OVER THE FA. PWAT VALUES WILL BE
HIGH ON WED...ABOUT 1.75 IN...BUT THERE IS NO GOOD EVIDENCE OF A
LLVL FOCUSING MECHANISM FOR CELLS TO GET HUNG UP ON AND CREATING A
SIGNFT QPF THREAT. THUS WILL COUNT ON THE OPEN UPPER WAVE TO
TRAVERSE THE AREA DURING THE DAY AND PRODUCE LESS THAN AN INCH OF
RAINFALL AT ANY GIVEN LOCATION.
SOUNDINGS LOOK RATHER INTERESTING ON THU WITH MLVL DRY AIR WORKING
IN AND STEEP LLVL LAPSE RATES SETTING UP. WITH A WEAK YET CONVERGENT
SFC FRONT PUSHING IN...THE ATMOS WILL BE SET FOR SCT TO NUMEROUS
STRONG TO SEVERE STORMS DEVELOPING IN THE AFTERNOON. THE FRONT WILL
PUSH INTO THE NC MTNS BEFORE NOON AND LOW END INSTABILITY SHOULD
KEEP DEEP CONVECTION IN CHECK...LEAVING THE FHILLS AND PIEDMONT WITH
THE BEST CHANCES FOR SEVERE ACTIVITY. SOME COLD POOL ORGANIZATION IS
POSSIBLE WITH 0-3 KM SHEAR INCREASING THROUGHOUT THE DAY. CONVECTIVE
ACTIVITY SHOULD LINGER INTO THE LATE EVENING THU AS THE FRONT SLOWS.
BUT BY 06Z FRI...A LOWER THETA/E AIRMASS AND NW/LY FLOW WILL REACH
THE FAR ERN ZONES. MAX TEMPS WILL BE A FEW DEGREES BELOW NORMAL WITH
ALL THE CLOUD COVER AND PRECIP...WHILE HIGH LLVL RH WILL KEEP MINS A
FEW DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 250 AM TUE...NOT MUCH CHANGE WAS NEEDED TO THE GOING FCST. FRI
AND THE WEEKEND STILL LOOKS MOSTLY QUIET AS RELATIVELY TIGHT H5
GRADIENT AND AN OVERALL SUBS ZONE TRAVERSES THE AREA. FRI LOOKS THE
DRIEST WITH ISOL POPS MAINTAINED SAT AND SUN ACROSS THE HIGHER
TERRAIN. THE UPPER PATTERN BECOMES MORE DIFFLUENT LATE SUN AND POPS
WERE BUMPED UP A BIT TO ACCOUNT FOR POCKETS OF S/W ENERGY
INTERACTING WITH MECH LIFT MON. WITH A DRIER COLUMN AND DEEP
SUBS...SFC TEMPS SHOULD REBOUND TO AROUND NORMAL FRI AND PERSIST
THROUGH THE WEEKEND. A LITTLE COOLER ON MON DUE TO INCREASED CLOUD
COVER.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
AT KCLT /09Z UPDATE/...LOW STRATUS HAVE MOVED IN AND BROUGHT CIGS AS
LOW AS 005. DENSE FOG WILL CONTINUE IN AREAS JUST SOUTH OF THE FIELD
BUT THIS DOES NOT APPEAR TO BE EXPANDING...WITH WEAK FLOW AT THE
SFC. HEAT ISLAND EXPECTED TO KEEP DRIER CONDITIONS AT THE FIELD AND
VFR VSBY. MODELS REFLECTING THE CIG INDICATE IT WILL HANG AROUND
THRU DAWN...THOUGH WITH CIRRUS MOVING OVER THE LAYER IT MAY BREAK UP
A BIT...HENCE TEMPO SCATTERING. ONCE THE LOW DECK BURNS OFF...CU
WILL DEVELOP AND FORM A CIG BY AFTERNOON...PERHAPS BRIEFLY FORMING
FIRST AT MVFR BEFORE MIXING TO VFR. CIGS AFTER SUNSET MAINLY WILL
COME FROM MID-HIGH CLOUDS ASSOCIATED WITH INCOMING SHORTWAVE TROUGH.
PRECIP CHANCES REMAIN TOO LOW TO MENTION THRU 06Z. LIGHT NELY WINDS
WILL VEER TO SE TUE EVENING AHEAD OF THE TROUGH.
ELSEWHERE...PATCHY MVFR FOG WILL AFFECT SOME OF THE TAF SITES MAINLY
AROUND DAYBREAK TUE THOUGH GUIDANCE AND OBS SUGGEST SOME POSSIBILITY
PRIOR TO THEN...WITH DENSE FOG REMAINING ACRS THE LOWER SC PIEDMONT.
SOME SCT-BKN MVFR CLOUDS WILL LINGER OVER THE NC FOOTHILLS AND
PIEDMONT THRU DAWN. VFR CUMULUS WILL DEVELOP TODAY ALONG WITH
ISOLATED SHOWERS...THOUGH SHRA/TSRA CHANCES TOO SMALL TO MENTION.
CIGS WILL GRADUALLY LOWER AND PRECIP CHANCES INCREASE WEST TO EAST
AFTER SUNSET WITH INCOMING SHORTWAVE TROUGH...BUT PRIOR TO 06Z ONLY
A PROB30 OR VC MENTION IS WARRANTED.
OUTLOOK...A RETURN TO AN ACTIVE/WET PATTERN IS EXPECTED BY MID-WEEK.
ANOTHER PERIOD OF DRYING IS POSSIBLE BY NEXT WEEKEND.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 94% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 94% HIGH 98% HIGH 85% MED 79%
KAVL HIGH 89% HIGH 100% HIGH 100% HIGH 83%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 98% HIGH 85% HIGH 93%
KAND HIGH 89% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...WIMBERLEY
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
823 PM MDT WED JUL 31 2013
.UPDATE...
ISSUED AT 811 PM MDT WED JUL 31 2013
A BROKEN UP LINE OF THUNDERSTORMS WHICH FORMED JUST NORTH OF THE
FRONT ACROSS EASTERN WYOMING INTO NEBRASKA IS QUICKLY LOOSING
INTENSITY. THE HRRR MESO SCALE MODEL DID A GOOD JOB OF FORECAST
THE LIFE CYCLE OF THESE STORMS THIS EVENING...BUT ENDED UP SHOWING
A LITTLE TOO MUCH COVERAGE INTO SOUTHWESTERN SOUTH DAKOTA. NONE
OF THEM ACTUALLY CROSSED THE BORDER INTO THE FORECAST AREA.
THE 00Z KUNR SOUNDING SHOWS A VERY DRY AIRMASS BELOW 700 MB.
IT APPEARS THAT THE HRRR FORECAST FOR THE NEXT CLUSTER OF ACTIVITY
MAY HAVE SIMILARLY OVER FORECAST THE AREAL COVERAGE...BUT SOME LIGHT
SHOWER ACTIVITY WILL LIKELY MOVE INTO CAMPBELL COUNTY BY 9 PM
MDT...AND THEN CONTINUE EASTWARD INTO THE BLKHLS REGION. GIVEN THE
SOUNDING DESCRIBED ABOVE...IT DOESN`T APPEAR THESE STORMS WILL
HAVE MUCH TO FEED ON. HOWEVER THE SLIGHT CHANCE POPS WILL REMAIN
IN THE GRIDS...AND SCATTERED SMALL AMOUNTS OF MEASURABLE PRECIP
ARE LIKELY.
&&
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 305 PM MDT WED JUL 31 2013
CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY JUST SOUTH OF THE
AREA ACROSS NEB...WHERE IT IS EXPECTED TO REMAIN OVER THE NEXT
COUPLE OF DAYS. UPPER LEVEL ANALYSIS HAS LOW PRESSURE ALONG THE
PACIFIC NW COAST...WITH RIDGE AXIS OVER THE ROCKIES REGION.
NORTHWESTERLY FLOW ALOFT IS IN PLACE OVER THE NORTHERN PLAINS AT
THIS TIME. SKIES ARE MOSTLY SUNNY ACROSS MUCH OF THE AREA NOW WITH
SOME WEAK TOWERING CU OVER THE BLACK HILLS...BUT NO SHOWERS AS OF
YET. REGIONAL RADARS SHOW ISOLATED SHOWERS AND STORMS OVER CENTRAL
AND SOUTHEASTERN WY. A FEW SHOWERS HAVE ALSO DEVELOPED OVER
CENTRAL SD WITH A WEAK DISTURBANCE PUSHING SOUTHEASTWARD. TEMPS
ARE IN THE MID 70S TO MID 80S WITH WITH RELATIVELY LIGHT NORTH-
NORTHWEST WINDS ACROSS MUCH OF THE AREA.
THE REST OF TODAY AND TONIGHT LOOKS RATHER QUIET COMPARED TO
RECENT DAYS AND WHAT IS EXPECTED THROUGH THE REST OF THE WEEK.
ISOLATED SHOWERS AND STORMS WILL TRY TO DEVELOP OR PUSH INTO
PORTIONS OF NORTHEASTERN WY AND SOUTHWESTERN SD LATE THIS AFTERNOON
AND EVENING. THE THREAT FOR ANY STRONGER STORMS IS RATHER LOW WITH
DRIER AIR IN PLACE AND BULK OF STRONGER INSTABILITY PUSHED SOUTH OF
THE CWA FOR THE SHORT TERM. BEST CHANCES FOR A STRONGER STORM WOULD
BE ACROSS FAR SOUTHWESTERN SD LATE TODAY. WILL KEEP CHANCES FOR
SHOWERS AND STORMS INTO THE OVERNIGHT ACROSS SOUTHERN PORTIONS OF
THE CWA AS LOW LEVEL JET INTENSIFIES OVER NEB AND LOW LEVEL THETA-E
ADVECTION INCREASES OVER THE AREA. THE BEST CHANCES FOR ACTIVITY
OVERNIGHT WILL BE ACROSS FAR SOUTHERN SD. LOWS WILL BE IN THE 50S
AND LOWER 60S WITH LIGHT WINDS.
WINDS WILL TURN EAST-SOUTHEAST ON THURSDAY AND INCREASE THROUGH THE
DAY AS LOW PRESSURE DEVELOPS ACROSS SOUTHEASTERN WY ALONG THE NEARLY
STATIONARY FRONTAL BOUNDARY. THIS WILL BRING INCREASING LOW LEVEL
MOISTURE AND INSTABILITY SLOWLY NORTHWARD INTO AT LEAST SOUTHERN
PORTIONS OF THE CWA. ALOFT...THE RIDGE OVER THE ROCKIES WILL SLOWLY
MOVE EAST AND GRADUALLY WEAKEN...ALLOWING WEAK SHORTWAVE ENERGY TO
PUSH THROUGH THE RIDGE AND ACROSS THE AREA. THIS SHOULD HELP TO
PRODUCE ISOLATED TO SCATTERED THUNDERSTORMS OVER MUCH OF THE
AREA...MAINLY DURING THE AFTERNOON AND INTO THURSDAY NIGHT. WITH
INCREASED INSTABILITY AND SHEAR IN PLACE ACROSS SOUTHERN PORTIONS OF
THE AREA...THERE WILL BE A SLIGHT RISK FOR SEVERE STORMS ACROSS MUCH
OF NORTHEASTERN WY THROUGH SOUTHERN SD DURING THE AFTERNOON AND
EVENING. LARGE HAIL AND STRONG WIND GUSTS LOOK TO BE THE MAIN
THREATS. AN ISOLATED TORNADO THREAT ALSO LOOKS POSSIBLE ACROSS FAR
SOUTHWSTERN SD OR SOUTHERN PARTS OF NORTHEASTERN WY IF THE LOW
PRESSURE AREA LIFTS FURTHER NORTH. HIGHS WILL BE IN THE LOW TO MID
80S ACROSS MUCH OF THE PLAINS...WITH 70S OVER THE BLACK HILLS. WILL
KEEP PCPN CHANCES OVERNIGHT AS LOW LEVEL JET DEVELOPS FURTHER NORTH
ACROSS THE NORTHERN HIGH PLAINS AND THETA-E ADVECTION INCREASES AS
WELL.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 305 PM MDT WED JUL 31 2013
UNSETTLED PATTERN WILL CONTINUE THROUGH THIS WEEKEND INTO EARLY
NEXT WEEK AS SERIES OF UPPER LEVEL DISTURBANCES MOVE THROUGH W/NW
FLOW. THIS PATTERN WILL BRING CONTINUED CHANCES FOR SHOWERS/STORMS
THROUGH THE WEEKEND INTO EARLY NEXT WEEK. SLIGHTLY COOLER THAN
AVERAGE TEMPS ARE EXPECTED FOR THE END OF THIS WEEK...WITH WARMING
TREND POSSIBLE FOR THE NEW WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 559 PM MDT WED JUL 31 2013
ISOLD -TSRA/SHRA WILL BE POSSIBLE OVER NORTHEAST WYOMING AND
SOUTHWESTERN SOUTH DAKOTA INCLUDING THE BLKHLS THIS EVENING. LCL
MVFR CIGS AND VIS WILL BE POSSIBLE IN THE HEAVIER PRECIP.
OTHERWISE...VFR CONDITIONS ARE EXPECTED.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...CARPENTER
SHORT TERM...26
LONG TERM...13
AVIATION...CARPENTER
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
913 PM CDT WED JUL 31 2013
.UPDATE...
REMOVING EVENING RAIN CHANCES.
&&
.DISCUSSION...
STORMS HAVE NEARLY DISSIPATED AT 9 PM THIS EVENING...WITH ONLY A
FEW SHOWERS NORTH OF STERLING CITY. WITH LOSS OF HEATING...DO NOT
EXPECT REGENERATION DESPITE A WEAK SURFACE TROUGH ACROSS THE
REGION. LOW IN THE MID 70S LOOK GOOD.
04
&&
.PREV DISCUSSION... /ISSUED 632 PM CDT WED JUL 31 2013/
DISCUSSION...
LOOK FOR VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR
THE NEXT 24 HOURS. SEE AVIATION BELOW FOR DETAILS.
AVIATION...
/THIS AFTERNOON AND EARLY EVENING/
..ISOLATED THUNDERSTORMS WITH POSSIBLE DOWNBURSTS...
A SURFACE BOUNDARY EXTENDING ALONG OR NEAR INTERSTATE 20 WILL
CONTINUE TO BE A FOCUS FOR SHOWERS AND THUNDERSTORM DEVELOPMENT
THIS AFTERNOON. WITH LITTLE IF ANY UPPER-LEVEL
SUPPORT...THUNDERSTORMS WILL BE SHORT LIVED. THE FREEZING LEVEL IS
AROUND FOURTEEN THOUSAND FEET ABOVE GROUND LEVEL. THUS...THE HAIL
THREAT IS VERY LOW. HOWEVER...MODEL FORECAST SOUNDING AT SEVERAL
LOCATIONS ACROSS WEST CENTRAL TEXAS INDICATE THE POTENTIAL FOR
DOWNBURST WINDS. THUS...I BELIEVE THAT IS THE PRIMARY THREAT THIS
AFTERNOON AND EVENING. WATCH FOR THUNDERSTORMS TO DISSIPATE AROUND
SUNSET. GIVEN THE ISOLATED NATURE OF THUNDERSTORMS...I DECIDED NOT
TO INCLUDE ANY THUNDER IN ANY OF OUR TERMINALS.
HUBER
/OVERNIGHT AND TOMORROW/
..VFR CONDITIONS WITH LIGHT AND VARIABLE WINDS...
MODELS INDICATE HIGH PRESSURE WILL CONTINUE TO DOMINATE THE REGION
FOR THE NEXT 24 HOURS. THEREFORE...EXPECT SURFACE WINDS TO BE
MAINLY LIGHT AND VARIABLE THROUGH TOMORROW AFTERNOON.
HUBER
PREV DISCUSSION... /ISSUED 346 PM CDT WED JUL 31 2013/
SHORT TERM...
A WEAK COLD FRONT WAS SITUATED ROUGHLY ALONG THE I-20 CORRIDOR THIS
AFTERNOON. THIS FRONT IS EXPECTED TO DROP A BIT FARTHER SOUTH INTO
NORTHERN PORTIONS OF THE CONCHO VALLEY AND HEARTLAND BEFORE STALLING
OUT TONIGHT. THE FRONT WILL BECOME MORE DIFFUSE ON THURSDAY AND
SHOULD WASH OUT ACROSS THE AREA BY AFTERNOON. AS OF 3 PM...ISOLATED
CONVECTION HAS FORMED JUST AHEAD OF THE FRONT OVER SOUTHERN PORTIONS
OF THE BIG COUNTRY. WILL KEEP ISOLATED CONVECTION IN THE FORECAST
THROUGH EARLY EVENING WITH ACTIVITY EXPECTED TO DISSIPATE AFTER
SUNSET WITH LOSS OF HEATING.
CONVECTION HAS ALSO DEVELOPED ACROSS THE HIGHER TERRAIN IN EASTERN
NEW MEXICO THIS AFTERNOON. LATEST NAM AND HRRR INDICATE THAT THIS
ACTIVITY MAY MAKE A RUN AT OUR WESTERN COUNTIES TOWARDS DAYBREAK
THURSDAY AS IT WEAKENS. NOT CONFIDENT THAT THIS WILL HAPPEN SO KEPT
THE FORECAST DRY OVERNIGHT. DRY AND HOT CONDITIONS CONTINUE THURSDAY
AFTERNOON WITH HIGHS 99 TO 102 AND HEAT INDICES 102 TO 105 DEGREES.
24
LONG TERM...
HOT AND DRY CONDITIONS WILL DOMINATE THE WEATHER ACROSS WEST CENTRAL
TEXAS FROM FRIDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. THE
SURFACE HIGH THAT IS CURRENTLY CENTERED OVER NEW MEXICO WILL
REPOSITION ITSELF OVER TEXAS THROUGH AT LEAST THE NEXT 7 DAYS. THIS
WILL RESULT IN NEAR NIL RAIN CHANCES...WITH HIGH TEMPERATURES
RANGING FROM 98 TO 103...WHILE OVERNIGHT LOWS FALL INTO THE MID AND
UPPER 70S. VERY LITTLE RELIEF IN THE HOT AND DRY PATTERN IS EXPECTED
THROUGH THE NEXT 7 DAYS...AND POSSIBLY BEYOND...AS THE UPPER LEVEL
HIGH REMAINS PARKED OVER THE LONE STAR STATE.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 76 100 75 101 75 / 5 5 0 0 0
SAN ANGELO 75 101 75 101 74 / 5 5 0 0 0
JUNCTION 75 99 73 99 72 / 5 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/04
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
632 PM CDT WED JUL 31 2013
.DISCUSSION...
LOOK FOR VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR
THE NEXT 24 HOURS. SEE AVIATION BELOW FOR DETAILS.
&&
.AVIATION...
/THIS AFTERNOON AND EARLY EVENING/
...ISOLATED THUNDERSTORMS WITH POSSIBLE DOWNBURSTS...
A SURFACE BOUNDARY EXTENDING ALONG OR NEAR INTERSTATE 20 WILL
CONTINUE TO BE A FOCUS FOR SHOWERS AND THUNDERSTORM DEVELOPMENT
THIS AFTERNOON. WITH LITTLE IF ANY UPPER-LEVEL
SUPPORT...THUNDERSTORMS WILL BE SHORT LIVED. THE FREEZING LEVEL IS
AROUND FOURTEEN THOUSAND FEET ABOVE GROUND LEVEL. THUS...THE HAIL
THREAT IS VERY LOW. HOWEVER...MODEL FORECAST SOUNDING AT SEVERAL
LOCATIONS ACROSS WEST CENTRAL TEXAS INDICATE THE POTENTIAL FOR
DOWNBURST WINDS. THUS...I BELIEVE THAT IS THE PRIMARY THREAT THIS
AFTERNOON AND EVENING. WATCH FOR THUNDERSTORMS TO DISSIPATE AROUND
SUNSET. GIVEN THE ISOLATED NATURE OF THUNDERSTORMS...I DECIDED NOT
TO INCLUDE ANY THUNDER IN ANY OF OUR TERMINALS.
HUBER
/OVERNIGHT AND TOMORROW/
...VFR CONDITIONS WITH LIGHT AND VARIABLE WINDS...
MODELS INDICATE HIGH PRESSURE WILL CONTINUE TO DOMINATE THE REGION
FOR THE NEXT 24 HOURS. THEREFORE...EXPECT SURFACE WINDS TO BE
MAINLY LIGHT AND VARIABLE THROUGH TOMORROW AFTERNOON.
HUBER
&&
.PREV DISCUSSION... /ISSUED 346 PM CDT WED JUL 31 2013/
SHORT TERM...
A WEAK COLD FRONT WAS SITUATED ROUGHLY ALONG THE I-20 CORRIDOR THIS
AFTERNOON. THIS FRONT IS EXPECTED TO DROP A BIT FARTHER SOUTH INTO
NORTHERN PORTIONS OF THE CONCHO VALLEY AND HEARTLAND BEFORE STALLING
OUT TONIGHT. THE FRONT WILL BECOME MORE DIFFUSE ON THURSDAY AND
SHOULD WASH OUT ACROSS THE AREA BY AFTERNOON. AS OF 3 PM...ISOLATED
CONVECTION HAS FORMED JUST AHEAD OF THE FRONT OVER SOUTHERN PORTIONS
OF THE BIG COUNTRY. WILL KEEP ISOLATED CONVECTION IN THE FORECAST
THROUGH EARLY EVENING WITH ACTIVITY EXPECTED TO DISSIPATE AFTER
SUNSET WITH LOSS OF HEATING.
CONVECTION HAS ALSO DEVELOPED ACROSS THE HIGHER TERRAIN IN EASTERN
NEW MEXICO THIS AFTERNOON. LATEST NAM AND HRRR INDICATE THAT THIS
ACTIVITY MAY MAKE A RUN AT OUR WESTERN COUNTIES TOWARDS DAYBREAK
THURSDAY AS IT WEAKENS. NOT CONFIDENT THAT THIS WILL HAPPEN SO KEPT
THE FORECAST DRY OVERNIGHT. DRY AND HOT CONDITIONS CONTINUE THURSDAY
AFTERNOON WITH HIGHS 99 TO 102 AND HEAT INDICES 102 TO 105 DEGREES.
24
LONG TERM...
HOT AND DRY CONDITIONS WILL DOMINATE THE WEATHER ACROSS WEST CENTRAL
TEXAS FROM FRIDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. THE
SURFACE HIGH THAT IS CURRENTLY CENTERED OVER NEW MEXICO WILL
REPOSITION ITSELF OVER TEXAS THROUGH AT LEAST THE NEXT 7 DAYS. THIS
WILL RESULT IN NEAR NIL RAIN CHANCES...WITH HIGH TEMPERATURES
RANGING FROM 98 TO 103...WHILE OVERNIGHT LOWS FALL INTO THE MID AND
UPPER 70S. VERY LITTLE RELIEF IN THE HOT AND DRY PATTERN IS EXPECTED
THROUGH THE NEXT 7 DAYS...AND POSSIBLY BEYOND...AS THE UPPER LEVEL
HIGH REMAINS PARKED OVER THE LONE STAR STATE.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 76 100 75 101 75 / 10 5 0 0 0
SAN ANGELO 75 101 75 101 74 / 20 5 0 0 0
JUNCTION 75 99 73 99 72 / 10 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
24/DANIELS/HUBER
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
215 PM CDT TUE JUL 30 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 215 PM CDT TUE JUL 30 2013
CURRENTLY AS OF 19Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED SUBTROPICAL
RIDGING OVER THE SOUTHWESTERN U.S....TROUGHING OVER SASKATCHEWAN AND
MANITOBA...AND WEST-NORTHWEST FLOW FROM MONTANA INTO THE FORECAST
AREA. WITHIN THE FLOW...A FEW SHORTWAVES WERE CROSSING NORTH DAKOTA.
CONDITIONS ARE DRY ACROSS THE FORECAST AREA...BUT PLENTY OF STRATUS
OF THE LOW TO MID LEVEL VARIETY EXISTS. THESE CLOUDS HAVE HELD
TEMPERATURES DOWN SOMEWHAT...BUT ENOUGH SUN HAS MADE IT THROUGH WITH
THE 850MB TEMPS BETWEEN 11-13C PER 12Z RAOBS TO BRING READINGS INTO
THE 70S. TO THE WEST...A COLD FRONT WAS PRESENT OVER FAR WESTERN
MN...JUST AHEAD OF THE SHORTWAVES. THE COLD FRONT SO FAR HAS NOT
DONE ANYTHING PRECIPITATION WISE...BUT THERE HAS BEEN CONVECTION
BEHIND THE FRONT OVER SOUTHERN SOUTH DAKOTA.
SYNOPTIC OVERVIEW...
MODELS ARE IN VERY GOOD AGREEMENT DROPPING A PORTION OF THE
TROUGHING OVER SOUTH CENTRAL CANADA THROUGH THE FORECAST AREA
WEDNESDAY AFTERNOON. THIS PORTION OF THE TROUGH...OR SHORTWAVE...IS
OF MOST CONCERN...SINCE IT WILL PUSH THE COLD FRONT TO OUR WEST
ACROSS THE FORECAST AREA. IT APPEARS THE SHORTWAVES CURRENTLY ACROSS
NORTH DAKOTA WILL HEAD EAST TOWARDS UPPER MI.
HAZARDS...
SOME SEVERE WEATHER POTENTIAL WEDNESDAY AFTERNOON GIVEN 0-6 KM SHEAR
VALUES AROUND 40 KT PRESENT WITH A FRONTAL PASSAGE. HOWEVER...THERE
ARE SERIOUS CONCERNS ON AVAILABLE INSTABILITY AS DESCRIBED IN THE
DETAILS BELOW. SHOULD SEVERE WEATHER OCCUR...HAIL WILL BE THE MAIN
CONCERN.
DETAILS...
A LIGHT SOUTHERLY FLOW AHEAD OF THE WESTERN MN COLD FRONT WILL ALLOW
SOME OF THE LOWER CEILING STRATUS AND FOG THAT HAS PRESENT JUST
SOUTH OF THE FORECAST AREA TO COME UP INTO NORTHEAST IOWA AND FAR
SOUTHWEST WISCONSIN TONIGHT. HAVE ADDED SOME FOG MENTION TO THESE
LOCATIONS. OTHERWISE...TONIGHT LOOKS FAIRLY QUIET WITH BASICALLY NO
ISENTROPIC LIFT AND ALL SHORTWAVE FORCING HEADING UP TO THE NORTH.
ONE ITEM OF INTEREST PRESENT IN SOME PAST HRRR RUNS AS WELL AS THE
30.12Z ECMWF AND HIRES-ARW IS A BAND OF SHOWERS FROM NEAR WABASHA
COUNTY TO TAYLOR COUNTY BETWEEN 00-09Z. GIVEN THE 30.17Z HRRR RUN IS
DRY AND AFOREMENTIONED FORCING SIGNALS ARE WEAK TO NONE...HAVE KEPT
THE FORECAST DRY IN THIS AREA. A MIX OF LOW AND HIGHER STRATUS
SHOULD PERSIST THROUGH MUCH OF THE NIGHT...HELPING TO KEEP
TEMPERATURES UP.
ON WEDNESDAY...THE NEXT SHORTWAVE OF FOCUS DROPPING OUT OF SOUTH
CENTRAL CANADA WILL PROVIDE A PERIOD OF DPVA ACROSS THE FORECAST
AREA...ALONG WITH GIVING THE COLD FRONT OVER FAR WESTERN MN A BIGGER
PUSH. THE BIG QUESTIONS ARE BOTH FRONTAL TIMING AND HOW WARM CAN WE
GET PRIOR TO FRONTAL ARRIVAL. ALTHOUGH THERE IS NOW LESS CONCERN
FOR LOW CEILING STRATUS OVER ABOUT THE NORTHWEST 2/3 OF THE FORECAST
AREA...ISENTROPIC LIFT FIELDS SUGGEST A GOOD AMOUNT OF MID/HIGH
CLOUDS WILL OVERSPREAD THE AREA AHEAD OF THE SHORTWAVE AND COLD
FRONT. THE 30.12Z NAM EVEN DEVELOPS SOME LIGHT PRECIPITATION OUT OF
THESE CLOUDS NORTH OF I-90. MAIN COLD FRONTAL TIMING STILL LOOKS TO
BE DURING THE AFTERNOON WHICH IS GOOD...BUT THE AFOREMENTIONED
CLOUDS MAY LIMIT HEATING AND THUS BOTH CAPE AND CONVECTIVE
DEVELOPMENT ON THE FRONT. MODEL CONSENSUS IS TO GET HIGH
TEMPERATURES PRIOR TO FRONTAL ARRIVAL UP INTO THE MID 70S TO AROUND
80...WHICH RESULTS IN ABOUT 500-1000 J/KG OF TALL...THIN CAPE. THE
SKINNY NATURE OF THE CAPE WILL HELP MINIMIZE THE SEVERE WEATHER
POTENTIAL DESPITE FAVORABLE SHEAR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE JUL 30 2013
SYNOPTIC OVERVIEW...
30.12Z ECMWF/GFS/CANADIAN ALL SUGGEST A REX BLOCK STAYING MOSTLY IN
PLACE OVER WESTERN CANADA INTO THE GULF OF ALASKA...ALONG WITH
TROUGHING OVER SOUTHEAST CANADA INTO THE GREAT LAKES
REGION...THROUGH THE LONG TERM PERIOD. THIS MEANS THE FORECAST AREA
WILL STAY IN COOL...NORTHWEST FLOW WITH SHORTWAVES COMING THROUGH
THAT CAN BE HARD TO TIME. WHETHER OR NOT THESE SHORTWAVES PRODUCE
PRECIPITATION WILL DEPEND ON MOISTURE AVAILABILITY.
WEDNESDAY NIGHT THROUGH FRIDAY...
IN THE WAKE OF WEDNESDAYS COLD FRONTAL PASSAGE...THE 30.12Z NAM
BRINGS SOME PRECIP THROUGH THE SOUTHWESTERN HALF OF THE FORECAST
AREA WEDNESDAY NIGHT. THIS IS A RESULT OF SOME WEAK 305K ISENTROPIC
LIFT AHEAD OF A WEAK SHORTWAVE TRAVERSING IOWA...AS WELL AS BEING IN
THE LEFT EXIT REGION OF A 100 KT JET STREAK. ALL OTHER AVAILABLE
GUIDANCE IS DRY...CONSISTENT TOO WITH THE PREVIOUS FORECAST.
THEREFORE...HAVE KEPT A DRY FORECAST GOING. MODELS HAVE TRENDED
DRIER ON THURSDAY WITH ANY CONVECTIVE FORCING WELL OFF TO OUR NORTH
OR SOUTHWEST. ADDITIONALLY...IT APPEARS THERE SHOULD BE A SURGE OF
DRY AIR ON THURSDAY TO HELP MIX DEWPOINTS DOWN...ALSO FAVORING A
DRIER FORECAST. THURSDAY NIGHT INTO FRIDAY MAY STAND TO HAVE THE
BEST CHANCE FOR PRECIPITATION IN THIS NORTHWEST FLOW...IF YOU
BELIEVE THE NAM. MODELS ARE IN GOOD AGREEMENT DROPPING A SHORTWAVE
THROUGH NORTHERN WI FRIDAY MORNING. THE NAM IS MOST ROBUST IN
GENERATING BOTH LIFT AND QPF FROM THIS SHORTWAVE. HOWEVER...THE
GFS/ECMWF/CANADIAN ARE ALL MUCH DRIER AND SOME EVEN SUGGEST A DRY
FORECAST. THEREFORE...CONFIDENCE IN THE NAM SCENARIO IS QUITE LOW.
DID MAINTAIN A 20 PERCENT CHANCE FOR LATE THURSDAY NIGHT ACROSS THE
FORECAST AREA...AS WELL AS SOUTH OF I-90 ON FRIDAY...IN THE EVENT
THE NAM IS RIGHT. WITH 850MB TEMP ANOMALIES HOVERING IN THAT 0.5-1
STANDARD DEVIATION BELOW NORMAL...TEMPERATURES SHOULD CONTINUE TO
RUN ABOUT 5F DEGREES BELOW NORMAL FOR HIGHS. GENERALLY FOLLOWED A
MODEL GUIDANCE CONSENSUS FOR BOTH HIGHS AND LOWS.
FRIDAY NIGHT THROUGH TUESDAY...
DESPITE A NORTHWEST FLOW DURING THE WEEKEND...CONFIDENCE OF HAVING
IT DRY IS INCREASING. THE REASON IS THAT MODELS HAVE BEEN
CONSISTENTLY SHOWING CANADIAN HIGH PRESSURE BUILDING INTO THE
FORECAST AREA IN THE WAKE OF THAT SHORTWAVE CROSSING NORTHERN WI
FRIDAY MORNING. GIVEN THE CANADIAN SOURCE REGION...THE WEEKEND DOES
LOOK COOL...BUT NOT NEARLY AS COLD AS LAST WEEKEND. 850MB TEMPS DROP
TO 10-12C ON SATURDAY AND 8-11C ON SUNDAY WHICH AT MOST ARE 1-1.5
STANDARD DEVIATIONS BELOW NORMAL. THESE TEMPS STILL SUPPORT HIGHS IN
THE 70S. THE BIGGER QUESTION WILL BE LOWS...WHICH HIGHLY DEPENDS ON
TIMING WHEN THE SURFACE HIGH BUILDS OVERHEAD FOR PRIME RADIATIONAL
COOLING CONDITIONS. LOWS IN THE TYPICAL COLDER SPOTS IN THE 40S ARE
CERTAINLY POSSIBLE.
HEADING INTO EARLY NEXT WEEK...THERE ARE SIGNS IN THE 30.12Z
ECMWF/GFS OF A MORE SIGNIFICANT SHORTWAVE DROPPING THROUGH THE
NORTHWEST FLOW...COMING THROUGH THE FORECAST AREA ON MONDAY. THIS IS
A BIT OF A CHANGE FOR THE ECMWF...BEGINNING TO LEAN MORE TOWARDS
WHAT THE PAST FEW GFS RUNS HAVE SUGGESTED. IN ANY EVENT...CHANCES OF
SHOWERS AND THUNDERSTORMS ARE REQUIRED FOR SUNDAY NIGHT AND MONDAY
TO ACCOUNT FOR THE SHORTWAVE AND ASSOCIATED FORCING. FOR MONDAY
NIGHT AND TUESDAY...CONTINUITY AND MODEL CONSENSUS SUGGESTS HOLDING
ONTO 20-30 PERCENT CHANCES DURING THIS TIME PERIOD. THESE CHANCES
ARE ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE. HOWEVER...NEW
30.12Z GUIDANCE...PARTICULARLY THE ECMWF...SUGGESTING THAT A DRIER
FORECAST MAY BE MORE CORRECT. GIVEN THE UNCERTAINTY BEING IN
NORTHWEST FLOW AND HOW FAR OUT TUESDAY IS IN THE FORECAST...HAVE
LEFT THE CHANCES ALONE FOR NOW. 850MB TEMPS REMAIN BELOW
NORMAL...BETWEEN 10-12C...KEEPING HIGHS IN THE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 12Z WEDNESDAY AFTERNOON)
ISSUED AT 1210 PM CDT TUE JUL 30 2013
MASS OF LOW STRATUS COUPLED WITH FOG REDUCING VSBYS BELOW 1SM WERE
FOUND ACROSS NEB EARLY THIS MORNING. THE CLOUDS WERE EXPERIENCING
SOME DIURNAL BUMP UP...BUT STILL IN THE IFR/MVFR RANGE. THE
EXPECTATION IS THAT THIS STRATUS DECK WILL MOVE ACROSS THE TAF SITES
LATER TODAY...WITH A SUBSEQUENT DROP IN VSBYS THROUGH THE NIGHT
TIME HOURS. LIFR/IFR WOULD RESULT IF NEB/S MORNING CONDITIONS ARE
REALIZED HERE. CONFIDENCE IN THIS OCCURING IS SHAKY THOUGH. LATEST
BUFKIT SOUNDINGS VIA RAP/NAM/GFS AREN/T OVERLY SATURATED IN THE
LOWEST LAYERS...BUT DO SUGGEST THAT IT COULD HAPPEN. FEEL MORE
CONFIDENT WITH THE POTENTIAL TO THE SOUTH. ITS AN ADVECTIVE TYPE OF
FOG/STRATUS THOUGH...AND WILL STAY WITH THE TREND OF BRINGING IT IN
FOR NOW. TRENDS WILL HAVE TO BE MONITORED CLOSELY...AND UPDATES MADE
AS NEEDED.
ASSUMING THE STRATUS/FOG DOES MOVE IN...SOUNDINGS WOULD MIX IT OUT
BY MID/LATE MORNING. A PRE-FRONTAL TROUGH MOVES IN FROM THE WEST
SOMEWHERE IN THE 12-15Z TIME FRAME...WITH THE FRONT DROPPING THROUGH
IN THE AFTERNOON. THE FRONT SHOULD SPARK SCATTERED -SHRA/TS AROUND
IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS FLAGSTAFF AZ
925 PM MST WED JUL 31 2013
.SYNOPSIS...
SHOWERS AND ISOLATED THUNDERSTORMS MAY CONTINUE OVERNIGHT AS A
DISTURBANCE APPROACHES FROM THE SOUTHEAST. DAYTIME THUNDERSTORM
COVERAGE SHOULD INCREASE ON THURSDAY AND FRIDAY RELATIVE TO
COVERAGE SEEN THIS AFTERNOON.
&&
.DISCUSSION...
WE UPDATED THE FORECAST GRIDS EARLIER THIS EVENING TO REFLECT
GREATER PRECIP CHANCES IN SOUTHEAST PORTIONS OF THE COUNTY WARNING
AREA AS A WEAK SHORT WAVE TROUGH MOVES TOWARD NORTHERN AZ FROM THE
SOUTHEAST. IN ADDITION...AN MCV IS APPARENT IN SOUTHWEST NAVAJO
COUNTY. WE RAISED OVERNIGHT MINIMUM TEMPERATURES IN ANTICIPATION
OF THICK CLOUD COVER OVER MUCH OF THE AREA.
&&
.PREVIOUS DISCUSSION /330 PM MST/...
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED FROM
NEAR DESERT VIEW AT THE GRAND CANYON...MOGOLLON RIM...TO THE WHITE
MOUNTAINS TODAY. THE STORMS ARE MOVING NORTHWARD INTO THE LCR THIS
AFTERNOON. THIS ACTIVITY IS EXPECTED TO CONTINUE INTO THIS EVENING.
VISIBLE SATELLITE SHOWED SEVERAL UPPER DISTURBANCES OVER NORTHERN
MEXICO THIS MORNING. THESE DISTURBANCES ARE MORNING NORTHWARD AND
MAY WELL CONTINUE THUNDERSTORM ACTIVITY WELL INTO THE NIGHT OVER
NORTHERN ARIZONA. THE 17Z RUN OF THE HRRR SHOWED RAIN SHOWERS
RE-DEVELOPING OVER THE RIM COUNTRY LATE THIS EVENING. HAVE KEPT
CHANCE POPS GOING THROUGH THE NIGHT FOR THE HIGHER TERRAIN OVER MUCH
OF NORTHERN ARIZONA.
HIGH PRESSURE WILL REMAIN EAST OF ARIZONA FOR THE NEXT WEEK. ARIZONA
WILL BE ON THE WESTERN EDGE OF THE HIGH WITH A SOUTH TO SOUTHWEST
FLOW OVER THE STATE. THE GFS AND EC ARE AT ODDS ON HOW MUCH MOISTURE
WILL MOVE OVER THE STATE AND IF/WHEN SIGNIFICANT DRYING WILL HAPPEN.
FORECAST LEANS MORE TOWARD THE EC GIVEN HOW IT HAS HANDLED THE
WETTER PATTERN SO FAR THIS SUMMER.
SHOWER AND THUNDERSTORM COVERAGE SHOULD INCREASE EACH DAY ACROSS
THE AREA THROUGH FRIDAY AND THEN REMAIN FAIRLY CONSTANT THROUGH THE
WEEKEND.
&&
.AVIATION...
FOR THE 06Z PACKAGE...MONSOON MOISTURE IS ON THE INCREASE.
AT LEAST ISOLATED THUNDERSTORMS MAY CONTINUE THROUGH THE OVERNIGHT
HOURS...WITH AREAS OF RAIN SHOWERS ESPECIALLY SOUTHEAST OF A
KPAN/KFLG/KRQE LINE. MVFR VISIBILITY MAY OCCUR IN AREAS OF
RAINFALL. THUNDERSTORMS WILL DEVELOP AGAIN ON THURSDAY AFTER 18Z
WITH THE ATTENDANT THREATS OF LOWERED VISIBILITY AND GUSTY WINDS. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...
MONSOON MOISTURE WILL PUSH BACK ACROSS NORTHERN
ARIZONA WITH AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS ON
THURSDAY AND FRIDAY.
SATURDAY THROUGH MONDAY...THE CHANCE FOR SHOWERS AND THUNDERSTORMS
WILL CONTINUE OVER NORTHERN ARIZONA.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........AT/MAS
AVIATION.......AT
FIRE WEATHER...MCCOLLUM
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
AREA FORECAST DISCUSSION
NWS TOPEKA KS
429 AM CDT Thu Aug 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CDT THU AUG 1 2013
Water vapor imagery and 08z RAP analysis shows the H5 ridge over the
desert southwest with a well developed deep trough over the Hudson
Bay. Between these two features northwest flow continues over the
forecast area, with roughly 30 to 40 knots of flow at 500 mb. At the
surface the ridge axis runs from NW to SE across the forecast area,
which is helping to reduce flow at the surface, bringing calm
morning conditions. Through the remainder of the morning a few areas
of patchy fog will form as radiational cooling will be enhanced by
low surface flow and mostly clear skies. Passing cirrus will help
retain some heat at the surface, preventing widespread dense fog,
but considering the moist low levels from recent rain and calm, cool
conditions there will be a marginal fog threat through the remainder
of the morning hours.
Radar trends indicate that a few showers have formed across central
Nebraska, and are moving east/southeastward into south central
Nebraska. The best isentropic/warm air advection upglide can be
found on a decently deep layer between 305 and 315 K Theta E
surfaces. Forecast soundings show about 500 to 1000 J/Kg of elevated
instability above the 700 mb layer, so any parcels that get lifted
to that level will have a chance to form into scattered
thunderstorms later today. The best chance for that scattered
T-storm development will be mainly across central Nebraska,
southward into far northern Kansas, where the best isentropic
upglide persists. Clouds will likely build in, especially north of
Interstate 70, so have gone with a slightly cooler temperature
forecast for the far northern row of counties, but should rain
develop in that area temps may struggle to reach the forecast highs
in the lower to middle 80s.
Warm air advection will continue through the evening and overnight
hours on Thursday night, and as the deeper moisture makes its way
into northeast Kansas the coverage and intensity of the rain showers
will pick up . Expect widespread rain/thunderstorm activity,
especially north of Interstate 70 by early Friday morning, with
perhaps some showers and thunderstorms further south, toward the
Interstate 35 corridor.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 336 AM CDT THU AUG 1 2013
Friday/Saturday...Expect some thunder to be ongoing Friday as
complex forecast to roll off the high plains across Nebraska then
into eastern Kansas along the thermal gradient and on the nose of
the llj. enough instability and shear to make strong to severe
storms possible...as well as steep lapse rates in the low levels
contributing to potential wind threat. despite the dry layer,
precipitable water values over the area remain in the 1.5 to 2
inch range, and must therefore also consider heavy rainfall a
possibility. Storm chances slowly shift eastward into sunrise on
Saturday, and may be able to catch a break during the day
Saturday. Will carry only an isolated pop given boundary resides
right over the forecast area and can`t rule out precip for good
just yet.
Sun/Mon...Stronger and more significant shortwave trof forecast
to come off the central Rockies and into eastern Kansas on Sunday.
Will carry high chance pops and cooler temperatures to reflect
this. subsidence behind this wave may temper precip chances on
Monday and have kept a decrease that time period.
Tues/Wed...Area remains under NW flow aloft with series of waves
dropping surface high pressure into our area early to mid week
next week. If this pattern verifies we would stay cooler than
normal with above average precipitation possible.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Thursday NIGHT)
ISSUED AT 1142 PM CDT WED JUL 31 2013
There is not much change from previous forecast thinking. With
cirrus overspreading from the west...it may be that much more
difficult for ground fog to form. Additionally the 00z models
continue to focus the better low level moisture convergence to the
north of the terminals through the day Thursday. Therefore have
left mention if TS out of the forecast with models showing the
best vertical motion and low level convergence after 06z Friday
when the low level jet increases.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Leighton
LONG TERM...67
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
416 AM CDT Thu Aug 1 2013
.SYNOPSIS...
ISSUED AT 410 AM CDT THU AUG 1 2013
The 00 utc Thursday objective upper air analysis showed an upper
anticyclone across western TX/eastern NM with an 80 knot jet streak
exiting central Kansas on the east side of the upper ridge. Based
on the 00 utc upper air sounding in combination with he 700 mb
analysis it appears very little change took place in the mid
levels. however, the same analysis showed a marked up tick in
boundary layer temperature, especially at the 850 mb level where
temperatures warmed an average of 5 to 10 degrees.
Regional mosaic 88d reflectivity shows a couple of areas of
decaying MCS/thunderstorms activity, one across the Texas
panhandle and one across east central Colorado. The KGLD 88D
indicates a convective outflow boundary moving southeast across
west central Kansas.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 410 AM CDT THU AUG 1 2013
The Latest HRRR model shows an increase in convection across west
central Kansas eastward to the highway 283 corridor. The current
meso alpha convective trends from 88d KPUB suggest at least some
thunderstorm activity could make it to extreme western Kansas
between 9 and 12Z. However there is greater conceive inhibition
indicated by the mesoanalysis as well as a decrease in overall
mucape. As a result we`ll minimize precipitation chances this
morning, relegating small chances to those areas generally west of
highway 83.
As warmer air will be in place in the boundary layer today,
temperatures will be considerably warmer, and likely in the mid
90s in most locations. surface winds will veer to the south with
time and increase to 15-20 knots sustained as mixing develops
during the mid to late morning. The consensus of the NAM WRF and
NMM indicate a better chance for another round of thunderstorms
somewhere across the region late in the afternoon and evening.
confidence is low with respect to where any thunderstorms will
occur, but possibilities exist associated with a cluster
associated with a shortwave to the north, and also across central
ks and the far southwest as convection rolls off the higher
terrain again.
.LONG TERM...(Friday through Wednesday)
ISSUED AT 259 AM CDT THU AUG 1 2013
On Friday afternoon the GFS and ECMWF both suggest a weak upper
level wave will move out into the plains with some afternoon
convection being possible near a surface boundary that appears to
extend from west to east across northern Kansas. 850mb warm air
advection still evident along and north of this boundary. We will
therefore retain precipitation chances across north central Kansas
while further south the warm +14/+15c 700mb temperatures and less
moisture will be present which appears to limit precipitation
chance in these locations until possibly early evening when better
instability develops. 850mb temperature trends south of this
boundary continues to support highs warmer than Thursday with the
potential for afternoon highs approaching 100 degrees across
portions of far southwest Kansas. Across north central Kansas the
afternoon temperatures will be more tricky given cloud and
precipitation potential. Given this will stay close to the
previous forecast with highs 7 to near 10 degrees cooler than
southwest Kansas.
A cold front will then move into southwest Kansas on Saturday.
This surface boundary will then remain in western Kansas through
early next week as an upper level trough/low moves out of Canada
and into the the great lakes region. High pressure at the surface
will move out of south central Canada and into the the Ohio
valley. More seasonal temperatures are likely over the weekend
into early next week given the cooler 925-850mb air that is
forecast to return to much of western Kansas. There will also be
chance for convection each day from Saturday through early next
week given the southeasterly upslope flow, higher 925-850mb dewpoints
forecast to be located just east/northeast of this surface
boundary and any subtle upper wave exiting the Rockies and
crossing the plains. Given this potential am unable to improve
much on the latest CRExtendFcst_Init and keep a chance of
precipitation in each period from Sunday into mid week. Warm
nights and seasonal afternoon temperatures also look on track.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday evening) ISSUED
AT 630 PM CDT WED JUL 31 2013
Vfr conditions are expected for the next 12-18 hours before better
chances for organized thudnerstorms again redevelop. An increased
surface pressure gradient will allow southerly winds to redevelop
by 15 z at 15 to 20 mph with higer surface gusts.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 94 70 98 69 / 10 50 10 20
GCK 96 70 97 68 / 20 40 20 20
EHA 97 70 98 68 / 20 40 10 20
LBL 96 71 100 69 / 20 40 10 20
HYS 93 70 93 69 / 20 50 30 30
P28 93 72 97 72 / 10 50 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1154 PM MDT WED JUL 31 2013
.UPDATE...
ISSUED AT 915 PM MDT WED JUL 31 2013
DUE TO SEVERE CONVECTION COMING TO AN END HAVE CANCELLED THE WATCH
EARLY. ADJUSTED PREICP. CHANCES TO ACCOUNT FOR THE AREA OF
CONVECTION THAT WILL MOVE INTO EAST CENTRAL CO AROUND MIDNIGHT.
OTHERWISE THOUGHTS FROM THE PREVIOUS UPDATE REMAIN UNCHANGED.
UPDATE ISSUED AT 809 PM MDT WED JUL 31 2013
STRONG/SEVERE THUNDERSTORMS HAVE DEVELOPED OVER YUMA COUNTY EAST
INTO CHEYENNE COUNTY KS. INITIALLY STORMS WERE TRIGGERED BY AN
OUTFLOW BOUNDARY FROM EARLIER CONVECTION TO THE SOUTH. THE STORMS
SEEM TO BE SUSTAINED BY THE STRENGTHENING LOW LEVEL JET AND A
SHORT WAVE TROUGH AT 500MB. FURTHER WEST AN AREA OF CONVECTION IS
MOVING TOWARD THE AREA WITH THE UPPER LEVEL TROUGH. AS THE NIGHT
PROGRESSES AM ANTICIPATING THE STORM GROUPS TO POSSIBLY MERGE AS
THEY MOVE TO THE EAST. AS A RESULT HAVE INCREASED PRECIP. CHANCES
FOR THE NIGHT AND SPEED UP THE TIME OF THE BEST CHANCES. STILL
WENT ON THE CONSERVATIVE SIDE LATE IN THE EVENING AND OVERNIGHT SINCE
THERE IS SOME UNCERTAINTY AS TO WHERE EXACTLY THE STORMS WILL
TRACK...BUT IN GENERAL THE NORTHERN HALF OF THE AREA LOOKS TO HAVE
THE BEST SHOT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 116 PM MDT WED JUL 31 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS AMPLIFIED RIDGE ACROSS
THE INTER-MOUNTAIN WEST WITH NW FLOW IN PLACE ACROSS THE HIGH
PLAINS. AT THE SURFACE A COLD FRONT IS CURRENTLY IN PLACE ACROSS
CENTRAL NEBRASKA WITH SEVERAL AREAS OF WEAK CONVERGENCE ALONG A PRE
FRONTAL TROUGH THROUGH THE CENTRAL PART OF OUR CWA...AND POSSIBLY
SEVERAL OTHER WEAK SURFACE FEATURES ASSOCIATED WITH OLD OUTFLOW FROM
OVERNIGHT CONVECTION IN THE EAST.
LATEST RAP ANALYSIS INDICATES SBCAPE IN EXCESS OF 3000 J/KG...AND
PWAT VALUES 1-1.5 INCHES ACROSS OUR CWA. THIS VERY MOIST AND
UNSTABLE AIR MASS HAS COMBINED WITH PREVIOUSLY MENTIONED SURFACE
FEATURES TO DEVELOPMENT OF SEVERAL ISOLATED THUNDERSTORMS ACROSS
THE SOUTHERN PART OF OUR CWA. WITH CU FIELD IN PLACE AND
FORCING INCREASING AHEAD OF APPROACHING COLD FRONT I WOULD
ANTICIPATE THUNDERSTORM COVERAGE TO INCREASE THROUGH THIS
AFTERNOON. RAP ALSO INDICATES 0-6KM BULK SHEER IN EXCESS OF 40KT
ACROSS THE SOUTHEASTERN HALF OF OUR CWA...AND WITH LLJ INCREASING
AROUND 00Z I WOULD EXPECT SHEER TO ONLY INCREASE. WHILE I AM
MAINLY ANTICIPATING HAIL/WIND/MULTI-CELL THREAT THROUGH
TONIGHT...TORNADOES COULDNT BE RULED OUT WITH SUPERCELLS THAT
DEVELOP CONSIDERING THE LARGE SCALE SHEER PROFILES. A SEVERE
THUNDERSTORM WATCH HAS ALREADY BEEN ISSUED FOR THE SOUTHERN HALF
OF OUR CWA...AND IF ADDITIONAL ACTIVITY DEVELOPS FURTHER NORTH OF
WATCH WE MAY NEED TO DO A LOCAL EXPANSION CONSIDERING THE
ENVIRONMENT.
WITH 0-6KM STORM MOTION GENERALLY TO THE SOUTHEAST MOST ACTIVITY
SHOULD BE TRANSITIONING OUT OF OUR CWA THIS EVENING...THOUGH WITH
GOOD THETA-E CONVERGENCE AHEAD OF LLJ WE SHOULD SEE ADDITIONAL
DEVELOPMENT TONIGHT ESPECIALLY ACROSS THE NORTHEAST.
.LONG TERM...(TOMORROW THROUGH WEDNESDAY)
ISSUED AT 1244 PM MDT WED JUL 31 2013
THE UPPER PATTERN THIS PERIOD WILL FEATURE A RIDGE CENTERED OVER
TEXAS AND OCCASIONAL SHORTWAVE TROUGHS MOVING OUT OF THE CENTRAL
AND NORTHERN ROCKIES ACROSS THE PLAINS. THIS MEANS THE SAME OLD
STORY THAT HAS BEEN RUNNING A FEW WEEKS NOW: DAILY CHANCES FOR
SHOWERS AND THUNDERSTORMS AND TEMPERATURES NEAR NORMAL. MESOSCALE
DETAILS WILL ULTIMATELY PLAY A LARGE ROLE IN DETERMINING WHERE
BETTER THUNDERSTORM CHANCES WILL BE ON ANY GIVEN DAY...BUT THEY
ARE DIFFICULT TO PREDICT BEYOND A DAY OR TWO AT BEST. AS A
RESULT...POPS WILL BE RATHER BROADBRUSHED ACROSS THE AREA. ON
THURSDAY...SEVERE STORMS WILL BE POSSIBLE GIVEN SUFFICIENT
INSTABILITY AND FAVORABLE SHEAR PROFILES. SEVERE POTENTIAL FOR THE
REMAINDER OF THE PERIOD WILL BE TIED TO SHORTWAVE IMPULSES WITH
LOW PREDICTABILITY AT THIS TIME RANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM MDT WED JUL 31 2013
VFR CONDITIONS FORECAST FOR THE 6Z TAFS. AREA OF
SHOWERS/THUNDERSTORMS CONTINUES TO TRACK EASTWARD AHEAD OF AN
UPPER LEVEL SHORT WAVE TROUGH. AM ANTICIPATING THE STORMS TO LAST
INTO KS THEN DISSIPATE NOT LONG AFTERWARD. LATER ON ANOTHER SHORT
WAVE TROUGH WILL MOVE OVER THE NORTHEASTERN PART OF THE AREA LATE
TONIGHT...HAVE A TEMPO GROUP FOR KMCK AS A RESULT. STORMS SHOULD BE
OUT OF THE AREA BY MID MORNING. DURING THE MID TO LATE AFTERNOON
STORMS WILL DEVELOP FROM WEST TO EAST ACROSS THE TRI-STATE
AREA...WITH THE BEST CHANCE FOR STORMS DURING THE EVENING OVER
THE EASTERN PART OF THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS JACKSON KY
220 AM EDT THU AUG 1 2013
.UPDATE...
ISSUED AT 220 AM EDT THU AUG 1 2013
EXCEPT FOR SOME ISOLATED SHOWERS AT THE VA BORDER...PRECIP HAS ENDED
ACROSS THE FORECAST AREA. HOWEVER...THERE WERE A FEW SHOWERS AND
THUNDERSTORMS WHICH HAVE POPPED UP ALONG THE COLD FRONT MOVING
SOUTHEAST THROUGH SE INDIANA AND SW OHIO. THE RUC AND HRRR SHOW THESE
DIMINISHING SOMEWHAT AS THEY ARRIVE IN OUR NW COUNTIES AROUND
DAWN...BUT SHOW AN INCREASE IN ACTIVITY ALONG THE BOUNDARY AS IT
MOVES SE THROUGH THE FORECAST AREA DURING DAYTIME HEATING. HAVE
UPDATED THE FORECAST TO REFLECT THIS...WITH POPS LIMITED TO 20
PERCENT.
UPDATE ISSUED AT 1050 PM EDT WED JUL 31 2013
UPDATED THE GRIDS TO REFINE POPS THROUGH THE REST OF THE NIGHT...BUT
ALSO KEPT IN THE DRIZZLE PATCHES AND THE FOG. HOURLY TEMPS AND
DEW POINTS WERE TWEAKED BASED ON CURRENT CONDITIONS AND OBS. THE
FORECAST WAS MOSTLY ON TRACK WITH THIS ZFP UPDATE PRIMARILY TO REMOVE
EVENING WORDING. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS
WITH THE ZFP TO FOLLOW SHORTLY.
UPDATE ISSUED AT 640 PM EDT WED JUL 31 2013
22Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE MOVING THROUGH
KENTUCKY. THIS HAS BROUGHT PLENTY OF LOW CLOUDS AND LIGHT PCPN TO THE
AREA TODAY RESULTING IN HIGH TEMPERATURES ONLY ON THE LOW 70S...FOR
MOST PLACES. THIS MEANT A DAY THAT SEEMED CLOSER TO EARLY OCTOBER
THAN THE LAST DAY OF JULY. THE SHOWERS HAVE DIMINISHED TO JUST A FEW
PATCHES CROSSING FAR SOUTHEAST PARTS OF THE AREA...THOUGH PATCHY
DRIZZLE AND AREAS OF FOG REMAIN BEHIND. EXPECT THE SMALL RAIN CHANCES
TO CONTINUE THROUGH THE NIGHT WHILE THE LOW MOVES OVER EAST
KENTUCKY...BUT THE SHOWERS OF ANY SIGNIFICANCE ARE DONE. HAVE
ADJUSTED THE POPS...WX AND SKY FOR THE REST OF THE NIGHT WHILE ALSO
MAKING MORE FINE TUNE TWEAKS TO THE TEMPERATURES AND DEW POINTS GRIDS
PER LATEST OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS ALONG WITH A FRESHENED ZFP AND HWO.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 312 PM EDT WED JUL 31 2013
THE MODELS ARE IN GOOD AGREEMENT AS A SHORT WAVE AND FRONT MOVE
ACROSS THE AREA. THE PREVIOUS MODELS SHOWED A WHOLE LOT MORE
PRECIPITATION DEVELOPING OVER THE AREA THAN WHAT HAS OCCURRED IN THE
LAST 8 HOURS. THE MODELS WERE SHOWING A MUCH MORE VIGOROUS SYSTEM
DEVELOPING AND WERE SHOWING A LOW MOVING ACROSS EASTERN KENTUCKY. THE
LOW ACTUALLY HAS PASSED FURTHER TO THE SOUTH AND HAS MOVED ACROSS
TENNESSEE INSTEAD HAS SUCH...THE HEAVIER RAIN HAS STAYED SOUTH OF
JACKSON. THE NAM WAS SHOWING A LARGE MASS OF RAIN MOVING ACROSS THE
AREA THIS EVENING...HOWEVER DOUBT IS STARTING TO CREEP IN WHETHER IT
WILL AMOUNT TO MORE THAT THAN A LITTLE DRIZZLE. THE LAST UPDATE
AROUND 2 PM...ALREADY BACK THE PROBABILITY OF PRECIPITATION DOWN AND
KEPT THE BEST CHANCES SOUTH OF JACKSON. TOMORROW SHOULD JUST SEE OF
ISOLATED THE SCATTERED SHOWERS WILL LITTLE OR NO ACCUMULATION. WITH
THE CLOUD COVER...EXPECT TEMPERATURES TO STAY BELOW NORMAL THROUGH
THE END OF THE PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 312 PM EDT WED JUL 31 2013
THERE IS GOOD MODEL AGREEMENT ON THE GENERAL PATTERN THROUGH THE
MIDDLE OF NEXT WEEK...BUT SIGNIFICANT DIFFERENCES IN THE DETAILS
DEVELOP AFTER THIS WEEKEND. THE OVERALL PATTERN...WHICH HAS BEEN THE
CASE FOR MUCH OF THIS SUMMER...REMAINS IN PLACE...WITH RIDGING IN
THE WESTERN U.S. AND TROUGHING IN THE EAST. AS SUCH TEMPERATURES
WILL CONTINUE TO AVERAGE BELOW NORMAL. A SHORT WAVE MOVING ACROSS
THE GREAT LAKES AND OH VALLEY THIS WEEKEND WILL HELP DRIVE A COLD
FRONT SOUTH ACROSS THE REGION...WITH LATEST GUIDANCE INDICATING THE
FRONT SHOULD BE SOUTH OF KY BY 12Z SUNDAY. AS SUCH PRECIPITATION
CHANCES STILL LOOK TO BE HIGHEST FROM SATURDAY INTO SATURDAY NIGHT
DURING THE UPCOMING WEEKEND.
AFTER THE WEEKEND SIGNIFICANT DIFFERENCES DEVELOP WITH HOW DEEP THE
EASTERN TROUGH BECOMES...AND HOW FAR SOUTH THE SURFACE COLD FRONT
ENDS UP BEFORE STALLING OUT. THE 00Z ECMWF HAS A MUCH DEEPER EASTERN
TROUGH WITH THE COOL AIR DRIVING WELL SOUTH...WITH THE BEST
PRECIPITATION CHANCES NEXT WEEK REMAINING TO OUR SOUTH AS WELL. THE 12Z
GFS AND 12Z GEM DO NOT HAVE THE TROUGH AS DEEP...AND ALSO INDICATE
BETTER PRECIPITATION CHANCES FOR EARLY NEXT WEEK. THE LATEST WPC
GUIDANCE ALSO KEEPS THE SURFACE FRONTAL BOUNDARY IN THE VICINITY OF
THE TN VALLEY FOR THE FIRST HALF OF NEXT WEEK. SPECIFIC TEMPERATURE
FORECASTS REALLY SHOW THE EXTREME MODEL DIFFERENCES. FOR 12Z WED
AUGUST 7 THE 00Z ECMWF SHOWS 8H TEMPERATURES FROM 11 TO 12 C
ACROSS E KY...WHILE THE 12Z GFS SHOWS 8H TEMPERATURES FROM 18 TO 20
C. NOT SURPRISINGLY THE GFS MOS TEMPERATURE GUIDANCE BY THE MIDDLE
OF NEXT WEEK IS AROUND 10 DEGREES F WARMER THEN THE ECMWF MOS
GUIDANCE....WITH THE GFS GUIDANCE ACTUALLY INDICATING ABOVE NORMAL
TEMPERATURES. EVEN IF THE GENERAL UPPER AIR PATTERN FORECAST BY THE
GFS NEXT WEEK WAS RIGHT...THE CORRESPONDING MOS TEMPERATURES STILL
LOOK WAY TOO HIGH. NOT ONLY HAS THE MEX MOS BEEN TOO WARM MUCH OF
THE SUMMER...BUT TODAY/S 12Z GFS RUN ALSO INDICATES CONSIDERABLE
CLOUDINESS AND PRECIPITATION NEXT TUESDAY AND WEDNESDAY...WHICH
WOULD HOLD DOWN MAXIMUM TEMPERATURES. USED THE STANDARD MODEL BLEND
FOR THE TEMPERATURE FORECAST WITH SOME MINOR TWEAKS...WHICH RESULTED
IN CONTINUED BELOW NORMAL TEMPERATURES...MAINLY DUE TO SUPPRESSED
DAYTIME HIGHS. WITH THE UNCERTAINTY ON EXACTLY WHERE THE QUASI
STATIONARY FRONT WILL SET UP NEXT WEEK...THE STANDARD BLEND PROVIDED
A REASONABLE SOLUTION FOR RAIN PROBABILITIES WITH AT LEAST A SLIGHT
OF SHOWERS AND THUNDERSTORMS IN THE FORECAST FROM MONDAY THROUGH
WEDNESDAY. THIS WILL ALSO BE IN GOOD AGREEMENT WITH NEIGHBORING
FORECAST OFFICES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 220 AM EDT THU AUG 1 2013
FOG AND LOW CLOUDS WERE PREVALENT...BUT CONDITIONS VARIED WIDELY AT
THE START OF THE PERIOD...RANGING FROM VLIFR TO VFR. MOST PLACES CAN
EXPECT CONDITIONS DOWN TO AT LEAST IFR EVENTUALLY TONIGHT. ISOLATED
SHOWERS AND STORMS MAY AFFECT SOME LOCATIONS NEAR AND NW OF
INTERSTATE 64 AROUND DAWN. THE FOG IS EXPECTED TO LIFT INTO A LOW
CLOUD LAYER DURING THE MORNING. THESE CLOUDS WILL THEN LIFT AND BREAK
UP DURING THE DAY...WITH MOST PLACES BECOMING VFR BY EVENING.
HOWEVER...THE POSSIBILITY FOR ISOLATED SHOWERS AND THUNDERSTORMS WILL
CREEP SOUTHEAST ACROSS THE AREA DURING THE DAY...BEFORE FIZZLING OUT
LATE IN THE DAY. THE PROBABILITY OF PRECIP IS TOO LOW AT ANY GIVEN
POINT AT THIS TIME TO WARRANT INCLUSION IN THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...JJ
LONG TERM...SBH
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1144 PM CDT Wed Jul 31 2013
.UPDATE...
ISSUED AT 1144 PM CDT WED JUL 31 2013
Updated aviation section for 06Z TAF package.
UPDATE ISSUED AT 849 PM CDT WED JUL 31 2013
A very weak surface convergence zone has developed along the
Wabash River this evening, and some isolated showers have
resulted. The most recent HRRR indicates that the convergence zone
and showers will slowly shift southeast through midnight. Decided
to add a slight chance/isolated pop over areas east of the Lakes
and Wabash through midnight.
All guidance shows a minor push of northwest winds and drier air
into the region overnight behind this convergence zone. Given some
variable cloud cover expected, the light northwest wind, and drier
air moving in, fog should not be a widespread problem overnight.
Made some adjustments to T/Td through the night to match these
overall trends and the current observations.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 245 PM CDT Wed Jul 31 2013
Early this afternoon, a few showers and storms continue to flare
up near the KY/TN MO/AR borders in best instability axis per LAPS
surface data. Otherwise considerable clouds persist given ample
low level moisture, though minor improvement has been noted with
daytime heating and weak mixing. Not seeing much up north into
Missouri and Illinois. May leave pops out starting at 00z. We have
slight chances even north of the Ohio River through 00z just in
case there is a little development in an expanding zone of
instability. It may take the weak wave moving southeast across
MO/CNTRL IL to kick something off, if at all. Will monitor.
Otherwise tonight in the wake of the weak surface low, light NNW
winds below 5 kts are anticipated. Low level moisture will remain.
So there may be some fog. Not sure how much at this time,
especially if lower clouds remain a factor. May have to include
patchy fog in the forecast. Weak high pressure and overall drying
means dry Thursday through Thursday night. Then our attention
turns to the next impulse and a frontal boundary that will
approach Friday through Friday night. We have increasing pops from
north to south for convection. The overall model agreement is good
enough to use a compromise. Temperatures and humidity will be a
bit more summer like, but still tolerable as we head into early
August.
.LONG TERM...(Saturday Through Wednesday)
Issued at 245 PM CDT Wed Jul 31 2013
The northeast U.S. / southeast Canadian cold core vortex will
continue to dominate the medium range weather pattern from
Saturday through the middle of next week. The North American
Oscillation (NAO) ensembles indicate slightly negative values
through at least August 6th, suggesting that the vortex will
remain dominate in holding the base of the westerlies either over
the WFO PAH forecast area, or just to the southwest.
With this in mind, adjusted the probability of precipitation (PoP)
gradient further to the southwest over parts of southeast
Missouri, as well as southwest Illinois and Kentucky. Given the
thickness and moisture gradient, combined with subtle forcing from
passing upper level jetlets and low level insolation/differential
heating, kept the highest PoPs to the south and west of the
forecast area.
In all of the medium range forecast period, the time period of
mixed/lowest confidence is from after midnight Monday through the
daytime hours on Tuesday. The latest run (12z Wednesday) of the
operational ECMWF supports much lower PoPs compared to the 00z
run, indicating the lower PoPs may be the way to go over
Kentucky, Indiana, and most of southern Illinois. Unfortunately,
this scenario places our office with lower PoPs versus surrounding
NWS offices, with the possible exception of Nashville and Little
Rock NWS offices.
The negative NAO scenario will also keep maximum temperature 3 to 7
degrees below normal highs for this time of year.
&&
.AVIATION...
ISSUED AT 1144 PM CDT WED JUL 31 2013
Brief VFR cigs possible through 09z, otherwise skc-sct040
overnight. VFR to MVFR vsbys expected through 13z. Expect sct-
bkn040 cu between 14z and 00z along with vfr vsbys. Light and
variable/calm winds overnight will be northwest/north at 5-10kts
after 14z, then go calm after 01z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...Noles
LONG TERM... Smith
AVIATION...RST
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1230 AM EDT THU AUG 01 2013
.FORECAST UPDATE...
Issued at 1230 AM EDT Thu Aug 01 2013
A quick update to add some patchy fog into the forecast early this
morning. A couple of obs sites have dropped below 2 miles, and with
mostly clear skies hanging on for a little while longer expect that
patchy fog could linger into the pre-dawn hours. Still do expect
stratus to gradually build in, which should end the patchy fog
threat toward dawn. Otherwise, forecast is still on track with
isolated showers along a weak surface trough slowly sinking SE into
southern Indiana over the next few hours.
Previous Update...
Issued at 1000 PM EDT Wed Jul 31 2013
Did an update to align near-term forecast with trends in obs. The
first frontal boundary is pushing southeast out of our forecast area
and taking with it the broken line of showers across the Lake
Cumberland region. Behind that line, there are areas of drizzle
associated with the low stratus that hung around for much of the
day. This drizzle should drift southeast and diminish within the
next few hours. The stratus is breaking up, with mostly clear skies
across our west and northwest counties. Have updated the forecast to
cover all these trends in the near-term.
Another feature of note is a surface trough stretching southwest
through central IN into southern IL. There are a few isolated
showers along this boundary and it is edging our way. Some hi-res
models bring those into our northern CWA. Have added isolated
showers across our north through about 2 AM EDT.
All of the latest guidance indicates low stratus will build across
the region, mainly after midnight. So, even though some areas are
experiencing mostly clear skies, believe that will change as the
night progresses. Have bumped up the cloud cover from around
midnight through sunrise, with clouds beginning to dissipate mid to
late morning. Cannot rule out some patchy fog/mist/haze with this
stratus that will build in overnight, reducing visibilities just a
bit. All updates will be out shortly.
&&
.SHORT TERM (Tonight through Thursday night)...
Issued at 310 PM EDT Tue Jul 31 2013
Weak surface trof sits just this side of US 41, with light NNE winds
in southern Illinois and western Kentucky, while we are still
southerly here in central Kentucky and southern Indiana. Extensive
low cloud deck maintains its hold on the Ohio Valley as soundings
are pretty well saturated up to about 700mb. A few showers have
tried to pop in south central Kentucky, but any instability to
support thunder is suppressed well down into Tennessee.
Still can`t rule out a shower through early evening, as is evident
by that weak activity in the south. More likely scenario is probably
sprinkles, but the main theme of the night will be low clouds. Could
also be some light fog, but because of the stratus we do not expect
visibilities to drop enough to have any impacts other than aviation.
Otherwise expect a muggy night with temps near or just a couple
degrees below normal.
Deep NW flow on Thursday will finally dry out the column, so morning
stratus will give way to a partly sunny afternoon. Temps will run
below normal, as 850mb temps at 14C will only allow for lower 80s,
even in fairly deep mixing. Decent radiational cooling conditions
Thursday night will provide more free air conditioning, with temps
dipping into the lower 60s in most locations, with even a few 50s
possible in the traditionally cooler spots.
.LONG TERM (Friday through Wednesday)...
Issued at 232 PM EDT Wed Jul 31 2013
Surface high pressure to start off this forecast period will begin
to lose its hold over the Ohio Valley by early Saturday as a frontal
boundary sags southward across Indiana. Latest GFS run (12Z) shows
the front clearing south of the forecast area by Sunday, allowing
for the next surface high to move on through. Once again, however,
the two major long-term deterministic models disagree and diverge by
Monday on the pattern. The GFS has the high shunting off of the East
Coast by Monday evening, allowing for some possible convection to
fire up, especially in southern Kentucky where GFS PW values run
close to 2 inches. The focus for precip relies on a series of
shortwaves rotating through early next week. The 00Z ECMWF,
meanwhile, has the high washing out somewhere over the East Coast,
leaving the region in a messy pattern with two weak surface lows to
our NE and SE. By Wednesday, the models are drastically different
with the GFS trying to bring a cold front associated with a surface
low through the region while the ECMWF has us dry and already under
northerly flow. The two models are spatially displaced on a Canadian
upper low that should ultimately be the determining factor in our
local weather for Monday through Wednesday. Therefore, once again,
confidence in the forecast for the latter half of this period
remains low at best. Given that yesterday`s 12Z ECMWF came in at a
bit of a closer agreement to the 12Z GFS for the same forecast time
frame, am leaning more toward the GFS in tweaking today`s forecast
for the upcoming work week.
To summarize the precip forecast, showers and thunderstorms should
begin to approach southern Indiana by Friday afternoon, eventually
overspreading the area by Saturday. Instability looks decent enough
to warrant good thunderstorm potential with the slight chance of
some storms becoming strong, but only if a break in the cloud cover
allows for decent daytime heating. Any stronger storm would contain
gusty winds. By the end of the weekend, any remaining activity
should be contained primarily in southern KY and clear of the
forecast area by Sunday night. Again, confidence beyond this point
is low, but should it pan out, we`ll see this brief lull in precip
chances overnight Sunday before at least a slight chance of
thunderstorms creeps back in on Monday. Currently, have depicted the
"best" (relatively speaking) precip chances Tuesday, waning after
sunset and potentially re-emerging on Wednesday.
Temperatures continue to look like they`ll remain near or slightly
below normal for this time of year, with the warmest two days during
this period occurring on Friday and Wednesday. Cloud cover and
precip will, of course, throw a wrench into the mix for temperature
forecasts. Highs on Friday will be in the mid 80s with lows in the
upper 60s. Have bumped up Saturday highs slightly, giving the area
low to mid 80s as highs. From Sunday onward, look for fluctuating
highs ranging from the low to mid (and possibly upper) 80s and lows
in the 60s to near 70.
&&
.AVIATION (00Z TAF Update)...
Issued at 725 PM EDT Wed Jul 31 2013
Rain potential is slim to none at all sites, so the main concern
will be cigs and vis overnight. Back edge of low stratus is
approaching SDF from the northwest and should arrive shortly before
02Z, with VFR conditions to follow for a few hours. This will take a
little longer to reach LEX if it can make it there. BWG broke out
earlier this afternoon, but there remains a chance to drop back to
MVFR until that back edge finally moves through, around 02-03Z. This
VFR window is in response to slight ridging ahead of our next
shortwave, which is slated to move across the Ohio Valley overnight.
The second band of low stratus across central IL is associated with
the shortwave for tonight. Latest guidance either builds lower
stratus or advects it in from the west around 05-06Z. The RAP and
WRF simulated GOES-R show the low stratus developing a little later,
closer to 07-09Z, particularly for BWG and SDF. So, confidence in
timing remains low, but it certainly appears fuel-alternate cigs are
a sure bet for all sites, with some bases approaching alternate
minimums at BWG and LEX. Expect vis to drop generally into the MVFR
range with the low stratus. Conditions should begin to improve
around or shortly after 15Z, with VFR conditions expected by the
afternoon hours. Winds will remain light and variable overnight and
pick up out of the northwest around mid morning Thursday, with
speeds in the 6-9 knot range expected through the afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........MJP/BJS
Short Term.......RAS
Long Term........LG
Aviation.........MJP
AREA FORECAST DISCUSSION
NWS GAYLORD MI
138 AM EDT THU AUG 1 2013
.SYNOPSIS...
ISSUED AT 355 PM EDT WED JUL 31 2013
A WEAK COLD FRONT WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS
TO NORTHERN MICHIGAN TONIGHT...WITH THE BEST CHANCES FOR EASTERN
UPPER AND NORTHWEST LOWER. A WEAK DISTURBANCE WILL BRING LOW CHANCES
OF SHOWERS TO NORTHEAST LOWER AND THE EASTERN U.P. FOR
THURSDAY...WITH A SLIGHTLY BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS FOR ALL OF NORTHERN MICHIGAN AGAIN ON FRIDAY...AS
ANOTHER WEAK COLD FRONT MOVES THROUGH THE AREA. HIGH PRESSURE WILL
BRING FAIR WEATHER FOR THIS WEEKEND.
&&
.UPDATE...
ISSUED AT 126 AM EDT THU AUG 1 2013
SCATTERED RAIN SHOWERS WILL HAVE EXITED ALL OF NE LOWER OVER THE
NEXT COUPLE OF HOURS. ALL LIGHTNING GONE. AND REGENERATION OF
ADDITIONAL SHOWERS IS MAYBE POSSIBLE DOWN NEAR THE M-55 CORRIDOR
EAST OF CADILLAC...ALONG EARLIER THUNDERSTORM OUTFLOW...UNTIL 08Z
OR SO. A PERIOD OF FOG/LOW CLOUD IS LIKELY ACROSS MUCH OF NRN
LOWER/EASTERN SECTIONS OF CHIP/MACK..WHERE RAIN HAD FALLEN.
OTHERWISE...A GUSTIER LOW LEVEL FLOW OUT OF THE WNW IS BUILDING IN
FROM THE WEST AND WILL LIKELY MIX OUT ANY FOG/LOW CLOUD FOR THE
LATE HOURS AND INTO THE DAYLIGHT. NEXT WAVE ALOFT ARRIVES BY
MID/LATE MORNING WITH SOME INCREASED CLOUDS AND SLIGHT CHANCE OF
RAIN FOR THE UPCOMING DAY. MORE ON THIS AT 4AM.
UPDATE ISSUED AT 1022 PM EDT WED JUL 31 2013
UPSTREAM COLD FRONT HAS REACHED NRN LAKE MICHIGAN LATE THIS
EVENING...AS THE NEXT WEAK MID LEVEL WAVE SWINGS INTO NRN MICHIGAN
ALONG THE 500 MB TROUGH AXIS. CONVECTIVE LINE THAT IMPACTED ERN
UPR MICHIGAN EARLIER THIS EVENING HAS PUSHED SE INTO FAR NRN LWR
MICHIGAN...AND HAS BUILT FURTHER SOUTHWARD TRYING TO MERGE WITH AN
AREA OF WEAKER CONVECTION GRAZING OUR SRN COUNTIES ATTM. INTENSITY
OF EMBEDDED STORMS HAS FURTHER DIMINISH WITH LOSS OF DIURNAL
INSTABILITY...BUT WITH LOW LEVEL CONVERGENCE AHEAD OF THE FRONT
COMBINED WITH OUR NEXT SHORT WAVE NOW ARRIVING...THUNDERSTORMS DO
CONTINUE TO DEVELOP. EASTWARD PROGRESSION HAS BEEN A BIT SLOWER
THAN PREVIOUSLY EXPECTED...AND HAVE MODIFIED TIMING OF WX/POPS TO
ACCOUNT FOR THIS. CONVECTION WILL CONTINUE ITS SLOW EASTWARD PUSH
INTO THE OVERNIGHT HOURS...WITH PRECIP FINALLY CLEARING OUR CWA
VERY LATE TONIGHT. SVR WX IS STILL NOT EXPECTED FOR THE REST OF
THE NIGHT...BUT DO EXPECT A FEW STORMS WILL PRODUCE WIND GUSTS OF
30 TO 40 MPH AND MAYBE SOME SMALL HAIL.
UPDATE ISSUED AT 720 PM EDT WED JUL 31 2013
WELL-ESTABLISHED LINE OF CONVECTION CONTINUES TO IMPACT THE ERN
HALF OF UPPER MICHIGAN AHEAD OF AN APPROACHING COLD FRONT...AND
ENHANCED BY A MODEST SHORT WAVE AND LOCALIZED LAKE BREEZE
CONVERGENCE. OVERALL INTENSITY OF THIS CONVECTION HAS WEAKENED
OVER THE PAST HOUR OR SO AS THE GUST FRONT AHEAD OF THE MAIN LINE
LIMITED THE INFLOW. MAIN LINE HAS ALSO MOVED OUT OF THE AREA OF
BEST LAKE BREEZE CONVERGENCE. LATEST NAM AND 3KM HRRR SHOWS THIS
AREA OF CONVECTION WILL TRY TO MERGE (TO A DEGREE) WITH ANOTHER
AREA OF WEAKER CONVECTION NOW MOVING INTO OUR FAR SW CWA OUT OF
CENTRAL LAKE MICHIGAN...AND WILL THEN SWEEP EASTWARD THRU NRN LWR
MICHIGAN DURING THE BALANCE OF THE EVENING. OVERALL INTENSITY...AND
LIKELY AREAL COVERAGE AS WELL...SHOULD CONTINUE TO DIMINISH WITH
LOSS OF DIURNAL INSTABILITY THIS EVENING. WILL CERTAINLY CONTINUE
TO KEEP A CLOSE EYE ON THE CONVECTIVE LINE MOVING OUT OF ERN UPR
MICHIGAN AND INTO THE STRAITS FOR ANY FURTHER STRENGTHENING...BUT
DO NOT EXPECT ANY SIGNIFICANT THREAT FOR SEVERE STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM EDT WED JUL 31 2013
FAST FLOW PATTERN CONTINUES ACROSS THE NORTHERN LAKES THIS
AFTERNOON...WITH LEAD SHORTWAVE TROUGH DAMPENING OUT AND MOVING OFF
TO THE EAST...WITH SECONDARY STRONGER SHORTWAVE AND ATTENDANT COLD
FRONT CUTTING INTO THE NORTHWEST LAKES. TOOK A WHILE...BUT
CONVECTION IS STARTING TO FIRE WITH THE LATTER FEATURES...MOST
NOTABLY ACROSS CENTRAL/EASTERN UPPER MICHIGAN WHERE A BROKEN LINE OF
THUNDERSTORMS HAS DEVELOPED IN THE LAST FEW HOURS. NOT MUCH TAKING
PLACE SOUTH OF THE BIG BRIDGE...WITH CLOUD COVER AND LACK OF
DYNAMICS IN WAKE OF FIRST WAVE PREVENTING ANY SHOWER/STORM
DEVELOPMENT. FORECAST CONCERNS CENTER ON SHOWER/STORM POTENTIAL THIS
EVENING...WITH ADDITIONAL LIGHT SHOWER CHANCES NEEDING ADDRESSING
FOR THURSDAY.
UPSTREAM COLD FRONT AND MID LEVEL SUPPORT EXPECTED TO CROSS NORTHERN
MICHIGAN THIS EVENING. JUST ENOUGH FORCING/LOW LEVEL CONVERGENCE TO
CONTINUE TO SUPPORT SHOWER AND STORM DEVELOPMENT ALONG THESE
FEATURES...AND WOULD EXPECT UPSTREAM ACTIVITY TO CONTINUE TO SLOWLY
CONGEAL THIS AFTERNOON. LACK OF PRE-FRONTAL DESTABILIZATION SHOULD
KEEP BOTH COVERAGE AND INTENSITY IN CHECK...AND WILL SIMPLY SPREAD A
BROKEN LINE OF SHOWERS/EMBEDDED STORMS FROM NORTHWEST TO SOUTHEAST
ACROSS THE REGION TONIGHT. ORGANIZED SEVERE WEATHER DEFINITELY NOT
EXPECTED...BUT SUPPOSE AN ISOLATED STRONGER STORM IS POSSIBLE
THROUGH THE REMAINDER OF THIS AFTERNOON...ESPECIALLY ACROSS EASTERN
UPPER MICHIGAN. SHOWER THREAT EXPECTED TO END DURING THE EARLY
MORNING HOURS. POST-FRONTAL DRYING NOT OVERLY AGGRESSIVE...AND WITH
EXPECTED RAINS...FEEL PATCHY/AREAS OF FOG A GOOD BET DURING THE
EARLY MORNING HOURS.
THURSDAY EXPECTED TO START OFF DRY...WITH NEXT LOW AMPLITUDE FAST
MOVING WAVE SPREADING ACROSS OUR AREA DURING THE LATE MORNING AND
EARLY AFTERNOON. MOISTURE PROFILES LIMITED...AS IS ANY SPECIFIC LOW
LEVEL CONVERGENCE BOUNDARY (PERHAPS WEAK LAKE INFLUENCED BOUNDARY
SOUTH SIDE OF EASTERN UPPER). THAT SAID...MODEL DERIVED SOUNDINGS
NOT TOO TERRIBLE FOR SHOWER DEVELOPMENT...WITH STEEP LOW LEVEL LAPSE
RATES AND PROJECTED ML CAPE NEAR 500 J/KG. ABOVE PROBABLY A TOUCH
AGGRESSIVE...AND WITH NO WELL DEFINED LOW LEVEL CONVERGENCE
BOUNDARIES...WILL TEMPER INHERITED POPS SOME...FEATURING JUST LOW
CHANCE IN CLIMATOLOGICALLY FAVORED AREAS OF EASTERN UPPER AND
NORTHEAST LOWER MICHIGAN. WILL KEEP THUNDER OUT OF THE EQUATION FOR
NOW. TEMPERATURES REMAINING BELOW NORMAL...WITH HIGHS IN THE LOWER
AND MIDDLE 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED JUL 31 2013
THURSDAY NIGHT AND FRIDAY...A COLD FRONT ASSOCIATED WITH A STORM
SYSTEM OVER HUDSON BAY...WILL PUSH INTO THE WRN LAKES THURSDAY
EVENING BEFORE SLOWLY SWEEPING OVER THE STATE FRIDAY. HIGH PRESSURE
WILL THEN QUICKLY BUILD BACK INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES FRIDAY NIGHT...AS THE COLD FRONT EXITS EAST OF THE
REGION. MODEL SOUNDINGS AND MSTR PROGS SHOWING LIMITED MSTR WILL
HINDER PCPN AMOUNTS AND CHC`S OVR NRN MI THURSDAY NIGHT. HOWEVER
THERE WILL BE SOME MSTR INCREASE OVER THE CWA FRIDAY JUST IN ADVANCE
OF THE COLD APPROACHING FRONT. 850/500MB RH WILL INCREASE FROM
AROUND 40PCT THURSDAY NIGHT TO 80PCT FRIDAY...WHILE MODEL SOUNDINGS
SHOW PWAT VALUES INCREASING TO 90PCT FRIDAY. 850/500MB QVECTORS
SHOWING LIMITED CONVERGENCE WITH APPROACHING COLD FRONT...CONFINED
MAINLY TO RIGHT ALONG THE BOUNDARY. OVERALL WILL KEEP MOST OF THE
FCST AREA DRY THURSDAY NIGHT...WITH BETTER CHANCES OF RAIN FRIDAY AS
BOUNDARY MOVES ACRS LAKE MICHIGAN. WILL MENTION HIGH TEMPS IN THE
MID 70S OVR THE CWA AIDED IN PART BY SOME SUN AND SOUTHWEST FLOW.
FOR THE WEEKEND...COOL UNSEASONAL CONDITIONS ARE EXPECTED ACRS THE
GREAT LAKES FOR THE FIRST WEEKEND IN AUGUST. AT UPPER LEVELS...
WHICH WILL RESEMBLE MORE THAT OF MID WINTER INSTEAD OF MID
SUMMER...A 500MB LOW WILL BECOME CENTERED OVER HUDSON BAY THROUGH
THE WEEKEND. WHILE AT THE SURFACE...AN AREA OF CANADIAN HIGH
PRESSURE WILL BUILD INTO THE NRN PLAINS AND GREAT LAKES THRU THE
WEEKEND. TEMPS WILL TREND BELOW NORMAL THRU SUNDAY...AS THE HUDSON
BAY 500MB LOW FORCES COLD 850MB TEMPS INTO THE REGION. 850MB TEMPS
WILL COOL FROM AROUND 11C FRIDAY TO BTWN 6C AND 8C BY SUNDAY.
CURRENT TRENDS CONT TO INDICATE DRY CONDS OVER NRN MI THIS WEEKEND
THOUGH SOME LAKE INFLUENCES ARE POSSIBLE. SUSPECT THE DRY AIR MOVING
INTO THE GREAT LAKES WILL LIMIT LAKE EFFECTS TO MAINLY CLOUDS...AS
850/500MB RH DIMINISHES TO UNDER 40 PCT. WILL KEEP AFTN TEMPS COOL
THROUGH THE WEEKEND...IN THE UPPER 60S TO LOWER 70S ACRS NRN MI...
AS 850MB TEMPS FALL TO AROUND 6C.
MONDAY THROUGH WEDNESDAY...UNSEASONABLY COOL TREND TO LINGER ACRS
THE NORTHERN GREAT LAKES REGION THRU MID WEEK...AS BROAD UPPER
TROUGH FROM THE WEEKEND LINGERS ACRS THE GREAT LAKES. 850MB TEMPS
LINGER AROUND 6C TO BEGIN THE UPCOMING WORK WEEK...KEEPING AFTN HIGHS
IN THE LOWER 70S. SMALL CHANCES OF SHOWERS WILL EXIST THROUGH THE
PERIOD...AS HIGH PRESSURE FROM THE WEEKEND EXITS EAST AND A WEAK
SYSTEM TRIES TO ORGANIZE OVER THE NRN PLAINS AND UPPER MIDWEST.
PCPN AMOUNTS AND CHC WILL BE HINDERED GREATLY BY LIMITED MOISTURE
AS 850/500MB RH REMAINS AROUND 60PCT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 126 AM EDT THU AUG 1 2013
THUNDERSTORM OUTFLOW FROM EARLIER MORE VIGOROUS ACTIVITY HAS
SHOVED DOWN INTO TVC AND TRYING TO MAKE IT TO MBL. THIS HAS
ALREADY RESULTED IN MVFR OVC CIGS AT TVC...WHICH MAY IMPACT MBL
BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE THE CIG SINCE THE SW
PUSH OF THIS OUTFLOW/COOLER AIR...IS SLOWING ACROSS THE GTV BAY
AREA. THIS CIG WILL LIKELY MIX OUT OVER THE NEXT COUPLE OF HOURS
WITH INCREASED WNW BL FLOW BEHIND A COLD FRONT THAT HAS PASSED
THROUGH NW LOWER. TOOK OUT ALL MENTION OF FOG FOR THE BALANCE OF
THE NIGHT. THIS IS NOT SO TRUE FOR PLN/APN...WHERE THE RAINFALL
OCCURRED. CAN SEE AN HOUR OR TWO OF MVFR FOG/CIGS BEFORE THE BL
FLOW INCREASES ENOUGH TO MIX THIS OUT. SHOULD BE A PERIOD OF
FAIRLY CLEAR SKIES UNTIL MORNING...WHERE SOME INCREASED MID LEVEL
CLOUD AND FEW-SCT CU FIRES OFF AHEAD OF NEXT APPROACHING
DISTURBANCE ALOFT AND COLD FRONT/SFC TROUGH. BELIEVE THAT A FEW
STRAY SHOWERS WILL BE AROUND TOMORROW LATE MORNING/AFTERNOON WITH
THE ARRIVAL OF THE FRONT/TROUGH AND COOLING TEMPS ALOFT/STEEPER
MID LEVEL LAPSE RATES. BEST SHOT AT APN WHERE A VCSH HAS BEEN
INTRODUCED.
ADDITIONAL ISOLATED/SCATTERED SHOWERS/POSSIBLE THUNDER...WILL
LIKELY FIRE OFF AROUND GREEN BAY...AND THERE IS SOME EVIDENCE THAT
ANOTHER DISTURBANCE WILL BE WORKING IN OVER THE WESTERN GREAT
LAKES THAT COULD HELP SUSTAIN ISOLATED ACTIVITY OVER LAKE
MICHIGAN...AND INTO THE TAF SITES OVERNIGHT THURSDAY NIGHT.
CERTAINLY NOT ENOUGH CONFIDENCE TO WARRANT A VCSH MENTION.
WINDS WILL BE A TAD GUSTY OUT OF THE WNW/NW THURSDAY (UPPER TEENS
IN KNOTS)...WITH SLIGHTLY BACKING WINDS AND NO MORE GUSTS HEADING
INTO THE EVENING.
&&
.MARINE...
ISSUED AT 355 PM EDT WED JUL 31 2013
LIGHT TO MODERATE SOUTHWEST FLOW WILL VEER WEST OVERNIGHT
BEHIND COLD FRONT PASSAGE. SOME SHOWERS/STORMS POSSIBLE ALONG THIS
FRONT...PERHAPS PRODUCING SOME LOCALIZED GUSTY WINDS. SUB ADVISORY
WINDS EXPECTED TO CONTINUE INTO THIS WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...SD
SYNOPSIS...NS
SHORT TERM...MB
LONG TERM...SR
AVIATION...SD
MARINE...MB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
354 AM CDT THU AUG 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT THU AUG 1 2013
IN THE UPPER LEVELS WE ARE STILL IN GENERALLY NORTHWESTERLY FLOW
WITH A RIDGE LOCATED TO THE WEST CENTERED OVER THE ROCKIES. AT THE
SURFACE WE HAVE HIGH PRESSURE SLIGHTLY TO OUR NORTHEAST WITH A GOOD
TONGUE OF MOISTURE REACHING UP THROUGH THE CENTRAL PLAINS. THIS
MOISTURE IS ALSO APPARENT AT 850HPA WITH DEWPOINTS NEAR 15 DEGREES.
CURRENT KUEX RADAR SHOWS A FEW THUNDERSTORMS ENTERING THE NORTHWEST
PORTION OF OUR CWA. THE RAP MODEL...AND TO SOME DEGREE THE WRF
MODELS...SEEMED TO HAVE THE BEST HANDLE FOR THIS TIME PERIOD WHICH
MAINTAINS CHANCES OF PRECIPITATION FOR THE WESTERN PART OF OUR CWA
INTO THE MORNING.
MAIN CONCERN FOR THIS FORECAST IS CONVECTION AND SEVERE WEATHER
POTENTIAL FOR TODAY. THE SURFACE HIGH WILL MOVE OFF TO THE EAST
AS A LOW DEVELOPS TO THE WEST. AS THE HIGH MOVES OFF...INCREASINGLY
SOUTHERLY FLOW WILL BRING IN MORE MOISTURE WITH AFTERNOON DEW
POINTS IN THE MID TO UPPER 60S. A WARM FRONT WILL LIFT NORTH
ACROSS NEBRASKA REACHING CENTRAL NEBRASKA THIS AFTERNOON. MODELS
ARE INDICATING INSTABILITY INCREASING TO 2000 TO 3000 J/KG ALONG
WITH DEEP LAYER SHEAR OF 40 TO 50 KTS. THESE PARAMETERS ARE
SUFFICIENT FOR SUPERCELL DEVELOPMENT ESPECIALLY IN THE VICINITY OF
THE WARM FRONT. STORMS WHICH DEVELOP WILL BE CAPABLE OF PRODUCING
VERY LARGE HAIL...STRONG WINDS...AND EVEN TORNADOES NEAR THE
BOUNDARY. PRECIPITABLE WATERS THIS AFTERNOON AVERAGE 1.50 INCHES AND ARE
130 PERCENT OF NORMAL. LOCALLY HEAVY RAINFALL IN EXCESS OF AN INCH
OR TWO IS POSSIBLE. CONVECTION THAT DEVELOPS IN THE AFTERNOON AND
EVENING IS EXPECTED TO PERSIST TONIGHT AS THE LLJ IS IN EXCESS OF
40 TO 45 KTS. EVEN WITH THIS POTENTIAL FOR STRONG
STORMS...CONFIDENCE IS STILL NOT HIGH FOR WIDESPREAD
PRECIPITATION AS MODELS ARE NOT CONSISTENT WITH DEVELOPMENT/QPF.
WENT WITH SCATTERED POPS THROUGHOUT THE DAY AND WILL NEED TO MONITOR
THE TREND AS THE DAY PROGRESSES AND CONVECTION UNFOLDS.
TEMPERATURES TODAY ARE DEPENDENT ON CLOUD COVER. GENERALLY WE
SHOULD SEE HIGH TEMPS A FEW DEGREES WARMER THAN YESTERDAY DUE TO
THE INCREASED MIDLEVEL TEMPS. REMAINING CLOUD COVER IN THE MORNING
AND CONVECTION IN THE AFTERNOON MIGHT REDUCE DAYTIME HEATING...BUT
BREAKS IN CLOUD COVER COULD ALLOW TEMPERATURES TO APPROACH THE LOW
90S...ESPECIALLY IN THE SOUTHWEST PART OF THE CWA.
LOWS TONIGHT ARE EXPECTED TO BE IN THE MID TO UPPER 60S IN THE
WARMER AIR MASS. THESE LOW TEMPS ARE NEAR AVERAGE FOR THIS TIME OF
YEAR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 346 AM CDT THU AUG 1 2013
FRIDAY MORNING THROUGH WEDNESDAY. CONCERN CONTINUES TO
REVOLVE AROUND PERIODIC CHANCES FOR RAIN DURING THE ENTIRE EXTENDED
PERIOD.
STARTING OUT FRIDAY MORNING IN THE UPPER LEVELS...MODELS STILL
CONSISTENT IN SHOWING ONE CLOSED LOW OVER THE PACIFIC NORTHWEST AND
ANOTHER ONE OVER NORTHERN ONTARIO. THESE CONTINUE TO DAMPEN THE HIGH
OVER THE SOUTHERN PLAINS. IMPRESSIVE NORTHERN STREAM FOR THIS TIME
OF YEAR WHICH WILL AFFECT THE NORTHERN HALF OF THE CONUS. AT THE
SURFACE...EXPECT LOW PRESSURE OVER SOUTHWEST NEBRASKA WITH A WARM
FRONT EXTENDING SOMEWHERE ACROSS THE CWA. BELIEVE ANY OVERNIGHT
CONVECTION SHOULD HAVE WORKED ITS WAY EAST OF THE CWA BY 12Z FRIDAY
AND WILL TAKE OUT LOW POPS THAT WERE PREVIOUSLY IN THE EASTERN PART
OF OUR AREA. WILL ALSO LEAVE ANY RAIN CHANCES OUT DURING THE DAYTIME
ON FRIDAY AS MOST OF THE CONVECTION THE PAST FEW WEEKS HAS OCCURRED
DURING THE EVENING AND OVERNIGHT TIME FRAME. SHOULD STILL BE IN THE
WARM SECTOR FOR MOST OF THE AREA ON FRIDAY BUT BY SATURDAY THE
SURFACE LOW PUSHES SOUTH AND OUR WINDS BECOME MORE NORTHEASTERLY
WITH SOME COOLER AIR PUSHING IN. HIGHS ON SAT SHOULD BE ABOUT 5
DEGREES BELOW THOSE ON FRIDAY.
AS HAS BEEN NOTED IN PREVIOUS AFDS...TOUGH TO TIME ANY SHORTWAVE
TROUGHS MOVING OVER THE AREA MORE THAN A DAY OR TWO OUT. HOWEVER
BOTH THE LATEST GFS AND EC OPERATIONAL RUNS SIMILAR IN SLIDING ONE
OF THESE WAVES THROUGH THE RIDGE AND OVER US SATURDAY NIGHT. FOR
THIS REASON WILL UP RAIN CHANCES SAT NIGHT AND CONTINUE INTO SUNDAY.
AFTER THAT WE CONTINUE WITH NORTHWEST FLOW AS THE BIG PICTURE POINTS
TO TROUGHING IN THE EAST AND WEST CONUS WITH WEAK RIDGING IN THE
CENTRAL THROUGH AT LEAST THE MIDDLE PART OF NEXT WEEK. THESE LEAVES
US OPEN TO ADDITIONAL DISTURBANCES MOVING THROUGH SO WILL CONTINUE
WITH 20-30 POPS.
IN REGARDS TO SEVERE...DEEP LAYER SHEAR LOOKS FAVORABLE AT LEAST
THROUGH THE WEEKEND WITH 0-6 KM BULK SHEAR PROGGED FROM 25 KT IN
THE SOUTHERN CWA TO 40 KT IN THE NORTH. INSTABILITY ALSO LOOKS OK.
ONE ISSUE THIS TIME OF YEAR IS WILL THERE BE ANY CAPPING TAKING
PLACE. MODELS DO HINT AT THAT AND WILL BE SOMETHING TO WATCH.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1203 AM CDT THU AUG 1 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. WINDS WILL BE
LIGHT AND VARIABLE THROUGH THE NIGHT BEFORE TRANSITIONING
SOUTHERLY AS SFC RIDGE OVER EASTERN NEBRASKA SHIFTS EAST. MAIN
CONCERN IS TIMING OF POTENTIAL CONVECTION FOR KGRI. IF STORMS
ACROSS WESTERN NEB HOLD TOGETHER...THEY MAY REACH THE TERMINAL
AFTER DAYBREAK THURSDAY. MODELS SUGGEST BETTER TIMING FOR
CONVECTION DURING THE AFTN/EVENING HOURS AND HAVE INCLUDED VCTS
FOR NOW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...MANGELS/FAY
LONG TERM...EWALD
AVIATION...FAY/MANGELS
AREA FORECAST DISCUSSION
NWS ELKO NV
211 AM PDT THU AUG 1 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRUSH THE SILVER STATE
TODAY BRINGING GUSTY WINDS...ALONG WITH A FEW THUNDERSTORMS ACROSS
NORTHERN NEVADA. HIGH TEMPERATURES WILL DIP INTO THE 80S TODAY AND
FRIDAY THEN WARM UP A BIT THIS WEEKEND AS HIGH PRESSURE SPREADS
BACK OVER THE GREAT BASIN.
&&
.SHORT TERM...TODAY THROUGH FRIDAY. THUNDERSTORM ACTIVITY
DISSIPATED OVER THE JACKPOT AREA OF NORTHERN NEVADA AROUND 06Z AS
PLANNED. MOUNTAIN SHOWERS ALONG WITH A LIGHTNING STRIKE EVERY NOW
AND THEN HAVE BEEN OCCURRING OVER NORTHERN HUMBOLDT COUNTY THIS
MORNING...FUELED BY A JET CORE ALOFT. THE MODELS ARE IN EXCELLENT
AGREEMENT THROUGH FRIDAY. AN UPPER LOW PRESSURE SYSTEM WILL BE
MOVING ONSHORE ACROSS OREGON TODAY...COINCIDING WITH THE PASSAGE
THROUGH THE GREAT BASIN OF THE STRONGEST SHORTWAVE EMANATING FROM
THE PARENT LOW FEATURE THIS AFTERNOON.
THIS MORNING. THE RIGHT REAR QUAD OF A 100 KT 250 MB JET CORE IS
CROSSING HUMBOLDT COUNTY AT THIS TIME. ADDED ISOLATED
THUNDERSTORMS...DRY BELOW 6000 FT TO HUMBOLDT COUNTY FOR THE
MORNING HOURS.
THIS AFTERNOON THROUGH THIS EVENING. THE STRONGEST SHORTWAVE LOBE
WILL PUSH INLAND OVER OREGON AND A 60-70 KT H4 JET CORE WILL BE
CROSSING WEST TO EAST ACROSS THE STATE. THE RR QUAD SHOULD ENSURE
SOME HEFTY WIND GUSTS MIX DOWN TO THE SURFACE OVER MOST OF THE LKN
CWFA....MAINLY A FIRE WEATHER CONCERN. HIGH TEMPERATURES WILL
RANGE FROM THE MID 80S TO AROUND 90 DEGREES.
TONIGHT THROUGH FRIDAY. A DRIER AND COOLER AIR MASS WILL BE
MOVING INTO THE REGION. AS THE UPPER LOW BEGINS TO PULL TO THE
NORTHEAST...CROSSING WASHINGTON STATE...A WEAKENING LOW LEVEL JET
CORE WILL LINGER LONG ENOUGH TO PRODUCE ANOTHER DAY OF BREEZY
WINDS. SURFACE GUSTS WILL BE LESS INTENSE WITH LESS COVERAGE THAN
THIS AFTERNOON...AND MORE PREVALENT OVER EAST CENTRAL NEVADA. LOW
TEMPERATURES WILL GENERALLY RANGE FROM THE MID 40S TO THE MID 50S.
HIGH TEMPERATURES WILL BE IN THE 80S.
.LONG TERM...FRIDAY NIGHT THROUGH NEXT WEDNESDAY. MODELS IN GOOD
AGREEMENT THROUGH SUNDAY. SOUTHWESTERLY FLOW WILL CONTINUE OVER THE
CWA THROUGH THE UPCOMING WEEKEND WITH BREEZY CONDITIONS ACROSS
CENTRAL NEVADA WITH A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST
AND HIGH PRESSURE OVER NEW MEXICO. NEXT MONDAY THE RIDGE BUILDS WITH
RISING HEIGHTS OVER THE GREAT BASIN AND SLIGHTLY WARMER
TEMPERATURES. THIS BUILDING RIDGE WILL BRING SOUTHERLY FLOW AND
MOISTURE WILL BEGIN TO RETURN TO PORTIONS OF CENTRAL AND EASTERN
NEVADA EARLY NEXT WEEK...HOWEVER MODELS DIFFER ON HOW MUCH MOISTURE
AND INSTABILITY. THUS HAVE LOW POPS ESPECIALLY OVER MOUNTAINS EARLY
NEXT WEEK. TEMPERATURES WILL BE NEAR NORMAL INCREASING TO SLIGHTLY
ABOVE NORMAL BY EARLY NEXT WEEK.
&&
.AVIATION...VFR CONDITIONS OVER THE NEXT 24HRS. WINDS WILL BE GUSTY
THIS AFTERNOON DECREASING AFTER SUNSET.
&&
.FIRE WEATHER...AN UPPER LEVEL TROUGH WILL MOVE THROUGH THE PACIFIC
NORTHWEST...RESULTING IN GUSTY SURFACE WINDS TODAY AND TO A LESSER
EXTEND ON FRIDAY.
TODAY...DRY THUNDERSTORM COVERAGE WILL BE MINIMAL AND MAINLY AFFECT
NORTHERN FIRE ZONES THROUGH THE EVENING. WIND GUSTS ABOVE 30 MPH
WILL BE MORE WIDESPREAD THAN WEDNESDAY AND WILL BE PROBLEMATIC
WHEN COMBINED WITH MINIMUM RELATIVE HUMIDITY VALUES SOLIDLY BELOW
15%. A RED FLAG WARNING IS IN EFFECT FOR ALL FIRE ZONES EXCEPT
FIRE ZONE 454. WIND SPEEDS...ESPECIALLY IN THE VALLEY
LOCALES...ARE EXPECTED TO BE JUST BELOW CRITERIA IN ZONE
454...ALTHOUGH MID- SLOPES AND HIGHER ELEVATION SITES COULD SEE
HIGHER WINDS.
BREEZY WINDS ARE FORECAST ON FRIDAY AS WELL...HOWEVER GUSTS ARE
EXPECTED TO GENERALLY BE BELOW 30 MPH. THE STRONGEST WINDS FRIDAY
WILL BE OVER ZONE 455 AND EASTERN ZONE 457.
HIGH PRESSURE WILL BEGIN TO BUILD OVER THE REGION. WARMER AND
DRIER CONDITIONS ARE EXPECTED.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 8 PM PDT THIS
EVENING FOR HUMBOLDT COUNTY...NORTHERN ELKO COUNTY...NORTHERN
LANDER COUNTY AND NORTHERN EUREKA COUNTY...RUBY MOUNTAINS/EAST
HUMBOLDT RANGE...SOUTH CENTRAL ELKO COUNTY...SOUTHEASTERN ELKO
COUNTY...SOUTHWESTERN ELKO COUNTY...WHITE PINE COUNTY.
RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR NORTHEASTERN
NYE COUNTY...NORTHWESTERN NYE COUNTY...SOUTHERN LANDER COUNTY
AND SOUTHERN EUREKA COUNTY.
&&
$$
92/87/87/92
AREA FORECAST DISCUSSION
NWS BUFFALO NY
145 AM EDT THU AUG 1 2013
.SYNOPSIS...
SHOWERS AND SCATTERED THUNDERSTORMS WILL OVERSPREAD THE REGION VERY
LATE TONIGHT AND THURSDAY AS A COLD FRONT APPROACHES THEN CROSSES
THE REGION. LINGERING MOISTURE AND SOMEWHAT UNSTABLE AIR BEHIND THE
FRONT MAY BRING A FEW MORE WIDELY SCATTERED SHOWERS ON FRIDAY. BELOW
AVERAGE TEMPERATURES WILL LAST THROUGH THE WEEKEND AND INTO AT LEAST
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
THE LATEST SURFACE MAP SHOWS LOW PRESSURE CENTERED JUST NORTH OF
LAKE ERIE WITH A WEAK TROUGH/COLD FRONT TRAILING SOUTH ACROSS
WESTERN OHIO/EASTERN INDIANA. REGIONAL RADARS STILL SHOW AN AREA OF
STEADY SHOWERS IN THE VICINITY OF THE LOW...STRETCHING NORTH TOWARD
GEORGIAN BAY AND WESTERN LAKE ONTARIO. RADAR TRENDS AND SHORT TERM
MESOSCALE MODEL GUIDANCE SUCH AS THE HRRR AND THE 00Z NAM SUGGESTS
THAT THE BULK OF THESE SHOWERS WILL STAY TO OUR WEST FOR MUCH OF THE
NIGHT UNTIL AN UPSTREAM SHORT WAVE OVER MICHIGAN PUSHES THE PCPN
INTO WESTERN NEW YORK BY DAYBREAK. SURFACE OBSERVATIONS AND REGIONAL
LIGHTNING PLOTS ALSO SHOW A FAIR AMOUNT OF ELEVATED CONVECTION
EMBEDDED WITHIN THE GENERAL AREA OF SHOWERS.
AS THE MID LEVEL SHORT WAVE AND ASSOCIATED SURFACE LOW TRACK JUST
NORTH OF LAKE ONTARIO LATER THIS MORNING...THE TRAILING COLD FRONT
WILL INTERACT WITH ABUNDANT LOW LEVEL MOISTURE THAT WILL BE
ADVECTING NORTH FROM THE OHIO VALLEY. AT THE SAME TIME...AN UPPER
LEVEL JET WILL STRENGTHEN ACROSS SOUTHERN QUEBEC...WITH THE FAVORED
RIGHT ENTRANCE REGION AND ASSOCIATED UPPER LEVEL DIVERGENCE PLACED
OVER THE LOWER LAKES. THE MOISTURE AND LARGE SCALE LIFT WILL KEEP
THE AREA OF SHOWERS AND SCATTERED THUNDERSTORMS INTACT.
EXPECT MOST OF THE RAIN TO FALL IN A 3-5 HOUR WINDOW JUST BEFORE
DAYBREAK THROUGH THIS MORNING IN THE WEST...AND HOUR OR TWO LATER IN
THE GENESEE VALLEY...AND FROM MID MORNING THROUGH MID AFTERNOON
THURSDAY ACROSS THE NORTH COUNTRY AND CENTRAL NY. MODEST INSTABILITY
WILL SUPPORT A FEW EMBEDDED THUNDERSTORMS. EXPECT BASIN AVERAGE
RAINFALL TOTALS TO RANGE FROM A QUARTER TO THIRD OF AN INCH IN MOST
LOCATIONS... ALTHOUGH ANY EMBEDDED CONVECTION WILL PRODUCE LOCALLY
HIGHER AMOUNTS.
FOLLOWING THE END OF THE SHOWERS LATER THIS MORNING IN THE
WEST...EXPECT A FEW BREAKS OF SUNSHINE ALTHOUGH LINGERING LOW LEVEL
MOISTURE AND COOLING TEMPS ALOFT WILL LIKELY PRODUCE PLENTY OF
CUMULUS DURING THE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
THURSDAY NIGHT A COLD FRONT WILL CONTINUE TO SLICE ACROSS THE
REMAINDER OF THE CWA...WITH A NARROW LINE OF SHOWERS LIKELY ALONG
THE IMMEDIATE FRONTAL BOUNDARY. THE DEEPEST MOISTURE WILL RUN OUT
AHEAD OF THE COLD FRONT...LEAVING A MORE STABLE ATMOSPHERE FOR THE
COLD FRONT TO SHIFT ACROSS...WITH SHOWERS LIKELY BUT NO THUNDER.
TEMPERATURES THURSDAY NIGHT WILL DROP BACK INTO THE 50S...WITH A
SPOT 40S NOT OUT OF THE QUESTION ACROSS THE VALLEYS OF THE INTERIOR
SOUTHERN TIER.
FOR FRIDAY AND INTO SATURDAY A -1SD UPPER LEVEL TROUGH WILL BE
ANCHORED ACROSS THE NORTHEAST AND SOUTHERN CANADA. MULTIPLE
SHORTWAVES WILL RIDE THROUGH THIS TROUGH SPARKING SHOWERS ON BOTH
FRIDAY AND SATURDAY. WILL COVER THIS WITH A BROAD BRUSH CHANCE POP
THROUGH THE TIME PERIOD...WITH GREATEST CHANCES DURING THE AFTERNOON
AND EARLY EVENING WHEN DAYTIME INSTABILITY SHOWERS WILL BE GREAT
CHANCES FOR OCCURRENCE.
ALSO OF NOTE FOR BOTH FRIDAY MORNING AND SATURDAY MORNING WILL BE A
MARGINAL SETUP FOR LAKE EFFECT RAIN. TEMPERATURES ALOFT BOTH
MORNINGS WILL DROP TO ABOUT +9 TO +10...WHICH WILL JUST TOUCH THE
DELTA 13C FROM 850 HPA DOWN TO THE SURFACE...WITH LIMITED LAKE
INSTABILITY. A LAKE EFFECT RAIN SHOWER IS POSSIBLE BOTH MORNINGS.
TEMPERATURES BOTH DAYS WILL AVERAGE JUST BELOW NORMAL WITH HIGHS IN
THE LOW TO MID 70S...AND NIGHTTIME LOWS DROPPING BACK INTO THE
50S...WITH AROUND 60 ALONG THE LAKESHORE PLAINS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THIS TIME
PERIOD...WITH AN AMPLIFIED PATTERN CONSISTING OF A RIDGE ACROSS THE
WEST AND TROUGH ACROSS THE EAST. VARIOUS SHORTWAVES RIDING THROUGH
THIS TROUGH WILL BRING CHANCES OF PRECIPITATION.
ON SUNDAY MODEL CONSENSUS IS NOW TO BRING A SHORTWAVE TROUGH
DROPPING FROM NEAR THE NORTHERN GREAT LAKES AND ACROSS OUR REGION.
THE CORE OF THE SHORTWAVE...MINUS 2 SD AT 500 HPA ACCORDING TO THE
06Z/31 GEFS WILL RIDE ACROSS THE NORTH COUNTRY. WITH ANOTHER SHOT OF
COLD AIR WITH THIS SHORT WAVE...AROUND 6 TO 7C AT 850 HPA...CREATING
STEEP LOW LEVEL LAPSE RATES...COMBINED WITH THE PASSAGE OF THE
SHORTWAVE A CHANCE OF SHOWERS WILL BE POSSIBLE SUNDAY. WILL HAVE THE
GREATEST CHANCE ACROSS LAKE ONTARIO AND THE NORTH COUNTRY WHERE THE
STEEPER LAPSE RATES AND GREATER HEIGHT FALLS WILL BE FOUND.
THE COOL POOL OF AIR ALOFT WILL ALSO CREATE A MOSTLY CLOUDY DAY WITH
COOL AFTERNOON TEMPERATURES. WITH NOT MUCH SUNSHINE SUNDAY HIGHS
WILL ONLY CLIMB INTO THE UPPER 60S TO LOWER 70S ACROSS THE REGION.
HIGH PRESSURE WILL START TO BUILD INTO THE REGION SUNDAY NIGHT AND
PUSH DRIER AIR ACROSS THE REGION. THIS DRIER AIR COUPLED WITH THE
LOSS OF DAYTIME HEATING AND THE SUBSIDENCE BEHIND THE SHORTWAVE WILL
BRING AN END TO THE SHOWERS AND ALLOW FOR SOME CLEARING
SKIES....ESPECIALLY ACROSS WNY. WINDS WILL VEER TO NORTHWEST WHICH
WITH THE UPSLOPE FLOW MAY LINGER LOW CLOUDS ACROSS THE WNY...AND
THIS WILL MAKE FOR A LITTLE BIT OF UNCERTAINTY TO OVERNIGHT LOWS.
TOTAL CLEARING WILL ALLOW FOR A VERY CHILLY NIGHT WITH MANY AREAS
DROPPING DOWN INTO THE 40S...WITH ONLY AROUND 50 NEAR THE
LAKESHORES. FOR NOW LEAVE SOME LOW CLOUDS IN THE GRIDS OVERNIGHT AND
NOT GO QUITE AS COLD AS WHAT A COMPLETE CLEARING NIGHT WOULD GIVE
US. THE OTHER CONCERN FOR SUNDAY NIGHT WILL BE LAKE EFFECT CLOUDS
AND POSSIBLE LIGHT SHOWERS SOUTHEAST OF LAKE ONTARIO. WITH A CHILLY
8C 850 HPA AIR CROSSING THE LAKE SOME LAKE EFFECT CLOUDS AND PERHAPS
EVEN A LIGHT SHOWER IS POSSIBLE...THOUGH SYNOPTIC MOISTURE IS
LACKING AND WILL HOLD POPS SOUTHEAST OF LAKE ONTARIO TO LOW
CHANCE.
ON MONDAY SOME BACKING TO THE WINDS AS HIGH PRESSURE DROPS JUST TO
THE SOUTH OF THE REGION WILL ALLOW FOR CLEARING SKIES. CLOUDS WILL
BE MOST PLENTIFUL ACROSS THE NORTH COUNTRY CLOSER TO THE UPPER LEVEL
LOW...AND IN FACT THERE MAY EVEN STILL BE A SHOWER THIS DAY...SO
WILL HAVE A LOW CHANCE POP ACROSS THIS REGION.
HIGHS MONDAY WILL LIKELY BE A COUPLE DEGREES WARMER THAN SUNDAY WITH
THE ADDITIONAL SUNSHINE...AND NOT AS COOL TEMPERATURES ALOFT. HIGHS
WILL REACH BACK INTO THE 70S ACROSS THE REGION...COOLEST ACROSS THE
NORTH COUNTRY WHERE SOME CLOUDINESS MAY LINGER.
ANOTHER SHORTWAVE WILL RIDE ALONG THE WESTERN PERIPHERY OF THIS
UPPER LEVEL TROUGH AND DROP ACROSS THE GREAT LAKES REGION TUESDAY
AND WEDNESDAY. THIS WILL BRING ADDITIONAL CHANCES FOR SHOWERS...WITH
TEMPERATURES REMAINING COOL.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL PREVAIL FOR MOST OF THE EARLY MORNING HOURS AS
THE FIRST AREA OF RAIN OVER SOUTHERN ONTARIO WILL REMAIN TO THE
NORTH AND WEST OF THE AREA THROUGH AT LEAST 08Z-09Z. THIS WILL LEAVE
THICKENING AND LOWERING MID LEVEL CLOUDS SPREADING FROM WEST TO EAST
ACROSS THE AREA. EXPECT A 3-5 HOUR PERIOD OF SHOWERS TO CROSS THE
REGION FROM WEST TO EAST LATE TONIGHT THROUGH THE FIRST HALF OF
THURSDAY AS A COLD FRONT AND STRENGTHENING MID LEVEL TROUGH CROSS
THE AREA. THE HEAVIER SHOWERS MAY PRODUCE PERIODS OF MVFR CIGS/VSBY
AND POSSIBLY EVEN A BRIEF PERIOD OF IFR. BEHIND THE COLD FRONT
EXPECT RAIN TO TAPER OFF...ALTHOUGH MVFR CIGS MAY LINGER FOR A FEW
HOURS BEFORE IMPROVING TO VFR DURING THE AFTERNOON.
FARTHER EAST AT KART...EXPECT THE SAME TREND JUST A FEW HOURS
LATER...WITH THE BULK OF THE RAIN AND POTENTIAL FOR LOWER CIGS/VSBY
COMING FROM MID MORNING THROUGH MID AFTERNOON THURSDAY.
OUTLOOK...
FRIDAY AND SATURDAY...MAINLY VFR WITH A SMALL CHANCE OF SHOWERS.
SUNDAY AND MONDAY...VFR.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE ACROSS THE
LOWER LAKES TONIGHT. AFTER A FRONT CROSSES THE LAKES ON
THURSDAY...THE WINDS WILL SWITCH TO THE SOUTHWEST AND PICK UP A
BIT...BUT CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. MORE IMPORTANTLY...THE FRONT WILL BRING A GOOD
CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS LATE TONIGHT AND
THURSDAY...WITH LOCAL INCREASES IN WIND AND WAVES POSSIBLE.
THE PRESSURE GRADIENT BETWEEN BETWEEN A SURFACE HIGH OVER THE MIDDLE
ATLANTIC STATES AND LOW PRESSURE PUSHING ACROSS HUDSON BAY WILL
CAUSE WESTERLY WINDS TO PICK UP A LITTLE MORE ON FRIDAY. WATERSPOUTS
WILL BECOME POSSIBLE AGAIN AT TIMES FRIDAY INTO THE WEEKEND AS TEMPS
COOL ALOFT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LEVAN
NEAR TERM...HITCHCOCK/TJP
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...HITCHCOCK/TJP
MARINE...HITCHCOCK/LEVAN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
215 AM EDT THU AUG 1 2013
.SYNOPSIS...
BENEATH AN APPROACHING UPPER LEVEL DISTURBANCE...A SURFACE TROUGH OF
LOW PRESSURE WILL DRIFT ACROSS CENTRAL AND EASTERN NC TODAY. A COLD
FRONT WILL FOLLOW AND SETTLE SOUTHEASTWARD ACROSS THE REGION
TONIGHT.
&&
.NEAR TERM /TONIGHT/...
AS OF 940 PM WEDNESDAY...
CURRENT BAND OF SHOWERS AND STORMS MOVING SLOWLY ACROSS WESTERN
PORTIONS OF THE AREA IS EXPECTED TO CONTINUE SLOWLY MOVING ACROSS
MOST OF THE AREA OVER THE NEXT 3-6 HOURS (LOWEST PROBABILITIES IN
THE SE/E)... WITH ADDITIONAL WEAK S/W ENERGY POSSIBLE LATER TONIGHT
MOVING THROUGH THE BROAD MID LEVEL CYCLONIC FLOW. HOWEVER... WITH
MLCAPE VALUES GENERALLY IN THE 500 TO 1000 J/KG OR LESS (ALONG WITH
NOCTURNAL STABILIZATION EXPECTED/UNDERWAY) DONT EXPECT ANY SEVERE
STORMS... THOUGH ISOLATED URBAN FLOODING WILL BE POSSIBLE AS PW`S
HAVE INCREASE INTO THE 1.8 TO 2.0" RANGE. WILL GO WITH POPS IN THE
LIKELY/CATEGORICAL RANGE FOR THE REST OF THE EVENING AND CHANCE POPS
AFTERWARD GIVEN THE MOIST AIRMASS AND ADDITIONAL S/W ENERGY (WITH
THE 850 MB TROUGH MOVING INTO THE AREA NEAR 12Z THURSDAY).
HOWEVER... THE LATEST HRRR GUIDANCE DOES NOT ADVERTISE MUCH AFTER
THIS CURRENT BAND MOVES THROUGH THE AREA... BUT THINK THE MOIST ATMO
AND POSSIBLE ADDITIONAL S/W ENERGY WARRANTS AT LEAST CHANCE POPS IN
THE WAKE OF THE CURRENT ACTIVITY. GIVEN THE EXPECTED CONSIDERABLE
CLOUD COVER... EXPECT LOW TEMPS WILL GENERALLY RANGE FROM UPPER
60S/NEAR 70 TO THE LOWER TO MAYBE EVEN MID 70S (MID 70S IN THE SE IF
THEY REMAIN DRY).
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 230 PM WEDNESDAY...
LOOKING AT A CONTINUATION OF SHORTWAVE PERTURBATIONS MOVING EAST
ACROSS THE AREA INITIALLY ON THURSDAY. THESE WILL NUDGE THE SURFACE
FRONT EASTWARD INTO CENTRAL NC TOWARDS MID DAY. ENSUING DEEP LAYER
FORCING WILL BE WELL PHASED WITH ABUNDANT DEEP MOISTURE TO ASSIST
THE CONVECTIVE PROCESS DURING DIURNAL DESTABILIZATION. AS
SUCH...POPS WILL REMAIN IN THE LIKELY CATEGORY THROUGH LATE
AFTERNOON...WITH A BETTER CHANCE OF THUNDERSTORMS WITH DRY AIR
PUSHING IN BEHIND THE TROF PRODUCING MLCAPES >1500J AND MID LEVEL
LAPSE RATES STEEPENING TO 6.5K/KM. HIGHS WILL BE SIMILAR TO TODAY
GIVEN LACK OF INSOLATION AND SIMILAR AIRMASS...LOW 80S NORTHWEST TO
MID 80S IN THE SOUTHEAST.
WILL COMMENCE TAPERING THE POPS OFF IN THE WEST BY EVENING AS FLOW
FLATTENS AND BECOMES MORE WESTERLY BEHIND THE TROF. WILL KEEP SMALL
CHANCES IN THE EAST THROUGH AROUND MIDNIGHT. MINS WILL BE A LITTLE
COOLER GIVEN DRIER AIR AND GRADUAL CLEARING OVERNIGHT...65-70.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 258 PM WEDNESDAY...
CONTINUED GOOD MODEL AGREEMENT ON THE OVERALL PATTERN THROUGH EARLY
NEXT WEEK WITH AN UPPER LEVEL RIDGE REMAINING OVER THE ROCKIES...
AND UPPER LEVEL TROUGHING OVER THE EAST US... ALLOWING TEMPS A FEW
DEGREES BELOW NORMAL AND ABOVE NORMAL PRECIP CHANCES. DRIER AIR WILL
BRIEFLY MOVE IN TO THE AREA ON FRIDAY AFTER THE FRONT PASSES WITH
PWS PROGGED TO FALL TO NEAR AN INCH. MOISTURE WILL BEGIN TO REBOUND
OVER THE WEEKEND... AHEAD OF ANOTHER FRONT THAT LOOKS LIKELY TO PUSH
IN TO THE AREA FROM THE NORTH... POTENTIALLY MORE BACKDOOR IN
CHARACTER... SUNDAY INTO EARLY MONDAY. ANOTHER FRONT LOOKS TO
APPROACH THE AREA ON WEDNESDAY... ALTHOUGH UNCERTAINTY INCREASES AT
THIS TIME. THE MOST RECENT GFS RUN KEEPS THIS BOUNDARY WELL NORTH OF
THE AREA... AS IT FLATTENS THE EAST COAST TROUGH INTO A MORE ZONAL
FLOW. THIS OUTCOME IS NOT SUPPORTED BY ENSEMBLE MEANS... AND WILL
THEREFORE DISCOUNT AT THIS TIME. HIGHS WILL GENERALLY BE IN THE MID
TO UPPER 80S... LOWS MID 60S TO LOWER 70S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 210 AM THURSDAY...
LIFR-VLIFR STRATUS OVER WESTERN NC...INCLUDING THE TRIAD
TERMINALS...WILL DEVELOP EASTWARD ACROSS THE REMAINDER OF CENTRAL NC
TAF SITES THROUGH AROUND 09Z. THESE CEILINGS WILL BE SLOW TO LIFT
AND SCATTER THROUGH MVFR RANGE TO VFR BETWEEN 16-19Z...PARTICULARLY
AT KRWI AND KFAY...WHERE MOIST SOUTH SOUTHWESTERLY FLOW WILL LINGER
LONGEST. THESE EASTERN TAF SITES ALSO STAND THE BEST CHANCE OF
EXPERIENCING SHOWERS AND ISOLATED THUNDERSTORMS THROUGH EARLY
AFTERNOON...WHILE CONVECTIVE COVERAGE ELSEWHERE WILL BE LESS -
WIDELY SCATTERED TO ISOLATED. A BROKEN LINE OF SHOWERS AND STORMS
IS EXPECTED TO FORM ALONG OR JUST AHEAD OF A COLD FRONT THAT WILL
CROSS CENTRAL NC LATE THIS AFTERNOON AND EARLY TONIGHT - AT TRIAD
TERMINALS BETWEEN 21-01Z AND EASTERN ONES BETWEEN 00-06Z. IFR-LIFR
CONDITIONS WILL LIKELY DEVELOP LATE TONIGHT MAINLY FROM KRDU AND
ESPECIALLY EASTWARD TO KRWI AND KFAY...WHERE DRIER AIR BEHIND THE
AFOREMENTIONED FRONT WILL BE SLOWEST TO ARRIVE.
LOOKING AHEAD: A SLIGHT CHANCE OF AFTERNOON SHOWERS AND STORMS AT
EASTERN TAF SITES SATURDAY...WITH A BETTER CHANCE - AROUND 40
PERCENT - AT ALL CENTRAL NC TERMINALS ON SUNDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...MLM
LONG TERM...SEC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1234 AM CDT THU AUG 1 2013
.UPDATE...
ISSUED AT 1233 AM CDT THU AUG 1 2013
NUDGE OVERNIGHT LOW TEMPERATURES DOWN A DEGREE OR TWO AS
TEMPERATURES ARE COOLING A BIT QUICKER UNDER MOSTLY CLEAR SKIES.
NO OTHER SIGNIFICANT CHANGES TO ONGOING FORECAST WERE MADE OTHER
THAN TO UPDATE FORECAST FOR LATEST OBS AND TRENDS.
UPDATE ISSUED AT 927 PM CDT WED JUL 31 2013
AT 9 PM CDT...LATEST RUC MODEL DEPICTS A RIDGE OF SURFACE HIGH
PRESSURE FROM EASTERN SOUTH DAKOTA NORTHWEST THROUGH SOUTHERN
SASKATCHEWAN. THE AREA OF HIGH PRESSURE WILL CONTINUE TO SLIDE
SOUTHEAST OVER THE REGION THROUGH THURSDAY. THIS WILL KEEP SKIES
MOSTLY CLEAR AND WINDS LIGHT NORTHWEST. COOL OVERNIGHT TEMPERATURES
WILL AGAIN BE IN THE OFFING WITH OVERNIGHT READINGS FROM THE UPPER
40S NORTHWEST AND CENTRAL TO THE LOWER 50S WESTERN DEVILS LAKE
BASIN. CURRENT FORECAST TENDING WELL.
UPDATE ISSUED AT 628 PM CDT WED JUL 31 2013
LATEST WATER VAPOR IMAGE SHOWS UPSTREAM SHORT WAVE MOVING THROUGH
EAST CENTRAL SASKATCHEWAN INTO MANITOBA NEAR LAKE WINNIPEG.
IMMEDIATELY UPSTREAM OF NORTH DAKOTA WEAK CHANNELED VORTICITY IN
NORTHWEST FLOW WILL BRING NO SIGNIFICANT FORCING THIS EVENING.
EXPECT NORTHWEST SURFACE FLOW TO DIMINISH OVERNIGHT AS REMAINING
CUMULUS FIELD DIMINISHES. CURRENT FORECAST LOOKS GOOD.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 304 PM CDT WED JUL 31 2013
MAIN HIGHLIGHTS IN THE SHORT TERM WILL BE THE POSSIBILITY OF A
SHOWER/SPRINKLES IN THE FAR NORTHEAST/TURTLE MOUNTAINS THURSDAY.
OTHERWISE EXPECT MOSTLY SUNNY...DRY...AND WARMER CONDITIONS.
THE LATEST SATELLITE IMAGERY SHOWS A SCATTERED TO AT TIMES A
BROKEN CUMULUS DECK ACROSS WESTERN AND CENTRAL NORTH DAKOTA. FOR
THE MOST PART EXPECT THE CUMULUS TO DISSIPATE TOWARD SUNSET.
WATER VAPOR IMAGERY SHOWS THE NEXT SHORTWAVE SLIDING SOUTHEAST
INTO CENTRAL SASKATCHEWAN THIS AFTERNOON. VISIBLE IMAGERY SHOWS
THICKER CLOUDS ACROSS SOUTH CENTRAL SASKATCHEWAN WITH SURFACE
OBSERVATIONS CLOSER TO THE SHORTWAVE REVEALING LIGHT RAIN AT
PRINCE ALBERT AND IN LA RONGE SASKATCHEWAN. HIGH RESOLUTION MODELS
ALONG WITH THE NAM/GFS/SREF KEEP THE PRECIPITATION ACROSS MANITOBA
THIS EVENING INTO TONIGHT...SO WILL NOT MENTION ANY POPS IN THE
TURTLE MOUNTAINS. THERE IS A REFLECTION OF A WEAK COLD FRONT AT
THE SURFACE...WHICH IS FORECAST TO REACH THE NORTHERN BORDER
BETWEEN 12Z AND 15Z THURSDAY. THE NAM SUGGESTS AN ISOLATED SHOWER
POSSIBLE NEAR THE INTERNATIONAL PEACE GARDEN PRIOR TO 18Z THURSDAY
ASSOCIATED WITH THE COLD FRONT...WHILE THE 09Z SREF ADVERTISES
SOME PRECIPITATION BETWEEN 18Z AND 21Z THURSDAY IN THE SAME AREA.
THE GFS/ECMWF ARE BOTH DRY. AFTER COORDINATING WITH GRAND
FORKS...WE AGREE THAT WE ARE NOT REAL CONFIDENT WITH MEASURABLE
PRECIPITATION AT THIS TIME. WILL LET THE EVENING AND NIGHT SHIFT
WATCH THE TRENDS AND ADJUST. ELSEWHERE...THE NAM/GFS SOUNDING
PROFILES SHOW A STRONG CAP IN PLACE ACROSS THE SOUTHWEST
THURSDAY AFTERNOON AND HAVE REMOVED THE SLIGHT CHC MENTION OF A
THUNDERSTORM. HIGHS THURSDAY WILL BE WARMER WITH AFTERNOON HIGHS
IN THE UPPER 70S TO LOWER 80S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 304 PM CDT WED JUL 31 2013
ACTIVE NORTHWEST FLOW AND BELOW NORMAL TEMPERATURES WILL HIGHLIGHT
THE EXTENDED FORECAST.
OVERALL...THE 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT ON
NORTHWEST FLOW ACROSS THE NORTHERN PLAINS THROUGH NEARLY THE
ENTIRE EXTENDED FORECAST PERIOD. THIS IS FORECAST TO RESULT IN
CONTINUED BELOW NORMAL TEMPERATURES WITH HIGHS IN THE 70S...WITH THE
COOLER EDGE OF GUIDANCE PREFERRED BASED UPON VERIFICATION OVER THE
PAST WEEK. WHILE IT IS HARD TO RULE OUT ISOLATED CONVECTION ANY
DAY IN A NORTHWEST FLOW REGIME...THE FAVORED TIME FRAME FOR
THUNDERSTORMS IS SATURDAY NIGHT THROUGH SUNDAY AS ENERGY FROM THE
PACIFIC NORTHWEST PROPAGATES ALONG THE CREST OF THE RIDGE INTO THE
NORTHERN PLAINS. AN EARLY LOOK AT SHEAR AND INSTABILITY PROFILES
SUGGESTS SEVERE STORMS MAY BE POSSIBLE DURING THIS TIME FRAME. THE
12 UTC GFS/ECMWF CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL
LOW ACROSS SOUTH CANADA AND POSSIBLY INTO THE FAR NORTH CENTRAL
CONUS NEXT WEDNESDAY THROUGH FRIDAY. WILL CONTINUE TO MONITOR AS
THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1233 AM CDT THU AUG 1 2013
HIGH PRESSURE OVERHEAD WILL CONTINUE MOSTLY CLEAR SKIES AND LIGHT
WINDS. VFR CONDITIONS FORECAST AT ALL TAF SITES THROUGH THE 06Z
TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...LTH
SHORT TERM...KS
LONG TERM...AYD
AVIATION...LTH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
156 AM EDT THU AUG 1 2013
.SYNOPSIS...
A WEAK COLD FRONT CROSSES LATE TONIGHT AND EARLY THURSDAY. HIGH
PRESSURE PASSES THURSDAY NIGHT/FRIDAY MORNING. A COLD FRONT CROSSES
THIS WEEKEND...FOLLOWED BY BELOW NORMAL TEMPERATURES EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
130 AM UPDATE...NO SIGNIFICANT CHANGE.
PREVIOUS DISCUSSION...
DISTURBANCE MOVING THRU CWA WITH MAINLY SCT -SHRA AND EVEN SOME
-DZ ABOUT THE AREA. WEAKENING VORT MAX HANGING OUT ACROSS SE OH CO
WITH LOBE APPENDAGE MOVING NE INTO N WV SERVING AS MAIN FOCUS FOR
LIFT. RUC AND HRRR SEEMS TO HAVE A MUCH BETTER HANDLE ON THINGS VS
OTHER MDLS AND HAVE USED THESE AS GUIDANCE. OTHERWISE LOOKING AT
AN ABUNDANCE OF LLVL MOISTURE REMAINDER OF AFTN.
FRONT POISED TO MOVE THRU LATE TONIGHT INTO EARLY THU MORNING WITH
A BAND OF SHRA WITH IT. THERE COULD BE AN AREA OF -RA OR DZ ALONG
AND E OF I79 TONIGHT BEFORE AFOREMENTIONED SHRA ARRIVE WITH
IMPRESSIVE DRYING SHOWING UP IN MID LVLS. THINK LOW STRATUS AND
FG WILL SETUP REGARDLESS THIS EVE...TRYING TO LIFT SOME AS FRONTAL
SHRA MOVE IN PREDAWN.
ALL OF THIS PUSHES E ON THU WITH AMPLIFYING UPR TROF ACROSS OH
VALLEY. HOWEVER...LLVL MOISTURE WILL BE VERY SLOW TO GIVE UP THE
GHOST. EVEN THOUGH LOW STRATUS LIFTS BY MIDDAY...SUSPECT THIS WILL
GIVE WAY TO AN ABUNDANCE OF CU GIVEN H85 MOISTURE UNDERNEATH A
DEVELOPING STOUT INVERSION ARND H7. AS FOR POPS DRY THINGS OUT FOR
MOST PART. DID LEAVE SOME LOW POPS FOR A FEW EARLY AFTN DEVELOPMENT
ACROSS THE MTNS.
FOR TEMPS...INHERITED NUMBERS LOOKED GOOD TONIGHT. ELECTED TO GO
CLOSER TO COOLER MET ON THU WITH EXPECTATION THAT EXTENT OF CLDS
HOLDS NUMBERS DOWN A BIT.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
A FEW OF THE MESO MODELS ARE SHOWING SOME LINGERING SHOWERS BEHIND
THE COLD FRONT THURSDAY NIGHT. DUE TO THE TIME OF DAY AND DRY AIR
PUSH...DO NOT THINK THAT THIS IS REALISTIC. WILL LEAVE DRY FOR NOW.
HIGH PRESSURE THEN PROVIDES A BRIEF PERIOD OF DRY WEATHER FRIDAY
MORNING. ALL MODELS ARE SHOWING SOME MOISTURE PUSHING BACK IN LATE
FRIDAY...ALTHOUGH TIMING DIFFERENCES EXIST. WILL INCLUDE A CHANCE OF
SHOWERS...AND POSSIBLY THUNDERSTORMS...BUT NOT BE TOO DEFINITIVE. WILL
INCREASE POPS INTO SATURDAY AS FRONT APPROACHES AND MOISTURE
DEEPENS. FRONT THEN PUSHES THROUGH LATE SATURDAY/SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LOTS OF MODEL DIFFERENCES IN HOW FAR SOUTH THE FRONT AND MOISTURE
PUSH FOR THE END OF THE WEEKEND AND BEGINNING OF NEXT WEEK. USED A
BLEND OF THE ECMWF MEAN AND THE GEFS...WHICH WOULD PUT THE FRONT
JUST SOUTH OF THE FORECAST AREA. WITH SOME WAVES POSSIBLE ALONG THE
FRONT...SOME PRECIPITATION COULD MAKE IT INTO THE FORECAST
AREA...WITH THE BEST CHANCES IN THE SOUTH.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
06Z THURSDAY THRU 06Z FRIDAY ...
WIDESPREAD MVFR CIGS HAVE DEVELOPED OVERNIGHT...ALONG WITH LOCAL
IFR CIGS...PARTICULARLY ALONG AND EAST OF A KCKB TO KCRW LINE.
THESE WILL LAST THROUGH AROUND 14-16Z...WHEN GRADUAL LIFTING TO
LOW VFR IS EXPECTED. STILL SOME SCATTERED SHOWERS/ISOLD
THUNDERSTORMS EXPECTED THRU 00Z AS A COLD FRONT APPROACHES THE
REGION...WITH BRIEF MVFR CONDITIONS IN VICINITY.
AFTER 00Z...AREAS THAT CLEAR WILL SEE IFR FOG DEVELOPING AFTER
06Z. MOUNTAIN TAF SITES SUCH AS AT KEKN OR KBKW WILL SEE EITHER
LOW STRATUS LINGERING...OR FOG.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: DEVELOPMENT OF LOW STRATUS/FOG OVERNIGHT MAY
VARY FROM CURRENT FORECAST. TIMING OF FRONT AND SHRA TONIGHT MAY
VARY. DEVELOPMENT OF FOG AND/OR LOW STRATUS TONIGHT MAY VARY FROM FORECAST.
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 THU 08/01/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H L L L L L L H H H M
HTS CONSISTENCY M H L L L L L M H H H M
BKW CONSISTENCY H M M M H H H H H H H M
EKN CONSISTENCY H H M M M H H H H H H H
PKB CONSISTENCY H H H L L L M H H H H M
CKB CONSISTENCY H H H M M L H M H H H M
AFTER 06Z FRIDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS LATE FRIDAY THROUGH
SATURDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...SL/30
SHORT TERM...RPY
LONG TERM...RPY
AVIATION...SL
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1117 PM CDT WED JUL 31 2013
.DISCUSSION...
LOOK FOR VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR
THE NEXT 24 HOURS. AVIATION BELOW HAS DETAILS.
&&
.AVIATION...
MODELS THIS CYCLE INDICATE NO NEED TO DEVIATE FROM THE PREVIOUS
TERMINAL FORECAST. SURFACE WINDS WILL BE LIGHT AND VARIABLE FOR
THE NEXT 24 HOURS.
HUBER
&&
.PREV DISCUSSION... /ISSUED 913 PM CDT WED JUL 31 2013/
UPDATE...
REMOVING EVENING RAIN CHANCES.
DISCUSSION...
STORMS HAVE NEARLY DISSIPATED AT 9 PM THIS EVENING...WITH ONLY A
FEW SHOWERS NORTH OF STERLING CITY. WITH LOSS OF HEATING...DO NOT
EXPECT REGENERATION DESPITE A WEAK SURFACE TROUGH ACROSS THE
REGION. LOW IN THE MID 70S LOOK GOOD.
04
PREV DISCUSSION... /ISSUED 632 PM CDT WED JUL 31 2013/
DISCUSSION...
LOOK FOR VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR
THE NEXT 24 HOURS. SEE AVIATION BELOW FOR DETAILS.
AVIATION...
/THIS AFTERNOON AND EARLY EVENING/
.ISOLATED THUNDERSTORMS WITH POSSIBLE DOWNBURSTS...
A SURFACE BOUNDARY EXTENDING ALONG OR NEAR INTERSTATE 20 WILL
CONTINUE TO BE A FOCUS FOR SHOWERS AND THUNDERSTORM DEVELOPMENT
THIS AFTERNOON. WITH LITTLE IF ANY UPPER-LEVEL
SUPPORT...THUNDERSTORMS WILL BE SHORT LIVED. THE FREEZING LEVEL IS
AROUND FOURTEEN THOUSAND FEET ABOVE GROUND LEVEL. THUS...THE HAIL
THREAT IS VERY LOW. HOWEVER...MODEL FORECAST SOUNDING AT SEVERAL
LOCATIONS ACROSS WEST CENTRAL TEXAS INDICATE THE POTENTIAL FOR
DOWNBURST WINDS. THUS...I BELIEVE THAT IS THE PRIMARY THREAT THIS
AFTERNOON AND EVENING. WATCH FOR THUNDERSTORMS TO DISSIPATE AROUND
SUNSET. GIVEN THE ISOLATED NATURE OF THUNDERSTORMS...I DECIDED NOT
TO INCLUDE ANY THUNDER IN ANY OF OUR TERMINALS.
HUBER
/OVERNIGHT AND TOMORROW/
.VFR CONDITIONS WITH LIGHT AND VARIABLE WINDS...
MODELS INDICATE HIGH PRESSURE WILL CONTINUE TO DOMINATE THE REGION
FOR THE NEXT 24 HOURS. THEREFORE...EXPECT SURFACE WINDS TO BE
MAINLY LIGHT AND VARIABLE THROUGH TOMORROW AFTERNOON.
HUBER
PREV DISCUSSION... /ISSUED 346 PM CDT WED JUL 31 2013/
SHORT TERM...
A WEAK COLD FRONT WAS SITUATED ROUGHLY ALONG THE I-20 CORRIDOR THIS
AFTERNOON. THIS FRONT IS EXPECTED TO DROP A BIT FARTHER SOUTH INTO
NORTHERN PORTIONS OF THE CONCHO VALLEY AND HEARTLAND BEFORE STALLING
OUT TONIGHT. THE FRONT WILL BECOME MORE DIFFUSE ON THURSDAY AND
SHOULD WASH OUT ACROSS THE AREA BY AFTERNOON. AS OF 3 PM...ISOLATED
CONVECTION HAS FORMED JUST AHEAD OF THE FRONT OVER SOUTHERN PORTIONS
OF THE BIG COUNTRY. WILL KEEP ISOLATED CONVECTION IN THE FORECAST
THROUGH EARLY EVENING WITH ACTIVITY EXPECTED TO DISSIPATE AFTER
SUNSET WITH LOSS OF HEATING.
CONVECTION HAS ALSO DEVELOPED ACROSS THE HIGHER TERRAIN IN EASTERN
NEW MEXICO THIS AFTERNOON. LATEST NAM AND HRRR INDICATE THAT THIS
ACTIVITY MAY MAKE A RUN AT OUR WESTERN COUNTIES TOWARDS DAYBREAK
THURSDAY AS IT WEAKENS. NOT CONFIDENT THAT THIS WILL HAPPEN SO KEPT
THE FORECAST DRY OVERNIGHT. DRY AND HOT CONDITIONS CONTINUE THURSDAY
AFTERNOON WITH HIGHS 99 TO 102 AND HEAT INDICES 102 TO 105 DEGREES.
24
LONG TERM...
HOT AND DRY CONDITIONS WILL DOMINATE THE WEATHER ACROSS WEST CENTRAL
TEXAS FROM FRIDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. THE
SURFACE HIGH THAT IS CURRENTLY CENTERED OVER NEW MEXICO WILL
REPOSITION ITSELF OVER TEXAS THROUGH AT LEAST THE NEXT 7 DAYS. THIS
WILL RESULT IN NEAR NIL RAIN CHANCES...WITH HIGH TEMPERATURES
RANGING FROM 98 TO 103...WHILE OVERNIGHT LOWS FALL INTO THE MID AND
UPPER 70S. VERY LITTLE RELIEF IN THE HOT AND DRY PATTERN IS EXPECTED
THROUGH THE NEXT 7 DAYS...AND POSSIBLY BEYOND...AS THE UPPER LEVEL
HIGH REMAINS PARKED OVER THE LONE STAR STATE.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 76 100 75 101 75 / 5 5 0 0 0
SAN ANGELO 75 101 75 101 74 / 5 5 0 0 0
JUNCTION 75 99 73 99 72 / 5 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
24/DANIAELS/HUBER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1023 AM EDT THU AUG 1 2013
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TONIGHT PROVIDING A LIGHT SOUTH FLOW.
COLD FRONT OVER THE GREAT LAKES SWINGS EAST AND GENERATES SHOWERS
AND SCATTERED THUNDERSTORMS OVER NEW ENGLAND LATER THURSDAY AND
THURSDAY NIGHT. ASIDE FROM A FEW SPOTTY SHOWERS...DRY WEATHER IS
ON TAP FOR THE WEEKEND AND INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1015 AM UPDATE...
SHOWERS ADVANCING EWD FROM E PA AND NJ. THESE SHOWERS ARE ASSOCD
WITH A MODEST LOW LEVEL JET AND ACCOMPANYING MOISTURE TRANSPORT
WHICH MOVES INTO WESTERN NEW ENG 18-21Z THEN APPROACHES E NEW ENG
BY 00Z. SHOWERS WILL BE MOVING INTO WESTERN ZONES THIS
AFTERNOON WITH SCT ACTIVITY POSSIBLE IN EASTERN NEW ENG TOWARD
EVENING. THE HRRR SUGGESTS THE PRECIP MAY SPLIT LATER TODAY WITH
A CONCENTRATION TO THE N AND A SECOND AREA MOVING INTO CT FROM
THE S. AND THE NAM OMEGA FIELDS HINT AT THE SAME THING. HIGHEST
POPS THIS AFTERNOON WILL BE ACROSS W ZONES WITH POPS DECREASING
EWD. PWATS INCREASING TO 1.50-1.75" SO LOCALLY HEAVY RAINFALL
POSSIBLE IN THE WEST.
SBCAPES ARE MINIMAL TO NIL THROUGH TODAY...BUT GUIDANCE IS
INDICATING SOME ELEVATED INSTABILITY MOVING INTO W ZONES LATER
THIS AFTERNOON...SO WE HAVE A CHC THUNDER HERE.
SUNSHINE WILL GIVE WAY TO INCREASING CLOUDS FROM WEST TO EAST.
MADE NO CHANGES TO TEMPS...RANGING FROM MID/UPPER 70S WEST TO
LOWER 80S EAST.
PREVIOUS DISCUSSION...
01/00Z GUIDANCE IS IN EXCELLENT AGREEMENT WITH THEIR OVERALL
SYNOPTIC PATTERNS. AS SUCH...USED THE CONSENSUS TIMING AS A GUIDE.
DID SLOW THE ARRIVAL OF RAINFALL THIS MORNING BASED ON UPSTREAM
RADAR DATA AND EXPECTED TIMING OF SYNOPTIC FEATURES.
WATER VAPOR IMAGERY SHOWING A POTENT MID-LEVEL SHORTWAVE OVER THE
GREAT LAKES. THIS SHORTWAVE WILL BE ONE OF THE FEATURES ARRIVING
LATER TODAY TO CONTRIBUTE TO DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS. STRONG UPPER LEVEL JET WILL PROVIDE PLENTY OF
VENTING LATE TODAY. CLOSER TO THE GROUND...EXPECTING EFFECTIVE
BULK SHEAR VALUES OF 25-30 KT. LOW-LEVEL LAPSE RATES ARE PROJECTED
TO BE NEAR MOIST ADIABATIC. AS SUCH...EXPECTING MORE SHOWERS THAN
THUNDERSTORMS. HOWEVER...THERE IS AT LEAST A POTENTIAL FOR
STRONGER TO POSSIBLE SEVERE THUNDERSTORMS. LATE TODAY.
THE BIGGER CONCERN WILL BE FOR LOCALLY HEAVY RAINFALL WITH
PRECIPITABLE WATER VALUES RISING INTO THE 1.5-2.0 INCH RANGE.
SHEAR VECTORS DO INDICATE STORMS SHOULD MOVE THIS AFTERNOON...SO
THE CONCERN WOULD BE PRIMARILY URBAN AND POOR-DRAINAGE AREAS.
SEASONABLE TEMPERATURES EXPECTED...AS REPRESENTED BY A BLEND OF
THE MOS GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
UPPER LOW OVER HUDSON BAY IS EXPECTED TO MOVE A NEGATIVELY-TILTED
TROUGH ACROSS SOUTHERN NEW ENGLAND TONIGHT. THIS WILL CONTRIBUTE
TO AN OVERALL SLOWING OF INDIVIDUAL CELL MOTION...FURTHER
ENHANCING THE RISK OF HEAVY RAINFALL. 01/00Z GUIDANCE IS QUITE
CONSISTENT MOVING THE STRONGEST OF THE FORCING MECHANISMS OFF THE
COAST SHORTLY AFTER MIDNIGHT. THAT SAID...THERE ARE STILL PLENTY
OF SYNOPTIC LIFTING MECHANISMS TO KEEP AT LEAST A CHANCE OF
SHOWERS IN THE FORECAST THROUGH MOST OF THE NIGHT. SHOWERS SHOULD
END FROM WEST TO EAST LATE TONIGHT INTO FRIDAY.
GRADUAL CLEARING FROM WEST TO EAST DURING THE DAY FRIDAY.
SEASONABLE TO SLIGHTLY ABOVE NORMAL TEMPERATURES. USED A BLEND OF
THE MOS GUIDANCE ONCE AGAIN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGHLIGHTS...
* EXTENDED PERIOD OF MOSTLY DRY...SEASONABLE WEATHER
* FEW SHOWERS EXPECTED SUNDAY
* NEXT CHANCE OF WIDESPREAD RAIN TUE INTO WED
OVERVIEW AND MODEL PREFERENCES...
01/00Z MODEL GUIDANCE SUITE CONTINUES TO SHOW DECENT SYNOPTIC
SCALE AGREEMENT THROUGH THE MEDIUM RANGE BUT THEN STRUGGLE WITH A
SERIES OF CUTOFF LOW PRESSURES WHICH WILL FUJIWHARA THROUGH A
BROAD TROF IN ONTARIO AND QUEBEC. DESPITE THE SYNOPTIC AGREEMENT
IN THE MEDIUM RANGE...THERE ARE STILL SOME SMALLER SCALE ISSUES TO
RESOLVE REGARDING A SERIES OF SHORTWAVES WHICH WILL SLIDE THROUGH
THE BASE OF THE TROF AND INTO NEW ENGLAND THROUGH THE WEEKEND.
RECENT TREND IN GUIDANCE IS TO SUGGEST A HIGHER CHANCE FOR -SHRA
SAT AND SAT NIGHT AS INITIAL WAVE AND ATTENDANT COLD FRONT SLIDES
NEAR THE REGION. HOWEVER...THEY DISAGREE ON THE AXIS OF QPF...THE
NAM ON THE NRN EDGE OF THE SOLUTION ENVELOPE AND THE ECMWF ON THE
SRN END. FEEL THE MORE SRN SOLUTION IS BEST GIVEN THAT THERE IS A
SECOND AND STRONGER WAVE PROJECTED TO SLIDE THROUGH THE REGION ON
SUN. THEREFORE...WILL BE ERRING AWAY FROM THE NAM SOLUTION FOR
THIS UPDATE WITH A CONTINUED ECMWF/GFS DETERMINISTIC BLEND THROUGH
THE WEEKEND AND EARLY NEXT WEEK.
FOR THE TUE AND MID WEEK TIMEFRAME GUIDANCE CONTINUES TO STRUGGLE
BETWEEN A SERIES OF CUTOFF LOW PRESSURES MOVING THROUGH A BROAD
TROF IN ONTARIO AND QUEBEC...AND A BUILDING RIDGE OVER THE SRN
CONUS. THE RESULT IS A NEARLY ZONAL MEAN JET ACROSS NEW ENGLAND.
EXPECT A DRY HIGH PRES TO START...BUT THERE ARE SERIOUS TIMING AND
STRENGTH DIFFERENCES IN THE PASSAGE OF SHORTWAVES THROUGH THIS
JET. AM NOTING LOW AND MID LVL FLOW IS GENERALLY W TO NW THROUGH
MON THROUGH EARLY WED...SO A MAINLY DRY FORECAST LOOKS BEST...BUT
THEN WILL INCREASE TO SLIGHT/CHANCE POPS FOR THE WED- THU
TIMEFRAME DUE TO THE POTENTIAL PASSAGE OF A SERIES OF WAVES. AS
MENTIONED EARLIER THOUGH...THIS WILL LIKELY NOT BE A WASHOUT THE
ENTIRE TIME GIVEN THE DIFFICULTY GUIDANCE IS HAVING IN RESOLVING
THE SHORTWAVES.
DETAILS...
THIS WEEKEND...
BROAD TROUGH WITH AXIS THROUGH NEW ENGLAND WILL ALLOW FOR A
SERIES OF FAST MOVING SHORTWAVES AND THEIR ATTENDANT SFC FRONTS TO
CROSS THE REGION. WITH LESS OVERALL MOISTURE THANKS TO W LOW-MID
LVL FLOW...AND HIGH PRES ATTEMPTING TO RIDGE OVER THE REGION FROM
THE SW. EXPECTING ONLY -SHRA ACTIVITY WITH BEST CHANCES LATE DAY
SAT AND AGAIN LATE DAY SUN...DURING THE TIMING OF PEAK VORT MAX
PASSAGE. TEMPS WILL BE NEAR TO SLIGHTLY COOLER THAN NORMAL...WITH
LIKELY PARTLY TO MOSTLY CLOUDY SKIES.
MON INTO TUE...
HIGH PRES BEGINS TO BUILD OVER THE REGION FROM THE W DESPITE TROF
THROUGH NRN NEW ENGLAND AND SRN CANADA. THE COMBINATION OF W-NW
FLOW AND SUBSIDENCE SHOULD YIELD A MOSTLY DRY FORECAST. TEMPS
WILL LIKELY CONTINUE TO LEAN ON THE COOL SIDE OF NORMAL.
WED INTO THU...
WILL TRANSITION FROM DRY TO UNSETTLED AND POTENTIALLY WET FOR
THIS PORTION OF THE EXTENDED. NOT EXPECTING A WASHOUT...BUT THE
THREAT FOR SOME RAIN...AND POSSIBLY EVEN A FEW THUNDERSTORMS ARE
POSSIBLE GIVEN THE INITIAL RETURN FLOW. AS MENTIONED BY PREVIOUS
FORECASTER...WILL NEED TO WATCH THIS TIME PERIOD CLOSELY...BECAUSE
OF THE POTENTIAL CONVECTIVE NATURE OF THE PRECIPITATION.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN TAFS FOR MOST OF THE DAYLIGHT HOURS. MODERATE
CONFIDENCE IN TIMING OF LOWER CONDITIONS TONIGHT.
GENERALLY VFR THROUGH THE DAYLIGHT HOURS. LOOKS LIKE A MID
MORNING TO EARLY AFTERNOON SEA BREEZE IS LIKELY UNTIL WINDS SHIFT
MORE TO THE SOUTH. CLOUDS INCREASE THROUGH THE DAY. POTENTIAL FOR
SHOWERS/SCT TSTMS INCREASES THIS AFTERNOON AND EVENING...HIGHEST
VALUES WEST.
TONIGHT...MVFR/IFR CIGS/VSBYS IN SHOWERS AND SCATTERED TSTMS.
HEAVY DOWNPOURS LIKELY...AND AREAS OF FOG POSSIBLE. COLD FRONT
MOVES THROUGH LATE TONIGHT WITH WINDS SHIFTING TO NORTHWEST.
CIGS/VSBYS SHOULD IMPROVE WITH THE WIND SHIFT.
FRIDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS POSSIBLE IN
RAIN...MAINLY EASTERN MA EARLY. CONDITIONS IMPROVE TO VFR THROUGH
THE DAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF...ESPECIALLY TRENDS. ANOTHER
SOUTHEAST SEABREEZE EXPECTED MID MORNING INTO THIS AFTERNOON.
SHOWERS APPROACH FROM THE WEST LATE IN THE DAY. TIMING OF LOWER
CONDITIONS MAY BE OFF BY A COUPLE OF HOURS EITHER SIDE OF 02/06Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. TIMING OF SHOWERS AND
LOWER CONDITIONS MAY BE OFF BY A COUPLE OF HOURS EITHER SIDE OF
02/00Z
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...
FRIDAY NIGHT THROUGH SUNDAY...MODERATE TO HIGH CONFIDENCE. MAINLY
VFR. LOW PROBABILITY OF BRIEF MVFR/IFR CONDITIONS IN ISOLATED TO
SCATTERED SHOWERS.
MONDAY...HIGH CONFIDENCE VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
SOUTH TO SOUTHWEST WINDS INCREASE TODAY AHEAD OF A COLD FRONT. THE
MAIN IMPACT WILL BE TO GRADUALLY INCREASE SEAS ACROSS THE SOUTHERN
COASTAL WATERS. WHILE WINDS AND WIND GUSTS SHOULD REMAIN LESS
THAN 25 KT OUTSIDE OF THUNDERSTORMS...A SMALL CRAFT ADVISORY MAY
EVENTUALLY BE NEEDED FOR 5 FT SEAS FRIDAY. THE SOUTHERN OUTER
COASTAL WATERS WOULD BE MOST AT RISK.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...
HIGH CONFIDENCE.
SEAS UP TO 5 FEET ON THE OUTER WATERS FRIDAY NIGHT INTO EARLY
SATURDAY WILL GRADUALLY DIMINISH AS HIGH PRESSURE BUILDS OVER THE
WATERS. WESTERLY WINDS WILL REMAIN BELOW 25 KTS FOR THE MOST PART.
&&
.CLIMATE...
THESE ARE THE LATEST STANDINGS FOR THE JULY AVERAGE TEMPERATURE.
ALL 4 OF THE MAJOR CLIMATE SITES FINISHED IN THE TOP 5.
BOSTON /LOGAN AIRPORT/
1. 78.0 IN 1983
2. 77.5 IN 1994 AND 1952
3. 77.3 IN 2011
4. 77.2 IN 2010 AND 1955
5. 77.1 IN 2013 AND 1911
PROVIDENCE /TF GREEN AIRPORT/
1. 78.4 IN 2013
2. 77.5 IN 2010
3. 76.6 IN 1983
4. 76.5 IN 1999
5. 76.4 IN 2008
HARTFORD/WINDSOR LOCKS /BRADLEY/
1. 77.9 IN 2013
2. 77.1 IN 2010 AND 1994
3. 77.0 IN 1955
4. 76.8 IN 1949
5. 76.5 IN 2006...1999 AND 1995
WORCESTER /AIRPORT/
1. 75.9 IN 1911
2. 74.3 IN 1952 AND 1901
3. 74.2 IN 1949
4. 74.1 IN 2013
5. 74.0 IN 2010
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/DOODY
NEAR TERM...BELK/KJC
SHORT TERM...BELK
LONG TERM...DOODY
AVIATION...BELK/DOODY
MARINE...BELK/DOODY
CLIMATE...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1022 AM EDT THU AUG 1 2013
.SYNOPSIS...
UNSETTLED WEATHER RETURNS THIS AFTERNOON...AS A LOW
PRESSURE SYSTEM...AND ASSOCIATED FRONTAL BOUNDARIES APPROACH FROM
THE GREAT LAKES REGION AND MID ATLANTIC REGION. THIS WILL BRING
WIDESPREAD SHOWERS TO THE REGION FOR THIS AFTERNOON AND EVENING.
DRIER WEATHER IS EXPECTED ON FRIDAY AS A WEAK RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1015 PM EDT...THE LATEST REGIONAL MOSAIC RADAR AND SATELLITE
IMAGERY SHOWS THE CLOUDS AND SHOWERS HAVE INCREASED RAPIDLY OVER
CNTRL NY AND NE PA. THE CLOUDS HAVE OVERSPREAD ERN NY AND WRN NEW
ENGLAND WITH LITTLE ADDITIONAL HEATING EXPECTED. SOME MAX TEMPS
WERE ALREADY REACHED ACROSS PORTIONS OF SRN VT...AND ERN NY. SOME
SLIGHT ADJUSTMENTS UPWARD WERE MADE FOR A FEW MORE HOURS BEFORE
THE SHOWERS ARRIVE.
THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT AND THE LOCAL WRF SHOWS
THE SHOWERS BECOMING MORE WIDESPREAD FROM SW TO NE OVER THE FCST
ARE BETWEEN NOON AND 3 PM. THE STEADIER SHOWERS SHOULD PERSIST INTO
THE EARLY EVENING...WHERE A FEW THUNDERSTORMS MAY POP UP NEAR THE
OCCLUDED FRONT TO CONNECTING THE CYCLONE NEAR THE ERN GREAT
LAKES...AND THE SFC WAVE OVER THE MID ATLANTIC REGION. ISENTROPIC
LIFT AHEAD OF THE BOUNDARY MAY YIELD POCKETS OF MODERATE TO HVY
RAINFALL. THE THE RIGHT REAR QUAD OF AN H250 JET STREAK WILL ALSO
ENHANCE THE RAIN A BIT.
IN ADDITION TO THE ISENTROPIC LIFT...STRONG A THETA E RIDGE BUILDS
ACRS THE REGION H10-H8 WITH PWATS INCREASING TO ABOVE 1.5 INCHES.
HAVE LIKELY TO CAT POPS ACRS THE REGION THIS AFTERNOON. THE TIMING
WAS TWEAKED SLIGHTLY. MAX TEMPS WILL RANGE FROM THE U60S TO M70S
ACROSS MOST OF THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
FOR TONIGHT...HEAVIEST RAIN EXPECTED DURING THE FIRST HALF OF THE
NIGHT AS AXIS OF HIGH PWATS AND THETA E RIDGE SHIFTS EAST OF FA
AFT 06Z. HAVE ALSO PLACED SLIGHT CHANCE OF TSTMS IN GRIDS AS
SHOWALTER INDICES BRIEFLY GO NEGATIVE THIS EVENING DESPITE SB
CAPES ONLY REACHING A FEW HUNDRED J/KG. EXPECT LOWS TONIGHT TO
RANGE FROM THE MID 50S TO LOWER 60S.
FRIDAY AND FRIDAY NIGHT EXPECT GENERALLY DRY CONDITIONS AS A WEAK
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION ON FRIDAY AND SLIDES
EAST FRIDAY NIGHT. HAVE KEPT LOW CHANCE POPS ACRS NORTHWEST THIRD
OF FA DURING THESE PERIODS AS CANNOT RULE OUT SOME SHOWERS OFF
EAST END OF LAKE ONTARIO INTO THIS AREA WITH FAIRLY GOOD COLD POOL
ALOFT. HIGHS ON FRIDAY ARE EXPECTED TO BE IN THE 70S TO LOWER 80S
WITH LOWS FRIDAY NIGHT IN THE 50S.
ON SATURDAY EXPECT SCATTERED SHOWERS AHEAD OF A SECOND COLD FRONT
WITH THE HIGHEST POPS ACROSS THE NORTHERN MOUNTAINS. SB CAPES ARE
FAIRLY LOW GENERALLY 200-500 J/KG WITH SHOWALTER INDICES REMAINING
POSITIVE THROUGHOUT SATURDAY AND SATURDAY NIGHT. SO WILL LEAVE ANY
MENTION OF THUNDER OUT AT THIS TIME. EXPECT HIGHS ON SATURDAY TO
BE IN THE 70S TO LOWER 80S WITH LOWS SATURDAY NIGHT RANGING FROM
THE UPPER 40S NORTHWEST TO UPPER 50S SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE EXTENDED FORECAST FEATURES A MEAN LONGWAVE TROUGH INFLUENCING
THE SENSIBLE OVER THE NORTHEAST. THE TROUGH WILL KEEP TEMPS SLIGHTLY
COOLER THAN NORMAL WITH INTERMITTENT DISTURBANCES IMPACTING NY AND
NEW ENGLAND IN THE W/NW FLOW ALOFT. THE 00Z/01 HPC GUIDANCE WAS
FOLLOWED CLOSELY.
SUNDAY-MONDAY NT...THE UPPER LEVEL TROUGH REMAINS QUITE AMPLIFIED
DURING THIS TIME FRAME...WITH EMBEDDED UPPER LEVEL IMPULSES DROPPING
SOUTHEAST INTO THE REGION. THESE OCCASIONAL BOUTS OF
SYNOPTIC/DYNAMICAL LIFT...COMBINED WITH ADDED LAKE MOISTURE...SHOULD
ALLOW FOR ISOLATED TO SCATTERED SHOWERS TO OCCUR SUNDAY...ESP IN THE
AFTERNOON...THEN AGAIN MONDAY...PARTICULARLY ACROSS THE SOUTHERN
ADIRONDACKS...SOUTHERN VT AND NW MA...WHERE LOW CHC POPS ARE
INDICATED...WITH SLIGHT CHC POPS EXTENDING FURTHER SOUTH. IT WILL BE
QUITE BREEZY SUNDAY GIVEN A FAIRLY TIGHT PRESSURE GRADIENT BETWEEN
THE LOW ACROSS SOUTHEAST CANADA...AND HIGH PRESSURE ACROSS THE GREAT
LAKES REGION. TEMPS WILL REMAIN BELOW NORMAL...WITH SUNDAY MAXES
GENERALLY ONLY IN THE LOWER/MID 70S IN VALLEYS FROM ALBANY N AND
W...AND 75-80 SOUTH OF ALBANY...WITH HIGHER ELEVATIONS ACROSS
THE SOUTHERN ADIRONDACKS AND WESTERN NEW ENGLAND ONLY REACHING THE
60S. FOR SUN NT/MON AM...EXPECT WIDESPREAD 40S ACROSS THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND...AND ALSO WITHIN PORTIONS OF
THE EASTERN CATSKILLS/SCHOHARIE VALLEY AND LAKE GEORGE/SARATOGA
REGION...WITH LOWER/MID 50S ELSEWHERE. ON MONDAY...MAXES MAY WARM
SLIGHTLY...WITH GENERALLY 75-80 IN VALLEYS...AND UPPER 60S TO LOWER
70S ACROSS HIGHER ELEVATIONS.
TUE-WED...MODELS DIFFER ON TIMING OF STRONGER UPPER LEVEL IMPULSES
APPROACHING FROM THE WEST...AND ALSO THE AMOUNT OF INCREASING LOW
LEVEL MOISTURE FROM THE SOUTHWEST. HOWEVER...GENERAL CONSENSUS AT
THIS TIME RANGE IS FOR AN INCREASED CHANCE FOR SHOWERS...WITH LOW
CHC POPS INDICATED. TEMPS ARE FORECAST TO REACH THE 70S IN
VALLEYS...AND 60S ACROSS HIGHER ELEVATIONS FOR MAXES...AND GENERALLY
50S TO LOWER 60S IN VALLEYS...AND LOWER 50S FOR HIGHER ELEVATIONS
FOR MINS. SHOULD SHOWERS OR A STEADIER RAINFALL OCCUR ON ANY OF
THESE DAYS...EVEN COOLER MAX TEMPS COULD OCCUR.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AFTER ANY PATCHES OF MIST BURN OFF AND ASSOCIATED MVFR VSBYS AT KGFL
AND KPSF LIFT BTWN 12Z-14Z/THU...VFR CONDITIONS WILL THEN OCCUR FROM
SUNRISE THROUGH LATE MORNING...BEFORE LOWERING INTO THE MVFR RANGE
FOR VSBYS/CIGS AS SHOWERS OR A PERIOD OF STEADY RAIN OVERSPREADS THE
TAF SITES BETWEEN 16Z-18Z. SOME EMBEDDED PERIODS OF IFR CIGS/VSBYS
COULD OCCUR WITHIN ANY HEAVIER RAIN ELEMENTS...ESP AT KPSF AND KPOU
WHICH WILL BE CLOSER TO WARM RAIN PROCESSES AND POTENTIAL SMALLER
DROPLET SIZE AND LOWER CIGS. THE STEADIEST RAIN SHOULD PERSIST MOST
OF THE AFTERNOON.
THE RAIN AND/OR SHOWERS SHOULD BECOME MORE SCATTERED AFTER
23Z/THU...AND SHOULD TAPER OFF FROM W TO E BETWEEN 00Z-04Z/THU.
HOWEVER...VERY MOIST CONDITIONS BEHIND A WIND SHIFT SHOULD CREATE
WIDESPREAD LOW MVFR TO IFR CIGS/VSBYS...ESP AT KGFL/KPSF/KPOU.
THERE IS A SLIGHT CHANCE FOR EMBEDDED THUNDERSTORMS THIS AFTERNOON
AND EVENING...BUT OVERALL PROBABILITY FOR ANY IMPACTING A TAF SITE
WILL BE RATHER LOW...SO WILL KEEP OUT MENTION IN TAFS AT THIS TIME.
SOUTH WINDS WILL INCREASE AFTER 14Z/THU TO 8-12 KT...WITH SOME
GUSTINESS DEVELOPING...ESP AT KALB WHERE GUSTS OF 25 KT OR SLIGHTLY
HIGHER COULD OCCUR. SOUTH WINDS SHOULD DECREASE THIS EVENING INTO
THE OVERNIGHT HOURS TO 5-10 KT...WITH WINDS GRADUALLY VEERING INTO
THE SOUTHWEST TO WEST TOWARD OR AFTER 04Z/FRI.
LOW LEVEL WIND SHEAR WILL DEVELOP AT KGFL/KPOU AND KPSF THIS
AFTERNOON AS WINDS AROUND 2000 FT AGL INCREASE FROM THE SOUTH AT
30-35 KT...WHILE SFC WINDS REMAIN GENERALLY UNDER 12 KT. AT
KALB...ENOUGH MIXING SHOULD ALLOW STRONGER WINDS TO TRANSFER
DOWNWARD AT TIMES...REDUCING LOW LEVEL WIND SHEAR POTENTIAL.
OUTLOOK...
FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
MONDAY: LOW OPERATIONAL IMPACT.BREEZY ISOLATED SHRA.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED CONCERNS ARE EXPECTED AT THIS TIME.
UNSETTLED WEATHER RETURNS TODAY AS A LOW PRESSURE SYSTEM...AND
ASSOCIATED FRONTAL BOUNDARIES APPROACH FROM THE GREAT LAKES REGION
AND THE OHIO VALLEY. THIS WILL BRING WIDESPREAD SHOWERS TO THE
REGION FOR THIS AFTERNOON AND EVENING. DRIER WEATHER IS EXPECTED
ON FRIDAY AS A WEAK RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION
WITH MORE SCATTERED SHOWERS EXPECTED OVER THE WEEKEND.
&&
.HYDROLOGY...
SOME LOCALLY HEAVY RAINFALL IS EXPECTED THIS AFTERNOON INTO THIS
EVENING WITH THE HEAVIEST AMOUNTS EXPECTED TO FALL ACROSS THE
EASTERN CATSKILLS AND SOUTHERN ADIRONDACKS. TOTAL RAINFALL AMOUNTS
ARE GENERALLY EXPECTED TO BE BETWEEN 0.75 AND 1.5 INCHES WITH
LOCALLY HIGHER AMOUNTS POSSIBLE IN WIDELY SCATTERED THUNDERSTORMS
THIS EVENING. WHILE THESE AMOUNTS WILL NOT BE ENOUGH TO PRODUCE
ANY WIDESPREAD FLOODING...PONDING OF WATER ON ROADWAYS AND
LOCALIZED FLOODING OF POORLY DRAINED LOW LYING AREAS IS POSSIBLE.
DRIER WEATHER IS EXPECTED ON FRIDAY AS A WEAK RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION. MORE UNSETTLED WEATHER IS
EXPECTED OVER THE WEEKEND WITH SCATTERED SHOWERS BOTH SATURDAY AND
SUNDAY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...KL/WASULA
FIRE WEATHER...11
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
634 AM CDT Thu Aug 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CDT THU AUG 1 2013
Water vapor imagery and 08z RAP analysis shows the H5 ridge over the
desert southwest with a well developed deep trough over the Hudson
Bay. Between these two features northwest flow continues over the
forecast area, with roughly 30 to 40 knots of flow at 500 mb. At the
surface the ridge axis runs from NW to SE across the forecast area,
which is helping to reduce flow at the surface, bringing calm
morning conditions. Through the remainder of the morning a few areas
of patchy fog will form as radiational cooling will be enhanced by
low surface flow and mostly clear skies. Passing cirrus will help
retain some heat at the surface, preventing widespread dense fog,
but considering the moist low levels from recent rain and calm, cool
conditions there will be a marginal fog threat through the remainder
of the morning hours.
Radar trends indicate that a few showers have formed across central
Nebraska, and are moving east/southeastward into south central
Nebraska. The best isentropic/warm air advection upglide can be
found on a decently deep layer between 305 and 315 K Theta E
surfaces. Forecast soundings show about 500 to 1000 J/Kg of elevated
instability above the 700 mb layer, so any parcels that get lifted
to that level will have a chance to form into scattered
thunderstorms later today. The best chance for that scattered
T-storm development will be mainly across central Nebraska,
southward into far northern Kansas, where the best isentropic
upglide persists. Clouds will likely build in, especially north of
Interstate 70, so have gone with a slightly cooler temperature
forecast for the far northern row of counties, but should rain
develop in that area temps may struggle to reach the forecast highs
in the lower to middle 80s.
Warm air advection will continue through the evening and overnight
hours on Thursday night, and as the deeper moisture makes its way
into northeast Kansas the coverage and intensity of the rain showers
will pick up . Expect widespread rain/thunderstorm activity,
especially north of Interstate 70 by early Friday morning, with
perhaps some showers and thunderstorms further south, toward the
Interstate 35 corridor.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 336 AM CDT THU AUG 1 2013
Friday/Saturday...Expect some thunder to be ongoing Friday as
complex forecast to roll off the high plains across Nebraska then
into eastern Kansas along the thermal gradient and on the nose of
the LLJ. enough instability and shear to make strong to severe
storms possible...as well as steep lapse rates in the low levels
contributing to potential wind threat. despite the dry layer,
precipitable water values over the area remain in the 1.5 to 2
inch range, and must therefore also consider heavy rainfall a
possibility. Storm chances slowly shift eastward into sunrise on
Saturday, and may be able to catch a break during the day
Saturday. Will carry only an isolated pop given boundary resides
right over the forecast area and can`t rule out precip for good
just yet.
Sun/Mon...Stronger and more significant shortwave trof forecast
to come off the central Rockies and into eastern Kansas on Sunday.
Will carry high chance pops and cooler temperatures to reflect
this. subsidence behind this wave may temper precip chances on
Monday and have kept a decrease that time period.
Tues/Wed...Area remains under NW flow aloft with series of waves
dropping surface high pressure into our area early to mid week
next week. If this pattern verifies we would stay cooler than
normal with above average precipitation possible.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING)
ISSUED AT 626 AM CDT THU AUG 1 2013
Expect morning fog near the aviation terminals to gradually clear
out as the sun rises. After that expect mostly VFR conditions at
the terminals. There is some uncertainty regarding afternoon
showers and thunderstorms. Generally they are expected to remain
north of the terminals, near the KS/NE border, however a few
showers may form along Interstate 70, perhaps putting the
terminals in play for afternoon showers. The best chance for rain
near the TAF site will be at KMHK, but even that probability is
low at this time. Will reassess shower potential with upcoming
issuance or with AMD should the need arise.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Leighton
LONG TERM...67
AVIATION...LEIGHTON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
607 AM CDT Thu Aug 1 2013
...Updated aviation discussion...
.SYNOPSIS...
ISSUED AT 410 AM CDT THU AUG 1 2013
The 00 utc Thursday objective upper air analysis showed an upper
anticyclone across western TX/eastern NM with an 80 knot jet streak
exiting central Kansas on the east side of the upper ridge. Based
on the 00 utc upper air sounding in combination with he 700 mb
analysis it appears very little change took place in the mid
levels. however, the same analysis showed a marked up tick in
boundary layer temperature, especially at the 850 mb level where
temperatures warmed an average of 5 to 10 degrees.
Regional mosaic 88d reflectivity shows a couple of areas of
decaying MCS/thunderstorms activity, one across the Texas
panhandle and one across east central Colorado. The KGLD 88D
indicates a convective outflow boundary moving southeast across
west central Kansas.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 410 AM CDT THU AUG 1 2013
The Latest HRRR model shows an increase in convection across west
central Kansas eastward to the highway 283 corridor. The current
meso alpha convective trends from 88d KPUB suggest at least some
thunderstorm activity could make it to extreme western Kansas
between 9 and 12Z. However there is greater conceive inhibition
indicated by the mesoanalysis as well as a decrease in overall
mucape. As a result we`ll minimize precipitation chances this
morning, relegating small chances to those areas generally west of
highway 83.
As warmer air will be in place in the boundary layer today,
temperatures will be considerably warmer, and likely in the mid
90s in most locations. surface winds will veer to the south with
time and increase to 15-20 knots sustained as mixing develops
during the mid to late morning. The consensus of the NAM WRF and
NMM indicate a better chance for another round of thunderstorms
somewhere across the region late in the afternoon and evening.
confidence is low with respect to where any thunderstorms will
occur, but possibilities exist associated with a cluster
associated with a shortwave to the north, and also across central
ks and the far southwest as convection rolls off the higher
terrain again.
.LONG TERM...(Friday through Wednesday)
ISSUED AT 259 AM CDT THU AUG 1 2013
On Friday afternoon the GFS and ECMWF both suggest a weak upper
level wave will move out into the plains with some afternoon
convection being possible near a surface boundary that appears to
extend from west to east across northern Kansas. 850mb warm air
advection still evident along and north of this boundary. We will
therefore retain precipitation chances across north central Kansas
while further south the warm +14/+15c 700mb temperatures and less
moisture will be present which appears to limit precipitation
chance in these locations until possibly early evening when better
instability develops. 850mb temperature trends south of this
boundary continues to support highs warmer than Thursday with the
potential for afternoon highs approaching 100 degrees across
portions of far southwest Kansas. Across north central Kansas the
afternoon temperatures will be more tricky given cloud and
precipitation potential. Given this will stay close to the
previous forecast with highs 7 to near 10 degrees cooler than
southwest Kansas.
A cold front will then move into southwest Kansas on Saturday.
This surface boundary will then remain in western Kansas through
early next week as an upper level trough/low moves out of Canada
and into the the great lakes region. High pressure at the surface
will move out of south central Canada and into the the Ohio
valley. More seasonal temperatures are likely over the weekend
into early next week given the cooler 925-850mb air that is
forecast to return to much of western Kansas. There will also be
chance for convection each day from Saturday through early next
week given the southeasterly upslope flow, higher 925-850mb dewpoints
forecast to be located just east/northeast of this surface
boundary and any subtle upper wave exiting the Rockies and
crossing the plains. Given this potential am unable to improve
much on the latest CRExtendFcst_Init and keep a chance of
precipitation in each period from Sunday into mid week. Warm
nights and seasonal afternoon temperatures also look on track.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 605 AM CDT THU AUG 1 2013
A shallow layer of near surface moisture is forecast to be
present for a few hours this morning. Given this along with the
11z observations will introduce a brief period of 4-5sm br early
this morning. after this vfr conditions are expected as mid- high
level moisture begins to increase from west to east. Precipitation
chances will begin to increase early tonight with the better
opportunity for thunder being in the hays area between 03z and 09z
Friday. South winds will increase to near 20kts by the late
afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 94 70 98 69 / 10 50 10 20
GCK 96 70 97 68 / 20 40 20 20
EHA 97 70 98 68 / 20 40 10 20
LBL 96 71 100 69 / 20 40 20 20
HYS 93 70 93 69 / 20 50 20 30
P28 93 72 97 72 / 10 50 20 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
533 AM CDT THU AUG 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT THU AUG 1 2013
IN THE UPPER LEVELS WE ARE STILL IN GENERALLY NORTHWESTERLY FLOW
WITH A RIDGE LOCATED TO THE WEST CENTERED OVER THE ROCKIES. AT THE
SURFACE WE HAVE HIGH PRESSURE SLIGHTLY TO OUR NORTHEAST WITH A GOOD
TONGUE OF MOISTURE REACHING UP THROUGH THE CENTRAL PLAINS. THIS
MOISTURE IS ALSO APPARENT AT 850HPA WITH DEWPOINTS NEAR 15 DEGREES.
CURRENT KUEX RADAR SHOWS A FEW THUNDERSTORMS ENTERING THE NORTHWEST
PORTION OF OUR CWA. THE RAP MODEL...AND TO SOME DEGREE THE WRF
MODELS...SEEMED TO HAVE THE BEST HANDLE FOR THIS TIME PERIOD WHICH
MAINTAINS CHANCES OF PRECIPITATION FOR THE WESTERN PART OF OUR CWA
INTO THE MORNING.
MAIN CONCERN FOR THIS FORECAST IS CONVECTION AND SEVERE WEATHER
POTENTIAL FOR TODAY. THE SURFACE HIGH WILL MOVE OFF TO THE EAST
AS A LOW DEVELOPS TO THE WEST. AS THE HIGH MOVES OFF...INCREASINGLY
SOUTHERLY FLOW WILL BRING IN MORE MOISTURE WITH AFTERNOON DEW
POINTS IN THE MID TO UPPER 60S. A WARM FRONT WILL LIFT NORTH
ACROSS NEBRASKA REACHING CENTRAL NEBRASKA THIS AFTERNOON. MODELS
ARE INDICATING INSTABILITY INCREASING TO 2000 TO 3000 J/KG ALONG
WITH DEEP LAYER SHEAR OF 40 TO 50 KTS. THESE PARAMETERS ARE
SUFFICIENT FOR SUPERCELL DEVELOPMENT ESPECIALLY IN THE VICINITY OF
THE WARM FRONT. STORMS WHICH DEVELOP WILL BE CAPABLE OF PRODUCING
VERY LARGE HAIL...STRONG WINDS...AND EVEN TORNADOES NEAR THE
BOUNDARY. PRECIPITABLE WATERS THIS AFTERNOON AVERAGE 1.50 INCHES AND ARE
130 PERCENT OF NORMAL. LOCALLY HEAVY RAINFALL IN EXCESS OF AN INCH
OR TWO IS POSSIBLE. CONVECTION THAT DEVELOPS IN THE AFTERNOON AND
EVENING IS EXPECTED TO PERSIST TONIGHT AS THE LLJ IS IN EXCESS OF
40 TO 45 KTS. EVEN WITH THIS POTENTIAL FOR STRONG
STORMS...CONFIDENCE IS STILL NOT HIGH FOR WIDESPREAD
PRECIPITATION AS MODELS ARE NOT CONSISTENT WITH DEVELOPMENT/QPF.
WENT WITH SCATTERED POPS THROUGHOUT THE DAY AND WILL NEED TO MONITOR
THE TREND AS THE DAY PROGRESSES AND CONVECTION UNFOLDS.
TEMPERATURES TODAY ARE DEPENDENT ON CLOUD COVER. GENERALLY WE
SHOULD SEE HIGH TEMPS A FEW DEGREES WARMER THAN YESTERDAY DUE TO
THE INCREASED MIDLEVEL TEMPS. REMAINING CLOUD COVER IN THE MORNING
AND CONVECTION IN THE AFTERNOON MIGHT REDUCE DAYTIME HEATING...BUT
BREAKS IN CLOUD COVER COULD ALLOW TEMPERATURES TO APPROACH THE LOW
90S...ESPECIALLY IN THE SOUTHWEST PART OF THE CWA.
LOWS TONIGHT ARE EXPECTED TO BE IN THE MID TO UPPER 60S IN THE
WARMER AIR MASS. THESE LOW TEMPS ARE NEAR AVERAGE FOR THIS TIME OF
YEAR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 346 AM CDT THU AUG 1 2013
FRIDAY MORNING THROUGH WEDNESDAY. CONCERN CONTINUES TO
REVOLVE AROUND PERIODIC CHANCES FOR RAIN DURING THE ENTIRE EXTENDED
PERIOD.
STARTING OUT FRIDAY MORNING IN THE UPPER LEVELS...MODELS STILL
CONSISTENT IN SHOWING ONE CLOSED LOW OVER THE PACIFIC NORTHWEST AND
ANOTHER ONE OVER NORTHERN ONTARIO. THESE CONTINUE TO DAMPEN THE HIGH
OVER THE SOUTHERN PLAINS. IMPRESSIVE NORTHERN STREAM FOR THIS TIME
OF YEAR WHICH WILL AFFECT THE NORTHERN HALF OF THE CONUS. AT THE
SURFACE...EXPECT LOW PRESSURE OVER SOUTHWEST NEBRASKA WITH A WARM
FRONT EXTENDING SOMEWHERE ACROSS THE CWA. BELIEVE ANY OVERNIGHT
CONVECTION SHOULD HAVE WORKED ITS WAY EAST OF THE CWA BY 12Z FRIDAY
AND WILL TAKE OUT LOW POPS THAT WERE PREVIOUSLY IN THE EASTERN PART
OF OUR AREA. WILL ALSO LEAVE ANY RAIN CHANCES OUT DURING THE DAYTIME
ON FRIDAY AS MOST OF THE CONVECTION THE PAST FEW WEEKS HAS OCCURRED
DURING THE EVENING AND OVERNIGHT TIME FRAME. SHOULD STILL BE IN THE
WARM SECTOR FOR MOST OF THE AREA ON FRIDAY BUT BY SATURDAY THE
SURFACE LOW PUSHES SOUTH AND OUR WINDS BECOME MORE NORTHEASTERLY
WITH SOME COOLER AIR PUSHING IN. HIGHS ON SAT SHOULD BE ABOUT 5
DEGREES BELOW THOSE ON FRIDAY.
AS HAS BEEN NOTED IN PREVIOUS AFDS...TOUGH TO TIME ANY SHORTWAVE
TROUGHS MOVING OVER THE AREA MORE THAN A DAY OR TWO OUT. HOWEVER
BOTH THE LATEST GFS AND EC OPERATIONAL RUNS SIMILAR IN SLIDING ONE
OF THESE WAVES THROUGH THE RIDGE AND OVER US SATURDAY NIGHT. FOR
THIS REASON WILL UP RAIN CHANCES SAT NIGHT AND CONTINUE INTO SUNDAY.
AFTER THAT WE CONTINUE WITH NORTHWEST FLOW AS THE BIG PICTURE POINTS
TO TROUGHING IN THE EAST AND WEST CONUS WITH WEAK RIDGING IN THE
CENTRAL THROUGH AT LEAST THE MIDDLE PART OF NEXT WEEK. THESE LEAVES
US OPEN TO ADDITIONAL DISTURBANCES MOVING THROUGH SO WILL CONTINUE
WITH 20-30 POPS.
IN REGARDS TO SEVERE...DEEP LAYER SHEAR LOOKS FAVORABLE AT LEAST
THROUGH THE WEEKEND WITH 0-6 KM BULK SHEAR PROGGED FROM 25 KT IN
THE SOUTHERN CWA TO 40 KT IN THE NORTH. INSTABILITY ALSO LOOKS OK.
ONE ISSUE THIS TIME OF YEAR IS WILL THERE BE ANY CAPPING TAKING
PLACE. MODELS DO HINT AT THAT AND WILL BE SOMETHING TO WATCH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 528 AM CDT THU AUG 1 2013
CONVECTION CONTINUES TO DEVELOP EARLY THIS MORNING ACROSS PORTIONS
OF WESTERN AND NORTHERN NEBRASKA. THE ACTIVITY IS ISOLATED
ATTM...WITH COVERAGE EXPECTED TO INCREASE TODAY. SCATTERED TSTMS
WILL PERSIST DURING THE DAY WITH HIT OR MISS CHCS FOR THE TERMINAL
ITSELF AND HAVE CARRIED A VCTS WITH THE BETTER CHCS FROM MID DAY
ON. SEVERE STORMS ARE POSSIBLE MAINLY THIS AFTN INTO TONIGHT WITH
LARGE HAIL AND DAMAGING WINDS THE PRIMARY HAZARDS. TSTMS SHOULD
MOVE SOUTH OF THE TERMINAL BY DAYBREAK FRIDAY. LOOK FOR LIGHT AND
VARIABLE WINDS THIS MORNING TO TRANSITION SOUTHERLY AS A SFC RIDGE
SHIFTS EAST AND LOW PRESSURE DEEPENS ALONG THE HIGH PLAINS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...MANGELS/FAY
LONG TERM...EWALD
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1017 AM EDT THU AUG 1 2013
.SYNOPSIS...
BENEATH AN APPROACHING UPPER LEVEL DISTURBANCE...A SURFACE TROUGH OF
LOW PRESSURE WILL DRIFT ACROSS CENTRAL AND EASTERN NC TODAY. A COLD
FRONT WILL FOLLOW AND SETTLE SOUTHEAST ACROSS THE REGION TONIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM THURSDAY...
THE LATEST SURFACE ANALYSIS SHOWED A WEAK TROUGH/COLD FRONT INTO THE
FOOTHILLS...SEPARATING THE MUCH MORE MOIST AIR...WITH DEW POINTS
MOSTLY IN THE LOWER 70S...FROM DRIER AND LOWER PW AIR BEHIND IT. THE
MORE NOTICEABLE WIND SHIFT BOUNDARY WAS LOCATED OVER THE OHIO
VALLEY...EXTENDING INTO KENTUCKY. THE LEAD BOUNDARY SHOULD NOT MOVE
MUCH DURING THE DAY AS THE FOLLOWING BOUNDARY CONTINUES TO MOVE
SOUTHEAST. MID-LEVEL DRYING ON WATER VAPOR WAS APPROACHING THE STATE
FROM THE WEST...AND ON THE 12Z UPPER-AIR ANALYSIS IT APPEARS THERE
WERE TWO MID-LEVEL SHORTWAVES...ONE MOVING THROUGH THE STATE
CURRENTLY DURING THE MORNING AND ANOTHER ASSOCIATED WITH THE STRONG
MID-LEVEL DRYING OVER KENTUCKY AND TENNESSEE. FOR THE AFTERNOON INTO
THE EVENING...THE GFS BUFR SOUNDINGS ARE MUCH MORE STABLE THAN THE
NAM AND RAP...WITH MID-LEVEL DRYING AND WARMING REDUCING POTENTIAL
INSTABILITY ESPECIALLY ALONG AND WEST OF ABOUT U.S. 1. JET SUPPORT
APPROACHING FROM THE WEST MAY JUST LAG PEAK HEATING...AND THE NAM
AND RAP SOUNDINGS SHOW GOOD LOW-LEVEL MOISTURE REMAINING THROUGHOUT
THE DAY...WHICH SHOULD RESULT IN A MOSTLY CLOUDY SKY ON AVERAGE
DESPITE SOME BREAKS. THE RAP FORECASTS MLCAPE RISING TO AS HIGH AS
2000J/KG TO 2500J/KG DURING THE AFTERNOON...WITH DCAPE AND
1000-500MB LAPSE RATES RISING AS THE DRIER AIR ALOFT MOVES IN FROM
THE WEST. GIVEN GREATER PEAK HEATING AND A STRONG SURFACE
BOUNDARY...VERY NUMEROUS SHOWERS AND THUNDERSTORMS MIGHT BE THE
RESULT...BUT MORE LIMITED HEATING AND LOW-LEVEL CONVERGENCE MAY END
UP LIMITING OVERALL LIFT. THE LATEST HRRR WRF HAS BEEN CONSISTENT
FROM ITS PREVIOUS COUPLE OF RUNS SHOWING MORE SCATTERED SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON. HAVE MAINTAINED THE LOW LIKELY
CHANCES FOR SHOWERS AND SCATTERED THUNDERSTORMS MOST AREAS AS THERE
SHOULD BE ENOUGH COMBINED LIFT WITH THE WEAK SURFACE AND MODEST
UPPER-LEVEL FEATURES IN THE DEEPER MOISTURE FOR NUMEROUS SHOWERS. AS
THE DRIER AIR ALOFT MOVES IN FROM THE WEST...HELPING TO INCREASE
DOWNDRAFT CAPE...THERE IS THE CHANCE FOR AN ISOLATED SEVERE WIND
GUST. CURRENT THOUGHT IS THAT THE BETTER POTENTIAL FOR THAT WOULD BE
WEST OF I-95.
OVERNIGHT...DEEPER COLUMN DRYING GRADUALLY TAKES PLACE DIMINISHING
THE CHANCES FOR SHOWERS FROM WEST-TO-EAST AS THE PRIMARY SURFACE
FRONT MOVES IN AND CONTINUES A SLOW EASTWARD PROGRESSION.
PRECIPITABLE WATER VALUES IN THE TRIAD...BY 12Z FRIDAY...FALL TO
NEAR AN INCH...FROM 1.75 TO 2 INCHES TODAY. THE FRONT SHOULD LIKELY
NOT MAKE IT ALL THE WAY THROUGH CENTRAL NORTH CAROLINA...AND LIGHT
WINDS AND CONTINUED HIGH MOISTURE SHOULD RESULT IN AT LEAST PATCHY
FOG...IF NOT AREAS OF FOG AND LOCALLY DENSE FOG...PARTICULARLY OVER
THE COASTAL PLAIN. WILL AWAIT THE LATEST GUIDANCE BEFORE INTRODUCING
ANY FOG POTENTIAL IN THE HWO...BUT HAVE ADDED IT TO THE GRIDDED AND
WORDED FORECASTS. AFTER HIGHS TODAY MOSTLY IN THE MID 80S PROVIDING
THERE ARE SOME BREAKS IN THE CLOUDS...OVERNIGHT LOWS SHOULD RANGE
FROM THE MID 60S NORTHWEST TO AROUND 70 SOUTHEAST.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 330 AM THURSDAY...
STALLED SURFACE FRONT ACROSS EASTERN NC WILL SERVE TO FOCUS
CONVECTION ACROSS NC COASTAL COUNTIES FRIDAY AFTERNOON/EARLY FRIDAY
EVENING...PEAKING DURING THE MAX HEATING/DESTABILIZATION AND PERHAPS
AIDED BY THE MERGER OF THE SEABREEZE BOUNDARY. WILL ADD SLIGHT
CHANCE POPS FOR A FEW OF OUR FAR SOUTHEASTERN ZONES
(SAMPSON-WAYNE-CUMBERLAND). WEST OF THE FRONT...CONSIDERABLE DRYING
EXTENDING FROM THE MID-LEVELS TO THE SURFACE WILL STABILIZE THE
BOUNDARY LAYER AND SUPPRESS ANY LIFT. MUCH LIKE IT WAS AT THE START
OF THE WORK WEEK...SFC DEWPOINTS IN THE UPPER 50S TO LOWER 60S WILL
RESULT IN NOTICEABLY LOWER AND COMFORTABLE RH VALUES FOR EARLY
AUGUST. HIGHS IN THE MID 80S NW TO UPPER 80S SE.
STALLED FRONTAL ZONE WILL QUICKLY WASH OUT/DISSIPATE OVER THE AREA
FRIDAY NIGHT/EARLY SATURDAY WITH DEWPOINT RECOVERY INTO THE UPPER 60S
ACROSS THE PIEDMONT AND A LIGHTLY SELY SURFACE WIND. LOWS 67 TO 72.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...
THE UPPER AIR PATTERN OVER THE CONUS WHICH FEATURES AN UPPER LEVEL
RIDGE OVER THE ROCKIES...WHILE KEEPING AN UPPER LEVEL TROUGH OVER
THE EASTERN US...CHANGES VERY LITTLE THROUGH THE LONG TERM
PERIOD...POTENTIALLY BECOMING MORE AMPLIFIED BY EARLY/MIDDLE
PART OF NEXT WEEK. THIS WILL FAVOR A CONTINUATION OF SLIGHTLY BELOW
TO NEAR NORMAL TEMPERATURES THROUGH THE PERIOD.
AS FAR AS RAIN CHANCES...THE POTENTIAL FOR WELL TIMED LOW AMPLITUDE
S/W DISTURBANCES EMBEDDED IN THE WESTERLY FLOW ALOFT COULD COMBINE
WITH WEAK SURFACE CONVERGENCE ALONG THE LEE SIDE TROUGHINESS TO
SUPPORT ISOLATED TO WIDELY SCATTERED DIURNAL SHOWERS AND STORMS
ACROSS THE AREA SATURDAY AFTERNOON. HOWEVER ANOTHER SYNOPTIC SCALE
COLD FRONT WILL MOVE THROUGH THE AREA ON SUNDAY...AND WILL LIKELY
BRING OUR BEST RAIN CHANCES THROUGH THE WEEKEND. ANTECEDENT
WESTERLY FLOW ALOFT IN ADVANCE OF THE FRONTAL PASSAGE COULD IMPEDE
CONVECTIVE COVERAGE/POPS AND THUS WILL CAP POPS AT CHANCE.
THE COLD FRONT SHOULD SETTLE JUST SOUTH OF THE AREA SUNDAY
NIGHT/MONDAY AS WEAK HIGH PRESSURE BUILDS OVER THE OHIO VALLEY AND
MID-ATLANTIC STATES. FOR NOW WILL KEEP MONDAY DRY WITH RAIN CHANCES
RETURNING ON TUESDAY AS WAVES OF LOW PRESSURE DEVELOP ALONG THE
FRONT TO OUR SOUTH IN RESPONSE TO S/W ENERGY DIVING SE THROUGH THE
BASE OF THE TROUGH. SUCH A SET-UP WOULD RESULT IN CAD-LIKE SENSIBLE
WEATHER IMPACTS.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 1015 AM THURSDAY...
IFR-MVFR STRATUS OVER CENTRAL NC THIS MORNING WILL BE SLOW TO LIFT
AND SCATTER THROUGH MVFR RANGE TO VFR BETWEEN 15-18Z. NUMEROUS
SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED...BRINGING WITH
THEM PERIODS OF LOWER CEILINGS AND VISIBILITIES...AND POSSIBLY A
STRONG WIND GUST. IFR-LIFR CONDITIONS IN FOG WILL LIKELY REDEVELOP
LATE TONIGHT MAINLY FROM KRDU AND ESPECIALLY EASTWARD TO KRWI AND
KFAY...WHERE DRIER AIR BEHIND A SLOW-MOVING COLD FRONT WILL BE
SLOWEST TO ARRIVE.
LOOKING AHEAD: A SLIGHT CHANCE OF AFTERNOON SHOWERS AND STORMS AT
EASTERN TAF SITES FRIDAY AND SATURDAY...WITH A BETTER CHANCE -
AROUND 40 PERCENT - AT ALL CENTRAL NC TERMINALS ON SUNDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...DJF
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...MWS/DJF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1015 AM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST THROUGH THE AREA TODAY INTO THIS
EVENING...PRECEDED AND ACCOMPANIED BY SCATTERED SHOWERS AND
THUNDERSTORMS. CLEARING SKIES ALONG WITH DRIER AIR WILL FOLLOW THE
FRONT...AND REMAIN OVER THE REGION ON FRIDAY.
ANOTHER COLD FRONT WILL BE ON ITS HEELS AND BRING A RETURN OF
SHOWERS TO THE FORECAST ON SATURDAY. A STRONGER AREA OF HIGH
PRESSURE SETTLES OVER THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EDT THURSDAY...
MOIST LOW LEVELS WITH NORTHWEST FLOW AHEAD OF A SLOW MOVING FRONT
IN THE OHIO VALLEY...HAS LIGHT SPOTTY SHOWERS MOVING SOUTHEAST
ACROSS THE MOUNTAINS THIS MORNING. HRRR HANDLING THIS THE BEST
THIS MORNING. UPDATED POPS TO CURRENT CONDITIONS.
AS OF 345 AM EDT THURSDAY...LEADING EDGE OF TROPICAL AIR WITH
DEW POINTS AROUND 70F RESIDING FROM NEAR FARMVILLE SOUTHWEST TO
NEAR DANVILLE VA AND GREENSBORO NC...CONTINUING SOUTHWEST TO NEAR
CHARLOTTE NC. SLIGHT BACKING OF WINDS ALOFT IN ADVANCE OF
APPROACHING TROF DIVING SOUTHEAST OUT OF THE UPPER MS AND OH
VALLEY...COUPLED WITH ONSET OF DAYTIME HEATING SHOULD ENABLE WARM
FRONT TO LIFT/MIX SLOWLY NORTHWARD INTO AT LEAST SOUTHEASTERN
PIEDMONT COUNTIES BEFORE SURFACE COLD FRONT...NOW MOVING SOUTHEAST
THROUGH SOUTHERN OH AND NORTHWESTERN KY...JUMPS INTO DEVELOPING
LEE TROF EAST OF THE BLUE RIDGE AND HALTS NORTHWARD PUSH OF SULTRY
AIRMASS.
PLENTY OF CLOUDS AND EARLIER ARRIVAL OF COLD FRONT AND/OR WINDS
VEERING INTO THE WEST SHOULD MINIMIZE SIGNIFICANT CONVECTIVE
THREAT TODAY ALONG AND WEST OF THE BLUE RIDGE...WITH ONLY
SCATTERED SHOWERS/THUNDERSTORMS EXPECTED UP UNTIL FRONTAL PASSAGE
BY EARLY TO MID AFTERNOON...FOLLOWED BY SOME LINGERING SHOWERS IN
UPSLOPE AREAS PERHAPS INTO EARLY EVENING AS TEMPERATURES ALOFT
SLOWLY COOL WITH APPROACH OF TROF AXIS.
HOWEVER...DESPITE PLENTY OF CLOUDS ACROSS THE PIEDMONT...AT LEAST
INITIALLY...EROSION OF COOL POOL...PROXIMITY OF CONFLUENCE IN
VICINITY OF WARM FRONT/LEE TROF...AND GREATER INSTABILITY DUE TO A
MUCH MORE MOIST AIRMASS AND PERHAPS SOME INSOLATION...ESPECIALLY
SOUTH OF THE FRONT...MAY SUPPORT MORE AGGRESSIVE THUNDERSTORM
DEVELOPMENT...WITH EVEN SOME ISOLATED SEVERE WEATHER POSSIBLE
THIS AFTERNOON ACROSS THE EXTREME SOUTHEASTERN VA/NC COUNTIES.
SOUTHEASTERN AREAS MAY ALSO SEE SOME LOCALLY HEAVY RAIN...BUT
HEAVY RAIN THAT OCCURRED EARLIER TONIGHT WAS RELATIVELY LOCALIZED
TO ONLY A SMALL PORTION OF A FEW COUNTIES...SO DO NOT PLAN ON
ISSUING ANY FLASH FLOOD WATCH AT THE PRESENT TIME...ALTHOUGH
POTENTIAL OF DOES EXIST FOR SOME LOCALIZED FLOODING ISSUES IF
STORMS TRAIN OVER THE SAME AREA IN CASWELL....PITTSYLVANIA...AND
HALIFAX COUNTIES.
THREAT OF PRECIPITATION EXPECTED TO RAPIDLY END OVER THE ENTIRE
BLACKSBURG FORECAST AREA THIS EVENING WITH LOSS OF DAYTIME HEATING
AND PASSAGE OF FRONT...TO BE FOLLOWED BY CLEARING SKIES WITH
DIMINISHING WINDS. WEAK SUBSIDENCE OVER MOIST BOUNDARY LAYER FROM
RECENT RAINFALL SHOULD SET THE STAGE FOR DEVELOPMENT OF FOG IN
MANY AREAS BY DAYBREAK FRIDAY...AND HAVE INCLUDED IN THE GRIDDED
FORECAST.
CONTINUED TO UNDERCUT MOS GUIDANCE FOR HIGH TEMPERATURES TODAY IN
MOST AREAS...THAT WILL REMAIN LOCKED IN COOL WEDGE UNTIL BEING
DISLODGED BY ARRIVAL OF WESTERLY WINDS AND COOL FRONT. PREFERRED
SOMEWHAT COOLER MAV GUIDANCE IN THE MOUNTAINS FOR LOW TEMPERATURES
TONIGHT (MOS GUIDANCE GENERALLY ACCEPTED ELSEWHERE) WITH ARRIVAL
OF SOMEWHAT LOWER DEW POINTS AS THE NIGHT PROGRESSES.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 430 AM EDT THURSDAY...
VERY LITTLE CHANGE EXPECTED IN THE UPPER ATMOSPHERIC PATTERN
THROUGH THE PERIOD WITH UPPER RIDGE LOCKED IN ACROSS THE SOUTHWEST
AND A DEEP/BROAD UPPER LOW ANCHORED ACROSS HUDSON BAY. THIS WILL
KEEP A LONG FETCH OF NW FLOW ACROSS THE REGION. AS A RESULT...THE
AREA REMAINS SUSCEPTIBLE TO ANY EMBEDDED NW FLOW DISTURBANCES AS A
RESULT AN OVERALL UNSETTLED PATTERN WILL REMAIN IN PLACE.
FRIDAY...THE AREA WILL BE BETWEEN SHORT WAVES...WITH THE THU
SYSTEM EXITING OFF THE COAST AND THE NEXT UPSTREAM SHORT WAVE
NOTED ACROSS THE UPPER MIDWEST. FRIDAY SHOULD OVERALL BE A QUIET
DAY WITH LOWER DEWPOINTS. ABUNDANT INSOLATION AND SOME WARMING AT
850MB AHEAD OF THE NEXT SHORT WAVE WILL OFFSET ANY EARLY CAA. THE
NET RESULT WILL BE NEAR NORMAL TEMPERATURES.
FOR SATURDAY...FAIRLY IMPRESSIVE FORCING FROM NW FLOW UPPER SHORT
WAVE TRACKS ACROSS THE AREA DURING PEAK HEATING. THE LIMITING
FACTOR IS SFC BASED INSTABILITY...WITH ANTECEDENT LOW DEWPOINTS
AS THE AIR MASS HAS LIMITED TIME TO RECOVER FROM THE DRY AIR MASS
IN PLACE FRIDAY. FEEL THAT DYNAMICS AND ELEVATED INSTABILITY WILL
ALLOW FOR AT LEAST SOME THUNDER...SO HAVE INTRODUCED THUNDER IN
THE AFTERNOON/EVENING. SPC HAS OUTLOOKED THE NORTHERN PART OF THE
CWA FOR 5 PERCENT RISK...MAINLY FROM THE STANDPOINT OF HEALTHY
SHEAR/DYNAMICS/UPPER FORCING. HOWEVER...AS NOTED...INSTABILITY IS
SEVERELY LACKING AT THIS POINT...SO AM NOT IMPRESSED. ANOTHER
ISSUE FOR SAT ARE MAX TEMPS. GFS HAS PROGGED AN AREA OF +20C TO
ADVECT NE INTO THE REGION FROM THE SE STATES SAT AFTERNOON...AND
AS A RESULT HAS PUSHED MAX TEMPS INTO THE LOW 90S ACROSS THE
PIEDMONT. ECMWF IS CONSIDERABLY COOLER. BASED ON THE PERSISTENT
COOL SUMMER AND RELATIVELY LOW MIN TEMPS EXPECTED SAT MORNING...I
JUST CANT BUY OFF ON THE 90S ADVERTISED BY THE GFS...ESPECIALLY
WITH THE VERY WET GROUND IN PLACE...SO HAVE TRENDED TOWARD THE
CONSIDERABLY COOLER ECMWF MOS. HAVE KEPT POPS IN THE CHC CATEGORY
FOR NOW AS WELL. THIS SYSTEM WILL LINGER ACROSS THE SOUTHERN PART
OF THE CWA SUN...SO HAVE KEPT CHC POPS ACROSS THE SOUTH AND SLIGHT
CHC NORTH AS THE ECMWF IS SOMEWHAT SLOWER IN PUSHING THE MOISTURE
SOUTH OF THE AREA. LOWER DEWPOINTS AND TEMPERATURES SHOULD BEGIN
TO ADVECT INTO THE REGION FROM THE NORTH SUN.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 500 AM EDT THURSDAY...
NORTHWEST FLOW WILL REMAIN IN PLACE THROUGH THE EXTENDED
PERIODS...CONTINUING TO LEAVE THE AREA SUSCEPTIBLE TO SHOWERS AND
THUNDERSTORMS. HOWEVER...THE MODELS ARE FAIRLY INSISTENT IN
PUSHING THE DEEPER MOISTURE SOUTH OF THE AREA. THE BAROCLINIC ZONE
LOOMS JUST TO OUR SE AND IS SUBJECT TO RETURN NORTH WITH ANY OF
THESE SHORT WAVES AT ANY TIME. HAVE NOT MADE ANY SIGNIFICANT
CHANGES TO EARLIER THINKING...ALTHOUGH PUSHED CHC POPS BACK INTO
THE AREA A LITTLE SOONER ON MON THAN EARLIER INDICATED. THERE ARE
LARGE DISCREPANCIES BETWEEN THE GFS/ECMWF IN DEWPOINTS...WITH THE
GFS VERY DRY/COOL...AND THE ECMWF MUCH MORE TEMPERATE...SUGGESTING
BETTER CHCS FOR SHRA ACTIVITY.
PREVIOUS EXTENDED DISCUSSION...
KEEPING WITH A BLEND OF THE 00Z ECMWF/06Z GFS IN THE FIRST COUPLE OF
DAYS THIS PERIOD THEN TRANSITIONING MORE TOWARD ECM/WPC BLEND.
STILL NOT LOOKING AT A WHOLE LOT OF PRECIPITATION OVERALL BUT THE NW
FLOW WITH BROAD TROUGH OVER THE NE INTO THE MID ATLANTIC WILL KEEP
SOME FRONTAL SYSTEMS MOVING THROUGH OVER THIS PERIOD WITH BOUNDARY
WASHING OUT/STALLING OUT TO OUR SOUTH. MOSTLY LOOKING AT JUST BELOW
NORMAL TEMPERATURE SETUP AT LEAST AFTER THE FIRST FRONT PASSES BY
SUNDAY AFTERNOON.
HIGH PRESSURE WILL SETTLE OVER THE MID ATLANTIC MONDAY FOLLOWED BY
ANOTHER SHORTWAVE AND ATTENDANT FRONT FOR EARLY TUESDAY. KEPT POPS
OVERALL IN THE SLIGHT CHANCE TO CHANCE RANGE...BUT APPEARS THE
PATTERN FAVORS THE WRN SLOPES OF WV/SW VA INTO NW NC TO HAVE BETTER
THREAT OF SHOWERS OR STORMS NEXT WEEK. THE 06Z GFS AT TIMES SHOWED
CONVECTIVE FEEDBACK/HIGHER QPF BULLSEYES WITH THE FRONT DRAPED OVER
US EARLY NEXT WEEK AND GENERALLY RULED THIS OUT...FAVORING HPC/ECMWF.
AFTER MIDWEEK THE FRONT EXPECTED TO STALL OUT THE SOUTHEAST WHILE
HIGH PRESSURE NOSES IN FROM THE MIDWEST. AT THIS STAGE THE PATTERN
STILL FAVORS SOME THREAT OF SHOWERS BUT OVERALL MID AND UPPER FLOW
STAYS WEST TO NORTHWEST.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 740 AM EDT THURSDAY...
HEAVIER PRECIPITATION HAS MOVED EAST OF THE AREA...LEAVING A FEW
SPRINKLES OR LIGHT SHOWERS...LOW CLOUDS...AND AREAS OF MOSTLY MVFR
BR AROUND THE REGION. EXPECT MAINLY IFR-MVFR CIGS TO PREVAIL
THROUGH 15Z...THEN IMPROVING MOSTLY TO MVFR THROUGH EARLY
AFTERNOON...THEN VFR BY MID TO LATE AFTERNOON. WOULD EXPECT
REDEVELOPMENT OF SHRA AND EVEN TSRA ACROSS THE PIEDMONT...PERHAPS
BEGINNING NEAR THE I-81 CORRIDOR BY 17/18Z AS THE MAIN FRONTAL
BOUNDARY/UPPER SHORT WAVE APPROACH FROM THE WEST. CLOUDS WILL
CLEAR EAST OF THE ALLEGHANYS AFTER 00Z...BUT EXPECT MVFR CIGS TO
LINGER ACROSS EASTERN WV OVERNIGHT...POSSIBLY SCATTERING OUT
BEFORE DAYBREAK. MAIN CONCERN OVERNIGHT WILL BE DEVELOPMENT OF
PATCHY DENSE FOG WITH LIFR CIGS/VSBYS AT LWB/BCB/LYH AND MVFR
DAN/BLF. WINDS WSW TODAY...SHIFTING TO WNW THIS EVENING...SPEEDS
REMAINING 10KTS OR LESS THROUGH TAF VALID PERIOD...BECOMING CALM
OVERNIGHT MOST SITES.
MEDIUM CONFIDENCE IN CIGS/VSBYS THROUGH TAF VALID PERIOD.
HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID PERIOD.
MEDIUM CONFIDENCE IN TSRA POTENTIAL PIEDMONT THIS AFTERNOON.
EXTENDED AVIATION DISCUSSION...
VFR EXPECTED FRIDAY OUTSIDE EARLY MORNING PATCHY LIFR-IFR FG/BR.
THE NEXT COLD FRONT IS PROGGED TO MOVE THROUGH THE AREA SATURDAY
EVENING INTO SUNDAY MORNING. ANTICIPATE A RETURN OF SCATTERED
SHOWERS AND STORMS AND SOME AREAS OF SUB-VFR CONDITIONS.
HIGH PRESSURE AND MAINLY VFR CONDITIONS RETURN BY MONDAY. EARLY
MORNING FOG WILL AGAIN BE A POSSIBILITY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...RCS/WERT
SHORT TERM...RAB
LONG TERM...RAB/WP
AVIATION...DS/JH/RAB/WERT
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST THU AUG 1 2013
.SYNOPSIS...SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
WILL CONTINUE INTO NEXT WEEK WITH NEAR NORMAL TEMPERATURES.
&&
.DISCUSSION...LOTS OF DEBRIS CLOUD WITH EMBEDDED WEAK CONVECTION
THIS MORNING. MOISTURE PLENTIFUL WITH 12Z KTWC SOUNDING COMING IN
WITH 1.65 AND 1.6 TO 1.7 INCHES A COMMON VALUE ACROSS SOUTHEAST
ARIZONA ON BLENDED SATELLITE ESTIMATES. CONDITIONAL INSTABILITY ON
SOUNDING NOT THE BEST...SUGGESTING EASY MOUNTAIN DEVELOPMENT AND
MODEST OUTFLOW SUPPORT FOR ESPECIALLY EASTERN VALLEYS. SLOW MOVING
HEAVY RAIN A CONCERN. EARLIER UPDATE TO EMPHASIZE CLOUD COVER AND TO
KNOCK A DEGREE OR TWO OFF HIGH TEMPERATURES. HRRR HINTING AT A LATE
AFTERNOON OR EARLY EVENING TIME FOR A FEW SLOW MOVING STORMS
SPREADING INTO ADDITIONAL VALLEY LOCATIONS.
&&
.PREV DISCUSSION...CONSIDERABLE DEBRIS CLOUDINESS ACROSS THE AREA
THIS MORNING. MUCH FURTHER SOUTH...THERE WAS AN MCS SOUTH OF GUYMAS
MOVING INTO THE GULF OF CALIFORNIA. OUTFLOW FOR THIS COMPLEX LIKELY
TO SEND UP A SURGE OF LOW LEVEL MOISTURE UP THE GULF TODAY. MOISTURE
IS BACK WITH PRECIPITABLE WATER VALUES THIS MORNING IN THE 1.45" TO
1.60" RANGE. SOUTHERLY FLOW WILL BE AROUND INTO THE WEEKEND AND
EARLY NEXT WEEK WITH UPPER LEVEL HIGH OVER TEXAS. SHOULD SEE AN
UPTICK IN AREAL COVERAGE OF STORMS TODAY...WITH SCATTERED MAINLY
AFTERNOON AND EVENING STORMS CONTINUING FOR THE NEXT 7 DAYS. HARD TO
PICK OUT WHICH DAY WILL BE MORE ACTIVE THAN ANOTHER. SO BASICALLY
KEPT NEAR CLIMO POPS IN THE FORECAST. HIGHS TODAY WILL BE SLIGHTLY
ABOVE NORMAL...THEN GRADUALLY COOL TO NEAR NORMAL OVER THE NEXT
SEVERAL DAYS.
&&
.AVIATION...SCT-BKN CLOUDS AT 6-10K FT AGL. ISOLD TSRA INCREASING TO
SCT AFT 01/19Z...MAINLY FROM KTUS SOUTH AND EAST INCLUDING
THE KOLS AND KDUG TERMINALS THRU 02/05Z. WIND GUSTS TO 45 KTS NEAR
ANY TSRA...AS WELL AS LOCAL MVFR/IFR CIGS/VSBYS. OTHERWISE...SURFACE
WIND GENERALLY LESS THAN 10 KTS THRU 02/16Z. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO
NEXT WEEK...RESULTING IN A CHANCE OF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS ACTIVITY ACROSS MOST OF SOUTHEAST ARIZONA.
OUTSIDE OF GUSTY THUNDERSTORM OUTFLOWS...WINDS DURING THIS PERIOD
ARE EXPECTED TO BE LIGHT...GENERALLY LESS THAN 15 MPH...AND
DIURNALLY DRIVEN.
&&
.CLIMATE...JULY 2013 FOR TUCSON GOES INTO THE RECORDS BOOKS AS THE
19TH WARMEST AND 38TH WETTEST ON RECORD. THE JULY CLIMATE REPORT FOR
TUCSON WILL BE POSTED LATER THIS MORNING ON OUR WEBSITE...FACEBOOK
AND ON TWITTER.
AFTER DOUGLAS RECORDED ITS WETTEST ANY MONTH ON RECORD DURING JULY
WITH 10.12"...THE MAIN STORY DOWN THERE FOR THE REMAINDER OF THE
2013 MONSOON IS THEIR ATTEMPT AT RECORDING THE WETTEST MONSOON ON
RECORD. DOUGLAS IS CURRENTLY 5.67" FROM THE RECORD OF 15.90" THAT
OCCURRED IN 1964. DATING BACK TO 1948...THERE HAVE BEEN THIRTEEN
OCCURRENCES WHICH RECORDED MORE THAN 5.67" FOR THE REMAINDER OF THE
MONSOON PERIOD. COMBINED NORMAL RAINFALL FOR AUGUST/SEPTEMBER IN
4.59". SINCE 1948...DOUGLAS HAS RECORD MORE THAN THE NORMAL TOTAL 27
TIMES. UNLESS SOMETHING REALLY ODD HAPPENS AT DOUGLAS AIRPORT...A
TOP 5 WETTEST MONSOON ON RECORD IS MOST DEFINITE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
344 PM MDT THU AUG 1 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
CURRENTLY...SHORTWAVE TROUGH AND UPPER VORT MAX ARE CURRENTLY
EJECTING EASTWARD ACROSS COLORADO...WHILE A SECONDARY WAVE MOVES
NORTHWARD OUT OF NEW MEXICO INTO SOUTHERN COLORADO. RADAR INDICATES
WIDESPREAD CONVECTION OVER THE MOUNTAIN AREAS AND SPREADING EAST
INTO THE I-25 CORRIDOR. TEMPERATURES HAVE BEEN WARM WITH UPPER 80S
TO LOWER 90S FOR THE PLAINS.
THROUGH TONIGHT...MODELS HAVING A HARD TIME WITH THIS UPPER LEVEL
DISTURBANCE AND THE AMOUNT OF CONVECTION FIRING ACROSS THE REGION.
THE LATEST RAP AND HRRR SEEM TO HAVE A BETTER HANDLE WITH THE LATEST
RUNS WITH CONVECTION SPREADING EAST ACROSS THE PLAINS THROUGH THE
EVENING HOURS. DEW POINTS IN THE UPPER 50S AND PWAT VALUES
APPROACHING AN INCH HAVE LED TO LOCALLY HEAVY RAINFALL WITH THESE
THUNDERSTORMS. OF CONCERN ARE AREA BURN SCARS...WHICH COULD SEE
LOCALIZED FLASH FLOODING WITH ANY HEAVY CELLS THAT MOVE OVER THEM.
WHILE THE WEST FORK COMPLEX HAS ONLY SEEN LIGHT PRECIP SO FAR
TODAY...THE UPPER DISTURBANCE MOVING NORTH OUT OF NEW MEXICO SHOULD
PROVIDE ENHANCED LIFT AND CONTINUED THREAT FOR HEAVY RAINFALL
THROUGH THIS EVENING. NOT MUCH OF A SEVERE WEATHER THREAT ACROSS
THE PLAINS THIS EVENING. THERE COULD BE SOME DIME TO PENNY SIZE
HAIL WITH THE STRONGEST CELLS...ESPECIALLY SOUTH OF HIGHWAY 50
THROUGH ABOUT 9PM TONIGHT. EXPECT MOST ACTIVITY TO SHIFT EAST WITH
THE UPPER WAVE AFTER MIDNIGHT WITH SHOWER AND THUNDERSTORM ACTIVITY
COMING TO AN END THROUGH FRIDAY MORNING. THE EXCEPTION WILL BE THE
SAN JUAN RANGE WHERE THE EJECTING UPPER DISTURBANCE WILL LIKELY KEEP
THUNDERSTORMS GOING INTO FRIDAY MORNING.
FRIDAY...THE UPPER LEVEL DISTURBANCE OUT OF NEW MEXICO WILL TRACK
INTO SOUTHWEST KANSAS BY FRIDAY AFTERNOON WHILE A WEAK BOUNDARY
SHIFTS SOUTH INTO THE PLAINS. DRIER AIR AND SUBSIDENCE BEHIND THE
DEPARTING WAVE SHOULD LIMIT THUNDERSTORM ACTIVITY TO THE MOUNTAIN
AREAS...AND NEAR THE NEW MEXICO BORDER. THE MAIN THREATS WILL
CONTINUE TO BE LOCALIZED HEAVY RAINFALL AND LIGHTNING. GIVEN THE
DECREASE IN MOISTURE...THE FLASH FLOOD RISK WILL LIKELY BE MINIMAL
OVER THE WEST FORK COMPLEX...BUT ANY CELLS THAT DO MOVE OVER THE
BURN SCAR COULD PRODUCE A QUICK BURST OF RAINFALL. TEMPERATURES
WILL REMAIN WARM WITH AFTERNOON HIGHS IN THE MID TO UPPER 90S ACROSS
THE LOWER ELEVATIONS. MOZLEY
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
...SUMMER MONSOON WILL STICK AROUND FOR A WHILE...
ALL IN ALL...GOOD NEW IN THE WEATHER DEPARTMENT...THE SUMMER MONSOON
LOOKS ALIVE AND WELL THROUGH AT LEAST NEXT WEEK. THERE WILL BE
WETTER DAYS AND DRIER DAYS...BUT THE MONSOON PLUME WILL GENERALLY
REMAIN OVER COLORADO. NOT EVERYONE WILL GET RAIN EVERYDAY...SUMMER
CONVECTION IS PRETTY MUCH ALWAYS HIT OR MISS. BUT...OVER
TIME...MOST WILL GET THERE SHARE OF THE MONSOON...MAYBE ONLY 1 DAY
IN THE NEXT 7...MAYBE 2 DAYS...MAYBE EVEN 3 DAYS OR MORE. BUT...THE
SHOWERS WILL BE AROUND...AND THE HUMIDITIES WILL BE UP...ALL GOOD
FOR COLORADO. WELL...MAYBE NOT SO GOOD FOR THE BURN SCAR AREAS...OF
COURSE.
FRIDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR ISOLATED TO
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE
AREA...ESPECIALLY MOUNTAINS AND RIDGES.
SATURDAY CONTINUES TO LOOK LIKE A GOOD CHANCE OF SHOWERS OVER MOST
OF THE AREA...BUT ESPECIALLY FOR THE EASTERN MOUNTAINS AND PLAINS.
A SIGNIFICANT SURFACE BOUNDARY IS STILL POISED TO MOVE THROUGH THE
EASTERN PLAINS THIS DAY AND INTERACT WITH THE MONSOON PLUME...TO
PRODUCE MORE WIDESPREAD PRECIPITATION THAN TYPICAL. WITH THE
GREATER NUMBER OF SHOWERS AROUND...AND THE GREATER LIFTING PROVIDED
BY THE SURFACE BOUNDARY...THIS WILL INCREASE THE HEAVY RAIN
POTENTIAL AT ANY ONE LOCATION THIS DAY. SO...THE BURN SCAR FLASH
FLOOD THREAT WILL BE UP.
SUNDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR
CONVECTION...ESPECIALLY MOUNTAINS AND RIDGES AGAIN.
LATER MONDAY THROUGH THE REMAINDER OF THE WEEK CONTINUES TO LOOK
INTERESTING WITH THE CHANCES FOR AFTERNOON AND NIGHTLY SHOWERS AND
THUNDERSTORMS GOING UP THROUGH THE PERIOD. STARTING MONDAY
NIGHT...A SERIES OF SURFACE BOUNDARIES WILL START TO MOVE THROUGH
THE EASTERN HALF OF THE FORECAST AREA. THESE BOUNDARIES WILL BE
TIED TO A SLOWLY MOVING BROAD UPPER LEVEL TROUGH DROPPING SOUTHWARD
THROUGH THE NORTHERN PLAINS DURING THE PERIOD. THE JET STREAM ON
THE SOUTH SIDE OF THIS TROUGH WILL TEND TO SEND SURFACE BOUNDARIES
SOUTH THROUGH THE PLAINS ON A REGULAR BASIS...THUS...INCREASING THE
AMOUNT OF LOW LEVEL UPSLOPE FLOW OVER THE EAST. THE INCREASED
LIFTING OF THE AIR ASSOCIATED WITH THE UPSLOPE COMBINED WITH A
STRONG MONSOON PRESENCE WILL SET THE STAGE FOR REPEATED ROUNDS OF
SHOWERS...HEAVY AT TIMES...THROUGH THE PERIOD. IF CURRENT FORECASTS
VERIFY...THE BURN SCAR AREAS WILL LIKELY NEED TO BE ON HIGH ALERT
MOST OF NEXT WEEK. LW
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 342 PM MDT THU AUG 1 2013
KALS...WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY IS IMPACTING THE
MOUNTAIN AREAS AROUND THE SAN LUIS VALLEY...WITH SEVERAL CELLS
MOVING IN AND AROUND THE TERMINAL. THIS ACTIVITY SHOULD PERSIST
THROUGH MUCH OF THE EVENING...THROUGH AT LEAST 08Z TONIGHT. REDUCED
VIS AND CIGS ARE LIKELY TO IFR CONDITION. DRIER CONDITIONS ARE
FORECAST TO MOVE INTO THE SAN LUIS VALLEY BY FRIDAY MORNING.
KCOS AND KPUB...BAND OF SPOTTY THUNDERSTORMS IN A LINE FROM KCOS TO
SOUTH OF KPUB IS MOVING EAST. FOR NOW IT LOOKS LIKE BOTH TERMINALS
WILL JUST HAVE CELLS IN THE VICINITY. IT IS POSSIBLE THAT A CELL
WILL MOVE OVER THE TERMINALS THROUGH THIS EVENING WITH REDUCED VIS
AND CIGS POSSIBLE IF THEY DO. KPUB WILL HAVE THE BEST CHANCE OF
SEEING THUNDERSTORMS THROUGH 02Z. MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MDT THIS EVENING FOR COZ067-068.
&&
$$
SHORT TERM...MOZLEY
LONG TERM...LW
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS ALBANY NY
207 PM EDT THU AUG 1 2013
.SYNOPSIS...
UNSETTLED WEATHER RETURNS THIS AFTERNOON...AS A LOW
PRESSURE SYSTEM...AND ASSOCIATED FRONTAL BOUNDARIES APPROACH FROM
THE GREAT LAKES REGION AND MID ATLANTIC REGION. THIS WILL BRING
OCCASIONAL SHOWERS TO THE REGION FOR THIS AFTERNOON AND EVENING.
DRIER WEATHER IS EXPECTED ON FRIDAY AS A WEAK RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT...THE LATEST REGIONAL MOSAIC RADAR AND SATELLITE
IMAGERY CONTINUED TO INDICATE AN INCREASE IN SHOWER ACTIVITY ACROSS
THE REGION...MAINLY FROM THE HUDSON VALLEY WEST AS ISENTROPIC LIFT
COMMENCES.
THERE WAS A BREAK IN THE SHOWERS ACROSS CENTRAL NY STATE BUT ANOTHER
LINE OF SHOWERS AND EVEN A FEW EMBEDDED THUNDERSTORMS WAS FORMING IN
WESTERN NY...ASSOCIATED WITH THE OCCLUDED FRONT.
TEMPERATURES WILL LIKELY NOT RISE MUCH IF AT ALL ACROSS THE REGION
AND IN SOME CASES MIGHT EVEN FALL A POINT OR TWO. THEY WILL TOP OUT
GENERALLY IN THE 70S.
THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT AND THE LOCAL WRF CONTINUE
TO INDICATE SHOWERS ACROSS OUR REGION...PEAKING IN THE EARLY
AFTERNOON....THEN TAPERING FOR A BIT. BOTH MODELS DUE BRING THE LINE
OF SHOWERS OVER WESTERN NEW YORK ACROSS OUR REGION AROUND 8PM. ANY
OF THESE SHOWERS OR STORMS COULD BE LOCALLY AND BRIEFLY HEAVY...BUT
NOT ENOUGH TO INCLUDE IN THE ENHANCED WORDING.
IN ADDITION TO THE ISENTROPIC LIFT...STRONG A THETA E RIDGE BUILDS
ACROSS THE REGION H10-H8 WITH PWATS INCREASING TO ABOVE 1.5 INCHES.
HAVE CAT POPS ACROSS THE REGION THIS AFTERNOON.
FOR THIS UPDATE...JUST MINOR RE-TOOLING BUT DID RAISE DEWPOINTS A
BIT INTO THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
FOR TONIGHT...HEAVIEST RAIN EXPECTED DURING THE FIRST HALF OF THE
NIGHT AS AXIS OF HIGH PWATS AND THETA E RIDGE SHIFTS EAST OF FA
AFT 06Z. HAVE ALSO PLACED SLIGHT CHANCE OF TSTMS IN GRIDS AS
SHOWALTER INDICES BRIEFLY GO NEGATIVE THIS EVENING DESPITE SB
CAPES ONLY REACHING A FEW HUNDRED J/KG. EXPECT LOWS TONIGHT TO
RANGE FROM THE MID 50S TO LOWER 60S.
FRIDAY AND FRIDAY NIGHT EXPECT GENERALLY DRY CONDITIONS AS A WEAK
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION ON FRIDAY AND SLIDES
EAST FRIDAY NIGHT. HAVE KEPT LOW CHANCE POPS ACROSS NORTHWEST THIRD
OF FA DURING THESE PERIODS AS CANNOT RULE OUT SOME SHOWERS OFF
EAST END OF LAKE ONTARIO INTO THIS AREA WITH FAIRLY GOOD COLD POOL
ALOFT. HIGHS ON FRIDAY ARE EXPECTED TO BE IN THE 70S TO LOWER 80S
WITH LOWS FRIDAY NIGHT IN THE 50S.
ON SATURDAY EXPECT SCATTERED SHOWERS AHEAD OF A SECOND COLD FRONT
WITH THE HIGHEST POPS ACROSS THE NORTHERN MOUNTAINS. SB CAPES ARE
FAIRLY LOW GENERALLY 200-500 J/KG WITH SHOWALTER INDICES REMAINING
POSITIVE THROUGHOUT SATURDAY AND SATURDAY NIGHT. SO WILL LEAVE ANY
MENTION OF THUNDER OUT AT THIS TIME. EXPECT HIGHS ON SATURDAY TO
BE IN THE 70S TO LOWER 80S WITH LOWS SATURDAY NIGHT RANGING FROM
THE UPPER 40S NORTHWEST TO UPPER 50S SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE EXTENDED FORECAST FEATURES A MEAN LONGWAVE TROUGH INFLUENCING
THE SENSIBLE OVER THE NORTHEAST. THE TROUGH WILL KEEP TEMPS SLIGHTLY
COOLER THAN NORMAL WITH INTERMITTENT DISTURBANCES IMPACTING NY AND
NEW ENGLAND IN THE W/NW FLOW ALOFT. THE 00Z/01 HPC GUIDANCE WAS
FOLLOWED CLOSELY.
SUNDAY-MONDAY NT...THE UPPER LEVEL TROUGH REMAINS QUITE AMPLIFIED
DURING THIS TIME FRAME...WITH EMBEDDED UPPER LEVEL IMPULSES DROPPING
SOUTHEAST INTO THE REGION. THESE OCCASIONAL BOUTS OF
SYNOPTIC/DYNAMICAL LIFT...COMBINED WITH ADDED LAKE MOISTURE...SHOULD
ALLOW FOR ISOLATED TO SCATTERED SHOWERS TO OCCUR SUNDAY...ESP IN THE
AFTERNOON...THEN AGAIN MONDAY...PARTICULARLY ACROSS THE SOUTHERN
ADIRONDACKS...SOUTHERN VT AND NW MA...WHERE LOW CHC POPS ARE
INDICATED...WITH SLIGHT CHC POPS EXTENDING FURTHER SOUTH. IT WILL BE
QUITE BREEZY SUNDAY GIVEN A FAIRLY TIGHT PRESSURE GRADIENT BETWEEN
THE LOW ACROSS SOUTHEAST CANADA...AND HIGH PRESSURE ACROSS THE GREAT
LAKES REGION. TEMPS WILL REMAIN BELOW NORMAL...WITH SUNDAY MAXES
GENERALLY ONLY IN THE LOWER/MID 70S IN VALLEYS FROM ALBANY N AND
W...AND 75-80 SOUTH OF ALBANY...WITH HIGHER ELEVATIONS ACROSS
THE SOUTHERN ADIRONDACKS AND WESTERN NEW ENGLAND ONLY REACHING THE
60S. FOR SUN NT/MON AM...EXPECT WIDESPREAD 40S ACROSS THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND...AND ALSO WITHIN PORTIONS OF
THE EASTERN CATSKILLS/SCHOHARIE VALLEY AND LAKE GEORGE/SARATOGA
REGION...WITH LOWER/MID 50S ELSEWHERE. ON MONDAY...MAXES MAY WARM
SLIGHTLY...WITH GENERALLY 75-80 IN VALLEYS...AND UPPER 60S TO LOWER
70S ACROSS HIGHER ELEVATIONS.
TUE-WED...MODELS DIFFER ON TIMING OF STRONGER UPPER LEVEL IMPULSES
APPROACHING FROM THE WEST...AND ALSO THE AMOUNT OF INCREASING LOW
LEVEL MOISTURE FROM THE SOUTHWEST. HOWEVER...GENERAL CONSENSUS AT
THIS TIME RANGE IS FOR AN INCREASED CHANCE FOR SHOWERS...WITH LOW
CHC POPS INDICATED. TEMPS ARE FORECAST TO REACH THE 70S IN
VALLEYS...AND 60S ACROSS HIGHER ELEVATIONS FOR MAXES...AND GENERALLY
50S TO LOWER 60S IN VALLEYS...AND LOWER 50S FOR HIGHER ELEVATIONS
FOR MINS. SHOULD SHOWERS OR A STEADIER RAINFALL OCCUR ON ANY OF
THESE DAYS...EVEN COOLER MAX TEMPS COULD OCCUR.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
A LOW PRESSURE SYSTEM WILL MOVE SOUTH OF THE REGION THIS
AFTERNOON...WHILE ANOTHER ONE PASSES NORTH INTO SRN QUEBEC. THE
OCCLUDED BOUNDARY TO THIS SYSTEM WILL CONTINUE THE THREAT OF
SHOWERS...AND PERHAPS A FEW RUMBLES OF THUNDER INTO THIS EVENING.
HIGH PRESSURE WILL BRIEFLY BUILD IN TOMORROW.
CONDITIONS WILL CONTINUE TO LOWER INTO THE MVFR RANGE AT ALL THE
TAF SITES IN TERMS OF CIGS AND VSBYS THIS AFTERNOON. KPSF AND KPOU
HAVE ALREADY HAD MVFR CIGS...AND THIS SHOULD LAST INTO THE
EVENING. KALB AND KGFL WILL LIKELY LOWER IN THE NEXT FEW HOURS
WITH CIGS AND PERHAPS VSBYS. THE RAIN SHIELD IS A LITTLE SPOTTY
AND SHOULD FILL IN BY THE MID AFTERNOON SOUTH AND EAST OF THE
CAPITAL REGION. THERE MAYBE A FEW RUMBLES THUNDER THIS EVENING
WHEN THE OCCLUDED FRONT ARRIVES. THE PROBABILITY IS NOT HIGH
ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME.
CIGS AND VSBYS WILL CONTINUE TO LOWER TO POTENTIALLY THE IFR RANGE
...AS THE AIR MASS MOISTENS...AND PERHAPS SOME HEAVIER SHOWERS IMPACT
THE SRN PORTION OF THE REGION /SOUTH AND EAST OF KALB/ SHORTLY
BEFORE OR JUST AFTER MIDNIGHT. THE LOW MVFR/IFR CIGS MAY CONTINUE
TO 11-13Z...BEFORE STRONGER MIXING KICKS IN BEHIND THE FRONT...AND
DRIER AIR FILTERS IN.
THE LATEST GUIDANCE SHOWS LESS OF A THREAT OF LLWS. IT HAS BEEN
REMOVED FROM THE TAFS...AS THE STRONGEST WINDS AT 2500 KFT AGL
WILL BE AROUND 30-35 KTS.
THE SOUTH WINDS AT 5-12 KTS WITH SOME GUSTS TO 20-25 KTS AT KALB
WILL PERSIST THIS AFTERNOON. THEY WILL SLOWLY VEER TO THE
SOUTHWEST TO WEST AT LESS THAN 10 KTS SHORTLY BEFORE MIDNIGHT. THE
WINDS WILL INCREASE FROM THE WEST TO NORTHWEST AT 5-10 KTS AFTER
12Z.
OUTLOOK...
FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...SLIGHT CHC TSRA.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
MONDAY: LOW OPERATIONAL IMPACT.BREEZY ISOLATED SHRA.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED CONCERNS ARE EXPECTED AT THIS TIME.
UNSETTLED WEATHER RETURNS TODAY AS A LOW PRESSURE SYSTEM...AND
ASSOCIATED FRONTAL BOUNDARIES APPROACH FROM THE GREAT LAKES REGION
AND THE OHIO VALLEY. THIS WILL BRING WIDESPREAD SHOWERS TO THE
REGION FOR THIS AFTERNOON AND EVENING. DRIER WEATHER IS EXPECTED
ON FRIDAY AS A WEAK RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION
WITH MORE SCATTERED SHOWERS EXPECTED OVER THE WEEKEND.
&&
.HYDROLOGY...
SOME LOCALLY HEAVY RAINFALL IS EXPECTED THIS AFTERNOON INTO THIS
EVENING WITH THE HEAVIEST AMOUNTS EXPECTED TO FALL ACROSS THE
EASTERN CATSKILLS AND SOUTHERN ADIRONDACKS. TOTAL RAINFALL AMOUNTS
ARE GENERALLY EXPECTED TO BE BETWEEN 0.75 AND 1.5 INCHES WITH
LOCALLY HIGHER AMOUNTS POSSIBLE IN WIDELY SCATTERED THUNDERSTORMS
THIS EVENING. WHILE THESE AMOUNTS WILL NOT BE ENOUGH TO PRODUCE
ANY WIDESPREAD FLOODING...PONDING OF WATER ON ROADWAYS AND
LOCALIZED FLOODING OF POORLY DRAINED LOW LYING AREAS IS POSSIBLE.
DRIER WEATHER IS EXPECTED ON FRIDAY AS A WEAK RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION. MORE UNSETTLED WEATHER IS
EXPECTED OVER THE WEEKEND WITH SCATTERED SHOWERS BOTH SATURDAY AND
SUNDAY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/11/WASULA
NEAR TERM...HWJIV/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1230 PM EDT THU AUG 1 2013
.SYNOPSIS...
UNSETTLED WEATHER RETURNS THIS AFTERNOON...AS A LOW
PRESSURE SYSTEM...AND ASSOCIATED FRONTAL BOUNDARIES APPROACH FROM
THE GREAT LAKES REGION AND MID ATLANTIC REGION. THIS WILL BRING
OCCASIONAL SHOWERS TO THE REGION FOR THIS AFTERNOON AND EVENING.
DRIER WEATHER IS EXPECTED ON FRIDAY AS A WEAK RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT...THE LATEST REGIONAL MOSAIC RADAR AND SATELLITE
IMAGERY CONTINUED TO INDICATE AN INCREASE IN SHOWER ACTIVITY ACROSS
THE REGION...MAINLY FROM THE HUDSON VALLEY WEST AS ISENTROPIC LIFT
COMMENCES.
THERE WAS A BREAK IN THE SHOWERS ACROSS CENTRAL NY STATE BUT ANOTHER
LINE OF SHOWERS AND EVEN A FEW EMBEDDED THUNDERSTORMS WAS FORMING IN
WESTERN NY...ASSOCIATED WITH THE OCCLUDED FRONT.
TEMPERATURES WILL LIKELY NOT RISE MUCH IF AT ALL ACROSS THE REGION
AND IN SOME CASES MIGHT EVEN FALL A POINT OR TWO. THEY WILL TOP OUT
GENERALLY IN THE 70S.
THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT AND THE LOCAL WRF CONTINUE
TO INDICATE SHOWERS ACROSS OUR REGION...PEAKING IN THE EARLY
AFTERNOON....THEN TAPERING FOR A BIT. BOTH MODELS DUE BRING THE LINE
OF SHOWERS OVER WESTERN NEW YORK ACROSS OUR REGION AROUND 8PM. ANY
OF THESE SHOWERS OR STORMS COULD BE LOCALLY AND BRIEFLY HEAVY...BUT
NOT ENOUGH TO INCLUDE IN THE ENHANCED WORDING.
IN ADDITION TO THE ISENTROPIC LIFT...STRONG A THETA E RIDGE BUILDS
ACROSS THE REGION H10-H8 WITH PWATS INCREASING TO ABOVE 1.5 INCHES.
HAVE CAT POPS ACROSS THE REGION THIS AFTERNOON.
FOR THIS UPDATE...JUST MINOR RE-TOOLING BUT DID RAISE DEWPOINTS A
BIT INTO THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
FOR TONIGHT...HEAVIEST RAIN EXPECTED DURING THE FIRST HALF OF THE
NIGHT AS AXIS OF HIGH PWATS AND THETA E RIDGE SHIFTS EAST OF FA
AFT 06Z. HAVE ALSO PLACED SLIGHT CHANCE OF TSTMS IN GRIDS AS
SHOWALTER INDICES BRIEFLY GO NEGATIVE THIS EVENING DESPITE SB
CAPES ONLY REACHING A FEW HUNDRED J/KG. EXPECT LOWS TONIGHT TO
RANGE FROM THE MID 50S TO LOWER 60S.
FRIDAY AND FRIDAY NIGHT EXPECT GENERALLY DRY CONDITIONS AS A WEAK
RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION ON FRIDAY AND SLIDES
EAST FRIDAY NIGHT. HAVE KEPT LOW CHANCE POPS ACROSS NORTHWEST THIRD
OF FA DURING THESE PERIODS AS CANNOT RULE OUT SOME SHOWERS OFF
EAST END OF LAKE ONTARIO INTO THIS AREA WITH FAIRLY GOOD COLD POOL
ALOFT. HIGHS ON FRIDAY ARE EXPECTED TO BE IN THE 70S TO LOWER 80S
WITH LOWS FRIDAY NIGHT IN THE 50S.
ON SATURDAY EXPECT SCATTERED SHOWERS AHEAD OF A SECOND COLD FRONT
WITH THE HIGHEST POPS ACROSS THE NORTHERN MOUNTAINS. SB CAPES ARE
FAIRLY LOW GENERALLY 200-500 J/KG WITH SHOWALTER INDICES REMAINING
POSITIVE THROUGHOUT SATURDAY AND SATURDAY NIGHT. SO WILL LEAVE ANY
MENTION OF THUNDER OUT AT THIS TIME. EXPECT HIGHS ON SATURDAY TO
BE IN THE 70S TO LOWER 80S WITH LOWS SATURDAY NIGHT RANGING FROM
THE UPPER 40S NORTHWEST TO UPPER 50S SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE EXTENDED FORECAST FEATURES A MEAN LONGWAVE TROUGH INFLUENCING
THE SENSIBLE OVER THE NORTHEAST. THE TROUGH WILL KEEP TEMPS SLIGHTLY
COOLER THAN NORMAL WITH INTERMITTENT DISTURBANCES IMPACTING NY AND
NEW ENGLAND IN THE W/NW FLOW ALOFT. THE 00Z/01 HPC GUIDANCE WAS
FOLLOWED CLOSELY.
SUNDAY-MONDAY NT...THE UPPER LEVEL TROUGH REMAINS QUITE AMPLIFIED
DURING THIS TIME FRAME...WITH EMBEDDED UPPER LEVEL IMPULSES DROPPING
SOUTHEAST INTO THE REGION. THESE OCCASIONAL BOUTS OF
SYNOPTIC/DYNAMICAL LIFT...COMBINED WITH ADDED LAKE MOISTURE...SHOULD
ALLOW FOR ISOLATED TO SCATTERED SHOWERS TO OCCUR SUNDAY...ESP IN THE
AFTERNOON...THEN AGAIN MONDAY...PARTICULARLY ACROSS THE SOUTHERN
ADIRONDACKS...SOUTHERN VT AND NW MA...WHERE LOW CHC POPS ARE
INDICATED...WITH SLIGHT CHC POPS EXTENDING FURTHER SOUTH. IT WILL BE
QUITE BREEZY SUNDAY GIVEN A FAIRLY TIGHT PRESSURE GRADIENT BETWEEN
THE LOW ACROSS SOUTHEAST CANADA...AND HIGH PRESSURE ACROSS THE GREAT
LAKES REGION. TEMPS WILL REMAIN BELOW NORMAL...WITH SUNDAY MAXES
GENERALLY ONLY IN THE LOWER/MID 70S IN VALLEYS FROM ALBANY N AND
W...AND 75-80 SOUTH OF ALBANY...WITH HIGHER ELEVATIONS ACROSS
THE SOUTHERN ADIRONDACKS AND WESTERN NEW ENGLAND ONLY REACHING THE
60S. FOR SUN NT/MON AM...EXPECT WIDESPREAD 40S ACROSS THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND...AND ALSO WITHIN PORTIONS OF
THE EASTERN CATSKILLS/SCHOHARIE VALLEY AND LAKE GEORGE/SARATOGA
REGION...WITH LOWER/MID 50S ELSEWHERE. ON MONDAY...MAXES MAY WARM
SLIGHTLY...WITH GENERALLY 75-80 IN VALLEYS...AND UPPER 60S TO LOWER
70S ACROSS HIGHER ELEVATIONS.
TUE-WED...MODELS DIFFER ON TIMING OF STRONGER UPPER LEVEL IMPULSES
APPROACHING FROM THE WEST...AND ALSO THE AMOUNT OF INCREASING LOW
LEVEL MOISTURE FROM THE SOUTHWEST. HOWEVER...GENERAL CONSENSUS AT
THIS TIME RANGE IS FOR AN INCREASED CHANCE FOR SHOWERS...WITH LOW
CHC POPS INDICATED. TEMPS ARE FORECAST TO REACH THE 70S IN
VALLEYS...AND 60S ACROSS HIGHER ELEVATIONS FOR MAXES...AND GENERALLY
50S TO LOWER 60S IN VALLEYS...AND LOWER 50S FOR HIGHER ELEVATIONS
FOR MINS. SHOULD SHOWERS OR A STEADIER RAINFALL OCCUR ON ANY OF
THESE DAYS...EVEN COOLER MAX TEMPS COULD OCCUR.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
AFTER ANY PATCHES OF MIST BURN OFF AND ASSOCIATED MVFR VSBYS AT KGFL
AND KPSF LIFT BTWN 12Z-14Z/THU...VFR CONDITIONS WILL THEN OCCUR FROM
SUNRISE THROUGH LATE MORNING...BEFORE LOWERING INTO THE MVFR RANGE
FOR VSBYS/CIGS AS SHOWERS OR A PERIOD OF STEADY RAIN OVERSPREADS THE
TAF SITES BETWEEN 16Z-18Z. SOME EMBEDDED PERIODS OF IFR CIGS/VSBYS
COULD OCCUR WITHIN ANY HEAVIER RAIN ELEMENTS...ESP AT KPSF AND KPOU
WHICH WILL BE CLOSER TO WARM RAIN PROCESSES AND POTENTIAL SMALLER
DROPLET SIZE AND LOWER CIGS. THE STEADIEST RAIN SHOULD PERSIST MOST
OF THE AFTERNOON.
THE RAIN AND/OR SHOWERS SHOULD BECOME MORE SCATTERED AFTER
23Z/THU...AND SHOULD TAPER OFF FROM W TO E BETWEEN 00Z-04Z/THU.
HOWEVER...VERY MOIST CONDITIONS BEHIND A WIND SHIFT SHOULD CREATE
WIDESPREAD LOW MVFR TO IFR CIGS/VSBYS...ESP AT KGFL/KPSF/KPOU.
THERE IS A SLIGHT CHANCE FOR EMBEDDED THUNDERSTORMS THIS AFTERNOON
AND EVENING...BUT OVERALL PROBABILITY FOR ANY IMPACTING A TAF SITE
WILL BE RATHER LOW...SO WILL KEEP OUT MENTION IN TAFS AT THIS TIME.
SOUTH WINDS WILL INCREASE AFTER 14Z/THU TO 8-12 KT...WITH SOME
GUSTINESS DEVELOPING...ESP AT KALB WHERE GUSTS OF 25 KT OR SLIGHTLY
HIGHER COULD OCCUR. SOUTH WINDS SHOULD DECREASE THIS EVENING INTO
THE OVERNIGHT HOURS TO 5-10 KT...WITH WINDS GRADUALLY VEERING INTO
THE SOUTHWEST TO WEST TOWARD OR AFTER 04Z/FRI.
LOW LEVEL WIND SHEAR WILL DEVELOP AT KGFL/KPOU AND KPSF THIS
AFTERNOON AS WINDS AROUND 2000 FT AGL INCREASE FROM THE SOUTH AT
30-35 KT...WHILE SFC WINDS REMAIN GENERALLY UNDER 12 KT. AT
KALB...ENOUGH MIXING SHOULD ALLOW STRONGER WINDS TO TRANSFER
DOWNWARD AT TIMES...REDUCING LOW LEVEL WIND SHEAR POTENTIAL.
OUTLOOK...
FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
MONDAY: LOW OPERATIONAL IMPACT.BREEZY ISOLATED SHRA.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED CONCERNS ARE EXPECTED AT THIS TIME.
UNSETTLED WEATHER RETURNS TODAY AS A LOW PRESSURE SYSTEM...AND
ASSOCIATED FRONTAL BOUNDARIES APPROACH FROM THE GREAT LAKES REGION
AND THE OHIO VALLEY. THIS WILL BRING WIDESPREAD SHOWERS TO THE
REGION FOR THIS AFTERNOON AND EVENING. DRIER WEATHER IS EXPECTED
ON FRIDAY AS A WEAK RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION
WITH MORE SCATTERED SHOWERS EXPECTED OVER THE WEEKEND.
&&
.HYDROLOGY...
SOME LOCALLY HEAVY RAINFALL IS EXPECTED THIS AFTERNOON INTO THIS
EVENING WITH THE HEAVIEST AMOUNTS EXPECTED TO FALL ACROSS THE
EASTERN CATSKILLS AND SOUTHERN ADIRONDACKS. TOTAL RAINFALL AMOUNTS
ARE GENERALLY EXPECTED TO BE BETWEEN 0.75 AND 1.5 INCHES WITH
LOCALLY HIGHER AMOUNTS POSSIBLE IN WIDELY SCATTERED THUNDERSTORMS
THIS EVENING. WHILE THESE AMOUNTS WILL NOT BE ENOUGH TO PRODUCE
ANY WIDESPREAD FLOODING...PONDING OF WATER ON ROADWAYS AND
LOCALIZED FLOODING OF POORLY DRAINED LOW LYING AREAS IS POSSIBLE.
DRIER WEATHER IS EXPECTED ON FRIDAY AS A WEAK RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION. MORE UNSETTLED WEATHER IS
EXPECTED OVER THE WEEKEND WITH SCATTERED SHOWERS BOTH SATURDAY AND
SUNDAY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/11/WASULA
NEAR TERM...HWJIV/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...KL/WASULA
FIRE WEATHER...11
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
625 PM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT...ATTACHED TO LOW PRESSURE OVER CANADA...WILL CROSS THE
AREA TONIGHT. HIGH PRESSURE FROM THE MIDWEST WILL THEN BUILD IN AND
AFFECT OUR WEATHER FRIDAY. ANOTHER COLD FRONT FROM CANADA WILL
ARRIVE OVER OUR AREA LATER SATURDAY AND MOVE AWAY BY SUNDAY. HIGH
PRESSURE WILL BUILD IN FOR SUNDAY AND PERSIST INTO EARLY NEXT WEEK.
A PAIR OF FRONTAL SYSTEMS SHOULD THEN MOVE THROUGH THE AREA TUESDAY
AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE LATEST RADAR IMAGERY SHOWED...NOT MUCH! THERE WERE SOME
THUNDERSTORMS TRYING TO GET A LITTLE MORE ORGANIZED IN LANCASTER
AND YORK COUNTIES BUT HAVE BEEN STRUGGLING AND THERE HAS BEEN A
PERSISTENT AREA OF SHOWERS AND STORMS ALONG THE LOWER DELMARVA
INTO EXTREME SRN DE. THERE ARE ALSO TSTMS NR WASHINGTON DC, BUT
ACRS OUR CWA THERE ARE SOME SCT SHWRS AND THAT`S ABOUT IT.
IT REMAINS TO BE SEEN IF ANY OF THE ACTIVITY TO OUR W WILL HOLD
TOGETHER TO IMPACT OUR AREA. THE HRRR DOES SHOW THAT AT LEAST SOME
SHOWERS WILL CROSS THE REGION. HAVE TRIMMED POPS BACK SOMEWHAT,
AND CONTINUED THE DOWNWARD TREND AS THE NIGHT PROGRESSES.
DUE TO THE LACK OF ORGANIZED ACTIVITY, HAVE OPTED TO DROP THE
FLASH FLOOD WATCH WITH THIS UPDATE. THERE STILL COULD BE SOME HEAVY
SHOWERS, BUT ANY FLOODING SHOULD BE LOCALIZED AND BRIEF.
THE COLD FRONT IS FORECAST TO CLEAR THE AREA LATER TONIGHT, WITH THE
SHOWERS/THUNDER ENDING BY 06Z. AS A RESULT, THE POPS ARE LOWERED A
BIT FASTER THAN PREVIOUSLY. THE FLOW WILL TURN WEST-NORTHWEST IN THE
WAKE OF THE COLD FRONT WITH SOME DRIER AIR WORKING IN. THE LOW-LEVEL
MOISTURE WILL TEND TO HOLD THE LONGEST ACROSS THE EASTERN AND
SOUTHERN ZONES, AND THEREFORE AS CLEARING OCCURS LATER THERE COULD
BE SOME LOCAL FOG.
AS FOR LOW TEMPERATURES, WE USED A GFS/NAM MOS BLEND WITH SOME MINOR
ADJUSTMENTS. THE LAMP/LAV GUIDANCE WAS USED TO ASSIST IN TRENDS THUS
FAR, AND HIGHS FOR THE REMAINDER OF THE AFTERNOON WERE LOWERED SOME.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
OUR WEATHER WILL BE DOMINATED BY AN UPPER-LEVEL TROUGH ACROSS THE
NORTHEAST, HOWEVER WEAK HIGH PRESSURE WILL BE BUILDING TO OUR
SOUTHWEST AND SOUTH. A COLD FRONT IS FORECAST TO BE TO OUR EAST TO
START THE DAY, WITH SOME DRYING CONTINUING TO WORK ITS WAY IN. THE
FORECAST SOUNDINGS SHOW THE DRYING NICELY, HOWEVER AS THE BOUNDARY
LAYER WARMS IT APPEARS WE ARE ABLE TO REACH THE CONVECTIVE
TEMPERATURES. AS A RESULT, SOME CUMULUS/STRATOCUMULUS SHOULD DEVELOP
FROM ABOUT MIDDAY ON. THERE MAY BE SOME MORE CLOUDS ACROSS THE FAR
NORTH IN THE AFTERNOON AS SHORT WAVE ENERGY GLANCES THAT AREA WITH
PERHAPS AN ISOLATED SHOWER. ELSEWHERE, NO SHOWERS ARE FORECAST ATTM
AS A CAP IS INDICATED TO DEVELOP DURING THE AFTERNOON.
THE HEATING OF THE BOUNDARY LAYER ALONG WITH SOME TIGHTENING OF THE
PRESSURE GRADIENT WILL ALLOW THE WINDS TO INCREASE SOME, AS THE
VERTICAL MIXING DEEPENS. WE DID INCREASE THE WINDS A BIT FROM
CONTINUITY. AS FOR HIGH TEMPERATURES, WE WENT WITH AN EVEN GFS/NAM
MOS BLEND THEN MADE SOME TWEAKS. GIVEN MORE SUNSHINE EXPECTED AND A
WESTERLY FLOW, TEMPERATURES ARE FORECAST TO BE WARMER COMPARED TO
TODAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A MEAN UPPER TROUGH WILL BE ACROSS THE MIDDLE ATLANTIC REGION DURING
MUCH OF THE LONG TERM PART OF THE FORECAST. THIS WILL PREVENT ANY
EXCESSIVE HEAT FROM BUILDING ACROSS THE AREA. IT WILL
PROMOTE...HOWEVER...RATHER QUICK CHANGES TO THE WEATHER WITH SEVERAL
SYSTEM SLATED TO AFFECT THE AREA THIS WEEKEND AND INTO THE MIDDLE OF
NEXT WEEK.
HIGH PRESSURE WILL BE ACROSS THE AREA FRIDAY NIGHT AND THE FIRST
PART OF SATURDAY...DRY WEATHER WITH MOSTLY SEASONABLE TEMPERATURES
EXPECTED. SATURDAY AND SATURDAY NIGHT WILL SEE AN INCREASING CHC FOR
SHOWERS AS ANOTHER COLD FRONT MOVES DOWN FROM THE NORTH AND CROSSES
THE AREA. THE SHOWERS SHOULD END ACROSS THE AREA SUNDAY MORNING WITH
ONLY SMALL TOTALS EXPECTED SUNDAY.
SEVERAL DRY DAYS ARE EXPECTED FROM LATER SUNDAY INTO MONDAY NIGHT AS
HIGH PRESSURE BUILDS BACK ACROSS THE REGION. TEMPERATURES DURING
THIS PERIOD WILL BE A FEW DEGREES BELOW NORMAL WITH HIGHS MOSTLY IN
THE LOW 80S (CENTRAL/SOUTH) AND MID TO UPPER 70S (NORTH). LOWS WILL
MOSTLY BE IN THE 50S NORTH/WEST AND LOW 60S SOUTH/EAST.
THE RETURN FLOW BEHIND THE DEPARTING HIGH WILL BRING INCREASED
MOISTURE AND BETTER CHC FOR SHOWERS FROM NEXT TUE INTO WED. WE
GENERALLY WENT ALONG WITH HPC POPS WITH ONLY MINOR CHANGES.
TEMPERATURES WILL BE WITHIN A FEW DEGREES OF NORMAL.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
CONDS RANGED FROM VFR TO IFR ACRS THE REGION, WITH THE LOWEST CIGS
RIGHT NOW ACRS THE I-95 CORRIDOR. EXPECT THE LWR (HOPEFULLY MVFR)
CIGS TO CONTINUE THRU THE EVENING UNTIL FROPA AND THEN AS THE WIND
BECOMES MORE WLY AND DRIER AIR MOVES IN, THE CIGS WILL IMPROVE TO
VFR. THIS COULD END UP HAPPENING SOONER THEN EXPECTED, OR LATER.
THERE ARE SOME TSRA OUT TWD LANCASTER AND WHILE ALL TSRA WAS
REMOVED FROM THE TAFS DUE TO THE ISOLD NATURE, THEY CAN NOT BE
RULED OUT, AT LEAST FOR THE NEXT FEW HOURS AND WILL BE HANDLED
WITH AMDTS IF THEY WERE TO OCCUR.
FRIDAY...VFR WITH SOME CLOUD BASES AROUND 5,000 FEET. WESTERLY WINDS
AROUND 10 KNOTS. HOWEVER, SOME GUSTS UP TO 20 KNOTS ARE ANTICIPATED
AS THE VERTICAL MIXING DEEPENS ESPECIALLY FROM MIDDAY ON.
OUTLOOK...
FRI NIGHT THRU SAT AFTERNOON...MOSTLY VFR.
SAT AFTERNOON THRU SUN MORNING...SCATTERED SHOWERS/TSTMS WITH
LOWER CONDITIONS POSSIBLE.
SUN AFTERNOON THRU TUESDAY...MOSTLY VFR. MORNING FOG POSSIBLE.
&&
.MARINE...
A SOUTHERLY FLOW WILL CONTINUE AHEAD OF A COLD FRONT. A WEAK SURFACE
LOW WILL MOVE ACROSS THE AREA THIS EVENING, FOLLOWED BY A COLD FRONT
LATER TONIGHT. THE SOUTHERLY FLOW HAS INCREASED WITH SOME GUSTS UP
TO 20 KNOTS. THIS IS EXPECTED TO CONTINUE FOR A TIME TONIGHT, THEN A
WIND SHIFT TO THE WEST LATE. A WESTERLY FLOW IS FORECAST FOR FRIDAY,
HOWEVER IT WILL BE LESS THAN 20 KNOTS. THE FLOW MAY ACTUALLY BACK A
BIT TO THE SOUTHWEST IN THE AFTERNOON GIVEN BETTER BOUNDARY LAYER
HEATING. SEAS HAVE BEEN SLOWLY BUILDING THIS AFTERNOON, AND WHILE
THEY COULD TOUCH 5 FEET ON THE OCEAN FOR A TIME WE BELIEVE THIS IS
MARGINAL AND MAY NOT LAST LONG. THEREFORE, WE WILL HOLD WITH NO
SMALL CRAFT ADVISORY ATTM. THE SEAS WILL LOWER SOME LATE AND ON
FRIDAY AS THE FLOW TURNS OFFSHORE FOR A TIME.
OUTLOOK...
SUB-SCA CONDITIONS EXPECTED ON THE WATERS THROUGH THE WEEKEND AND
EARLY NEXT WEEK. POSSIBLE SCA SEAS NEXT TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GORSE/NIERENBERG
SHORT TERM...GORSE
LONG TERM...O`HARA
AVIATION...GORSE/NIERENBERG/O`HARA
MARINE...GORSE/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
620 PM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT...ATTACHED TO LOW PRESSURE OVER CANADA...WILL CROSS THE
AREA TONIGHT. HIGH PRESSURE FROM THE MIDWEST WILL THEN BUILD IN AND
AFFECT OUR WEATHER FRIDAY. ANOTHER COLD FRONT FROM CANADA WILL
ARRIVE OVER OUR AREA LATER SATURDAY AND MOVE AWAY BY SUNDAY. HIGH
PRESSURE WILL BUILD IN FOR SUNDAY AND PERSIST INTO EARLY NEXT WEEK.
A PAIR OF FRONTAL SYSTEMS SHOULD THEN MOVE THROUGH THE AREA TUESDAY
AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE LATEST RADAR IMAGERY SHOWED...NOT MUCH! THERE WERE SOME
THUNDERSTORMS TRYING TO GET A LITTLE MORE ORGANIZED IN LANCASTER
AND YORK COUNTIES BUT HAVE BEEN STRUGGLING AND THERE HAS BEEN A
PERSISTENT AREA OF SHOWERS AND STORMS ALONG THE LOWER DELMARVA
INTO EXTREME SRN DE. THERE ARE ALSO TSTMS NR WASHINGTON DC, BUT
ACRS OUR CWA THERE ARE SOME SCT SHWRS AND THAT`S ABOUT IT.
IT REMAINS TO BE SEEN IF ANY OF THE ACTIVITY TO OUR W WILL HOLD
TOGETHER TO IMPACT OUR AREA. THE HRRR DOES SHOW THAT AT LEAST SOME
SHOWERS WILL CROSS THE REGION. HAVE TRIMMED POPS BACK SOMEWHAT,
AND CONTINUED THE DOWNWARD TREND AS THE NIGHT PROGRESSES.
THE COLD FRONT IS FORECAST TO CLEAR THE AREA LATER TONIGHT, WITH THE
SHOWERS/THUNDER ENDING BY 06Z. AS A RESULT, THE POPS ARE LOWERED A
BIT FASTER THAN PREVIOUSLY. THE FLOW WILL TURN WEST-NORTHWEST IN THE
WAKE OF THE COLD FRONT WITH SOME DRIER AIR WORKING IN. THE LOW-LEVEL
MOISTURE WILL TEND TO HOLD THE LONGEST ACROSS THE EASTERN AND
SOUTHERN ZONES, AND THEREFORE AS CLEARING OCCURS LATER THERE COULD
BE SOME LOCAL FOG.
AS FOR LOW TEMPERATURES, WE USED A GFS/NAM MOS BLEND WITH SOME MINOR
ADJUSTMENTS. THE LAMP/LAV GUIDANCE WAS USED TO ASSIST IN TRENDS THUS
FAR, AND HIGHS FOR THE REMAINDER OF THE AFTERNOON WERE LOWERED SOME.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
OUR WEATHER WILL BE DOMINATED BY AN UPPER-LEVEL TROUGH ACROSS THE
NORTHEAST, HOWEVER WEAK HIGH PRESSURE WILL BE BUILDING TO OUR
SOUTHWEST AND SOUTH. A COLD FRONT IS FORECAST TO BE TO OUR EAST TO
START THE DAY, WITH SOME DRYING CONTINUING TO WORK ITS WAY IN. THE
FORECAST SOUNDINGS SHOW THE DRYING NICELY, HOWEVER AS THE BOUNDARY
LAYER WARMS IT APPEARS WE ARE ABLE TO REACH THE CONVECTIVE
TEMPERATURES. AS A RESULT, SOME CUMULUS/STRATOCUMULUS SHOULD DEVELOP
FROM ABOUT MIDDAY ON. THERE MAY BE SOME MORE CLOUDS ACROSS THE FAR
NORTH IN THE AFTERNOON AS SHORT WAVE ENERGY GLANCES THAT AREA WITH
PERHAPS AN ISOLATED SHOWER. ELSEWHERE, NO SHOWERS ARE FORECAST ATTM
AS A CAP IS INDICATED TO DEVELOP DURING THE AFTERNOON.
THE HEATING OF THE BOUNDARY LAYER ALONG WITH SOME TIGHTENING OF THE
PRESSURE GRADIENT WILL ALLOW THE WINDS TO INCREASE SOME, AS THE
VERTICAL MIXING DEEPENS. WE DID INCREASE THE WINDS A BIT FROM
CONTINUITY. AS FOR HIGH TEMPERATURES, WE WENT WITH AN EVEN GFS/NAM
MOS BLEND THEN MADE SOME TWEAKS. GIVEN MORE SUNSHINE EXPECTED AND A
WESTERLY FLOW, TEMPERATURES ARE FORECAST TO BE WARMER COMPARED TO
TODAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A MEAN UPPER TROUGH WILL BE ACROSS THE MIDDLE ATLANTIC REGION DURING
MUCH OF THE LONG TERM PART OF THE FORECAST. THIS WILL PREVENT ANY
EXCESSIVE HEAT FROM BUILDING ACROSS THE AREA. IT WILL
PROMOTE...HOWEVER...RATHER QUICK CHANGES TO THE WEATHER WITH SEVERAL
SYSTEM SLATED TO AFFECT THE AREA THIS WEEKEND AND INTO THE MIDDLE OF
NEXT WEEK.
HIGH PRESSURE WILL BE ACROSS THE AREA FRIDAY NIGHT AND THE FIRST
PART OF SATURDAY...DRY WEATHER WITH MOSTLY SEASONABLE TEMPERATURES
EXPECTED. SATURDAY AND SATURDAY NIGHT WILL SEE AN INCREASING CHC FOR
SHOWERS AS ANOTHER COLD FRONT MOVES DOWN FROM THE NORTH AND CROSSES
THE AREA. THE SHOWERS SHOULD END ACROSS THE AREA SUNDAY MORNING WITH
ONLY SMALL TOTALS EXPECTED SUNDAY.
SEVERAL DRY DAYS ARE EXPECTED FROM LATER SUNDAY INTO MONDAY NIGHT AS
HIGH PRESSURE BUILDS BACK ACROSS THE REGION. TEMPERATURES DURING
THIS PERIOD WILL BE A FEW DEGREES BELOW NORMAL WITH HIGHS MOSTLY IN
THE LOW 80S (CENTRAL/SOUTH) AND MID TO UPPER 70S (NORTH). LOWS WILL
MOSTLY BE IN THE 50S NORTH/WEST AND LOW 60S SOUTH/EAST.
THE RETURN FLOW BEHIND THE DEPARTING HIGH WILL BRING INCREASED
MOISTURE AND BETTER CHC FOR SHOWERS FROM NEXT TUE INTO WED. WE
GENERALLY WENT ALONG WITH HPC POPS WITH ONLY MINOR CHANGES.
TEMPERATURES WILL BE WITHIN A FEW DEGREES OF NORMAL.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
CONDS RANGED FROM VFR TO IFR ACRS THE REGION, WITH THE LOWEST CIGS
RIGHT NOW ACRS THE I-95 CORRIDOR. EXPECT THE LWR (HOPEFULLY MVFR)
CIGS TO CONTINUE THRU THE EVENING UNTIL FROPA AND THEN AS THE WIND
BECOMES MORE WLY AND DRIER AIR MOVES IN, THE CIGS WILL IMPROVE TO
VFR. THIS COULD END UP HAPPENING SOONER THEN EXPECTED, OR LATER.
THERE ARE SOME TSRA OUT TWD LANCASTER AND WHILE ALL TSRA WAS
REMOVED FROM THE TAFS DUE TO THE ISOLD NATURE, THEY CAN NOT BE
RULED OUT, AT LEAST FOR THE NEXT FEW HOURS AND WILL BE HANDLED
WITH AMDTS IF THEY WERE TO OCCUR.
FRIDAY...VFR WITH SOME CLOUD BASES AROUND 5,000 FEET. WESTERLY WINDS
AROUND 10 KNOTS. HOWEVER, SOME GUSTS UP TO 20 KNOTS ARE ANTICIPATED
AS THE VERTICAL MIXING DEEPENS ESPECIALLY FROM MIDDAY ON.
OUTLOOK...
FRI NIGHT THRU SAT AFTERNOON...MOSTLY VFR.
SAT AFTERNOON THRU SUN MORNING...SCATTERED SHOWERS/TSTMS WITH
LOWER CONDITIONS POSSIBLE.
SUN AFTERNOON THRU TUESDAY...MOSTLY VFR. MORNING FOG POSSIBLE.
&&
.MARINE...
A SOUTHERLY FLOW WILL CONTINUE AHEAD OF A COLD FRONT. A WEAK SURFACE
LOW WILL MOVE ACROSS THE AREA THIS EVENING, FOLLOWED BY A COLD FRONT
LATER TONIGHT. THE SOUTHERLY FLOW HAS INCREASED WITH SOME GUSTS UP
TO 20 KNOTS. THIS IS EXPECTED TO CONTINUE FOR A TIME TONIGHT, THEN A
WIND SHIFT TO THE WEST LATE. A WESTERLY FLOW IS FORECAST FOR FRIDAY,
HOWEVER IT WILL BE LESS THAN 20 KNOTS. THE FLOW MAY ACTUALLY BACK A
BIT TO THE SOUTHWEST IN THE AFTERNOON GIVEN BETTER BOUNDARY LAYER
HEATING. SEAS HAVE BEEN SLOWLY BUILDING THIS AFTERNOON, AND WHILE
THEY COULD TOUCH 5 FEET ON THE OCEAN FOR A TIME WE BELIEVE THIS IS
MARGINAL AND MAY NOT LAST LONG. THEREFORE, WE WILL HOLD WITH NO
SMALL CRAFT ADVISORY ATTM. THE SEAS WILL LOWER SOME LATE AND ON
FRIDAY AS THE FLOW TURNS OFFSHORE FOR A TIME.
OUTLOOK...
SUB-SCA CONDITIONS EXPECTED ON THE WATERS THROUGH THE WEEKEND AND
EARLY NEXT WEEK. POSSIBLE SCA SEAS NEXT TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GORSE/NIERENBERG
SHORT TERM...GORSE
LONG TERM...O`HARA
AVIATION...GORSE/NIERENBERG/O`HARA
MARINE...GORSE/O`HARA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
326 PM CDT THU AUG 1 2013
.SYNOPSIS...
ISSUED AT 324 PM CDT THU AUG 1 2013
12Z UA ANALYSIS HAS A WEAK 850MB COLD FRONT FROM LAKE HURON TO THE
MN/IA BORDER. A RESPECTABLE SHORTWAVE RAN FROM THE DAKOTAS INTO
WESTERN NEBRASKA WHILE A MOISTURE GRADIENT RAN FROM WESTERN MISSOURI
INTO NEBRASKA. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOW
CONVECTION ASSOCIATED WITH THE DAKOTAS SHORT WAVE AND NEW CONVECTION
ON THE NORTH EDGE OF THE MOISTURE GRADIENT ACROSS NEBRASKA.
18Z SFC ANALYSIS HAS WEAK LOWS IN COLORADO AND SOUTHEAST WYOMING AND
ANOTHER IN WESTERN MINNESOTA. WEAK BOUNDARIES CONNECTED THE
MINNESOTA LOW TO THE LOW IN WYOMING WHILE SEVERAL WEAK TROFS WERE
ACROSS THE GREAT LAKES. A SFC MOISTURE BOUNDARY RAN FROM NEBRASKA
INTO NORTHWEST MISSOURI. DEW POINTS WERE IN THE 50S ACROSS THE GREAT
LAKES AND UPPER MIDWEST WITH 60S ACROSS MUCH OF THE PLAINS AND OHIO
VALLEY. DEW POINTS IN THE 70S WERE ACROSS THE SOUTHERN PLAINS AND
DEEP SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 324 PM CDT THU AUG 1 2013
DEEP MIXING THIS AFTERNOON HAS DROPPED THE DEW POINTS INTO THE LOW
TO MID 50S ACROSS WISCONSIN...NORTHERN ILLINOIS...AND NORTHEAST
IOWA. THE DEEP MIXING COMBINED WITH SUBSIDENCE HAS PREVENTED ANY
DIURNAL CLOUD DEVELOPMENT.
BASED ON SATELLITE AND RAP TRENDS USING THE MCS/LIFT TOOLS...THE
AGITATED CU DEVELOPMENT ALONG THE MN/IA BORDER SHOULD SLOWLY EVOLVE
INTO ISOLATED TO SCATTERED SHOWERS AND POSSIBLY A COUPLE OF
THUNDERSTORMS ACROSS THE NORTHERN CWFA DURING THE EVENING HOURS. THE
MORE SUBSTANTIAL STORM DEVELOPMENT ACROSS NEBRASKA MAY INDUCE SOME
ISOLATED SHOWERS OR A THUNDERSTORM ACROSS THE SOUTHERN HALF OF THE
CWFA BY MID TO LATE EVENING. STARTING AROUND MIDNIGHT THERE MAY BE A
LULL IN ACTIVITY FOR SEVERAL HOURS.
THE MCS TOOL IS REASONABLY CONSISTENT INDICATING A RESPECTABLE MCS
WILL DEVELOP THIS EVENING ACROSS EASTERN NEBRASKA/WESTERN IOWA AND
MOVE EAST SOUTHEAST OVERNIGHT ARRIVING IN THE SOUTHERN TWO THIRDS OF
THE CWFA PRIOR TO SUNRISE. CORFIDI VECTORS DO NOT SUGGEST ANY BACK
BUILDING BUT THE BACKWARD PROPAGATING VECTORS DO BECOME
PERPENDICULAR ACROSS THE SOUTHERN HALF OF THE CWFA SUGGESTING A WEAK
THREAT OF STORMS MOVING OVER THE SAME AREA.
THE DRIER AIR ACROSS THE AREA MAY RESULT IN SOME SMALL HAIL IN THE
STRONGER STORMS BEFORE THE ATMOSPHERE SATURATES LATE TONIGHT.
ON FRIDAY THE NOCTURNAL MCS WILL BE OVER THE CWFA DURING THE MORNING
HOURS AND WILL SLOWLY DECAY INTO MORE SHOWERS THAN THUNDERSTORMS BY
LATE MORNING. BOUNDARIES LEFT OVER FROM THIS MCS WILL THEN PROVIDE
THE FOCUS FOR NEW DEVELOPMENT DURING THE AFTERNOON. THE MCS TOOL
WHEN APPLIED TO SOME MODELS SUGGESTS THE POTENTIAL FOR ANOTHER MCS
AFFECTING THE AREA LATE FRIDAY AFTERNOON AND INTO FRIDAY NIGHT.
TEMPERATURES ON FRIDAY MAY REMAIN IN THE 60S FOR THE MORNING UNTIL
THE RAIN ENDS AND THEN CLIMBING INTO THE 70S DURING THE
AFTERNOON. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 324 PM CDT THU AUG 1 2013
FORECAST FOCUS IS ON PERIODS FOR PRECIPITATION CHANCES AND BELOW
NORMAL TEMPERATURES THROUGH NEXT WEEK.
FRIDAY NIGHT AND SATURDAY...CHANCES FOR SHOWERS AND A FEW
THUNDERSTORMS CONTINUE FRIDAY EVENING AS UPPER SHORTWAVE ENERGY
WORKS ITS WAY ACROSS THE AREA. THE BETTER CHANCES LOOK TO BE ACROSS
THE SOUTHERN FORECAST SECTIONS...AND WILL DIMINISH SATURDAY MORNING
AS THE SHORTWAVE DEPARTS.
SUNDAY THROUGH THURSDAY...SEVERAL SHORTWAVES ARE FORECAST TO MOVE
THROUGH THE CONTINUED NORTHWEST FLOW AND BRING A COUPLE
OPPORTUNITIES FOR SHOWERS AND STORMS. AS CAN BE EXPECTED...FORECAST
MODELS ARE SHOWING QUITE A BIT OF VARIATION IN TIMING AND PLACEMENT
OF THESE SMALLER SCALE FEATURES. THEREFORE CONFIDENCE IN WHICH DAYS
HOLD THE BEST CHANCE FOR PRECIPITATION IS LOW. SEASONABLY COOL
TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MIDDLE 70S TO LOWER 80S
RANGE...AND LOWS IN THE MIDDLE 50S TO LOWER 60S FOR MOST OF THE WEEK.
STOFLET
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1246 PM CDT THU AUG 1 2013
VFR WX IS EXPECTED THROUGH 06Z/02 AS HIGH PRESSURE MOVES EAST INTO
THE GREAT LAKES. A DISTURBANCE ALOFT WILL INITIATE ISOLATED TO
SCATTERED CONVECTION ACROSS EASTERN IOWA JUST PRIOR TO 00Z/02 THAT
MAY BECOME LOOSELY ORGANIZED AFT 00Z/02 WITH SOME TSRA. A BRIEF
PERIOD OF MVFR CONDITIONS MAY BE SEEN IF A SHRA/TSRA AFFECTS A TAF
SITE. AFT 06Z/02 AN ORGANIZED TSRA COMPLEX WILL MOVE INTO EASTERN
IOWA AND ILLINOIS. VFR CONDITIONS ARE FORECAST AFT 06Z/02 BUT THE
POTENTIAL DOES EXIST FOR MVFR/IFR CONDITIONS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...STOFLET
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1256 PM CDT THU AUG 1 2013
.UPDATE...
ISSUED AT 1246 PM CDT THU AUG 1 2013
DEW POINTS HAVE BEEN DROPPING SINCE SUNRISE WHICH EXPLAINS THE
LACK OF DIURNAL CU ACROSS THE AREA. THE VORT MAX IS MAKING GOOD
PROGRESS THROUGH THE DAKOTAS AND SHOULD BE MOVING INTO EASTERN
IOWA BY LATE AFTERNOON/EVENING. THE FACT THAT DEW POINTS ARE
DROPPING MEANS EVAPORATIVE COOLING WILL BE A FACTOR THAT MAY DELAY
THE START OF PRECIPITATION.
TRENDS FROM THE RAP CONTINUE TO SUGGEST LATE AFTERNOON/EVENING
CONVECTION DEVELOPING ACROSS THE AREA THAT MAY BECOME LOOSELY
ORGANIZED DURING THE EVENING. THE DRIER AIR SUGGESTS THE POTENTIAL
FOR SMALL HAIL TONIGHT WITH DISCRETE STORMS THAT HAVE A STRONGER
UPDRAFT.
THE MCS TOOL CONTINUES TO SUGGEST AN ORGANIZED MCS WILL MOVE INTO
THE CWFA LATE TONIGHT WITH POSSIBLY LOCALLY HEAVY RAIN. ..08..
UPDATE ISSUED AT 1008 AM CDT THU AUG 1 2013
SATELLITE HAS A SMALL AMOUNT OF ACCAS FROM ROUGHLY THE MISSISSIPPI
RIVER BACK INTO SOUTHERN MINNESOTA. CONVECTION IS PERSISTING
ACROSS THE PLAINS IN RESPONSE TO THE SHORTWAVE MOVING THROUGH THE
DAKOTAS AND FAR NORTHERN NEBRASKA. THE INVERSION HAS BROKEN
EVIDENT BY THE WIND FARMS DROPPING OFF THE RADAR RETURNS.
QUIET AND DRY CONDITIONS WILL BE SEEN FROM LATE MORNING THROUGH
MID AFTERNOON AS THE WEAK SFC HIGH MOVES EAST OF THE CWFA. THE
APPROACHING SHORTWAVE LATE THIS AFTERNOON AND INTO EARLY EVENING
SHOULD HELP GENERATE ELEVATED SHOWERS AND POSSIBLY A FEW
THUNDERSTORMS THAT MOVE INTO THE NORTHWEST PART OF THE CWFA. ..08..
&&
.SYNOPSIS...
ISSUED AT 246 AM CDT THU AUG 1 2013
ANALYSIS AT 2 AM SHOWS WEAK HIGH PRESSURE OVERHEAD RESULTING IN CALM
WINDS WITH PATCHY SHALLOW GROUND FOG DEVELOPING IN FAVORED LOW LYING
LOCATIONS. WEAK PRESSURE RISE LOBE FROM THE WEST SUGGESTS ANY FOG
TO REMAIN PATCHY THROUGH SUNRISE. STRONG NORTHWEST FLOW PER ANALYSIS
AND ALSO SATELLITE AND UPSTREAM RADARS SUPPORTS GOOD UPGLIDE EVENT
TO ARRIVE ACROSS AREA TONIGHT FROM THE HIGH PLAINS. AREA TEMPERATURES
AND DEWPOINTS IN THE MEANWHILE TODAY SUGGEST ANOTHER WARM BUT
COMFORTABLE DAY. UPSTREAM ANALYSIS SUPPORTS STRONG NORTHWEST FLOW
TO KEEP AREA BELOW NORMAL WITH OCCASIONAL CHANCES OF RAIN THROUGH
NEXT WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 246 AM CDT THU AUG 1 2013
TODAY...ANOTHER NEAR IDEAL SUMMER DAY WITH MOSTLY SUNNY SKIES AND HIGHS
OF 79-84 DEGREES FROM NORTH TO SOUTH WITH DEWPOINTS IN THE UPPER 50S
TO LOWER 60S. THE MODERATE HUMIDITY AND WESTERLY WINDS OF 5 TO 15 MPH
TO MAKE FOR IDEAL CONDITIONS FOR MANY OUTSIDE ACTIVITIES. SOME ELEVATED
ALTO-CUMULUS MAY DEVELOP IN FAR NORTHWEST SECTIONS TOWARD SUNSET AS
ELEVATED UPPER AIR DISTURBANCE MOVES TOWARD THE REGION.
TONIGHT...SHOWERS TO DEVELOP ACROSS NORTH 1/2 AND BLOOM INTO SHOWERS
AND STORMS AS LOW LEVEL FORCING INCREASES BY EARLY OVERNIGHT HOURS.
WARM ADVECTION WING TOOL INDICATES THE BEST AXIS OF HEAVIER RAINS ARE
SUGGESTED TO BE ROUGHLY ALONG HIGHWAY 30. POPS LIKELY OVER MOST OF
THE REGION TO CHANCE IN SE SECTIONS. FORCING TOOLS ALSO SUGGESTS
HIGHER POPS MAY BE NEEDED AFTER MIDNIGHT AND ALSO HIGHER RAINFALL
AMOUNTS WITH LOCALLY UP TO NEAR 1 INCH AMOUNTS POSSIBLE DUE TO MINOR
TRAINING OF STORMS AND SHOWERS AND PW VALUES WELL OVER 1 INCH. ISOLATED
PEA SIZE HAIL MAY BE POSSIBLE IN STRONGEST STORMS TOWARD SUNRISE FRIDAY.
NICHOLS
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 246 AM CDT THU AUG 1 2013
FORECAST FOCUS ON BELOW NORMAL TEMPERATURES THROUGH AT LEAST THE
MIDDLE OF AUGUST.
FRIDAY INTO SATURDAY...RESPECTABLE WAVE IN THE FLOW WILL CONTINUE TO
TRIGGER SHOWERS AND A FEW THUNDERSTORMS ACROSS MOST OF THE CWA
FRIDAY INTO SATURDAY MORNING. SOME AREAS MAY PICK UP OVER AN INCH OF
RAIN AS PWATS INCREASE TO OVER 1.50 INCHES. HAVE RAISED POPS INTO
THE LIKELY CATEGORY OVER MOST OF THE CWA AS THIS SIGNAL HAS BEEN
PERSISTENT FOR DAYS. MODELS SUGGEST EXTENSIVE CLOUD COVER WILL
REMAIN MUCH OF THE DAY AND THEREFORE HAVE LOWERED TEMPERATURES A
COUPLE OF DEGREES FROM EARLIER FORECAST. THIS WOULD THEN KEEP HIGHS
IN THE UPPER 70S AT MOST LOCATIONS. CHANCES OF RAIN WILL CONTINUE
INTO SATURDAY MORNING BUT MODELS WANT TO DRY THINGS OUT BY AFTERNOON.
SUNDAY THROUGH WEDNESDAY...SEVERAL MORE SIGNIFICANT WAVES IN THE
NORTHWEST FLOW ARRIVES ABOUT SUNDAY NIGHT AND AROUND NEXT WEDNESDAY.
THIS SHOULD BRING MORE OPPORTUNITIES FOR SHOWERS AND THUNDERSTORMS.
HIGHS MAINLY IN THE UPPER 70S TO LOWER 80S AND LOWS IN THE LOWER TO
MID 60S FOR MUCH OF THIS TIME FRAME.
LATE NEXT WEEK THROUGH THE MIDDLE OF AUGUST...THE ECMWF IS BACK WITH
THE POLAR VORTEX DROPPING SOUTHWARD TOWARDS LAKE SUPERIOR AND THEN
PUSHING EASTWARD. THIS WILL REINFORCE THE BELOW NORMAL TEMPERATURES
WITH VERY COOL AIR ONCE AGAIN PLUNGING OUT OF CANADA. THE PATTERN
SEEMS TO FAVOR BELOW NORMAL TEMPERATURES CONTINUING AT LEAST THROUGH
THE MIDDLE OF AUGUST. PRECIPITATION LOOKS TO BE NORMAL TO ABOVE
NORMAL FOR AT LEAST THE FIRST HALF OF THE MONTH.
HAASE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1246 PM CDT THU AUG 1 2013
VFR WX IS EXPECTED THROUGH 06Z/02 AS HIGH PRESSURE MOVES EAST INTO
THE GREAT LAKES. A DISTURBANCE ALOFT WILL INITIATE ISOLATED TO
SCATTERED CONVECTION ACROSS EASTERN IOWA JUST PRIOR TO 00Z/02 THAT
MAY BECOME LOOSELY ORGANIZED AFT 00Z/02 WITH SOME TSRA. A BRIEF
PERIOD OF MVFR CONDITIONS MAY BE SEEN IF A SHRA/TSRA AFFECTS A TAF
SITE. AFT 06Z/02 AN ORGANIZED TSRA COMPLEX WILL MOVE INTO EASTERN
IOWA AND ILLINOIS. VFR CONDITIONS ARE FORECAST AFT 06Z/02 BUT THE
POTENTIAL DOES EXIST FOR MVFR/IFR CONDITIONS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...08
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
248 PM CDT Thu Aug 1 2013
...Updated long term section...
.SHORT TERM...(Today and tonight)
ISSUED AT 410 AM CDT THU AUG 1 2013
The Latest HRRR model shows an increase in convection across west
central Kansas eastward to the highway 283 corridor. The current
meso alpha convective trends from 88d KPUB suggest at least some
thunderstorm activity could make it to extreme western Kansas
between 9 and 12Z. However there is greater conceive inhibition
indicated by the mesoanalysis as well as a decrease in overall
mucape. As a result we`ll minimize precipitation chances this
morning, relegating small chances to those areas generally west of
highway 83.
As warmer air will be in place in the boundary layer today,
temperatures will be considerably warmer, and likely in the mid
90s in most locations. surface winds will veer to the south with
time and increase to 15-20 knots sustained as mixing develops
during the mid to late morning. The consensus of the NAM WRF and
NMM indicate a better chance for another round of thunderstorms
somewhere across the region late in the afternoon and evening.
confidence is low with respect to where any thunderstorms will
occur, but possibilities exist associated with a cluster
associated with a shortwave to the north, and also across central
ks and the far southwest as convection rolls off the higher
terrain again.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 247 PM CDT THU AUG 1 2013
The extended forecast well consist of multiple disturbances moving
around an upper level high across the Southern United States and
into the Central Plains. These disturbances will enhance lift as
well as increase instability in the mid levels of the atmosphere.
Meanwhile, ample moisture and frontal boundaries at the surface will
create enough lift to create thunderstorms across Western Kansas
periodically throughout the extended period.
A warm front is progged to move north across Southwest Kansas Friday
night into Saturday before stalling out across Northwest and Central
Kansas by Sunday morning. Partly cloudy skies are anticipated early
Saturday morning, increasing and becoming mostly cloudy by Saturday
night. A chance of thunderstorms will be possible along this
boundary, especially late Saturday afternoon into Saturday night
when POPs increase to above 50 percent. A slight chance of
thunderstorms will be possible Sunday along this boundary, but I`m
less confident that they will actually form. Otherwise anticipate
mostly cloudy skies and winds from the east to southeast. Another
fairly good chance of thunderstorms will be possible once again
Monday afternoon into Monday night as an upper level shortwave moves
into the Central Plains. As for temperatures, highs Saturday are
expected to range from the upper 80s across West Central Kansas to
upper 90s across the KS/OK border. Highs Sunday are forecasted to
range from the lower 80s across central Kansas to lower 90s across
the KS/OK border. Lows Saturday morning through Monday morning will
generally range from the upper 60s across West Central Kansas to
lower 70s across South Central Kansas.
The upper level high then shifts farther east into the Lower
Mississippi Valley during the middle of the week as an upper level
long wave trough treks into the Western United States. A few more
shortwaves are progged to move into the Central Plains during this
time bringing additional chances of thunderstorms to Western Kansas.
However, since this is out on day 6 and 7 confidence is low on the
exact position and timing of these thunderstorms. Otherwise expect
partly cloudy skies and winds generally from the east to southeast.
Highs Monday through Wednesday are forecasted to range from the mid
80s across West Central Kansas to lower 90s across the KS/OK border.
Lows Saturday morning through Monday morning will generally range
from the upper 60s across West Central Kansas to lower 70s across
South Central Kansas.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1250 PM CDT THU AUG 1 2013
A trough of low pressure will remain in the lee of the rockies
through tonight, resulting in south winds at 12-15kts. Isolated
thunderstorms will develop near the Colorado border by 21-23z and
could affect KGCK by 00-02z. On Friday, surface low pressure will
move into northwest Kansas, with winds becoming southwest at 20
kts at the taf sites. VFR conditions will persist outside of
thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 70 102 70 91 / 20 10 20 40
GCK 70 100 69 89 / 20 20 20 40
EHA 70 100 69 93 / 20 10 20 40
LBL 71 103 70 95 / 20 20 20 30
HYS 70 96 70 88 / 50 20 30 50
P28 72 102 73 95 / 20 20 20 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...HOVORKA_42
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1254 PM CDT Thu Aug 1 2013
...Updated for aviation discussion...
.SYNOPSIS...
ISSUED AT 410 AM CDT THU AUG 1 2013
The 00 utc Thursday objective upper air analysis showed an upper
anticyclone across western TX/eastern NM with an 80 knot jet streak
exiting central Kansas on the east side of the upper ridge. Based
on the 00 utc upper air sounding in combination with he 700 mb
analysis it appears very little change took place in the mid
levels. however, the same analysis showed a marked up tick in
boundary layer temperature, especially at the 850 mb level where
temperatures warmed an average of 5 to 10 degrees.
Regional mosaic 88d reflectivity shows a couple of areas of
decaying MCS/thunderstorms activity, one across the Texas
panhandle and one across east central Colorado. The KGLD 88D
indicates a convective outflow boundary moving southeast across
west central Kansas.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 410 AM CDT THU AUG 1 2013
The Latest HRRR model shows an increase in convection across west
central Kansas eastward to the highway 283 corridor. The current
meso alpha convective trends from 88d KPUB suggest at least some
thunderstorm activity could make it to extreme western Kansas
between 9 and 12Z. However there is greater conceive inhibition
indicated by the mesoanalysis as well as a decrease in overall
mucape. As a result we`ll minimize precipitation chances this
morning, relegating small chances to those areas generally west of
highway 83.
As warmer air will be in place in the boundary layer today,
temperatures will be considerably warmer, and likely in the mid
90s in most locations. surface winds will veer to the south with
time and increase to 15-20 knots sustained as mixing develops
during the mid to late morning. The consensus of the NAM WRF and
NMM indicate a better chance for another round of thunderstorms
somewhere across the region late in the afternoon and evening.
confidence is low with respect to where any thunderstorms will
occur, but possibilities exist associated with a cluster
associated with a shortwave to the north, and also across central
ks and the far southwest as convection rolls off the higher
terrain again.
.LONG TERM...(Friday through Wednesday)
ISSUED AT 259 AM CDT THU AUG 1 2013
On Friday afternoon the GFS and ECMWF both suggest a weak upper
level wave will move out into the plains with some afternoon
convection being possible near a surface boundary that appears to
extend from west to east across northern Kansas. 850mb warm air
advection still evident along and north of this boundary. We will
therefore retain precipitation chances across north central Kansas
while further south the warm +14/+15c 700mb temperatures and less
moisture will be present which appears to limit precipitation
chance in these locations until possibly early evening when better
instability develops. 850mb temperature trends south of this
boundary continues to support highs warmer than Thursday with the
potential for afternoon highs approaching 100 degrees across
portions of far southwest Kansas. Across north central Kansas the
afternoon temperatures will be more tricky given cloud and
precipitation potential. Given this will stay close to the
previous forecast with highs 7 to near 10 degrees cooler than
southwest Kansas.
A cold front will then move into southwest Kansas on Saturday.
This surface boundary will then remain in western Kansas through
early next week as an upper level trough/low moves out of Canada
and into the the great lakes region. High pressure at the surface
will move out of south central Canada and into the the Ohio
valley. More seasonal temperatures are likely over the weekend
into early next week given the cooler 925-850mb air that is
forecast to return to much of western Kansas. There will also be
chance for convection each day from Saturday through early next
week given the southeasterly upslope flow, higher 925-850mb dewpoints
forecast to be located just east/northeast of this surface
boundary and any subtle upper wave exiting the Rockies and
crossing the plains. Given this potential am unable to improve
much on the latest CRExtendFcst_Init and keep a chance of
precipitation in each period from Sunday into mid week. Warm
nights and seasonal afternoon temperatures also look on track.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1250 PM CDT THU AUG 1 2013
A trough of low pressure will remain in the lee of the rockies
through tonight, resulting in south winds at 12-15kts. Isolated
thunderstorms will develop near the Colorado border by 21-23z and
could affect KGCK by 00-02z. On Friday, surface low pressure will
move into northwest Kansas, with winds becoming southwest at 20
kts at the taf sites. VFR conditions will persist outside of
thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 94 70 98 69 / 10 50 10 20
GCK 96 70 97 68 / 20 40 20 20
EHA 97 70 98 68 / 20 40 10 20
LBL 96 71 100 69 / 20 40 20 20
HYS 93 70 93 69 / 20 50 20 30
P28 93 72 97 72 / 10 50 20 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1225 PM CDT Thu Aug 1 2013
...Update to aviation forecast discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CDT THU AUG 1 2013
Water vapor imagery and 08z RAP analysis shows the H5 ridge over the
desert southwest with a well developed deep trough over the Hudson
Bay. Between these two features northwest flow continues over the
forecast area, with roughly 30 to 40 knots of flow at 500 mb. At the
surface the ridge axis runs from NW to SE across the forecast area,
which is helping to reduce flow at the surface, bringing calm
morning conditions. Through the remainder of the morning a few areas
of patchy fog will form as radiational cooling will be enhanced by
low surface flow and mostly clear skies. Passing cirrus will help
retain some heat at the surface, preventing widespread dense fog,
but considering the moist low levels from recent rain and calm, cool
conditions there will be a marginal fog threat through the remainder
of the morning hours.
Radar trends indicate that a few showers have formed across central
Nebraska, and are moving east/southeastward into south central
Nebraska. The best isentropic/warm air advection upglide can be
found on a decently deep layer between 305 and 315 K Theta E
surfaces. Forecast soundings show about 500 to 1000 J/Kg of elevated
instability above the 700 mb layer, so any parcels that get lifted
to that level will have a chance to form into scattered
thunderstorms later today. The best chance for that scattered
T-storm development will be mainly across central Nebraska,
southward into far northern Kansas, where the best isentropic
upglide persists. Clouds will likely build in, especially north of
Interstate 70, so have gone with a slightly cooler temperature
forecast for the far northern row of counties, but should rain
develop in that area temps may struggle to reach the forecast highs
in the lower to middle 80s.
Warm air advection will continue through the evening and overnight
hours on Thursday night, and as the deeper moisture makes its way
into northeast Kansas the coverage and intensity of the rain showers
will pick up . Expect widespread rain/thunderstorm activity,
especially north of Interstate 70 by early Friday morning, with
perhaps some showers and thunderstorms further south, toward the
Interstate 35 corridor.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 336 AM CDT THU AUG 1 2013
Friday/Saturday...Expect some thunder to be ongoing Friday as
complex forecast to roll off the high plains across Nebraska then
into eastern Kansas along the thermal gradient and on the nose of
the LLJ. enough instability and shear to make strong to severe
storms possible...as well as steep lapse rates in the low levels
contributing to potential wind threat. despite the dry layer,
precipitable water values over the area remain in the 1.5 to 2
inch range, and must therefore also consider heavy rainfall a
possibility. Storm chances slowly shift eastward into sunrise on
Saturday, and may be able to catch a break during the day
Saturday. Will carry only an isolated pop given boundary resides
right over the forecast area and can`t rule out precip for good
just yet.
Sun/Mon...Stronger and more significant shortwave trof forecast
to come off the central Rockies and into eastern Kansas on Sunday.
Will carry high chance pops and cooler temperatures to reflect
this. subsidence behind this wave may temper precip chances on
Monday and have kept a decrease that time period.
Tues/Wed...Area remains under NW flow aloft with series of waves
dropping surface high pressure into our area early to mid week
next week. If this pattern verifies we would stay cooler than
normal with above average precipitation possible.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1221 PM CDT THU AUG 1 2013
Expect a broken cumulus cloud deck to develop between 3500 and
5000 feet this afternoon and evening. Thunderstorms become more
likely at/near TAF sites after 04Z, as it appears that a
thunderstorm complex may move southeast out of Nebraska and impact
all TAF sites. These storms may persist beyond 12Z, and perhaps as
long as 18Z. Have kept south winds predominant but any tstorms
would cause varying winds, particularly from the north early with
an eventual shift out of the east as the storms pass.
Barjenbruch
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Leighton
LONG TERM...67
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
330 PM CDT THU AUG 1 2013
.SHORT TERM...
A SOMEWHAT ACTIVE AFTERNOON FOR PORTIONS OF THE FORECAST AREA
BRINGS HIGHER RAIN CHANCES. A COLD FRONT HAS BEEN SLOWLY TRACKING
RIGHT ACROSS MID MISSISSIPPI AND SHOULD BE APPROACHING LATER THIS
AFTERNOON. CONVECTION HAS BEGUN TO FIRE OFF AHEAD OF THE BOUNDARY
NORTH OF THE CWA. LOCAL WRF ALONG WITH HRRR IN FAIRLY GOOD AGREEMENT
DENOTING THAT CURRENT ACTIVITY WHICH IS TYPICAL OF THIS TIME OF
YEAR WILL INCREASE IN COVERAGE AS WELL AS INTENSITY AND MOVE ACROSS
THE CWA. PRECIP WATER VALUES ARE STILL QUITE HIGH AT OVER 2
INCHES...SO EXPECT VERY HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
WIND SHEAR IS QUITE LIGHT AND WEST BULB TEMP WELL ABOVE 13K FEET
MEANS LITTLE THREAT OF HAIL OR TORNADOES. THUS THE MAIN THREAT WILL
BE GUSTY WINDS ON THE ORDER OF 35-45 MPH. SEVERE GUSTS NOT
IMPOSSIBLE BUT UNLIKELY. CONVECTION WILL LIKELY PERSIST THROUGH
SUNSET BUT NOT MUCH LONGER AFTER THAT. MAIN THREAT AREA APPEARS TO
BE EAST OF INTERSTATE 55 FROM MS ALL THE WAY TO SOUTH OF NEW
ORLEANS. HAVE BUMPED UP POPS SLIGHTLY FROM PREVIOUS FORECAST.
MEFFER
&&
.LONG TERM...
UPPER LEVEL TROUGH WILL LIFT NORTH AND RIDGE WILL BEGIN EXTENDING IN
OVER THE AREA FRIDAY THROUGH THE WEEKEND. WHILE A FEW STORMS MAY
DEVELOP...CONVECTION SHOULD BE QUITE LIMITED. EASTERN EDGE OF THE
UPPER LEVEL RIDGE WILL BEGIN WEAKENING LATE THIS WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. THIS WILL ALLOW FOR A FEW RAIN CHANCES TO
INCREASE ACROSS THE AREA. TEMPERATURES THROUGH THE ENTIRE PERIOD
WILL NOT CHANCE MUCH WITH HIGHS GENERALLY IN THE 90-95 DEGREE RANGE
WITH HEAT INDEX VALUES 100 TO 105. MID WEEK ONWARD THE RIDGE WILL
MOVE DIRECTLY OVER THE NORTHERN GULF COAST. ECMWF SUGGESTS A
SLIGHTLY STRONGER RIDGE WITH LOWER POPS AND HIGHER TEMPS WHILE GFS
IS MORE OF A WEAKER RIDGE WHICH WOULD ALLOW FOR MORE CONVECTION. SO
HAVE MADE LITTLE TO NO CHANGES TO THE EXTENDED FORECAST.
MEFFER
&&
AVIATION...
GENERALLY VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 00Z
SATURDAY AT THE TERMINAL LOCATIONS. THE POSSIBLE EXCEPTIONS WILL BE
ASSOCIATED WITH THE POTENTIAL FOR LIGHT FOG DEVELOPMENT TOWARD
DAYBREAK FRIDAY MORNING AT THE MORE FOG PRONE TAF SITES. THE
TERMINALS IN THE SOUTH HALF OF THE FORECAST AREA ARE THE ONES THAT
WILL HAVE THE BEST CHANCE OF SEEING ANY CONVECTION...NAMELY
KHUM...KNEW AND KMSY...BUT RAIN CHANCES WILL REMAIN SLIM.
18
&&
MARINE...
A RIDGE OF HIGH PRESSURE WILL FLUCTUATE BETWEEN THE EASTERN AND
CENTRAL GULF THROUGHOUT THE FORECAST PERIOD. GENERALLY LIGHT SOUTH
TO WESTERLY AND AT TIMES VARIABLE WINDS AROUND 10 KNOTS OR LESS ARE
EXPECTED ALONG WITH WAVES HEIGHTS OF 2 FEET OR LESS.
MEFFER
&&
DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NATURAL GAS WELL BLOWOUT SUPPORT.
SLURRY SUPPORT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 74 95 73 94 / 10 10 10 10
BTR 77 96 76 95 / 10 10 10 10
ASD 76 94 76 93 / 20 20 10 20
MSY 79 93 78 92 / 20 20 10 20
GPT 77 93 77 93 / 20 20 10 20
PQL 73 94 73 93 / 20 20 10 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
524 PM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE COAST AND INTO THE CAROLINAS
OVERNIGHT. HIGH PRESSURE RETURNS ON FRIDAY AND SATURDAY. ANOTHER
COLD FRONT CROSSES THE REGION ON SUNDAY WITH HIGH PRESSURE BUILDING
BACK INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THURSDAY AFTN...A COLD FRONT WAS SITUATED OVER WEST VIRGINIA AND WAS
MOVING TO THE SOUTHEAST. VARIOUS SURFACE TROUGHS FURTHER TO THE EAST
WERE RESULTING IN AREAS OF CONVERGENCE WITH SOME DOWNSLOPING AND
DRYING MOVING INTO THE CWA. THE MAIN CONVERGENCE WAS ALONG A BAND
NEAR THE CHESAPEAKE. ANOTHER WAS APPROACHING OUR NORTHWEST COUNTIES
FROM THE BLUE RIDGE. HAVE DROPPED POPS GENERALLY WEST OF INTERSTATE
95 FOR THE REST OF THE AFTN. NORTHWEST COUNTIES MAY EXPERIENCE A
BRIEF TSTM BUT OVERALL CONDITIONS SHOULD BE DRY OVER WRN PORTIONS.
A SHORT WAVE TROUGH AND RRQ OF UPPER LEVEL JET WILL MAINTAIN THE
POSSIBILITY OF TSTMS NEAR COASTAL AREAS WELL INTO THE EVENING HOURS.
THE THREAT FOR LOCALLY HEAVY RAINFALL WILL CONTINUE OVER THE EASTERN
SHORE AND HAMPTON ROADS AND NEAR THE CHESAPEAKE THROUGH THE EARLY
EVENING HOURS.
DEW POINTS SLOWLY DROP AND MIN TEMPERATURES WILL BE A BIT COOLER
THAN THURSDAY MORNING OVER INLAND AREAS. LOWS SHOULD DROP IN THE MID
TO UPR 60S INLAND TO AROUND 70 NEAR THE COAST FRIDAY MORNING.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
DRY WEATHER WILL PREVAIL FRIDAY AS WEAK HIGH PRESSURE BUILDS INTO
THE REGION BEHIND THE AFOREMENTIONED SHORT WAVE TROUGH. PLENTY OF
SUNSHINE SHOULD ALLOW TEMPERATURE TO APPROACH 90 DEGREES OVER INLAND
AREAS AND THE MID 80S NEAR THE COAST. MOSTLY CLEAR SKIES CONTINUE
FRIDAY NIGHT WITH LOWS IN THE MID 60S WELL INLAND TO THE LWR 70S IN
THE HAMPTON ROADS AREA.
MID LEVEL MOISTURE INCREASES AHEAD OF THE NEXT COLD FRONT SATURDAY.
HAVE A CHC FOR SHOWERS AND THUNDERSTORMS BY THE AFTN...MAINLY OVER
NORTHERN AND EASTERN PORTIONS. HIGH TEMPERATURES WILL BE IN THE UPR
80S TO AROUND 90.
THE COLD FRONT MOVES IN FROM THE N/NW SUNDAY. MAINLY USED NAM/SREF
FOR THE TIMING OF THE FRONT...THE GFS LOOKS TOO FAST AND AGGRESSIVE.
HAVE A CHC FOR TSTMS WITH THE FRONTAL PASSAGE...ENDING FROM N TO S
THROUGH THE AFTN. CLOUD COVER SHOULD HOLD TEMPERATURES DOWN TO THE
MID TO UPR 80S SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MEDIUM RANGE LOOKS TO BE CHARACTERIZED BY AN UPPER LEVEL RIDGE
OVER THE INTERMOUNTAIN WEST INTO WESTERN CANADA, WHILE AN UPPER
LEVEL TROUGH PERSISTS OVER THE NORTHEASTERN CONUS. THIS WILL PROMOTE
RELATIVELY COOLER AND DRIER AIR TO DRAIN OUT OF THE CANADIAN
PRAIRIES ACROSS THE NORTHEASTERN AND MID-ATLANTIC REGIONS.
FORECAST PERIOD BEINGS SUNDAY NIGHT WITH A WEAKENING BACKDOOR FRONT
DROPPING ACROSS THE AREA, LIKELY BECOMING STALLED ACROSS THE
CAROLINAS BEFORE WASHING OUT EARLY NEXT WEEK. IN ITS WAKE, EXPECT A
MAINLY DRY FORECAST, THOUGH WE DID RETAIN A SLIGHT CHC POP MAINLY
SOUTH OF HIGHWAY 58 CORRIDOR IN S VA/NE NC. SFC HIGH SLIDES OFFSHORE
TUESDAY/WEDNESDAY, WITH S-SW FLOW RETURNING AND BUMPING TEMPS UP
CLOSER TO SEASONAL VALUES FOR MIDWEEK. AS FOR SENSIBLE WX, WILL ALSO
SEE INCREASING (MAINLY DIURNALLY DRIVEN) SHRA/TSTM CHCS BOTH DAYS AS
SHORTWAVE ENERGY EMBEDDED IN THE LONGWAVE TROUGH MOVES ACROSS THE
NORTHERN MID-ATLANTIC. FOR TEMPERATURES, EXPECT MAXIMA TO AVERAGE
BELOW NORMAL FOR THE PERIOD, GENERALLY BE IN THE LOW TO MID
80S...AGAIN EXPECTING TEMPS TO RISE BACK UP TOWARDS NORMAL AHEAD OF
ANOTHER SLOW MOVING FRONT BY LATE NEXT WEEK. EARLY MORNING LOWS TO
AVERAGE IN THE LOWER TO MIDDLE 60S.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
WITH COLD FRONT MOVING THROUGH THIS AFTERNOON AND SHOWERS AND SOME
THUNDERSTORMS DEVELOPING ACROSS THE AREA. SEVERAL SHORT LINES HAVE
FORMED. TRIED TO TIME THEM THROUGH THE TERMINALS. ALSO FOLLOWING
RUC TIMING AS WELL AS THAT SEEMS TO HAVE A GOOD HANDLE ON THE
CURRENT CONVECTION. HRRR TRIES TO BRING CONVECTION OVER NORTHWEST
VIRGINIA INTO CENTRAL AND SOUTHEAST VIRGINIA TOWARD MIDNIGHT. NOT
SURE IF THIS WILL HOLD TOGETHER SO DID NOT INCLUDE IN THE TAFS.
WILL HAVE WATCH FOR LATER CHANGES. COULD SEE SOME FOG DEVELOP
AFTER THESE SHOWERS AS THE COLD FRONT DOES NOT CROSS THE AREA
UNTIL THE EARLY MORNING HOURS. AFTER SUNRISE ON FRIDAY CONDITIONS
WILL BECOME VFR AND REMAIN SO THROUGH MUCH OF SATURDAY. NEXT
SYSTEM APPROACHES SATURDAY AND SUNDAY WITH MORE THUNDERSTORMS
DEVELOPING AND COULD SEE SOME MVFR TO IFR CONDITIONS IN THE
THUNDERSTORMS.
&&
.MARINE...
LATEST OBS REFLECT S-SW WINDS ~15 KT. PRESSURE GRADIENT CONTINUES TO
TIGHTEN OVER THE WATERS AHEAD OF WK LO PRES, WHICH WILL PASS BY JUST
TO OUR NORTH THROUGH TODAY. ASSOCIATED CDFNT WILL PUSH ACROSS THE
WATERS TONIGHT. NOTING WINDS AT LOW END SCA IN THE BAY THIS AFTN,
AND SCA REMAINS IN PLACE OVER THE CHES BAY THROUGH 23Z/7PM FOR
FREQUENT WIND GUSTS ~20KT. CONSIDERED ADDING SCA FOR THE CURRITUCK
SOUND, BUT WL CAP OFF WINDS AT 15 KT THROUGH 7PM WITH THE IDEA THAT
BRIEF WINDOW OF HIGHER WINDS WILL BE MORE CONVECTIVE THAN ANYTHING
ELSE...AND THUS BEST HANDLED WITH SMW AS NEEDED.
WINDS WILL DIMINISH AFTER 00Z/8P AS GRADIENT SLACKENS WITH THE
APPROACH OF THE WEAKENING FRONT. WINDS VEER TO SW OVERNIGHT,
EVENTUALLY BECOMING WNW ERY FRIDAY. FRONT CONTINUES TO WEAKEN JUST
TO OUR SOUTH/SOUTHEAST TOMORROW, AS SFC HI PRES REBUILDS WEST OF THE
WATERS FRI INTO ERY SAT. SUB-SCA CONDS ARE EXPECTED DURING THIS
PERIOD, WITH WAVES/SEAS AVERAGING 2-4FT. NEXT CDFNT (BACKDOOR FRONT)
DROPS SOUTH ACROSS THE WATERS LATER SUN. POTENTIAL EXISTS FOR
ANOTHER BRIEF SURGE AHEAD OF THIS FRONT DURING THE DAY SUNDAY. WINDS
VEER AROUND TO THE E-SE MONDAY AS SFC HIGH PIVOTS OFF THE
MID-ATLANTIC COAST LATER MONDAY AND TUESDAY. LIGHT SOUTHERLY FLOW
FOLLOWS FOR LATER TUE/WED...AHEAD OF NEXT FRONT WHICH FOLLOWS BY
LATE NEXT WEEK.
&&
.EQUIPMENT...
THE NOAA RADIO TRANSMITTER OUT OF RICHMOND HAS RETURNED TO
SERVICE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ630>632-634.
&&
$$
SYNOPSIS...LSA
NEAR TERM...LSA
SHORT TERM...LSA
LONG TERM...MAM
AVIATION...JAB
MARINE...MAM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
359 PM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE COAST AND INTO THE CAROLINAS
OVERNIGHT. HIGH PRESSURE RETURNS ON FRIDAY AND SATURDAY. ANOTHER
COLD FRONT CROSSES THE REGION ON SUNDAY WITH HIGH PRESSURE BUILDING
BACK INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THURSDAY AFTN...A COLD FRONT WAS SITUATED OVER WEST VIRGINIA AND WAS
MOVING TO THE SOUTHEAST. VARIOUS SURFACE TROUGHS FURTHER TO THE EAST
WERE RESULTING IN AREAS OF CONVERGENCE WITH SOME DOWNSLOPING AND
DRYING MOVING INTO THE CWA. THE MAIN CONVERGENCE WAS ALONG A BAND
NEAR THE CHESAPEAKE. ANOTHER WAS APPROACHING OUR NORTHWEST COUNTIES
FROM THE BLUE RIDGE. HAVE DROPPED POPS GENERALLY WEST OF INTERSTATE
95 FOR THE REST OF THE AFTN. NORTHWEST COUNTIES MAY EXPERIENCE A
BRIEF TSTM BUT OVERALL CONDITIONS SHOULD BE DRY OVER WRN PORTIONS.
A SHORT WAVE TROUGH AND RRQ OF UPPER LEVEL JET WILL MAINTAIN THE
POSSIBILITY OF TSTMS NEAR COASTAL AREAS WELL INTO THE EVENING HOURS.
THE THREAT FOR LOCALLY HEAVY RAINFALL WILL CONTINUE OVER THE EASTERN
SHORE AND HAMPTON ROADS AND NEAR THE CHESAPEAKE THROUGH THE EARLY
EVENING HOURS.
DEW POINTS SLOWLY DROP AND MIN TEMPERATURES WILL BE A BIT COOLER
THAN THURSDAY MORNING OVER INLAND AREAS. LOWS SHOULD DROP IN THE MID
TO UPR 60S INLAND TO AROUND 70 NEAR THE COAST FRIDAY MORNING.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
DRY WEATHER WILL PREVAIL FRIDAY AS WEAK HIGH PRESSURE BUILDS INTO
THE REGION BEHIND THE AFOREMENTIONED SHORT WAVE TROUGH. PLENTY OF
SUNSHINE SHOULD ALLOW TEMPERATURE TO APPROACH 90 DEGREES OVER INLAND
AREAS AND THE MID 80S NEAR THE COAST. MOSTLY CLEAR SKIES CONTINUE
FRIDAY NIGHT WITH LOWS IN THE MID 60S WELL INLAND TO THE LWR 70S IN
THE HAMPTON ROADS AREA.
MID LEVEL MOISTURE INCREASES AHEAD OF THE NEXT COLD FRONT SATURDAY.
HAVE A CHC FOR SHOWERS AND THUNDERSTORMS BY THE AFTN...MAINLY OVER
NORTHERN AND EASTERN PORTIONS. HIGH TEMPERATURES WILL BE IN THE UPR
80S TO AROUND 90.
THE COLD FRONT MOVES IN FROM THE N/NW SUNDAY. MAINLY USED NAM/SREF
FOR THE TIMING OF THE FRONT...THE GFS LOOKS TOO FAST AND AGGRESSIVE.
HAVE A CHC FOR TSTMS WITH THE FRONTAL PASSAGE...ENDING FROM N TO S
THROUGH THE AFTN. CLOUD COVER SHOULD HOLD TEMPERATURES DOWN TO THE
MID TO UPR 80S SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MEDIUM RANGE LOOKS TO BE CHARACTERIZED BY AN UPPER LEVEL RIDGE
OVER THE INTERMOUNTAIN WEST INTO WESTERN CANADA, WHILE AN UPPER
LEVEL TROUGH PERSISTS OVER THE NORTHEASTERN CONUS. THIS WILL PROMOTE
RELATIVELY COOLER AND DRIER AIR TO DRAIN OUT OF THE CANADIAN
PRAIRIES ACROSS THE NORTHEASTERN AND MID-ATLANTIC REGIONS.
FORECAST PERIOD BEINGS SUNDAY NIGHT WITH A WEAKENING BACKDOOR FRONT
DROPPING ACROSS THE AREA, LIKELY BECOMING STALLED ACROSS THE
CAROLINAS BEFORE WASHING OUT EARLY NEXT WEEK. IN ITS WAKE, EXPECT A
MAINLY DRY FORECAST, THOUGH WE DID RETAIN A SLIGHT CHC POP MAINLY
SOUTH OF HIGHWAY 58 CORRIDOR IN S VA/NE NC. SFC HIGH SLIDES OFFSHORE
TUESDAY/WEDNESDAY, WITH S-SW FLOW RETURNING AND BUMPING TEMPS UP
CLOSER TO SEASONAL VALUES FOR MIDWEEK. AS FOR SENSIBLE WX, WILL ALSO
SEE INCREASING (MAINLY DIURNALLY DRIVEN) SHRA/TSTM CHCS BOTH DAYS AS
SHORTWAVE ENERGY EMBEDDED IN THE LONGWAVE TROUGH MOVES ACROSS THE
NORTHERN MID-ATLANTIC. FOR TEMPERATURES, EXPECT MAXIMA TO AVERAGE
BELOW NORMAL FOR THE PERIOD, GENERALLY BE IN THE LOW TO MID
80S...AGAIN EXPECTING TEMPS TO RISE BACK UP TOWARDS NORMAL AHEAD OF
ANOTHER SLOW MOVING FRONT BY LATE NEXT WEEK. EARLY MORNING LOWS TO
AVERAGE IN THE LOWER TO MIDDLE 60S.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
WITH COLD FRONT MOVING THROUGH THIS AFTERNOON AND SHOWERS AND SOME
THUNDERSTORMS DEVELOPING ACROSS THE AREA. SEVERAL SHORT LINES HAVE
FORMED. TRIED TO TIME THEM THROUGH THE TERMINALS. ALSO FOLLOWING
RUC TIMING AS WELL AS THAT SEEMS TO HAVE A GOOD HANDLE ON THE
CURRENT CONVECTION. HRRR TRIES TO BRING CONVECTION OVER NORTHWEST
VIRGINIA INTO CENTRAL AND SOUTHEAST VIRGINIA TOWARD MIDNIGHT. NOT
SURE IF THIS WILL HOLD TOGETHER SO DID NOT INCLUDE IN THE TAFS.
WILL HAVE WATCH FOR LATER CHANGES. COULD SEE SOME FOG DEVELOP
AFTER THESE SHOWERS AS THE COLD FRONT DOES NOT CROSS THE AREA
UNTIL THE EARLY MORNING HOURS. AFTER SUNRISE ON FRIDAY CONDITIONS
WILL BECOME VFR AND REMAIN SO THROUGH MUCH OF SATURDAY. NEXT
SYSTEM APPROACHES SATURDAY AND SUNDAY WITH MORE THUNDERSTORMS
DEVELOPING AND COULD SEE SOME MVFR TO IFR CONDITIONS IN THE
THUNDERSTORMS.
&&
.MARINE...
LATEST OBS REFLECT S-SW WINDS ~15 KT. PRESSURE GRADIENT CONTINUES TO
TIGHTEN OVER THE WATERS AHEAD OF WK LO PRES, WHICH WILL PASS BY JUST
TO OUR NORTH THROUGH TODAY. ASSOCIATED CDFNT WILL PUSH ACROSS THE
WATERS TONIGHT. NOTING WINDS AT LOW END SCA IN THE BAY THIS AFTN,
AND SCA REMAINS IN PLACE OVER THE CHES BAY THROUGH 23Z/7PM FOR
FREQUENT WIND GUSTS ~20KT. CONSIDERED ADDING SCA FOR THE CURRITUCK
SOUND, BUT WL CAP OFF WINDS AT 15 KT THROUGH 7PM WITH THE IDEA THAT
BRIEF WINDOW OF HIGHER WINDS WILL BE MORE CONVECTIVE THAN ANYTHING
ELSE...AND THUS BEST HANDLED WITH SMW AS NEEDED.
WINDS WILL DIMINISH AFTER 00Z/8P AS GRADIENT SLACKENS WITH THE
APPROACH OF THE WEAKENING FRONT. WINDS VEER TO SW OVERNIGHT,
EVENTUALLY BECOMING WNW ERY FRIDAY. FRONT CONTINUES TO WEAKEN JUST
TO OUR SOUTH/SOUTHEAST TOMORROW, AS SFC HI PRES REBUILDS WEST OF THE
WATERS FRI INTO ERY SAT. SUB-SCA CONDS ARE EXPECTED DURING THIS
PERIOD, WITH WAVES/SEAS AVERAGING 2-4FT. NEXT CDFNT (BACKDOOR FRONT)
DROPS SOUTH ACROSS THE WATERS LATER SUN. POTENTIAL EXISTS FOR
ANOTHER BRIEF SURGE AHEAD OF THIS FRONT DURING THE DAY SUNDAY. WINDS
VEER AROUND TO THE E-SE MONDAY AS SFC HIGH PIVOTS OFF THE
MID-ATLANTIC COAST LATER MONDAY AND TUESDAY. LIGHT SOUTHERLY FLOW
FOLLOWS FOR LATER TUE/WED...AHEAD OF NEXT FRONT WHICH FOLLOWS BY
LATE NEXT WEEK.
&&
.EQUIPMENT...
THE NOAA RADIO TRANSMITTER OUT OF RICHMOND IS OFF THE AIR.
TECHNICIANS ARE WORKING THE ISSUE. THERE IS NO ESTIMATE FOR SERVICE
RESTORATION AT THIS TIME.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ630>632-634.
&&
$$
SYNOPSIS...LSA
NEAR TERM...LSA
SHORT TERM...LSA
LONG TERM...MAM
AVIATION...JAB
MARINE...MAM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
237 PM EDT THU AUG 1 2013
.SYNOPSIS...
A MOIST AIR MASS WILL REMAIN IN PLACE TODAY AS A COLD FRONT
APPROACHES FROM THE WEST. THE COLD FRONT WILL MOVE OFF THE COAST
TONIGHT. HIGH PRESSURE RETURNS ON FRIDAY. ANOTHER COLD FRONT
CROSSES THE REGION SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY AFTN UPDATE...
STLT AND RADAR TRENDS INDICATE THAT DOWNSLOPING AND DRYING HAVE
ENDED SIGNIFICANT PCPN OVER THE PIEDMONT AREA. POPS HAVE BEEN
LOWERED WEST OF INTERSTATE 95 FOR THE REST OF THE AFTN IN THAT
AREA.
PREVIOUS DISCUSSION...
A WARM FRONT LIFTED TO THE NORTH OF THE CWA THIS MORNING. A MOIST
AIR MASS WILL REMAIN IN PLACE TODAY WITH PRECIPITABLE WATER CLOSE
TO 2 INCHES. A LEE SIDE TROUGH NEAR THE BLUE RIDGE SEPARATES S/SW
WINDS AND DEW POINTS AROUND 70 TO LOWER 70S FROM DEW POINTS IN THE
LOW TO MID 60S TO THE WEST. THE MAIN COLD FRONT IS SITUATED OVER
THE OHIO VALLEY.
SHOWERS CONTINUE THURSDAY MORNING ACROSS THE AREA WITH THE BIGGEST
CONCENTRATION NEAR THE COAST AND IN AREAS OF NORTH OF RICHMOND. AN
80H TROUGH WHICH WAS NEAR THE OH VALLEY SURFACE FRONT EARLY THIS
MORNING WILL SWEEP ACROSS THE REGION THIS AFTN AND EVENING. IT WILL
HELP TO PRODUCE WIDESPREAD SHOWER ACTIVITY WITH SOME EMBEDDED
THUNDERSTORMS. CONVECTIVE TEMPERATURES WILL RANGE FROM THE UPR 70S
TO MID 80S DURING THE AFTN. CLOUD COVER WILL PUT A DAMPER ON TSTM
ACTIVITY BUT AREAS OF HEAVY RAINFALL CAN BE EXPECTED. THE POTENTIAL
FOR MINOR FLOODING WILL BE GREATEST IN THOSE LOCATIONS WHICH
RECEIVED COPIOUS RAINFALL DURING THE PAST 24 HOURS...MAINLY OVER
PORTIONS OF NOTTOWAY AND DINWIDDIE COUNTIES TO NEAR PETERSBURG WHICH
RECEIVED ITS RAINFALL LATE WEDNESDAY AFTN. ALSO 2 TO 3 INCHES OF
RAIN FELL IN NORTHEAST NORTH CAROLINA IN A NARROW BAND FROM THE
PERQUIMANS COUNTY NEAR THE ALBEMARLE SOUND TO PORTIONS OF CURRITUCK
COUNTY.
DUE TO CLOUD COVER AND AN EVALUATION OF MODEL GUIDANCE...HIGH
TEMPERATURES WERE LOWERED A BIT FOR TODAY WITH FORECAST MAXIMUMS IN
THE LOWER 80S IN MOST LOCATIONS.
PRECIPITATION DIMINISHES FROM W TO E THIS EVENING AS THE 80H TROUGH
MOVES OFFSHORE. MODELS ESPECIALLY THE NAM SUGGEST THAT THE SURFACE
FRONTAL PASSAGE WILL BE WEAK BUT A SUBTLE LOWERING OF THE DEW POINT
CAN BE EXPECTED TOWARD MORNING. LOWS TONIGHT ARE FORECAST IN THE MID
60S TO LWR 70S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOOKS LIKE DRY WX WILL PREVAIL FRIDAY AS THE SFC COLD FRONT MAKES
ENOUGH PROGRESS SOUTH AND HIGH PRESSURE IS ABLE TO RETURN. PARTLY
TO MOSTLY SUNNY AND WARMER WITH HIGHS IN THE MID 80S TO AROUND 90.
LOWS FRIDAY NIGHT IN THE MID 60S TO LOW 70. AN APPROACHING MID-LEVEL
TROF AND INCREASING MOISTURE WILL LEAD TO A CHC FOR SHOWERS BY SAT
AFTN (ESPECIALLY N-NW). HIGHS IN THE 80S TO LOW 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MEDIUM RANGE LOOKS TO BE CHARACTERIZED BY AN UPPER LEVEL RIDGE
OVER THE INTERMOUNTAIN WEST INTO WESTERN CANADA, WHILE AN UPPER
LEVEL TROUGH PERSISTS OVER THE NORTHEASTERN CONUS.
HIGH PRESSURE OF CANADIAN ORIGIN LOOKS TO SHUNT MEANDERING FRONT
SOUTH OF THE AREA SUNDAY/SUNDAY NIGHT...WITH THE FRONT LIKELY
BECOMING STALLED ACROSS THE CAROLINAS BEFORE WASHING OUT EARLY NEXT
WEEK. SLIGHT CHC TO LOW CHC POP CONTINUES FOR LATE SAT/SUNDAY FOR
SOME SPOTTY SHRAS DURING THIS PERIOD. GIVEN THAT THE WEAKENING FRONT
WILL REMAIN IN THE AREA MON, HELD ONTO A SLIGHT CHC POP MAINLY SOUTH
OF HIGHWAY 58 CORRIDOR IN S VA/NE NC, AND KEPT FORECAST DRY FARTHER
NORTH. ADDITIONAL LOW CHC POPS ON TUESDAY (MAINLY DIURNALLY DRIVEN)
AS SHORTWAVE ENERGY EMBEDDED IN THE LONGWAVE TROUGH MOVES ACROSS.
DROPPED POPS FOR WEDNESDAY WITH FLATTER/ QUASI-ZONAL FLOW SETTING
UP. FOR TEMPERATURES, EXPECT MAXIMA TO AVERAGE BELOW NORMAL FOR THE
PERIOD, GENERALLY RUNNING IN THE LOW TO MID 80S...THOUGH TEMPS
WILL LIKELY BE CREEPING BACK UP TOWARDS NORMAL AHEAD OF ANOTHER
SLOW MOVING FRONT BY LATER NEXT WEEK. EARLY MORNING LOWS TO
AVERAGE IN THE LOWER TO MIDDLE 60S.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
WITH COLD FRONT MOVING THROUGH THIS AFTERNOON AND SHOWERS AND SOME
THUNDERSTORMS DEVELOPING ACROSS THE AREA. SEVERAL SHORT LINES HAVE
FORMED. TRIED TO TIME THEM THROUGH THE TERMINALS. ALSO FOLLOWING
RUC TIMING AS WELL AS THAT SEEMS TO HAVE A GOOD HANDLE ON THE
CURRENT CONVECTION. HRRR TRIES TO BRING CONVECTION OVER NORTHWEST
VIRGINIA INTO CENTRAL AND SOUTHEAST VIRGINIA TOWARD MIDNIGHT. NOT
SURE IF THIS WILL HOLD TOGETHER SO DID NOT INCLUDE IN THE TAFS.
WILL HAVE WATCH FOR LATER CHANGES. COULD SEE SOME FOG DEVELOP
AFTER THESE SHOWERS AS THE COLD FRONT DOES NOT CROSS THE AREA
UNTIL THE EARLY MORNING HOURS. AFTER SUNRISE ON FRIDAY CONDITIONS
WILL BECOME VFR AND REMAIN SO THROUGH MUCH OF SATURDAY. NEXT
SYSTEM APPROACHES SATURDAY AND SUNDAY WITH MORE THUNDERSTORMS
DEVELOPING AND COULD SEE SOME MVFR TO IFR CONDITIONS IN THE
THUNDERSTORMS.
&&
.MARINE...
LATEST OBS REFLECT S-SW WINDS ~15 KT. PRESSURE GRADIENT CONTINUES
TO TIGHTEN OVER THE WATERS AHEAD OF WK LO PRES, WHICH WILL PASS BY
JUST TO OUR NORTH THROUGH TODAY. ASSOCIATED CDFNT WILL PUSH ACROSS
THE WATERS TONIGHT. NOTING WINDS AT LLVL SCA IN THE BAY EARLY THIS
AFTN, AND HV GONE AHEAD AND HOISTED SCA THROUGH 23Z/7PM FOR
FREQUENT WIND GUSTS ~20KT. WINDS WILL DIMINISH EARLY THIS EVENING
AS GRADIENT SLACKENS WITH THE APPROACH OF THE WEAKENING FRONT.
WINDS VEER TO SW TONIGHT...EVENTUALLY BECOMING WNW LATE TNGT/ERY
FRIDAY. FRONT CONTINUES TO WEAKEN TO OUR SOUTH TOMORROW, AS SFC
HI PRES REBUILDS OVR THE WTRS FRI INTO ERY SAT. SUB-SCA CONDS ARE
EXPECTED DURING THIS PERIOD. NEXT CDFNT (BACKDOOR FRONT) DROPS
SOUTH ACROSS THE WATERS SUN. POTENTIAL EXISTS FOR ANOTHER BRIEF
SURGE AHEAD OF THIS FRONT DURING THE DAY SUNDAY. WINDS VEER
AROUND TO THE E-SE MONDAY AS SFC HIGH PIVOTS OFF THE MID-ATLANTIC
COAST LATER MONDAY AND TUESDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ630>632-634.
&&
$$
SYNOPSIS...JDM/LSA
NEAR TERM...LSA
SHORT TERM...JDM/MAS
LONG TERM...MAM
AVIATION...JAB
MARINE...ALB/MAM
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
320 PM CDT THU AUG 1 2013
.DISCUSSION...
ACTIVE WEATHER EXPECTED THIS EVENING AS A MATURE MCS ACROSS
NORTHERN NEBRASKA SHOULD ROLL EAST SOUTHEAST. SEVERE WATCH
REMAINS IN EFFECT FOR NORTHEAST NEBRASKA AND NORTHWEST IOWA...AND
A TORNADO WATCH IN EFFECT FOR MUCH OF NORTH CENTRAL NEBRASKA. HOP
WRF AND RAP SEEM TO HAVE THE BEST HANDLE ON DEVELOPING CONVECTION...
THUS WILL HAVE HIGH POPS THIS EVENING WITH A SEVERE THREAT. HAVE
ISSUED A COUPLE OF SEVERE WARNINGS IN EXTREME NORTHEAST NEBRASKA...
BUT WE HAVEN`T BEEN ABLE TO GET ANY HAIL REPORTS BIGGER THAN
DIME TO NICKEL SIZE. EFFECTIVE SHEAR REMAINS QUITE HIGH AT 50 TO
60 KNOTS...BUT MID LEVEL LAPSE RATES ARE SLIGHTLY MARGINAL. WILL
ALSO CONTINUE TO MONITOR TRENDS AND ISSUE WARNINGS AS NECESSARY
FOR LARGE HAIL AND DAMAGING WINDS WITHIN THE STRONGEST CORES...AND
MAY HAVE TO EVENTUALLY EXTEND THE WATCH FURTHER EAST/SOUTHEAST
TOWARD THE I80 CORRIDOR IN TIME. THE BACK EDGE OF THE PRECIPITATION
WILL PROBABLY STILL BE IN THE AREA FRIDAY MORNING MOVING OUT OF
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. THE AFTERNOON MAY BE MOSTLY
DRY...ALTHOUGH THERE DOES APPEAR TO BE ANOTHER WEAK SURGE OF
MOISTURE MOVING SOUTH...WHICH COULD BRING A SLIGHT CHANCE OF
STORMS FRIDAY NIGHT.
BY SATURDAY...HIGH PRESSURE NOSING SOUTH OUT OF THE DAKOTAS SHOULD
KEEP SATURDAY DRY AND SLIGHTLY COOLER. THIS NORTHEASTERLY FLOW
BECOMES EAST SATURDAY NIGHT. AT THE SAME TIME...THERE IS ANOTHER
WAVE MOVING OUT OF THE ROCKIES...SO IT WILL BE A BATTLE OF HOW FAR
EAST THIS SYSTEM CAN GET BY DAYBREAK SUNDAY...VERSUS THE DRY
EASTERLY FLOW WITH HIGH PRESSURE ACROSS THE MID MISSISSIPPI RIVER
VALLEY. CHANCES SHOULD SPREAD ACROSS THE FORECAST AREA SUNDAY
THOUGH...BUT MAY STILL STRUGGLE TO MOVE INTO WESTERN IOWA. WAVE
COULD MOSTLY BE EAST SOUTHEAST OF THE AREA SO SHOULD BE MOSTLY DRY
SUNDAY NIGHT.
FOR THE EXTENDED FORECAST...THE REGION REMAINS IN PESKY NORTHWEST
FLOW. FORECAST CHALLENGES REMAIN TRYING TO TIME WEAK WAVES INTO
THE AREA...THUS OVERALL FORECAST CONFIDENCE REMAINS LOW. TOWARD
THE END OF THE PERIOD...ANOTHER FRONT SETTLING SOUTH COULD BRING
SOME COOLER TEMPS TO THE REGION BY THURSDAY...BUT COULD ALSO SHUNT
ANY PRECIP THREAT OUT OF THE AREA AS WELL.
DEWALD
&&
.AVIATION...18Z TAFS FOR KOFK...KOMA AND KLNK.
SCATTERED TSTMS ARE EXPECTED TO DEVELOP AND MOVE ACROSS THE
REGION...POSSIBLY HITTING TAF SITES LATE THIS AFTERNOON AND INTO
THE EVENING HOURS. CONDITIONS SHOULD REMAIN VFR FOR THE MOST
PART...HOWEVER SOME OF THESE STORMS COULD CONTAIN LARGE HAIL AND
DAMAGING WINDS AND MVFR TO IFR CONDITIONS.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
310 PM CDT THU AUG 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 PM CDT THU AUG 1 2013
MORNING MAP ANALYSIS INDICATES MID TO UPPER LEVEL RIDGING OVER THE
WESTERN CONUS...WITH A TROUGH OVER THE EAST. MID TO UPPER LEVEL JET
ENERGY EXTENDS FROM THE WEST-CENTRAL CONUS...NORTHEAST INTO THE
NORTHERN ROCKY MOUNTAIN RANGE...AND THEN SOUTHEAST ACROSS PORTIONS
OF THE PLAINS AND MISSISSIPPI VALLEY...AND FINALLY EAST/NORTHEAST
INTO THE EASTERN CONUS. NORTHWESTERLY MID TO UPPER LEVEL FLOW
PERSISTS OVER THE CENTRAL PLAINS AS A RESULT. A ~110KT UPPER LEVEL
JET STREAK IS ALSO NOTED EXTENDING FROM THE NORTHERN
PLAINS...SOUTHEAST INTO THE MID-MISSISSIPPI VALLEY. MID TO UPPER
LEVEL FLOW MAXES OUT AT AROUND 100KTS NEAR 200MB PER RAP ANALYSIS
AND 12Z SOUNDING DATA FROM KOAX. AT THE SURFACE A RIDGE OF HIGH
PRESSURE EXTENDS FROM THE MISSOURI RIVER VALLEY...SOUTH/SOUTHEAST
INTO PORTIONS OF THE MID-MISSISSIPPI VALLEY. LEE SIDE TROUGHING ALSO
EXTENDS FROM SOUTHEASTERN WYOMING INTO EASTERN COLORADO AND AS A
RESULT...SOUTHERLY LOW LEVEL FLOW IS INFILTRATING OUR CWA.
FOR THE REST OF THIS AFTERNOON AND EVENING...CONTINUED SOUTHERLY LOW
LEVEL FLOW...ENHANCED BY THE DEVELOPMENT OF A 25-30KT 850MB JET
STREAK...WILL PROMOTE INCREASING THERMAL ADVECTION ACROSS MUCH OF
OUR AREA. ISENTROPIC UPGLIDE AND
SATURATION...PRIMARILY ALONG THE 310-320K SURFACES...IS EXPECTED TO
PROMOTE PRECIPITATION PRODUCTION ACROSS THE AREA. INCREASED VALUES
OF LOW LEVEL MOISTURE SHOULD CONTINUE PROMOTING DECENT VALUES OF
POTENTIAL INSTABILITY...WITH THE NAM AND OPERATIONAL GFS BOTH
SUGGESTING MUCAPE VALUES NEAR 3000J/KG ACROSS MUCH OF THE AREA. IN
ADDITION TO THE POTENTIAL INSTABILITY...DEEP LAYER BULK SHEAR VALUES
ON THE ORDER OF 40-50KTS IS ALSO EXPECTED. GIVEN ALL THIS...SEVERE
WEATHER REMAINS POSSIBLE THIS AFTERNOON INTO THIS EVENING...WITH
LARGE HAIL AND STRONG THUNDERSTORM WIND GUSTS BEING THE PRIMARY
SEVERE WEATHER THREATS. IN ADDITION THE HAIL AND WIND THREAT
HOWEVER...FORECAST PROXIMITY SOUNDINGS FROM VARIOUS MODELS SUGGEST A
SIGNIFICANTLY VEERING LOW LEVEL WIND PROFILE THUS HELPING PROMOTE
SRH VALUES NEAR 200M^2/S^2 ACROSS PORTIONS OF OUR CWA. GIVEN
THIS...WILL ALSO CONTINUE THE TORNADO MENTION IN THE HWO.
GUIDANCE SUGGESTS THE AFOREMENTIONED THERMAL ADVECTION SHOULD HELP
MAINTAIN PRECIPITATION PRODUCTION ACROSS THE AREA TONIGHT...WITH
MUCH OF THIS ACTIVITY MOVING OFF TO EAST BY EARLY FRIDAY MORNING. IT
WOULD APPEAR AS THOUGH THE SEVERE WEATHER THREAT SHOULD DIMINISH
HEADING INTO THE OVERNIGHT HOURS. THAT BEING SAID...WITH A
PERSISTENT SOUTHERLY LOW LEVEL WIND FIELD...INCREASING SIGNIFICANTLY
ABOVE THE BOUNDARY LAYER PRIMARILY DUE TO A ~50KT LOW LEVEL
JET...MAY HELP PROMOTE NOCTURNAL MCS DEVELOPMENT. WILL CONTINUE THE
MENTION OF SEVERE WEATHER ACROSS THE AREA THROUGH THE OVERNIGHT
HOURS AS A RESULT...BUT THE DETAILS OF ANY POTENTIAL MCS DEVELOPMENT
WILL NOT LIKELY BECOME ANY MORE CLEAR UNTIL LATER TONIGHT.
THE PRIMARY AXIS OF THERMAL ADVECTION SHOULD DEPART THE AREA TO THE
EAST ON FRIDAY...THUS ALLOWING FOR DECREASING PRECIPITATION CHANCES.
THAT BEING SAID...MID LEVEL PERTURBATIONS MOVING OVER THE AREA WITHIN
THE MEAN FLOW SHOULD STILL PROMOTE ENOUGH OMEGA FOR FURTHER
PRECIPITATION PRODUCTION ACROSS PORTIONS OF OUR CWA STARTING FRIDAY
AFTERNOON. SHOULD THUNDERSTORM ACTIVITY BE REALIZED FRIDAY
AFTERNOON...THEN SEVERE WEATHER COULD ONCE AGAIN BE REALIZED AS
GUIDANCE SUGGESTS MUCAPE VALUES NEAR 3000J/KG WILL ACCOMPANY DEEP
LAYER BULK SHEAR VALUES OF 30-40KTS. GIVEN ALL THIS...WILL GO AHEAD
AND OUTLOOK SEVERE WEATHER FOR FRIDAY AS WELL.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CDT THU AUG 1 2013
FORECAST CONCERNS MAINLY FOCUSED ON THUNDERSTORMS.
MODELS ARE IN GOOD AGREEMENT THAT THE NORTHWEST FLOW REGIME WILL
PERSIST THROUGH THE PERIOD. THUS...EXPECT A PERIOD OF UNSETTLED
WEATHER WITH NORMAL OR BELOW NORMAL TEMPERATURES.
AT THE SURFACE...A BROAD AREA OF LOW PRESSURE ON THE LEE SIDE OF
THE ROCKIES WILL ANCHOR A WEAK FRONTAL BOUNDARY THAT WILL
OSCILLATE FROM KS TO SD THROUGH THE PERIOD. THE LOCATION OF THIS
BOUNDARY WILL BE THE FOCUS OF AFTERNOON CONVECTIVE INITIATION. THEN
STORMS SHOULD DRIFT SOUTH AND EAST THROUGH THE EVENING HOURS AS AN
MCS. THERE WILL BE GOOD INSTABILITY AND MOISTURE AVAILABLE...SO
SEVERE STORMS CAN NOT BE RULED OUT.
ALOFT...THE NORTHWEST FLOW WILL ALLOW FREQUENT AND WEAK WAVES TO
MOVE OVER THE AREA. THIS WILL OFFER ENOUGH SUPPORT TO GET INITIATE
THE CONVECTION.
TOWARDS THE END OF THE PERIOD (THURSDAY) A STRONGER COOL FRONT IS
FORECAST TO MOVE SOUTH ACROSS THE AREA. IF THIS
OCCURS...TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL AND IT
WILL BE DRY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 145 PM CDT THU AUG 1 2013
VFR CONDITIONS FORECAST THROUGH THE NEXT 24 HOURS.
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO DEVELOP AND MOVE
ACROSS THE REGION THIS AFTERNOON AND INTO THE OVERNIGHT HOURS.
SOME OF THIS ACTIVITY COULD CONTAIN VERY STRONG WIND GUSTS. FOR
NOW WILL GO WITH VCTS 20-12Z AND REFINE SHOWER/THUNDERSTORM TIMING
AFTER CONFIDENCE INCREASES FOLLOWING DEEP CONVECTIVE DEVELOPMENT.
THE SYNOPTIC SURFACE WIND WILL REMAIN FROM THE SOUTH/SOUTHEAST
THROUGH THE TAF PERIOD AT AROUND 08KTS...BUT AGAIN A STRONG AND
VARIABLE WIND WILL BE POSSIBLE IN AND NEAR THUNDERSTORM ACTIVITY.
VISIBILITY RESTRICTION IS NOT CURRENTLY FORECAST...BUT SOME
VISIBILITY RESTRICTION IN RAIN WILL BE POSSIBLE SHOULD SHOWER AND
THUNDERSTORM ACTIVITY INFILTRATE THE AREA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...BRYANT
LONG TERM...EDDY
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
145 PM CDT THU AUG 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT THU AUG 1 2013
IN THE UPPER LEVELS WE ARE STILL IN GENERALLY NORTHWESTERLY FLOW
WITH A RIDGE LOCATED TO THE WEST CENTERED OVER THE ROCKIES. AT THE
SURFACE WE HAVE HIGH PRESSURE SLIGHTLY TO OUR NORTHEAST WITH A GOOD
TONGUE OF MOISTURE REACHING UP THROUGH THE CENTRAL PLAINS. THIS
MOISTURE IS ALSO APPARENT AT 850HPA WITH DEWPOINTS NEAR 15 DEGREES.
CURRENT KUEX RADAR SHOWS A FEW THUNDERSTORMS ENTERING THE NORTHWEST
PORTION OF OUR CWA. THE RAP MODEL...AND TO SOME DEGREE THE WRF
MODELS...SEEMED TO HAVE THE BEST HANDLE FOR THIS TIME PERIOD WHICH
MAINTAINS CHANCES OF PRECIPITATION FOR THE WESTERN PART OF OUR CWA
INTO THE MORNING.
MAIN CONCERN FOR THIS FORECAST IS CONVECTION AND SEVERE WEATHER
POTENTIAL FOR TODAY. THE SURFACE HIGH WILL MOVE OFF TO THE EAST
AS A LOW DEVELOPS TO THE WEST. AS THE HIGH MOVES OFF...INCREASINGLY
SOUTHERLY FLOW WILL BRING IN MORE MOISTURE WITH AFTERNOON DEW
POINTS IN THE MID TO UPPER 60S. A WARM FRONT WILL LIFT NORTH
ACROSS NEBRASKA REACHING CENTRAL NEBRASKA THIS AFTERNOON. MODELS
ARE INDICATING INSTABILITY INCREASING TO 2000 TO 3000 J/KG ALONG
WITH DEEP LAYER SHEAR OF 40 TO 50 KTS. THESE PARAMETERS ARE
SUFFICIENT FOR SUPERCELL DEVELOPMENT ESPECIALLY IN THE VICINITY OF
THE WARM FRONT. STORMS WHICH DEVELOP WILL BE CAPABLE OF PRODUCING
VERY LARGE HAIL...STRONG WINDS...AND EVEN TORNADOES NEAR THE
BOUNDARY. PRECIPITABLE WATERS THIS AFTERNOON AVERAGE 1.50 INCHES AND ARE
130 PERCENT OF NORMAL. LOCALLY HEAVY RAINFALL IN EXCESS OF AN INCH
OR TWO IS POSSIBLE. CONVECTION THAT DEVELOPS IN THE AFTERNOON AND
EVENING IS EXPECTED TO PERSIST TONIGHT AS THE LLJ IS IN EXCESS OF
40 TO 45 KTS. EVEN WITH THIS POTENTIAL FOR STRONG
STORMS...CONFIDENCE IS STILL NOT HIGH FOR WIDESPREAD
PRECIPITATION AS MODELS ARE NOT CONSISTENT WITH DEVELOPMENT/QPF.
WENT WITH SCATTERED POPS THROUGHOUT THE DAY AND WILL NEED TO MONITOR
THE TREND AS THE DAY PROGRESSES AND CONVECTION UNFOLDS.
TEMPERATURES TODAY ARE DEPENDENT ON CLOUD COVER. GENERALLY WE
SHOULD SEE HIGH TEMPS A FEW DEGREES WARMER THAN YESTERDAY DUE TO
THE INCREASED MIDLEVEL TEMPS. REMAINING CLOUD COVER IN THE MORNING
AND CONVECTION IN THE AFTERNOON MIGHT REDUCE DAYTIME HEATING...BUT
BREAKS IN CLOUD COVER COULD ALLOW TEMPERATURES TO APPROACH THE LOW
90S...ESPECIALLY IN THE SOUTHWEST PART OF THE CWA.
LOWS TONIGHT ARE EXPECTED TO BE IN THE MID TO UPPER 60S IN THE
WARMER AIR MASS. THESE LOW TEMPS ARE NEAR AVERAGE FOR THIS TIME OF
YEAR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 346 AM CDT THU AUG 1 2013
FRIDAY MORNING THROUGH WEDNESDAY. CONCERN CONTINUES TO
REVOLVE AROUND PERIODIC CHANCES FOR RAIN DURING THE ENTIRE EXTENDED
PERIOD.
STARTING OUT FRIDAY MORNING IN THE UPPER LEVELS...MODELS STILL
CONSISTENT IN SHOWING ONE CLOSED LOW OVER THE PACIFIC NORTHWEST AND
ANOTHER ONE OVER NORTHERN ONTARIO. THESE CONTINUE TO DAMPEN THE HIGH
OVER THE SOUTHERN PLAINS. IMPRESSIVE NORTHERN STREAM FOR THIS TIME
OF YEAR WHICH WILL AFFECT THE NORTHERN HALF OF THE CONUS. AT THE
SURFACE...EXPECT LOW PRESSURE OVER SOUTHWEST NEBRASKA WITH A WARM
FRONT EXTENDING SOMEWHERE ACROSS THE CWA. BELIEVE ANY OVERNIGHT
CONVECTION SHOULD HAVE WORKED ITS WAY EAST OF THE CWA BY 12Z FRIDAY
AND WILL TAKE OUT LOW POPS THAT WERE PREVIOUSLY IN THE EASTERN PART
OF OUR AREA. WILL ALSO LEAVE ANY RAIN CHANCES OUT DURING THE DAYTIME
ON FRIDAY AS MOST OF THE CONVECTION THE PAST FEW WEEKS HAS OCCURRED
DURING THE EVENING AND OVERNIGHT TIME FRAME. SHOULD STILL BE IN THE
WARM SECTOR FOR MOST OF THE AREA ON FRIDAY BUT BY SATURDAY THE
SURFACE LOW PUSHES SOUTH AND OUR WINDS BECOME MORE NORTHEASTERLY
WITH SOME COOLER AIR PUSHING IN. HIGHS ON SAT SHOULD BE ABOUT 5
DEGREES BELOW THOSE ON FRIDAY.
AS HAS BEEN NOTED IN PREVIOUS AFDS...TOUGH TO TIME ANY SHORTWAVE
TROUGHS MOVING OVER THE AREA MORE THAN A DAY OR TWO OUT. HOWEVER
BOTH THE LATEST GFS AND EC OPERATIONAL RUNS SIMILAR IN SLIDING ONE
OF THESE WAVES THROUGH THE RIDGE AND OVER US SATURDAY NIGHT. FOR
THIS REASON WILL UP RAIN CHANCES SAT NIGHT AND CONTINUE INTO SUNDAY.
AFTER THAT WE CONTINUE WITH NORTHWEST FLOW AS THE BIG PICTURE POINTS
TO TROUGHING IN THE EAST AND WEST CONUS WITH WEAK RIDGING IN THE
CENTRAL THROUGH AT LEAST THE MIDDLE PART OF NEXT WEEK. THESE LEAVES
US OPEN TO ADDITIONAL DISTURBANCES MOVING THROUGH SO WILL CONTINUE
WITH 20-30 POPS.
IN REGARDS TO SEVERE...DEEP LAYER SHEAR LOOKS FAVORABLE AT LEAST
THROUGH THE WEEKEND WITH 0-6 KM BULK SHEAR PROGGED FROM 25 KT IN
THE SOUTHERN CWA TO 40 KT IN THE NORTH. INSTABILITY ALSO LOOKS OK.
ONE ISSUE THIS TIME OF YEAR IS WILL THERE BE ANY CAPPING TAKING
PLACE. MODELS DO HINT AT THAT AND WILL BE SOMETHING TO WATCH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 145 PM CDT THU AUG 1 2013
VFR CONDITIONS FORECAST THROUGH THE NEXT 24 HOURS.
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO DEVELOP AND MOVE
ACROSS THE REGION THIS AFTERNOON AND INTO THE OVERNIGHT HOURS.
SOME OF THIS ACTIVITY COULD CONTAIN VERY STRONG WIND GUSTS. FOR
NOW WILL GO WITH VCTS 20-12Z AND REFINE SHOWER/THUNDERSTORM TIMING
AFTER CONFIDENCE INCREASES FOLLOWING DEEP CONVECTIVE DEVELOPMENT.
THE SYNOPTIC SURFACE WIND WILL REMAIN FROM THE SOUTH/SOUTHEAST
THROUGH THE TAF PERIOD AT AROUND 08KTS...BUT AGAIN A STRONG AND
VARIABLE WIND WILL BE POSSIBLE IN AND NEAR THUNDERSTORM ACTIVITY.
VISIBILITY RESTRICTION IS NOT CURRENTLY FORECAST...BUT SOME
VISIBILITY RESTRICTION IN RAIN WILL BE POSSIBLE SHOULD SHOWER AND
THUNDERSTORM ACTIVITY INFILTRATE THE AREA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...MANGELS/FAY
LONG TERM...EWALD
AVIATION...BRYANT
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
508 PM EDT THU AUG 1 2013
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL MOVE THROUGH THE AREA THIS EVENING.
HIGH PRESSURE OVER WESTERN TENNESSEE WILL MOVE EAST ACROSS THE
TENNESSEE VALLEY AND EXTEND A RIDGE NORTH INTO OHIO AND PENNSYLVANIA
THROUGH EARLY FRIDAY AFTERNOON. A TROUGH OF LOW PRESSURE WILL MOVE
EAST ACROSS THE REGION FRIDAY AFTERNOON AND EVENING. HIGH PRESSURE
WILL MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND BE OFF THE EAST COAST
AND BY TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
TWEAKED THE TIMING OF THE CONVECTION ACROSS THE AREA THIS EVENING.
ALSO CHANGED CHANCE WORDING TO SCATTERED FOR THIS EVENING.
ORIGINAL DISCUSSION...
UPPER LEVEL TROUGH AND ASSOCIATED POSITIVE VORTICITY
MAXIMUM WILL MOVE EAST ACROSS THE REGION OVERNIGHT. NEARLY SILENT
SURFACE TROUGH WAS NOT VERY ACTIVE THIS MORNING BUT DECIDED TO
MAKE ITS PRESENCE KNOWN BY FIRING SOME THUNDERSTORMS ALONG THE
LINE. I WAS A BIT CONCERNED ABOUT THIS FEATURE BEFORE THE LAST
UPDATE BUT LITTLE IN THE WAY OF ACTIVITY WAS ASSOCIATED WITH THE
FEATURE. SO...BACK TRACKED AND ADDED A MENTION OF SHOWERS AND
THUNDERSTORMS THIS EVENING AS THE TROUGH AXIS MOVES EAST ACROSS
THE AREA.
OTHER THAN THE THREAT FOR THUNDERSTORMS THIS EVENING...WE SHOULD SEE
DIMINISHING CHANCES FOR PRECIPITATION BY MIDNIGHT AND A RETURN TO
FAIR WEATHER FOR THE OVERNIGHT HOURS AS NEGATIVE VORTICITY ADVECTION
FOLLOWS THE TROUGH INTO THE REGION.
TEMPERATURES OVERNIGHT SHOULD HOVER IN THE LOWER 60S OVERNIGHT BUT
SHOULD BE A FEW DEGREES COLDER THAN LAST NIGHT. COLD AIR MASS BEHIND
THE FRONT RESULTED IN MOSTLY DRIER AIR RATHER THAN A SIGNIFICANT
DROP IN TEMPERATURES.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
SURFACE HIGH PRESSURE RIDGE WILL BUILD EAST ACROSS THE AREA TOMORROW
MORNING AND THEN THAT FEATURE WILL BE FOLLOWED BY ANOTHER WEAK
APPROACHING COLD FRONT AND ASSOCIATED MOISTURE. SO WILL KEEP A
CHANCE FOR SHOWERS AND THUNDERSTORMS GOING IN THE AFTERNOON. I THINK
THE BETTER CHANCE MAY HOLD OFF UNTIL LATER IN THE DAY INTO FRIDAY
NIGHT.
COLD FRONT SLIPS THROUGH LATE FRIDAY NIGHT INTO SATURDAY MORNING
WITH SOME UPPER LEVEL SUPPORT THAT APPEARS TO STAY OVER THE NORTHERN
TIER COUNTIES AND LAKE ERIE. ANOTHER SHOT OF POSITIVE VORTICITY
SCOOTS IN ACROSS THE AREA SATURDAY AFTERNOON AND NIGHT AND THIS
COULD SET OFF SOME AFTERNOON AND EARLY EVENING THUNDERSTORMS.
FINALLY...BY SUNDAY MORNING...MUCH DRIER AIR...SURFACE HIGH PRESSURE
AND FAIRLY STRONG NEGATIVE VORTICITY ADVECTION MOVE SOUTHEAST INTO
THE AREA AND WE SHOULD SEE ANOTHER ROUND OF FAIR WEATHER. AS SURFACE
HIGH PRESSURE BUILDS SOUTHEAST...FORECAST AREA SHOULD SEE A SLIGHT
INCREASE IN THE WINDS TO PRODUCE A GENTLE BREEZE THROUGH THE DAY
INTO SUNDAY NIGHT. FAIR WEATHER CONTINUES SUNDAY NIGHT UNDER THE
INFLUENCE OF THE HIGH PRESSURE.
TEMPERATURES SHOULD JUMP BACK UP INTO THE MIDDLE TO UPPER 70S ON
FRIDAY AHEAD OF THE COLD FRONT. CLOUDS AND SHOWERS WILL HELP BLANKET
THE AREA AND KEEP TEMPERATURES UP IN THE MIDDLE 60S THROUGH THE
NIGHT. SOME LOWER 60S IN THE VALLEYS EXTREME EASTERN ERIE AND
CRAWFORD COUNTIES IN PENNSYLVANIA.
THEN ON SATURDAY AFTER COLD FRONTAL PASSAGE WILL LIKELY SEE
TEMPERATURES DROP BACK INTO THE MIDDLE 70S NORTH TO UPPER 70S IN THE
WEST. AS FAIR WEATHER RETURNS SATURDAY NIGHT INTO SUNDAY COOLER
TEMPERATURES IN THE 50S CAN BE EXPECTED FOLLOWED BY HIGHS IN THE
LOWER TO MIDDLE 70S. WARMER TEMPERATURES EXPECTED IN THE WEST.
SUNDAY NIGHT TEMPERATURES SIMILAR TO SATURDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LITTLE CHANGE TO LARGE SCALE PATTERN DURING THIS PERIOD AS THE
UPPER LEVEL TROUGH REMAINS IN PLACE OVER ONTARIO AND QUEBEC WHICH
WILL KEEP CONDITIONS COOLER THAN NORMAL AND AT TIMES UNSETTLED.
HAVE GENERALLY USED THE ECMWF FOR TIMING PRECIPITATION INTO THE
REGION AS THE GFS AND ECMWF DIVERGE SOMEWHAT BEGINNING ON TUESDAY.
WILL KEEP TUESDAY DRY WITH LOW CHANCE AND SLIGHT CHANCE POPS ON
WEDNESDAY AND THURSDAY.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
LOW CLOUDS HAVE LIFTED AND DECREASED IN COVERAGE IN THE EAST
WHILE INSTABILITY AND CONVECTIVE DEVELOPMENT HAS TAKEN PLACE OVER
LOWER MICHIGAN AND NORTHERN INDIANA. SCATTERED SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED NEAR TOL. THE HRRR MODEL HAS A DECENT
HANDLE ON THIS ACTIVITY AND MOVES SOUTHEAST MOSTLY AROUND LAKE
ERIE AND DISSIPATES IT BEFORE SUNSET. WILL MENTION VCSH AT TOL,
FDY AND MFD AND LEAVE THE OTHER TAF SITES DRY.
BOUNDARY LAYER MOISTURE WILL REMAIN HIGH OVERNIGHT AND WITH LIGHT
WINDS AND CLEARING SKIES...DENSE FOG MAY DEVELOP DOWN TO IFR VSBY
NEAR YNG FROM 10-12 UTC. LIGHTER FOG IS POSSIBLE NEAR CAK. IF
AFTERNOON SHOWERS REACH OTHER TAF SITES FOG MAY NEED TO BE ADDED.
MODEL SOUNDINGS SHOW THE MOISTURE LAPSE INCREASING WITH HEIGHT
NEAR YNG OVERNIGHT WHICH INDICATES FAVORABLE CONDITIONS FOR FOG
DEVELOPMENT.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH SHOWERS.
&&
.MARINE...
SMALL CRAFT CONDITIONS PREVAIL OVER THE LAKE AT MID AFTERNOON.
EXPECT THE PRESSURE GRADIENT TO WEAKEN THIS EVENING ALLOWING THE
EXPIRATION OF THE SCA AT 00UTC. MODERATE RISK OF RIP CURRENTS WILL
LINGER TO ABOUT 22 UTC. ANOTHER TROUGH/WEAK FRONT WILL MOVE ACROSS
THE LAKE FRIDAY NIGHT AND PRODUCE WINDS OF 10 TO 20 KNOTS WITH WAVES
OF 2-4 FEET. HIGH PRESSURE WILL GRADUALLY BUILD OVER THE LAKE LATE
SATURDAY NIGHT AND SUNDAY WITH WEST TO NORTHWEST FLOW OF 5 TO 15
KNOTS. A SMALL CRAFT ADVISORY MAY BE NEEDED ON SUNDAY. HIGH PRESSURE
WILL LINGER NEAR THE LAKE MONDAY AND TUESDAY AND PRODUCE LIGHT WINDS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
LEZ145>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...DJB/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...LAPLANTE
AVIATION...LAPLANTE
MARINE...LAPLANTE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
347 PM EDT THU AUG 1 2013
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL MOVE THROUGH THE AREA THIS EVENING.
HIGH PRESSURE OVER WESTERN TENNESSEE WILL MOVE EAST ACROSS THE
TENNESSEE VALLEY AND EXTEND A RIDGE NORTH INTO OHIO AND PENNSYLVANIA
THROUGH EARLY FRIDAY AFTERNOON. A TROUGH OF LOW PRESSURE WILL MOVE
EAST ACROSS THE REGION FRIDAY AFTERNOON AND EVENING. HIGH PRESSURE
WILL MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND BE OFF THE EAST COAST
AND BY TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPPER LEVEL TROUGH AND ASSOCIATED POSITIVE VORTICITY MAXIMUM WILL
MOVE EAST ACROSS THE REGION OVERNIGHT. NEARLY SILENT SURFACE TROUGH
WAS NOT VERY ACTIVE THIS MORNING BUT DECIDED TO MAKE ITS PRESENCE
KNOWN BY FIRING SOME THUNDERSTORMS ALONG THE LINE. I WAS A BIT
CONCERNED ABOUT THIS FEATURE BEFORE THE LAST UPDATE BUT LITTLE IN
THE WAY OF ACTIVITY WAS ASSOCIATED WITH THE FEATURE. SO...BACK
TRACKED AND ADDED A MENTION OF SHOWERS AND THUNDERSTORMS THIS
EVENING AS THE TROUGH AXIS MOVES EAST ACROSS THE AREA.
OTHER THAN THE THREAT FOR THUNDERSTORMS THIS EVENING...WE SHOULD SEE
DIMINISHING CHANCES FOR PRECIPITATION BY MIDNIGHT AND A RETURN TO
FAIR WEATHER FOR THE OVERNIGHT HOURS AS NEGATIVE VORTICITY ADVECTION
FOLLOWS THE TROUGH INTO THE REGION.
TEMPERATURES OVERNIGHT SHOULD HOVER IN THE LOWER 60S OVERNIGHT BUT
SHOULD BE A FEW DEGREES COLDER THAN LAST NIGHT. COLD AIR MASS BEHIND
THE FRONT RESULTED IN MOSTLY DRIER AIR RATHER THAN A SIGNIFICANT
DROP IN TEMPERATURES.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
SURFACE HIGH PRESSURE RIDGE WILL BUILD EAST ACROSS THE AREA TOMORROW
MORNING AND THEN THAT FEATURE WILL BE FOLLOWED BY ANOTHER WEAK
APPROACHING COLD FRONT AND ASSOCIATED MOISTURE. SO WILL KEEP A
CHANCE FOR SHOWERS AND THUNDERSTORMS GOING IN THE AFTERNOON. I THINK
THE BETTER CHANCE MAY HOLD OFF UNTIL LATER IN THE DAY INTO FRIDAY
NIGHT.
COLD FRONT SLIPS THROUGH LATE FRIDAY NIGHT INTO SATURDAY MORNING
WITH SOME UPPER LEVEL SUPPORT THAT APPEARS TO STAY OVER THE NORTHERN
TIER COUNTIES AND LAKE ERIE. ANOTHER SHOT OF POSITIVE VORTICITY
SCOOTS IN ACROSS THE AREA SATURDAY AFTERNOON AND NIGHT AND THIS
COULD SET OFF SOME AFTERNOON AND EARLY EVENING THUNDERSTORMS.
FINALLY...BY SUNDAY MORNING...MUCH DRIER AIR...SURFACE HIGH PRESSURE
AND FAIRLY STRONG NEGATIVE VORTICITY ADVECTION MOVE SOUTHEAST INTO
THE AREA AND WE SHOULD SEE ANOTHER ROUND OF FAIR WEATHER. AS SURFACE
HIGH PRESSURE BUILDS SOUTHEAST...FORECAST AREA SHOULD SEE A SLIGHT
INCREASE IN THE WINDS TO PRODUCE A GENTLE BREEZE THROUGH THE DAY
INTO SUNDAY NIGHT. FAIR WEATHER CONTINUES SUNDAY NIGHT UNDER THE
INFLUENCE OF THE HIGH PRESSURE.
TEMPERATURES SHOULD JUMP BACK UP INTO THE MIDDLE TO UPPER 70S ON
FRIDAY AHEAD OF THE COLD FRONT. CLOUDS AND SHOWERS WILL HELP BLANKET
THE AREA AND KEEP TEMPERATURES UP IN THE MIDDLE 60S THROUGH THE
NIGHT. SOME LOWER 60S IN THE VALLEYS EXTREME EASTERN ERIE AND
CRAWFORD COUNTIES IN PENNSYLVANIA.
THEN ON SATURDAY AFTER COLD FRONTAL PASSAGE WILL LIKELY SEE
TEMPERATURES DROP BACK INTO THE MIDDLE 70S NORTH TO UPPER 70S IN THE
WEST. AS FAIR WEATHER RETURNS SATURDAY NIGHT INTO SUNDAY COOLER
TEMPERATURES IN THE 50S CAN BE EXPECTED FOLLOWED BY HIGHS IN THE
LOWER TO MIDDLE 70S. WARMER TEMPERATURES EXPECTED IN THE WEST.
SUNDAY NIGHT TEMPERATURES SIMILAR TO SATURDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LITTLE CHANGE TO LARGE SCALE PATTERN DURING THIS PERIOD AS THE
UPPER LEVEL TROUGH REMAINS IN PLACE OVER ONTARIO AND QUEBEC WHICH
WILL KEEP CONDITIONS COOLER THAN NORMAL AND AT TIMES UNSETTLED.
HAVE GENERALLY USED THE ECMWF FOR TIMING PRECIPITATION INTO THE
REGION AS THE GFS AND ECMWF DIVERGE SOMEWHAT BEGINNING ON TUESDAY.
WILL KEEP TUESDAY DRY WITH LOW CHANCE AND SLIGHT CHANCE POPS ON
WEDNESDAY AND THURSDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
LOW CLOUDS HAVE LIFTED AND DECREASED IN COVERAGE IN THE EAST
WHILE INSTABILITY AND CONVECTIVE DEVELOPMENT HAS TAKEN PLACE OVER
LOWER MICHIGAN AND NORTHERN INDIANA. SCATTERED SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED NEAR TOL. THE HRRR MODEL HAS A DECENT
HANDLE ON THIS ACTIVITY AND MOVES SOUTHEAST MOSTLY AROUND LAKE
ERIE AND DISSIPATES IT BEFORE SUNSET. WILL MENTION VCSH AT TOL,
FDY AND MFD AND LEAVE THE OTHER TAF SITES DRY.
BOUNDARY LAYER MOISTURE WILL REMAIN HIGH OVERNIGHT AND WITH LIGHT
WINDS AND CLEARING SKIES...DENSE FOG MAY DEVELOP DOWN TO IFR VSBY
NEAR YNG FROM 10-12 UTC. LIGHTER FOG IS POSSIBLE NEAR CAK. IF
AFTERNOON SHOWERS REACH OTHER TAF SITES FOG MAY NEED TO BE ADDED.
MODEL SOUNDINGS SHOW THE MOISTURE LAPSE INCREASING WITH HEIGHT
NEAR YNG OVERNIGHT WHICH INDICATES FAVORABLE CONDITIONS FOR FOG
DEVELOPMENT.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH SHOWERS.
&&
.MARINE...
SMALL CRAFT CONDITIONS PREVAIL OVER THE LAKE AT MID AFTERNOON.
EXPECT THE PRESSURE GRADIENT TO WEAKEN THIS EVENING ALLOWING THE
EXPIRATION OF THE SCA AT 00UTC. MODERATE RISK OF RIP CURRENTS WILL
LINGER TO ABOUT 22 UTC. ANOTHER TROUGH/WEAK FRONT WILL MOVE ACROSS
THE LAKE FRIDAY NIGHT AND PRODUCE WINDS OF 10 TO 20 KNOTS WITH WAVES
OF 2-4 FEET. HIGH PRESSURE WILL GRADUALLY BUILD OVER THE LAKE LATE
SATURDAY NIGHT AND SUNDAY WITH WEST TO NORTHWEST FLOW OF 5 TO 15
KNOTS. A SMALL CRAFT ADVISORY MAY BE NEEDED ON SUNDAY. HIGH PRESSURE
WILL LINGER NEAR THE LAKE MONDAY AND TUESDAY AND PRODUCE LIGHT WINDS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
LEZ145>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...LAPLANTE
AVIATION...LAPLANTE
MARINE...LAPLANTE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
217 PM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA EARLY TODAY. WEAK HIGH PRESSURE
WILL FOLLOW....BUILDING IN THIS AFTERNOON AND EVENING. A SECOND
COLD FRONT WILL MOVE THROUGH ON SATURDAY. CANADIAN HIGH PRESSURE
WILL BUILD SOUTHEAST ACROSS THE GREAT LAKES SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS ARE BECOMING MORE DIURNAL AND CONVECTIVE THIS AFTERNOON AS
COLD FRONT PULLS AWAY TO THE EAST FAIRLY QUICKLY. DRIER AIR IS
ALSO WORKING INTO THE REGION AIDING IN CLEARING THE SKIES OUT AND
PROVIDE MORE SUNSHINE. DECIDED TO PULL PRECIPITATION OUT OF THE
WESTERN AREAS AND LEAVE A MENTION OF SLIGHT CHANCE IN THE EXTREME
EAST FOR A LITTLE WHILE LONGER.
BUMPED TEMPERATURES DOWN A DEGREE OR TWO TO ACCOUNT FOR THE COLD
AIR ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
FOLLOWED A NAM/GFS MIX THROUGH THE SHORT TERM FORECAST WITH
GRIDDED POPS SHADED TOWARD THE SREF WHICH WAS IN HINDSIGHT VERY
GOOD LAST NIGHT. THIS EVENING THE AXIS OF THE UPPER TROF OVER THE
GREAT LAKES REGION WILL BE IN EASTERN OHIO WITH WEAK HIGH PRESSURE
BUILDING IN FROM THE WEST/SOUTHWEST. EXPECTING DRY CONDITIONS
THROUGH THE NIGHT WITH GENERALLY PC SKIES. NEXT SHORT WAVE ALREADY
DROPPING OUT OF THE NRN PLAINS AND BY FRIDAY MORNING COLD FRONT
WILL EXTEND ACROSS LAKE MI WITH THE JET ENERGY MOVING ACROSS SRN
LWR MI. SREF BROUGHT CHC POPS INTO WESTERN COUNTIES THROUGH THE
MORNING FRIDAY AND EVERYWHERE DURING THE AFTERNOON AND NIGHT.
SATURDAY MORNING MODELS BEGINNING TO DIFFER A BIT ON ORIENTATION
AND POSITION OF DEVELOPING MOISTURE WITH THE APPROACHING COLD
FRONT. GFS A JUST A BUT FURTHER SOUTH WITH MOISTURE AND MORE
EAST/WEST VS NW/SE WITH THE NAM. FOLLOWED GFS MORE CLOSELY WITH
MOISTURE DROPPING SOUTH THROUGH THE AFTERNOON. SATURDAY NIGHT AND
SUNDAY SHOULD BE DRY WITH ANOTHER HIGH BUILDING IN.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
UPPER LEVEL TROUGH WILL REMAIN ANCHORED OVER THE GREAT LAKES REGION
THROUGH THE DURATION OF THE EXTENDED FORECAST. BELOW NORMAL
TEMPERATURES WILL CONTINUE WITH HIGHS GENERALLY IN THE MID 70S.
HIGH PRESSURE AT THE SURFACE WILL BE CENTERED OVER OHIO ON
MONDAY...BUILDING TOWARDS THE MID-ATLANTIC OVERNIGHT. THE 12Z/31
ECMWF WAS FASTER IN RETURNING LOW LEVEL MOISTURE AND A CHANCE OF
SHOWERS BACK INTO THE AREA ON MONDAY WHILE THE 00Z/01 CONSENSUS IS
DRIER WITH ISENTROPIC ASCENT AND BETTER CHANCES OF SHOWERS REMAINING
SW OF THE AREA AND PRIMARILY DURING THE MONDAY NIGHT AND TUESDAY
TIME FRAME. THE GOING FORECAST HAS A GOOD HANDLE ON THIS WITH JUST A
20 POP IN THE WEST ON MONDAY...INCREASING TO A 30 PERCENT CHANCE ON
TUESDAY...THEN BACKING OFF AGAIN TOWARDS WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
LOW CLOUDS HAVE LIFTED AND DECREASED IN COVERAGE IN THE EAST WHILE
INSTABILITY AND CONVECTIVE DEVELOPMENT HAS TAKEN PLACE OVER LOWER
MICHIGAN AND NORTHERN INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS
HAVE DEVELOPED NEAR TOL. THE HRRR MODEL HAS A DECENT HANDLE ON
THIS ACTIVITY AND MOVES SOUTHEAST MOSTLY AROUND LAKE ERIE AND
DISSIPATES IT BEFORE SUNSET. WILL MENTION VCSH AT TOL, FDY AND MFD
AND LEAVE THE OTHER TAF SITES DRY.
BOUNDARY LAYER MOISTURE WILL REMAIN HIGH OVERNIGHT AND WITH LIGHT
WINDS AND CLEARING SKIES...DENSE FOG MAY DEVELOP DOWN TO IFR VSBY
NEAR YNG FROM 10-12 UTC. LIGHTER FOG IS POSSIBLE NEAR CAK. IF
AFTERNOON SHOWERS REACH OTHER TAF SITES FOG MAY NEED TO BE ADDED.
MODEL SOUNDINGS SHOW THE MOISTURE LAPSE INCREASING WITH HEIGHT
NEAR YNG OVERNIGHT WHICH INDICATES FAVORABLE CONDITIONS FOR FOG
DEVELOPMENT.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH SHOWERS.
&&
.MARINE...
WINDS INCREASED OVER THE LAKE OUT OF THE NORTHWEST AND THEREFORE
ARE STRONG ENOUGH TO SUPPORT WAVES UP TO 4 FEET ALONG THE SHORE.
WILL ISSUE A SMALL CRAFT ADVISORY WITH THIS UPDATE.
PREVIOUS DISCUSSION...
SOUTHWESTERLY WINDS WILL BRIEFLY BE ELEVATED AHEAD OF A WEAK
FRONT CROSSING THE LAKE EARLY THIS MORNING. WESTERLY WINDS OF 10
TO NEAR 20 KNOTS ON THE EAST END OF THE LAKE CAN BE EXPECTED
BEHIND THE FRONT TODAY. WAVES WILL INCREASE TO 2 TO 4 FEET ON THE
EAST HALF OF THE LAKE AND PRESENT A MODERATE RISK OF RIP CURRENTS.
ANOTHER WEAK TROUGH WILL CROSS THE LAKE ON FRIDAY AND MAINTAIN
10-15 KNOT SOUTHWESTERLY WINDS. HIGH PRESSURE WILL BUILD OVER THE
LAKE LATE SATURDAY INTO SUNDAY WITH WINDS SHIFTING TO NORTHERLY
NEAR 10 KNOTS AND 1-3 FOOT WAVES WITH THE ONSHORE FLOW.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
LEZ145>149.
&&
$$
SYNOPSIS...TK
NEAR TERM...LOMBARDY
SHORT TERM...TK
LONG TERM...KEC
AVIATION...LAPLANTE
MARINE...KEC
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
502 PM EDT THU AUG 1 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE REGION TODAY...BEFORE HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST FRIDAY AND LINGERS INTO SATURDAY.
ANOTHER WEAK COLD FRONT WILL PUSH IN FROM THE NORTH SUNDAY NIGHT AND
MOVE SOUTH THROUGH MONDAY. THE FRONTAL BOUNDARY STALLS TO THE SOUTH
OF THE FORECAST AREA THROUGH THE MIDDLE OF NEXT WEEK...KEEPING THE
PATTERN UNSETTLED WITH THUNDERSTORM CHANCES EACH AFTERNOON.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 455 PM...AREA RADARS CONTINUE TO INDICATE A BROKEN LINE OF
SHRA/TSRA ACROSS THE PIEDMONT...EAST OF I-85. THE ACTIVITY SHOULD
TRACK EAST...GENERALLY EXITING THE FORECAST AREA IN TWO HOURS. I
WILL UPDATE THE FORECAST TO INCREASE POPS AND QPF ALONG AND AHEAD OF
THE LINE AND DECREASE THEM BEHIND THE LINE. BY MID
EVENING...CONDITIONS ACROSS THE CWA SHOULD BE QUIET...WITH LINGERING
ISO SHRAS. I WILL ALSO UPDATE THE TEMP/DWPTS TO ALIGN WITH OBS.
AS OF 230 PM...CONVECTION HAS BEGUN TO FIRE ALONG THE BLUE RIDGE AND
NOW PROPAGATING OUT ONTO THE PIEDMONT FROM THE STATESVILLE AREA SW
TO THE SC MTNS. A FEW STORMS HAVE ALREADY BECOME SEVERE...PRODUCING
HAIL LARGER THAN 1" DIAMETER AND DAMAGING WINDS. GIVEN THE SPC
MESOANALYSIS PAGE SHOWING SBCAPE OF 2500-3000 J/KG...DCAPE AROUND
1000 J/KG...AND EFFECTIVE SHEAR OF 25-30KTS AHEAD OF THIS BROKEN
LINE...EXPECT THE TRENDS TO CONTINUE ACRS THE UPSTATE AND SWRN NC
PIEDMONT THRU THE REST OF THE AFTN. WILL UPDATE POPS TO LIKELY ALONG
AND SE OF THE CURRENT LINE POSITION.
TONIGHT...WITH SHORTWAVE TROF PASSING TO THE EAST...EXPECT
CONVECTION TO WANE FAIRLY QUICKLY EARLY THIS EVENING. HAVE POPS DOWN
TO SILENT BY MIDNIGHT ACRS THE ENTIRE CWFA. THERE WILL BE LINGERING
LLVL MOISTURE AND A SLOW-MOVING FNTL BNDRY SAGGING SEWD THRU THE
CWFA OVERNIGHT. SO PROBABLY WILL SEE PATCHY TO AREAS OF FOG AND
STRATUS BY DAYBREAK...ESP IN THE MTN VLYS. TEMPS WILL BE NEAR
NORMAL...MAINLY IN THE 60S.
FRIDAY...MODELS IN DECENT AGREEMENT ON THE COLD FRONT PUSHING ALL
THE WAY THRU THE CWFA TO THE SE BY MID MORNING. ALOFT...SUBSIDENCE
IN WAKE OF SHORTWAVE PASSAGE WILL WARM MID LVL TEMPS. FCST SNDGS
ACRS THE CWFA ARE CAPPED IN THE MID LVLS. CANNOT RULE OUT A STRAY
SHWR OR TWO IN THE SRN/CENTRAL NC MTNS...IF DEWPTS DON/T MIX OUT
ENUF. BUT NOT ENUF TO WARRANT ANY MENTION IN THE GRIDS. SO A DRY
FCST. WITH DECENT SUNSHINE...EXPECT NEAR NORMAL MAX TEMPS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 230 PM EDT THURSDAY...THE OVERALL UPPER PATTERN REMAINS IN
PLACE ACROSS THE REGION THROUGH THE SHORT RANGE...WITH AN UPPER
LOW/TROF OVER THE NORTHEAST AND A RIDGE AXIS OVER THE ROCKIES...
KEEPING A NW FLOW OVERHEAD. THE PERIOD BEGINS WITH DRY WEATHER
OVERNIGHT ON FRIDAY NIGHT...WHICH CONTINUES INTO SATURDAY MORNING.
THERE IS VERY LITTLE IN THE GUIDANCE TO SUGGEST MUCH IN THE WAY OF
CONVECTIVE PRECIP ON SATURDAY AFTERNOON AND THE GFS CONTINUES TO BE
DRY. HOWEVER...THE NAM DEVELOPS SOME CONVECTION OVER THE MOUNTAINS
AND IT IS HARD TO KEEP THAT FROM HAPPENING ON A TYPICAL DAY...SO NOT
MUCH WAS CHANGED FROM THE EARLIER FORECAST. A SHORT WAVE DROPPING
DOWN INTO THE EASTERN UPPER TROF SATURDAY NIGHT AND SUNDAY MORNING
WILL PROVIDE FOR A BETTER SITUATION CONVECTIVELY. THE MODELS SUGGEST
A FRONT DROPPING DOWN FROM THE NW EARLY SUNDAY...PERHAPS CROSSING
THE FCST AREA TOO EARLY IN THE DAY TO TRIGGER MUCH CONVECTION. WILL
MAINTAIN A CHANCE POP ON THE TN BORDER OVERNIGHT SATURDAY AND INTO
SUNDAY MORNING...WITH THE CHANCE OF UPSTREAM CONVECTION ALONG THE
FRONT REACHING THE FCST AREA BEFORE IT WEAKENS. A CHANCE POP WAS
ALSO KEPT THROUGH SUNDAY AFTERNOON IN THE EVENT THAT THE FRONT DOES
NOT MAKE AS MUCH SOUTHWARD PROGRESS AS SHOWN BY THE GFS. TEMPS WERE
KEPT NEAR A BLEND OF THE GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 200 PM THURSDAY...THE EXTENDED RANGE BEGINS JUST AFTER THE
PASSAGE OF A WEAK FRONTAL BOUNDARY DURING THE DAY ON SUNDAY. HIGH
PRESSURE QUICKLY BUILDS IN OVER THE MIDWEST...AND THE FRONT STALLS
RIGHT ALONG THE PERIPHERY OF THE HIGH JUST TO THE SOUTH OF THE CWA
FOLLOWING AN UPPER LEVEL TROUGH. MODELS DIVERGE GREATLY ON PLACEMENT
OF THE FRONT AND STRENGTH OF THE HIGH...SO KEEP CHANCE POPS IN ON
SUNDAY AFTERNOON AND MONDAY. THE POSITION OF THE FRONT WILL KEEP THE
PATTERN UNSETTLED...WITH MULTIPLE WEAK SHORTWAVES EXPECTED TO CROSS
THE CWA THROUGH MID-WEEK. AN UPPER LEVEL LOW APPROACHES THE CWA BY
LATE NEXT WEEK...AGAIN BRINGING WITH IT THE POSSIBILITY OF HEAVY
RAIN AND THUNDERSTORMS. MODELS STILL DIVERGE GREATLY ON SYNOPTIC
PATTERN AND TIMING OF FEATURES THROUGH THE END OF THE PERIOD
HOWEVER...SO KEPT POPS NEAR CLIMO EACH DAY FOLLOWING A MAINLY
DIURNAL TREND. HIGH TEMPS WILL REMAIN A DEGREE OR TWO BELOW
AVERAGE...WITH LOWS RIGHT AROUND NORMAL.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
AT KCLT...A BROKEN LINE OF CONVECTION IS DEVELOPING NW OF THE
TERMINAL AT TIME OF TAF ISSUANCE. WITH PLENTY OF INSTBY AND JUST
ENUF SHEAR...EXPECT THE LINE TO AFFECT THE TERMINAL WITHIN THE NEXT
COUPLE HOURS. THE LATEST HRRR SHOWS SEVERAL CLUSTERS OF STORMS ACRS
THE NC PIEDMONT THRU AT LEAST 00Z THIS EVENING. SO WILL GO WITH A
TEMPO FIRST TWO HOURS...THEN PREVAILING TSRA THRU 00Z.
THEREAFTER...A COLD FRONT WILL PUSH THRU AND BRING THE WINDS AROUND
TO NE. GUIDANCE MIXED ON WHETHER ANY FOG OR STRATUS WILL BE ABLE TO
DEVELOP. IF WIDESPREAD RAIN FALLS ACRS THE REGION...MAY SEE MORE
RESTRICTIONS. WILL GO WITH JUST MVFR VSBY TOWARD DAYBREAK. VFR
CONDITIONS AND LGT NELY WINDS FRIDAY MORNING THRU 18Z.
ELSEWHERE...CONVECTION HAS CLEARED THRU KAVL AND KHKY...BUT
ADDITIONAL SCATTERED SHRA/TSRA ARE EXPECTED TO DEVELOP THRU THE
AFTN. SO WILL KEEP VCTS IN FOR REST OF THE AFTN. THE UPSTATE TAF
SITES ARE A BIT MORE UNCERTAIN. THE HRRR HAS A LINE OF STORMS BACK
BUILD AT LEAST TO KGMU/KGSP. NOT CONFIDENT ENUF TO GO WITH
TEMPO...SO KEEPING JUST VCTS. KAND LOOKS TO HAVE THE LOWEST CHC OF
TSRA...BUT STILL HIGH ENUF FOR VCTS. CONVECTION SHUD WANE QUICKLY
AFTER SUNSET. GUIDANCE MIXED ON HOW MUCH RESTRICTIONS ACRS THE
REGION...BUT GIVEN THE MOIST GROUND...LIGHT WIND...AND DRY MID
LVLS...EXPECT AT LEAST PATCHY FOG AND STRATUS OVERNIGHT...ESP IN THE
MTN VLYS. VFR CONDITIONS EXPECTED AFTER DAYBREAK THRU THE REST OF
THE TAF PERIOD.
OUTLOOK...EXPECT CONDITIONS TO IMPROVE FOR THE WEEKEND AS HIGH
PRESSURE BUILDS IN BEHIND COLD FRONT. WET CONDITIONS WILL RETURN
FOR THE START OF NEXT WEEK ASSOCIATED WITH ANOTHER FRONTAL PASSAGE.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-21Z
KCLT MED 79% HIGH 91% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 91% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 88% HIGH 80% MED 65%
KHKY HIGH 100% HIGH 100% HIGH 95% HIGH 100%
KGMU HIGH 100% HIGH 91% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 92% HIGH 95% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...VISIN
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...VISIN
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
238 PM EDT THU AUG 1 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE REGION TODAY...BEFORE HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST FRIDAY AND LINGERS INTO SATURDAY.
ANOTHER WEAK COLD FRONT WILL PUSH IN FROM THE NORTH SUNDAY NIGHT AND
MOVE SOUTH THROUGH MONDAY. THE FRONTAL BOUNDARY STALLS TO THE SOUTH
OF THE FORECAST AREA THROUGH THE MIDDLE OF NEXT WEEK...KEEPING THE
PATTERN UNSETTLED WITH THUNDERSTORM CHANCES EACH AFTERNOON.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 230 PM...CONVECTION HAS BEGUN TO FIRE ALONG THE BLUE RIDGE AND
NOW PROPAGATING OUT ONTO THE PIEDMONT FROM THE STATESVILLE AREA SW
TO THE SC MTNS. A FEW STORMS HAVE ALREADY BECOME SEVERE...PRODUCING
HAIL LARGER THAN 1" DIAMETER AND DAMAGING WINDS. GIVEN THE SPC
MESOANALYSIS PAGE SHOWING SBCAPE OF 2500-3000 J/KG...DCAPE AROUND
1000 J/KG...AND EFFECTIVE SHEAR OF 25-30KTS AHEAD OF THIS BROKEN
LINE...EXPECT THE TRENDS TO CONTINUE ACRS THE UPSTATE AND SWRN NC
PIEDMONT THRU THE REST OF THE AFTN. WILL UPDATE POPS TO LIKELY ALONG
AND SE OF THE CURRENT LINE POSITION.
TONIGHT...WITH SHORTWAVE TROF PASSING TO THE EAST...EXPECT
CONVECTION TO WANE FAIRLY QUICKLY EARLY THIS EVENING. HAVE POPS DOWN
TO SILENT BY MIDNIGHT ACRS THE ENTIRE CWFA. THERE WILL BE LINGERING
LLVL MOISTURE AND A SLOW-MOVING FNTL BNDRY SAGGING SEWD THRU THE
CWFA OVERNIGHT. SO PROBABLY WILL SEE PATCHY TO AREAS OF FOG AND
STRATUS BY DAYBREAK...ESP IN THE MTN VLYS. TEMPS WILL BE NEAR
NORMAL...MAINLY IN THE 60S.
FRIDAY...MODELS IN DECENT AGREEMENT ON THE COLD FRONT PUSHING ALL
THE WAY THRU THE CWFA TO THE SE BY MID MORNING. ALOFT...SUBSIDENCE
IN WAKE OF SHORTWAVE PASSAGE WILL WARM MID LVL TEMPS. FCST SNDGS
ACRS THE CWFA ARE CAPPED IN THE MID LVLS. CANNOT RULE OUT A STRAY
SHWR OR TWO IN THE SRN/CENTRAL NC MTNS...IF DEWPTS DON/T MIX OUT
ENUF. BUT NOT ENUF TO WARRANT ANY MENTION IN THE GRIDS. SO A DRY
FCST. WITH DECENT SUNSHINE...EXPECT NEAR NORMAL MAX TEMPS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 230 PM EDT THURSDAY...THE OVERALL UPPER PATTERN REMAINS IN
PLACE ACROSS THE REGION THROUGH THE SHORT RANGE...WITH AN UPPER
LOW/TROF OVER THE NORTHEAST AND A RIDGE AXIS OVER THE ROCKIES...
KEEPING A NW FLOW OVERHEAD. THE PERIOD BEGINS WITH DRY WEATHER
OVERNIGHT ON FRIDAY NIGHT...WHICH CONTINUES INTO SATURDAY MORNING.
THERE IS VERY LITTLE IN THE GUIDANCE TO SUGGEST MUCH IN THE WAY OF
CONVECTIVE PRECIP ON SATURDAY AFTERNOON AND THE GFS CONTINUES TO BE
DRY. HOWEVER...THE NAM DEVELOPS SOME CONVECTION OVER THE MOUNTAINS
AND IT IS HARD TO KEEP THAT FROM HAPPENING ON A TYPICAL DAY...SO NOT
MUCH WAS CHANGED FROM THE EARLIER FORECAST. A SHORT WAVE DROPPING
DOWN INTO THE EASTERN UPPER TROF SATURDAY NIGHT AND SUNDAY MORNING
WILL PROVIDE FOR A BETTER SITUATION CONVECTIVELY. THE MODELS SUGGEST
A FRONT DROPPING DOWN FROM THE NW EARLY SUNDAY...PERHAPS CROSSING
THE FCST AREA TOO EARLY IN THE DAY TO TRIGGER MUCH CONVECTION. WILL
MAINTAIN A CHANCE POP ON THE TN BORDER OVERNIGHT SATURDAY AND INTO
SUNDAY MORNING...WITH THE CHANCE OF UPSTREAM CONVECTION ALONG THE
FRONT REACHING THE FCST AREA BEFORE IT WEAKENS. A CHANCE POP WAS
ALSO KEPT THROUGH SUNDAY AFTERNOON IN THE EVENT THAT THE FRONT DOES
NOT MAKE AS MUCH SOUTHWARD PROGRESS AS SHOWN BY THE GFS. TEMPS WERE
KEPT NEAR A BLEND OF THE GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 200 PM THURSDAY...THE EXTENDED RANGE BEGINS JUST AFTER THE
PASSAGE OF A WEAK FRONTAL BOUNDARY DURING THE DAY ON SUNDAY. HIGH
PRESSURE QUICKLY BUILDS IN OVER THE MIDWEST...AND THE FRONT STALLS
RIGHT ALONG THE PERIPHERY OF THE HIGH JUST TO THE SOUTH OF THE CWA
FOLLOWING AN UPPER LEVEL TROUGH. MODELS DIVERGE GREATLY ON PLACEMENT
OF THE FRONT AND STRENGTH OF THE HIGH...SO KEEP CHANCE POPS IN ON
SUNDAY AFTERNOON AND MONDAY. THE POSITION OF THE FRONT WILL KEEP THE
PATTERN UNSETTLED...WITH MULTIPLE WEAK SHORTWAVES EXPECTED TO CROSS
THE CWA THROUGH MID-WEEK. AN UPPER LEVEL LOW APPROACHES THE CWA BY
LATE NEXT WEEK...AGAIN BRINGING WITH IT THE POSSIBILITY OF HEAVY
RAIN AND THUNDERSTORMS. MODELS STILL DIVERGE GREATLY ON SYNOPTIC
PATTERN AND TIMING OF FEATURES THROUGH THE END OF THE PERIOD
HOWEVER...SO KEPT POPS NEAR CLIMO EACH DAY FOLLOWING A MAINLY
DIURNAL TREND. HIGH TEMPS WILL REMAIN A DEGREE OR TWO BELOW
AVERAGE...WITH LOWS RIGHT AROUND NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AT KCLT...A BROKEN LINE OF CONVECTION IS DEVELOPING NW OF THE
TERMINAL AT TIME OF TAF ISSUANCE. WITH PLENTY OF INSTBY AND JUST
ENUF SHEAR...EXPECT THE LINE TO AFFECT THE TERMINAL WITHIN THE NEXT
COUPLE HOURS. THE LATEST HRRR SHOWS SEVERAL CLUSTERS OF STORMS ACRS
THE NC PIEDMONT THRU AT LEAST 00Z THIS EVENING. SO WILL GO WITH A
TEMPO FIRST TWO HOURS...THEN PREVAILING TSRA THRU 00Z.
THEREAFTER...A COLD FRONT WILL PUSH THRU AND BRING THE WINDS AROUND
TO NE. GUIDANCE MIXED ON WHETHER ANY FOG OR STRATUS WILL BE ABLE TO
DEVELOP. IF WIDESPREAD RAIN FALLS ACRS THE REGION...MAY SEE MORE
RESTRICTIONS. WILL GO WITH JUST MVFR VSBY TOWARD DAYBREAK. VFR
CONDITIONS AND LGT NELY WINDS FRIDAY MORNING THRU 18Z.
ELSEWHERE...CONVECTION HAS CLEARED THRU KAVL AND KHKY...BUT
ADDITIONAL SCATTERED SHRA/TSRA ARE EXPECTED TO DEVELOP THRU THE
AFTN. SO WILL KEEP VCTS IN FOR REST OF THE AFTN. THE UPSTATE TAF
SITES ARE A BIT MORE UNCERTAIN. THE HRRR HAS A LINE OF STORMS BACK
BUILD AT LEAST TO KGMU/KGSP. NOT CONFIDENT ENUF TO GO WITH
TEMPO...SO KEEPING JUST VCTS. KAND LOOKS TO HAVE THE LOWEST CHC OF
TSRA...BUT STILL HIGH ENUF FOR VCTS. CONVECTION SHUD WANE QUICKLY
AFTER SUNSET. GUIDANCE MIXED ON HOW MUCH RESTRICTIONS ACRS THE
REGION...BUT GIVEN THE MOIST GROUND...LIGHT WIND...AND DRY MID
LVLS...EXPECT AT LEAST PATCHY FOG AND STRATUS OVERNIGHT...ESP IN THE
MTN VLYS. VFR CONDITIONS EXPECTED AFTER DAYBREAK THRU THE REST OF
THE TAF PERIOD.
OUTLOOK...EXPECT CONDITIONS TO IMPROVE FOR THE WEEKEND AS HIGH
PRESSURE BUILDS IN BEHIND COLD FRONT. WET CONDITIONS WILL RETURN
FOR THE START OF NEXT WEEK ASSOCIATED WITH ANOTHER FRONTAL PASSAGE.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 93% HIGH 100% HIGH 91% HIGH 91%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 94% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...VISIN
NEAR TERM...ARK
SHORT TERM...PM
LONG TERM...VISIN
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
209 PM EDT THU AUG 1 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE REGION TODAY...BEFORE HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST FRIDAY AND LINGERS INTO SATURDAY.
ANOTHER WEAK COLD FRONT WILL PUSH IN FROM THE NORTH SUNDAY NIGHT AND
MOVE SOUTH THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM...STRATUS IS GRADUALLY ERODING WITH DAYTIME HEATING
AND SOME DOWNSLOPE NWLY FLOW ATOP THE CLOUD LAYER. MEANWHILE...SOME
MID AND HIGH CLOUDS CONTINUE TO STREAM ACRS THE CWFA...AS AN UPR
SHORTWAVE TROF ENTERS FROM THE WEST. SO EXPECTING A MIX OF SUN AND
CLOUDS INTO EARLY AFTN. FROM THERE...FCST SNDGS INDICATE WE SHUD
DESTABILIZE TO 2000-2500 J/KG OF SBCAPE BY PEAK HEATING...ESP ALONG
THE BLUE RIDGE AND EAST. THERE SHUD BE DECENT LLVL CONVERGENCE ALONG
THE ERN SLOPES AND A LEE TROF ACRS THE PIEDMONT...KEEPING PWATS IN
THE 1.25-1.5" RANGE. SO I THINK THERE SHUD BE DECENT COVERAGE OF
SHWRS AND TSTMS ACRS THE ERN HALF OF THE CWFA. THIS IS IN LINE WITH
THE PREVIOUS FCST...SO ONLY MINOR TWEAKS TO THE POP GRIDS WERE MADE.
SOME DRY MID LVL AIR AND EFFECTIVE SHEAR OF 30-35 KTS ATOP THE MOIST
BL SHUD RESULT IN A BETTER MICROBURST THREAT WITH THE STRONGEST
CONVECTION THIS AFTN...ESP AREAS EAST OF I-85...WHERE THE BEST
INSTBY WILL BE. FREEZING LVLS ARE AROUND 14 KFT ON THE MRNG
SNDGS...SO A FIRST GUESS CORE HEIGHT (55 DBZ)IS AROUND 25.5 KFT.
TONIGHT...FRONT MAKES ITS WAY ACROSS THE CWFA WITH LOWER LLVL THETA-E
ADVECTING IN ON NWLY WINDS. POPS WILL DIMINISH TO UNMENTIONABLY LOW
VALUES BY EVENING AND SKIES WILL BECOME MOSTLY CLEAR. SFC DEWPOINTS
DON/T DROP OFF ALL THAT MUCH SO LOW TEMPS REMAIN NEAR NORMAL PIEDMONT
AND A COUPLE DEGREES BELOW NORMAL MTNS/FOOTHILLS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 AM EDT THU...THE UPPER PATTERN SHOWS AN INFLUX OF H7-H5
DNVA AND FLAT RIDGING ENCOMPASSING THE AREA FRI IN SUPPORT OF A
SMALL SCALE SFC HIGH. THIS WILL BE ENOUGH TO OFFSET ANY CONVECTIVE
CHANCES AS RISING SFC PARCELS ARE SUPPRESSED BY WARM AIR ALOFT. THUS
WITH NO TRIGGERS IN THE AREA...WILL COUNT ON A DRY DAY WITH MAX
TEMPS AROUND NORMAL OR A DEGREE OR TWO ABOVE.
THE SFC HIGH BEGINS TO BREAK DOWN SAT AS UPPER HEIGHTS DROP AND
INCOMING POCKETS OF S/W ENERGY TRAVERSE THE CWFA. THE 00Z NAM IS
MORE DEFINITIVE IN A COUPLED S/W CROSSING AROUND 18Z WITH THE 00Z
GFS ON BOARD TO SOME DEGREE. THE BEST LLVL MOISTURE FLUX WILL REMAIN
SHUNTED TO THE WEST...YET SOUNDINGS INDICATE ENOUGH MLVL COOLING TO
ALLOW SOME AFTERNOON ELCAPE ACROSS MOST AREAS. WITH MECH LIFT
CONTINUING WEST...THERE WILL BE AN INCREASING CHANCE OF SHRA/TSTMS
ACROSS THE MTNS AND THE REST OF THE CWFA BY THE AFTERNOON...ENOUGH
SO TO INTRODUCE NEAR CLIMO POPS. MAX TEMPS WILL BE TRICKY DEPENDING
ON THE OVERALL CLOUDINESS...BUT LLVL THICKNESSES AND MOS SUPPORT
L90S NON/MTNS AND THE GRIDS HAVE BEEN ADJ IN THIS DIRECTION.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 305 AM EDT THU...THE EXT RANGE LOOKS TO REMAIN ACTIVE AS THE
UPPER FLOW BRINGS IN ROUNDS OF S/W ENERGY AROUND A LARGE OCCLUDED
CANADIAN SYSTEM. THE MODELS ARE HANDLING THE ERN CONUS SYNOPTIC
PATTERN DIFFERENTLY AND THE TIMING OF TWO ILL DEFINED SFC FRONTS OR
TROFS OF LOW PRESSURE EXPECTED TO AFFECT THE CWFA SUN THOUGH THE
PERIOD.
FOR NOW...WILL COUNT ON THE FIRST FRONT TO DEVELOP IN RESPONSE TO
RATHER STRONG HIGH PRESSURE MOVING SOUTH OUT OF CANADA SUN. THERE IS
A DEFINED N/S INSTABILITY GRADIENT ASSOCIATED WITH THIS FEATURE AND
THUNDER CHANCES WILL BE LIMITED TO THE SRN HALF OF THE CWFA SUN
NIGHT THROUGH MON. EXPECT THIS FRONT TO STALL OUT JUST TO THE
SOUTH...WHILE ANOTHER SFC BOUNDARY FORMS ACROSS THE OH VALLEY MON
NIGHT AND PUSHES INTO THE AREA DURING THE DAY TUE. THERE ISNT MUCH
UPPER SUPPORT WITH EITHER OF THESE FRONTS...PRETTY MUCH BACK DOOR
FRONTS...BUT DEEP CONVECTION PRODUCING STRONG TO SEVERE STORMS ARE
POSSIBLE EACH AFTERNOON MON AND TUE. THERE MAY ALSO BE A HYDRO
CONCERN WITH THE BOUNDARIES MERGING AND PERHAPS STALLING OVER THE
AREA. HOWEVER...ITS TOO EARLY TO TELL WHAT THE DEGREE OF THIS THREAT
WILL BE ATTM. WED COULD DRY OUT IN A RELATIVE SENSE WITH THE MODELS
DIVERGING A SUPPRESSIVE SFC HIGH SCENARIO. MAX TEMPS WILL GENERALLY
BE HELD A COUPLE DEGREES BELOW NORMAL THROUGH THE PERIOD...WITH MINS
AROUND NORMAL.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...A BROKEN LINE OF CONVECTION IS DEVELOPING NW OF THE
TERMINAL AT TIME OF TAF ISSUANCE. WITH PLENTY OF INSTBY AND JUST
ENUF SHEAR...EXPECT THE LINE TO AFFECT THE TERMINAL WITHIN THE NEXT
COUPLE HOURS. THE LATEST HRRR SHOWS SEVERAL CLUSTERS OF STORMS ACRS
THE NC PIEDMONT THRU AT LEAST 00Z THIS EVENING. SO WILL GO WITH A
TEMPO FIRST TWO HOURS...THEN PREVAILING TSRA THRU 00Z.
THEREAFTER...A COLD FRONT WILL PUSH THRU AND BRING THE WINDS AROUND
TO NE. GUIDANCE MIXED ON WHETHER ANY FOG OR STRATUS WILL BE ABLE TO
DEVELOP. IF WIDESPREAD RAIN FALLS ACRS THE REGION...MAY SEE MORE
RESTRICTIONS. WILL GO WITH JUST MVFR VSBY TOWARD DAYBREAK. VFR
CONDITIONS AND LGT NELY WINDS FRIDAY MORNING THRU 18Z.
ELSEWHERE...CONVECTION HAS CLEARED THRU KAVL AND KHKY...BUT
ADDITIONAL SCATTERED SHRA/TSRA ARE EXPECTED TO DEVELOP THRU THE
AFTN. SO WILL KEEP VCTS IN FOR REST OF THE AFTN. THE UPSTATE TAF
SITES ARE A BIT MORE UNCERTAIN. THE HRRR HAS A LINE OF STORMS BACK
BUILD AT LEAST TO KGMU/KGSP. NOT CONFIDENT ENUF TO GO WITH
TEMPO...SO KEEPING JUST VCTS. KAND LOOKS TO HAVE THE LOWEST CHC OF
TSRA...BUT STILL HIGH ENUF FOR VCTS. CONVECTION SHUD WANE QUICKLY
AFTER SUNSET. GUIDANCE MIXED ON HOW MUCH RESTRICTIONS ACRS THE
REGION...BUT GIVEN THE MOIST GROUND...LIGHT WIND...AND DRY MID
LVLS...EXPECT AT LEAST PATCHY FOG AND STRATUS OVERNIGHT...ESP IN THE
MTN VLYS. VFR CONDITIONS EXPECTED AFTER DAYBREAK THRU THE REST OF
THE TAF PERIOD.
OUTLOOK...EXPECT CONDITIONS TO IMPROVE FOR THE WEEKEND AS HIGH
PRESSURE BUILDS IN BEHIND COLD FRONT. WET CONDITIONS WILL RETURN
FOR THE START OF NEXT WEEK ASSOCIATED WITH ANOTHER FRONTAL PASSAGE.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 93% HIGH 100% HIGH 91% HIGH 91%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 94% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...ARK/WIMBERLEY
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
557 PM CDT THU AUG 1 2013
.UPDATE...
ISSUED AT 552 PM CDT THU AUG 1 2013
HAVE TAKEN A STEP TO INCLUDE SOME STRONG TO SEVERE STORM WORDING
IN THE SERVICE PRODUCTS FOR THE EVENING FORECAST FOR NORTHEAST
IOWA.
CURRENT MLCAPE NEAR 1000 J/KG WITH SBCAPE NEAR 1500 J/KG ALONG I-35
CORRIDOR IN IA...WITH A GRADIENT TO NEAR 0 J/KG A FEW COUNTIES
EAST /PER SPC RAPV2 MESO PAGE/. DEEP SHEAR IS IMPRESSIVE WITH SUPERCELL
LIKE NUMBERS OF 0-6KM SHEAR OF 50 KTS. STORMS IN NORTHCENTRAL IA
QUICKLY SHOWED SUPERCELL TRAITS AND SPLITTING BEHAVIOR THIS
AFTERNOON AND HAVE HAD REPORTS OF SEVERE HAIL OR JUST BELOW OVER
THE PAST 1.5 HOURS.
WITH RAP SHORT TERM FORECASTS ADVECTING THE MOISTURE AND WARM
FRONT EAST IN THE NEXT SEVERAL HOURS AND WIND SHEAR REMAINING IN
PLACE...FELT THE NEED TO INCLUDE THIS THREAT INTO THE FORECAST
AREA AND PRODUCTS. WHILE THE RAP BUILDS CAPE EAST...THE LATEST LAPS
ANALYSIS KEPT THE CAPE GRADIENT ON THE WRN FORECAST AREA
BOUNDARY...WRN MITCHELL/FLOYD. THE FORCING FOR THESE STORMS IS WEAK LOW-LEVEL
MOISTURE ADVECTION AND CONVERGENCE...THUS THE AREAL PATTERN TO THE
STORMS...NOT A SURFACE-BASED BOUNDARY. THE BROAD FORCING IN THE
LOW-LEVELS WILL TRY TO MIGRATE EAST TONIGHT TOWARD THE MISSISSIPPI
RIVER PER LATEST RAP GUIDANCE. THUS...EVEN WITH LIMITED CAPE...WANTED TO
BE SAFE WITH STRONG/SEVERE THREATS A BIT INTO THE FORECAST AREA.
SPC UPDATED THE DAY 1 OUTLOOK IN LAST 20 MINS TO ALSO MOVE THE
SLIGHT RISK FURTHER EAST.
STILL EXPECT THE STRONGEST STORMS TO BE RIGHT-MOVING AND THAT
VECTOR IS HARD SOUTH...ABOUT 150 DEGREES AT 30-35 KTS. FOR
NOW...THINKING NE IA FOR THE NEXT FEW HOURS...ESPECIALLY FURTHER
WEST TOWARD I-35.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 343 PM CDT THU AUG 1 2013
MAIN FORECAST CONCERNS THIS PACKAGE...SHRA/TSRA CHANCES TONIGHT/
FRI...TEMPERATURES.
DATA ANALYSIS AT 18Z HAD BROAD LOW PRESSURE OVER HUDSONS BAY AND A
RIDGE OF HIGH PRESSURE FORM MO TO SASKAT. A WEAK TROUGH WAS LOCATED
NEAR THE MN/DAKOTAS BORDER. IMPACTS OF THE HUDSON BAY LOW ON THE
REGION WERE MAINLY DIURNAL CUMULUS OVER THE NORTHEAST 2/3 OF MN/WI...
AND SUPPORTING THE A SEASONABLY COOL/DRY AIRMASS UNDER THE DEEP
NORTHWEST FLOW BEHIND THE LOW AND EAST OF THE RIDGE AXIS. AS OF EARLY
AFTERNOON CONVECTION REMAINED NEAR OR WEST OF THE SFC RIDGE AXIS...
OVER PORTIONS OF SD/NEB.
01.12Z MODELS LOOK TO HAVE INITIALIZED WELL...BUT FOR THE GFS WITH
ITS USUAL SFC DEW POINT ANALYSIS BEING OFF A BIT OVER THE UPPER
MIDWEST. DPROG/DT OF 500MB HGTS AT 01.12Z SHOWED THE MODEL RUNS OF
30.12Z AND 31.12Z VERIFIED WELL ACROSS NOAM/EASTERN PAC EVEN WITH THE
SMALLER SCALE FEATURES IN THE FLOW. SOLUTIONS VERY SIMILAR FOR
TONIGHT/FRI...CONVERGING TOWARD A TIGHTER/COMMON CONSENSUS. SOLUTIONS
THEN DIVERGE FOR THE 3RD PERIOD /FRI NIGHT/ WITH THE NAM AGAIN
STRONGER ON A SHORTWAVE DROPPING THRU THE NORTHWEST FLOW TOWARD THE
AREA AND IS MORE ROBUST WITH LIFT/MOISTURE OVER THE AREA. NO ONE
MODE WITH CLEARLY BETTER RUN-TO-RUN CONSISTENCY THAN THE OTHERS.
CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED ALL MODELS WERE QUITE
REASONABLE WITH THE SFC MASS FIELDS OVER THE CENTRAL CONUS. GFS WAS
IMPROVING ON SFC DEW POINTS. PER WV IMAGERY MODELS ALL LOOKED TO
HAVE A GOOD HANDLE ON THE MORE IDENTIFIABLE SHORTWAVES IN THE FLOW
OVER NOAM. MODELS REASONABLE WITH THE 12-18Z PRECIP OVER THE CENTRAL/
NORTHERN PLAINS AND WITH THE SCT SHRA IN FAR NORTHEAST MN/WI.
FAVORED THE MODEL/ENSEMBLE CONSENSUS FOR TONIGHT/FRI. WITH THE
NAM AGAIN APPEARING AS AN OUTLIER FRI NIGHT FAVORED THE NON-NAM
MODEL CONSENSUS. SHORT TERM FCST CONFIDENCE GOOD TONIGHT/FRI THEN
AVERAGE FRI NIGHT.
FOR THE SHORT TERM...MODELS STILL SPREADING SOME 850-700MB MOISTURE
TRANSPORT/THETA-E CONVERGENCE ACROSS ABOUT THE SOUTHWEST THIRD OF
THE FCST AREA TONIGHT/FRI. THE FLOW IS MORE PARALLEL TO THE THERMAL
GRADIENTS THAN IS PERPENDICULAR TO IT...THUS THE OVERALL CONVERGENCE
AND LIFT OF THE AIRMASS STAYS ON THE WEAK SIDE. EVEN MU CAPE OVER
THE SOUTHWEST END OF THE FCST AREA REMAINS ON THE LOW SIDE TONIGHT.
THUS NOT SURE HOW MUCH TSRA THERE WILL BE TONIGHT. WITH THE
CONSISTENCY OF THE MODEL SIGNAL TO PRODUCE SOME PRECIP OVER THE
SOUTHWEST 1/3 OF THE FCST AREA...CONTINUED TO CARRY 20-50 PERCENT
SHRA/TSRA CHANCES OVER ABOUT THE SOUTHWEST 1/2 OF THE FCST AREA.
SOME OF THIS MOISTURE TRANSPORT AND WEAK LIFT CONTINUES TO TRANSLATE
ACROSS THE SOUTH END OF THE FCST AREA FRI...WITH MU CAPES AS HIGH AS
PERHAPS 1K-2K J/KG NEAR THE SOUTH BORDER OF THE FCST AREA FRI
AFTERNOON. CONTINUED MAINLY 20-40 PERCENT SHRA/TSRA CHANCES ACROSS
THE SOUTH 1/3 OF THE FCST AREA FOR FRI. FURTHER NORTH...WITH LESS
MOISTURE OR INCREASE OF MOISTURE AND MORE UNDER THE WEST EDGE OF
THE NORTHWEST FLOW AROUND THE HUDSON BAY LOW/VORTEX...TREND SKY
GRIDS MORE TOWARD CLEAR TO PARTLY CLOUDY TONIGHT/FRI.
BIGGER QUESTIONS ARE FRI NIGHT. AGAIN NAM BRINGS A STRONGER
NORTHWEST FLOW SHORTWAVE TOWARD THE AREA...WHICH HELPS TO GENERATE A
RATHER STRONG LOOKING 850-500MB FN CONVERGENCE BAND NORTHWEST TO
SOUTHEAST ACROSS THE AREA OVER THE AREA BY LATER FRI NIGHT. MUCH OF
THE MOISTURE THE NAM BRINGS LOOKS TO BE IN THE 800-600MB LAYER...
WITH LITTLE IN THE WAY OF INSTABILITY. APPEARS EVEN IF NAM WAS
CORRECT ANY PRECIP MAINLY LATER FRI NIGHT WOULD BE SPRINKLES/-RA
FROM AN 8K-10K FT DECK. NAM HAS SOME MOISTURE TRANSPORT AT 700MB
BUT THIS AGAIN NEARLY PARALLEL TO THE THERMAL GRADIENT. WITH NAM
LOOKING RATHER SUSPECT...LEFT FRI NIGHT DRY PER CONSENSUS OF OTHER
MODELS...WHICH BLENDS WELL WITH ALL NEIGHBORING GRIDS. WOULD EXPECT
AT LEAST SOME SCT/PERHAPS BKN MID CLOUD DECKS AND DID NOT ADD
VALLEY FOG TO THE LATE FRI NIGHT GRIDS FOR NOW.
USED A BLEND OF THE NUMERICAL GUIDANCE LOWS/HIGHS FOR TONIGHT THRU
FRI NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 343 PM CDT THU AUG 1 2013
MAIN FORECAST CONCERNS FOR SAT THRU SUN NIGHT...TEMPERATURES SAT
THRU SUN...VALLEY FOG POTENTIAL CENTERED ON 12Z SUN...SHRA/TSRA
CHANCES SUN NIGHT.
MODELS REMAIN IN DECENT AGREEMENT SAT THRU SUN AS HGTS RISE A BIT
OVER THE WESTERN GREAT LAKES AND WEAK SHORTWAVE RIDGING ALOFT BUILDS
IN. BY SUN NIGHT MODELS A BIT AT ODDS WITH TIMING/STRENGTH OF A
SHORTWAVE TO LOWER HGTS AND DROP SOUTHEAST INTO THE UPPER MIDWEST.
GIVEN NO ONE MODEL WITH CLEARLY BETTER RUN-TO-RUN CONSISTENCY THAN
THE OTHERS...SIDED WITH THE MODEL/ENSEMBLE CONSENSUS. FCST
CONFIDENCE THIS PERIOD AVERAGE TO GOOD.
PROBLEMS WITH NAM ADDRESSED FOR FRI NIGHT EXTEND INTO SAT MORNING.
CONTINUED TO DISCOUNT NAM FOR SAT MORNING FOR SAME REASONS AND LEFT
SAT DRY AS HGTS RISE AND CAN HIGH PRESSURE NOSES SOUTHEAST INTO THE
WESTERN GREAT LAKES. LEFT SKIES FOR SAT GENERALLY MOSTLY SUNNY AS
WELL. 850MB TEMPS IN THE +9 TO +12C RANGE...STILL ABOUT 1 STANDARD
DEVIATION BELOW NORMAL. WITH PLENTIFUL SUNSHINE ON SAT...HIGHS
SHOULD CLIMB TO THE MID 70S-NEAR 80...EVEN WITH LIGHT NORTH WINDS
AND THE HIGH SLOWLY BUILDING IN. THE HIGH STILL SETTLES ACROSS
MN/IA/WI FOR SAT NIGHT. DEPENDING ON HOW DEW POINT DROP/DRYING
OCCURS ON SAT...AND RECOVERY IN THE EVENING...SAT NIGHT SHOWING
SIGNS FOR A FAVORABLE RADIATIONAL VALLEY FOG NIGHT. WILL ADD MENTION
OF AT LEAST PATCHY VALLEY FOG TO FCST GRIDS FOR A FEW HOURS
CENTERED ON 12Z SUN. LATEST MODEL SET HAVE ALL EITHER WEAKENED THE
SHORTWAVE DUE TO APPROACH SUNDAY OR DELAYED IT INTO SUN NIGHT...WITH
LITTLE IN THE WAY OF LOWER LEVEL MOISTURE TRANSPORT/INCREASE INTO
THE AREA UNTIL SUN NIGHT. THE DRY CAN HIGH PRESSURE IS NOW EXPECTED
TO HOLD OVER THE AREA THRU SUN. REMOVED THE SMALL SUN AFTERNOON
SHRA/TSRA CHANCES FROM THE WEST END OF THE FCST AREA. EVEN WITH A
WEAKER WAVE TO APPROACH SUN NIGHT...MODEL CONSENSUS CONTINUES WITH
AN INCREASE OF 850-700MB MOISTURE TRANSPORT/PW VALUES INTO THE AREA
SUN NIGHT...MORE SO AFTER MIDNIGHT. LEFT THE MODEL/ENSEMBLE CONSENSUS
ROUGHLY 30 PERCENT SHRA/TSRA CHANCE FOR SUN NIGHT BUT COULD PROBABLY
TRENDED MUCH OF THIS AFTER MIDNIGHT/EARLY MON MORNING.
USED A BLEND OF THE NUMERICAL GUIDANCE HIGHS/LOWS FOR SAT/SUN/SUN
NIGHT. CONTINUED TO TREND TOWARD COOLER OF GUIDANCE LOWS SAT NIGHT
WITH THE DRY/COOL CAN HIGH SETTLING OVERHEAD.
MEDIUM RANGE MODEL RUNS OF 01.12Z AND 01.00Z IN RATHER GOOD AGREEMENT
WITH EACH OTHER AND THEIR 31.00Z RUNS AT THE START OF THE DAY 4-7
PERIOD WITH A CONTINUATION OF THE BLOCKY WEST COAST PATTERN AND
DOWNSTREAM TROUGHING/NORTHWEST FLOW OVER CENTRAL/EASTERN NOAM.
DIFFERENCES SLOWLY EMERGE/GROW FOR TUE-THU WITH SLOW PROGRESSION EAST
OF THE WEST COAST BLOCK AND A SHARPER TROUGH/SHORTWAVE ROTATING
AROUND THE WEST SIDE OF THE EASTERN CAN VORTEX AND DROPPING INTO THE
WESTERN GREAT LAKES BY THU. EVEN WITH THE DIFFERENCES BY THU...FCST
CONFIDENCE REMAINS GOOD THAT TEMPS WILL REMAIN BELOW NORMAL THRU
THE DAY 4-7 PORTION OF THE FCST. THERE WILL BE SHRA/TSRA CHANCES NEXT
WEEK BUT THESE WILL BE DIFFICULT TO TIME DUE TO SHORTWAVE DETAIL
DIFFERENCES AMONG THE MODELS IN THIS TIME FRAME. THUS FCST CONFIDENCE
REMAINS BELOW AVERAGE CONCERNING MON-THU PRECIP CHANCES. FOR NOW
FAVORED THE MODEL/ENSEMBLE CONSENSUS THRU THE PERIOD.
AS THE SFC...THE MON-THU PERIOD LOOKS TO BE DOMINATED BY HIGH
PRESSURE WITH WEAK REFLECTIONS OF THE PASSING MID LEVEL SHORTWAVES.
THE STRONGER TROUGH/SHORTWAVE ROTATING AROUND THE WEST SIDE OF THE
EASTERN CAN VORTEX AND HEADED FOR THE REGION LOOKS TO DRIVE A
STRONGER COLD FRONT SOUTH ACROSS THE AREA TUE NIGHT/WED...WITH MORE
CAN HIGH PRESSURE TO BUILD IN BEHIND IT FOR LATER IN THE WEEK.
APPEARS MUCH OF THE MOISTURE FLUX INTO THE AREA WITH THE PASSING
SHORTWAVES WILL MAINLY BE ABOVE THE SFC...MORE IN THE 850-700MB
LAYER...AS HIGH PRESSURE CONTROLS THE AREA AND LIMITED CONNECTION
TO THE GULF OR SOUTHERN PLAINS MOISTURE. SFC DEW POINTS LOOKING TO
REMAIN IN THE MORE COMFORTABLE 50S TO PERHAPS MID 60S RANGE. THE
CONTINUED NORTHWEST FLOW WILL NOT HELP DEEP MOISTURE RETURN INTO
THE AREA EITHER. THIS WILL LIMIT THE MOISTURE THE PASSING WAVES AND
ROUNDS OF LOWER LEVEL THERMO-DYNAMIC FORCING WILL HAVE TO WORK WITH.
MODEL/ENSEMBLE CONSENSUS SHRA/TSRA CHANCES IN THE 20-30 PERCENT RANGE
MUCH OF THE DAY 4-7 PERIOD LIKELY DUE TO THIS...AND LOOK WELL TRENDED
UNTIL TIMING DETAILS BECOME CLEARER. UNDER THE NORTHWEST FLOW
ALOFT...THEN INCREASING INFLUENCE OF THE EASTERN CAN VORTEX LATE NEXT
WEEK...850MB TEMPS REMAIN AROUND 1 STANDARD DEVIATION BELOW NORMAL
EARLY IN THE WEEK...TRENDING TO 1 TO 2 BELOW NORMAL BY THU/FRI.
DECENT CONFIDENCE FOR MON-THU HIGHS/LOWS TO STAY SOME 1 TO 2
CATEGORIES BELOW NORMAL...EVEN COOLER LATER IN THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1232 PM CDT THU AUG 1 2013
VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD AND THE MAIN
FOCUS IS ON INCREASING MOISTURE SURGE / UPPER LEVEL IMPULSE MOVING
ACROSS THE DAKOTAS INTO WESTERN MINNESOTA. THIS WEATHER SYSTEM IS
LIKELY TO GENERATE SHOWERS AND THUNDERSTORMS ACROSS THAT AREA...THEN
TRACK INTO SOUTHERN MINNESOTA AND IOWA THROUGH THE EVENING. THE
HIGHEST CHANCES LOOK TO REMAIN SOUTH/WEST OF THE TAF SITES...HOWEVER
WILL CONTINUE TO HONOR VCSH GROUP AT KRST FOR A FEW HOURS THIS
EVENING. BROKEN MID LEVEL DECK COULD LINGER THROUGH PARTS OF THE
OVERNIGHT...GIVING WAY TO MOSTLY CLEAR SKIES BY SUNRISE. FOR
FRIDAY...EXPECTING MOSTLY SUNNY SKIES AND LIGHT WEST/NORTHWEST WINDS
AS FRONTAL BOUNDARY REMAINS SOUTH IN IOWA AND HIGH PRESSURE BUILDS IN
FROM THE NORTH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....ZT