Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/21/19
Area Forecast Discussion
National Weather Service La Crosse WI
1048 PM CDT Tue Aug 20 2019
.SHORT TERM...(Tonight into Wednesday)
Issued at 215 PM CDT Tue Aug 20 2019
Weak frontal boundary dropping south across the local area this
evening. Weak low level moisture transport focuses back into the
boundary, while RAP soundings point to some elevated instability.
Could be enough forcing to spark isolated showers/storms.
Models remain in good agreement with sliding an upper level trough
axis southeast across the Upper Mississippi River Valley Wed/Wed
night. Meanwhile at the sfc, high pressure builds in from the
plains. In addition, little if any saturation for this northern
stream wave to tap into. Outside of some clouds, expect minimal
impacts from the upper level trough as a result.
However, to the southwest, an MCS is expected to kick off across the
central plains tonight - taking an eastward track Wed. Expect some
waning in areal extent/intensity as it loses the influence of the
low level jet, but still follows along the edge of the main bubble
of instability. Most models would keep the pcpn just south of the
forecast area, although a few suggest it could skirt across
northeast IA/southwest WI. Trending the forecast dry for the moment.
.LONG TERM...(Thursday through Tuesday)
Issued at 215 PM CDT Tue Aug 20 2019
Looking like an extended period of dry, and relatively cool
conditions for the rest of the week - or at least through Sat.
Upper level shortwave ridge builds into the area Thu, easing east
early Sat. The sfc high follows suit, shifting across the eastern
great lakes by 12z Sat. Several dry and mostly sunny days should
result.
Upper level trough then progged to push in from the northern plains
late Sat night-Sunday. Southerly fetch picks up ahead of the
shortwave, returning warmer-more moist air to feed the system.
Expect showers/storms to develop in response to the lift/moisture
interaction...with high chances to the north. How far south, mostly
along and ahead of an associated sfc front, is in question - and
certainly tough to answer this far out. Some hints that an MCS could
spark Sun night to the southwest, moving east on Mon. All said, Sun
and Mon currently holding a decent shot for rain for the area.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1048 PM CDT Tue Aug 20 2019
Brief MVFR conditions are possible tonight in stratocumulus. A
cold front and weak disturbance sags southeast across the area
bringing a few showers overnight. High pressure builds in on
Wednesday providing VFR conditions. Mid to high level clouds will
be found at the TAF sites at times from mid Wednesday morning into
the afternoon.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Rieck
LONG TERM....Rieck
AVIATION...Wetenkamp
Area Forecast Discussion
National Weather Service Denver/Boulder CO
923 PM MDT Tue Aug 20 2019
.UPDATE...
Issued at 839 PM MDT Tue Aug 20 2019
Minor updates were made to POPs to reflect the current convection.
Right now, it appears the majority of the storms will be sub-
severe this evening. However, better instability exists over the
I-76 corridor northeast of DIA up to the Cheyenne Ridge as the
RAP mesoanalysis has over 2000 j/kg of mixed layer CAPE with up
to 3000 j/kg near the Nebraska border. This is enough to support
the potential for a severe storm or two with large hail the
primary threat. The Severe Thunderstorm Watch goes until 11pm for
Weld and Morgan Counties which should be sufficient to encompass
the threat.
Storms may continue into the early morning hours across the far
northeast corner. Stratus and fog may develop but there is low
confidence on the fog.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 220 PM MDT Tue Aug 20 2019
Fair weather CU over the higher terrain and east-west ridges this
afternoon will eventually give way to convection by this late
afternoon. By 21z, will expect to see some isolated gusty
convection fire off the mountains, foothills and ridges and expect
these to migrate off onto the east plains while strengthening
into the evening hours as they move into much better moisture.
Latest NAM12 run has MLCAPES out on the far northeast plains in
the 3000-3800 J/kg range on the southern slope of a theta-e ridge
extending from southeast Wyoming eastward into western and
southern Nebraska. Rich surface boundary layer moisture of 8-10
g/kg will reside over the far NE plains lending to the potential
for strong to severe storms this evening along with the potential
for heavy rain and large hail. Storm motion for this evening is on
the weak side as 500-300mb layer winds are only in the 15 to 25kt
range. A few of the stronger, slower or back-built storms could
present some local hydro issues later this evening out along the
I-76 corridor mainly northeast of Denver. Behind tonight`s batch
of convection will be the passage of much cooler air behind an
approaching cold front currently near the Sheridan WY / Black
Hills SD vicinity as a decent 1022mb surface high spreads
southward across north plains states tonight. Will look for the
main wind shift arrival in the 05-07z Wednesday timeframe. This
will likely keep a north to northeasterly component to the surface
winds overnight and into Wednesday morning along with areas of
low clouds towards dawn.
For Wednesday, with the initial cool moist, stable air, will look
for light easterlies through the morning along with the potential
for low clouds and patchy fog over the far eastern plains. Highs
along the urban corridor and plains should only reach into the
lower to mid 80s. Forecast soundings indicate the profile
remaining fairly stable in the lower levels through late
afternoon, so with persistent easterlies through the day, the
best MLCAPES and boundary layer specific humidities will build up
against the Urban Front Range and foothills. Will keep the
scattered pops across the area, and at this time will expect the
main impact to be heavy rain associated with the storms along with
potential local hydro issues. Storm motion from 500-300mb winds
aloft is still fairly weak and with surface easterlies and
disorganized flow in the low to mid-levels, a few storms may have
difficulty exiting locations which may be a problem for flood
prone area such as an urban areas and burn scars.
With cooler temperatures along with higher daytime dew points and
relative humidity, the fire danger should relax for Wednesday.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 220 PM MDT Tue Aug 20 2019
Scattered thunderstorms will continue into the evening hours
along the Front Range and across the northeast plains Wednesday. A
few severe storms with large hail will be possible due CAPE
climbing to 1500-2500 J/kg and 0-6km Bulk Shear climbing to 30-40
kts.
A weak westerly flow aloft will again be over the state Thursday.
Surface low pressure over central Colorado and Wyoming will
produce southeast winds across eastern Colorado Thursday. This
will help keep moisture over the much of the area. Isolated to
scattered storms should form over the Front Range and eastern
plains Thursday afternoon and evening. Temperatures warm a little
over Wednesday`s highs with readings in the mid to upper 80s.
On Friday, moisture is starting to get pushed to the east by the
westerly flow aloft. May have enough moisture for a few storms.
The best chance will be across the eastern plains. With the
drying, expect temperatures to warm back around 90 degrees.
For the weekend and early next week, the upper level ridge will
shift south as westerly flow aloft increase. This will dry out the
airmass and warm it up. Dry conditions with highs in the 90s is
expected for the weekend. A weak cold front may back into the area
Sunday night and early Monday. This will bring cooler air with
highs expected to reach the upper 80s for Monday and Tuesday.
Could see enough moisture return to the area for storms on
Tuesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 839 PM MDT Tue Aug 20 2019
A thunderstorm or two may briefly pass over the terminals this
evening with minor, if any, impacts. Outflow boundaries may continue
to develop and push through the terminals tonight shifting winds
temporarily. The next concern shifts to the possible development
of stratus during the early morning hours. With plenty of low
level moisture in place, it is better than a 50 percent chance
that stratus develops so I included a from group for it at DEN.
There is some uncertainty, though, as most models have downslope
winds for much of the night so it is not a sure bet.
Strong thunderstorms will be possible Wednesday afternoon with
gusty winds and lower ceilings the primary threats.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Danielson
SHORT TERM...Fredin
LONG TERM...Meier
AVIATION...Danielson
Area Forecast Discussion
National Weather Service Dodge City KS
635 PM CDT Tue Aug 20 2019
...Updated aviation discussion...
.SHORT TERM...(This afternoon through Wednesday night)
Issued at 1145 AM CDT Tue Aug 20 2019
Quiet across SW Kansas late this morning, with only some
scattered cirrus and mid cloud. With downsloping SW winds
increasing through the afternoon, and gusting to near 30 mph,
temperatures will soar this afternoon despite local cooling from
minimal cloud cover. Increased max temperature grids 1-2 degrees
across the board, with many locations reaching 100-103. Also
issued a heat advisory across the SE zones 1-7 pm, where lingering
humidity will push the heat index over 105 for several hours this
afternoon.
Convection evolution this afternoon is complex and a bit
perplexing. A strong 596 dm upper high is centered just east of
Medicine Lodge at midday. Apparently, a weak disturbance is
rotating around this anticyclone, northward through the Texas
panhandle, that has already initiated weak convection near
Amarillo. HRRR and other CAMs, with support from 12z GFS, develop
scattered convection across SW KS starting around 3 pm. Increased
pops to scattered category for the central/eastern zones after 3
pm. Storms will form in a very hot, well-mixed boundary layer with
downburst wind gusts to 60 mph being the primary threat.
Midlevel clouds and scattered showers/embedded thunder will
persist much of the night, especially N/NE zones, fed by the low
level jet. Much more organized MCS with attendant hail/wind threat
is expected to remain well to the north of SW KS tonight, focusing
on Nebraska.
MCS-outflow reinforced cold front is expected to be along the
Kansas/Nebraska border at sunrise Wednesday. The front is shown by
all models to make steady southward progress through Kansas during
the daylight hours Wednesday. 12z NAM/GFS/extended HRRR show
excellent agreement showing strong convective initiation along the
cold front across SW KS around 3-4 pm. With the added focus of
the boundary, CAPE/shear will support strong to marginally severe
convection with locally very heavy rain. SPC 5% wind/hail
probability for the entire CWA is justified, and increased severe
risks may be assigned once the cold front focusing mechanism is
nailed down more specifically. The heat will relax Wednesday, but
temperatures will still have time to reach the mid to upper 90s
ahead of the incoming front across the southern counties.
.LONG TERM...(Thursday through Tuesday)
Issued at 200 PM CDT Tue Aug 20 2019
Heat relief is expected on Thursday behind the frontal boundary.
12z NAM shows the strongest cooler air wedge coming into SW KS,
perhaps enforced by a spurious closed low passing over Kansas
aloft. 12z GFS is not far behind, forecasting surface temperatures
holding in the 70s most of the day for most zones, with some 80s
near the Oklahoma/Colorado borders and even upper 60s NE zones.
Model guidance is trending strongly cooler for Thursday, but much
of this cooling is a function of holding cloud cover through the
daylight hours. If the clouds can hold through 5-6 pm, then the
coolest guidance will verify. NBM appeared too warm in the mid to
upper 80s, and trimmed substantially, but stayed above the cool
guidance. Regardless, Thursday will be the most comfortable day we
have seen in some time.
Kept modest pops in the grids Thursday and Thursday night as the
front meanders and slowly washes out. However, models are trending
eastward with the most significant rainfall during this period,
focusing in central/eastern Kansas.
A warming trend will occur Friday through Sunday. The only
disparity in the models is exactly how quickly this will occur.
Model consensus and 12z MEX guidance suggests afternoon
temperatures will return to near 100 on Sunday. 12z ECMWF supports
this thinking, with the highest thickness values on Sunday,
enhanced by prefrontal compressional heating ahead of the next
cold front scheduled for Monday. Rain chances will also dwindle
during the Friday through Sunday time range, with most locations
remaining dry.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 635 PM CDT Tue Aug 20 2019
Widely scattered to isolated thunderstorms will continue into the
early evening before diminishing due to the loss of daytime
heating. The storms will mainly be in the vicinity of Dodge City
and Hays. A cold front will move south through western and central
Kansas during the day Wednesday. Widely scattered thunderstorms
are expected to develop again along the front. VFR to MVFR cigs
may develop in the Hays area toward the end of the period.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 71 96 66 79 / 20 30 60 30
GCK 67 95 64 79 / 30 20 60 30
EHA 68 95 64 89 / 20 20 60 20
LBL 70 97 65 90 / 20 20 60 20
HYS 69 89 65 79 / 30 50 60 40
P28 73 98 69 87 / 10 20 50 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT this evening for KSZ066-081-088>090.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Gerard
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1154 PM EDT Tue Aug 20 2019
.AVIATION...
Mid level clouds in wake of MCV enhanced vorticity max will fade
overnight with at least some chance for a period stratus/fog early
in the morning given moisture from evening rain and light flow. Any
MVFR conditions will lift by mid morning as southwest flow increases
in advance of approaching cold front. This front bring a wind shift
late in the day and perhaps a period of lower VFR cigs.
For DTW...VFR conditions will start the period, but a period of MVFR
cigs/vsbys may occur by daybreak given moist low levels and light
winds. Otherwise, cigs in/around 5kft will be possible Wednesday
before cold fropa by early evening scours lower moisture out to some
degree.
.DTW THRESHOLD PROBABILITIES...
* Moderate confidence in cigs aob 5kft late tonight/Wednesday
morning, low late Wednesday.
&&
.PREV DISCUSSION...
Issued at 337 PM EDT Tue Aug 20 2019
DISCUSSION...
Scattered showers and thunderstorms continue oriented southwest to
northeast along an area of subtle isentropic ascent and where
greatest moisture transport vectors have set up across the state. A
couple of moving pieces to note and watch out for heading into the
remainder of the afternoon and evening. To start, SPC RAP guidance
and latest hi-res models hold CAPE between 1500 - 2000 J/kg mainly
across the Tri-Cities area into the Thumb (tied to increase moisture
surge) and a secondary area of higher CAPE up to 2000 J/kg building
in across the southern Metro area. Additionally, low-level lapse
rates aoa 7C/km in conjunction with supportive TEI profiles and
larger dew point depression spread at the surface help support the
idea of strong wind gusts to 40 mph, with a possible isolated
downburst to 60 mph. Hail cannot be completely ruled out as mid-
level lapse rates also hold around 7C/km with effective bulk shear
around 25 knots.
Second, an MCV complex currently located over southern Lake Huron
and northern Indiana has maintained a more east to west propagation,
contrary to many CAMS advertising a northwest to southeast
propagation. This system is also translating faster to the east
relative to the 12Z hi-res output. Given that the MCV complex is
moving east into an area of high instability, there is a chance this
system will hold together and produce showers and thunderstorms for
the southern Metro region centered between 20-04Z. Prior to the
potential arrival of the MCV, amplification of a shortwave will allow
the nose of higher theta-e to fill in across the Metro area between
20 - 00Z, which will bring the chance to see isolated to scattered
showers and thunderstorms. Overall the main message -- Isolated to
scattered thunderstorms will remain possible from Flint up to the
Tri- Cities and Thumb this afternoon, with isolated to scattered
thunderstorm chances expanding across the Metro area during the early
evening onwards. Low-level cap in place may help diminish activity
vs. the competing instability in place but the approaching MCV will
have to continue to be monitored as it travels east towards the cwa.
There will be a marginal risk for severe weather for all of SE MI,
mainly for wind gust concerns.
PV anomaly (tied to the MCV) is projected to move east of the cwa by
06Z Wednesday and will travel into New England by Wednesday
afternoon, leaving SE MI under zonal flow in the mid-levels.
Subsidence on the back side of the anomaly will allow for clearing
of cloud cover overnight, especially for the Tri-Cities and Thumb
with more active subsidence in place. Did not include in this
forecast package due to uncertainty, but given residual
precipitation and moist boundary layer with the subsidence, will
need to watch for fog development overnight.
Upper-level closed low and developing surface low pressure system
will move east across Ontario Wednesday into Thursday and will allow
a cold front to pull across SE MI sometime between Wednesday morning
- Wednesday afternoon and will bring the chance for showers
and thunderstorms. Will carry a chance of precipitation through the
passage of the front as atmosphere is relatively dry (1000-500 MB RH
aob 50%) and lack of overall synoptic forcing. Warm and humid
temperatures will be able to hold on through the afternoon with
highs in the 80s, but relief will fill in during the evening and
will lead to overnight lows in the 50s to lower 60s and DP dropping
into the 50s.
Southern periphery of a high pressure system to fill in throughout
Thursday which will start an extended period of dry weather with
lower humidity and temperatures that are below the seasonal norm
with highs in the 70s.
Friday will be cloudy and cooler as upper level trough lingers over
the region. A cold front dropping through the state in advance of
Canadian surface high pressure will keep clouds prevalent with
northerly flow but model soundings look very dry minimizing the rain
potential. Cool northerly flow continues Saturday into Sunday as the
surface high, centered to our north over Ontario, slides east. An
amplifying mid level ridge axis will then pass over on Sunday
allowing southern return flow back into the state. After a few days
where highs only reach in the 70s, temps on Sunday should finally
rise back into the low 80s which is normal for late August. Next
shot for showers will hold off til around Monday when a strong mid
level wave and associate surface low lift through the northern
Lakes. Increasing warm air advection ahead of the front will push
temperatures into the mid 80s Monday.
MARINE...
Light southerly winds this evening will give way to northwest winds
tomorrow as a cold front drops south through the Central Great
Lakes. A push of much cooler air over Lake Huron Wednesday evening
will result in winds increasing to 20 to 30 knots, with
brief/slightly higher gusts possible over northern Lake Huron. Winds
will gradually diminish on Thursday into Friday as high pressure
nudges into the region from the northwest.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
AVIATION.....DG
DISCUSSION...AM/DRK
MARINE.......SF
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
335 PM MDT Tue Aug 20 2019
.SYNOPSIS...
Shower and thunderstorm activity will be on the upswing this
afternoon and through much of the week, with scattered to numerous
thunderstorms expected into the early evening hours. Storms will
be slow-moving, and will tend to produce highly localized
downpours and flooding, while other areas remain dry. Thunderstorm
coverage will be around 30 to 50 percent in the lowlands.
Temperatures will slowly cool back down into the 90s Wednesday and
Thursday. Drier conditions are expected by Sunday, with
temperatures warming back up early next week.
&&
.DISCUSSION...
RAP analysis has the subtropical ridge centered roughly over New
Mexico this afternoon, with light and variable steering flow. Low
level moisture did push into the region overnight, but most areas
near and west of the Rio Grande have seen dewpoints mix out into
the mid-40s. Despite this, PW values remain around 1.25 inches.
Dewpoints remain in the 50s over the Tularosa Basin and Hudspeth
County.
Convection was fairly impressive when it fired up in the higher
terrain late this morning, and continues to pulse up now and
then, even in parts of the lowlands. NAM/GFS suggest moderate
instability axis focused near the Rio Grande, with and 850-700 mb
moist axis just west of the Rio Grande, despite surface dewpoints
having mixed out into the upper-40s.
Overall, the UofAZ WRF (various 12Z and 06Z runs) appear to be
doing fairly well with on-going convection, and suggest scattered
coverage across most areas east of the Divide through early
evening, somewhat favoring areas west of the Rio Grande. Given the
higher dewpoints further east, and on-going trends, we will keep
scattered coverage in place east of the Rio Grande this evening as
well.
Heading into tomorrow, the subtropical ridge begins breaking down
into two centers, with a weakness over NM where plenty of recycled
mid-level moisture will remain trapped. Temperatures aloft will
remain more favorable than they have been much of the season
(around -6C at 500 mb... whereas we`ve been seeing a lot of -3s
and -4s this year), with moderate instability developing in the
afternoon. There`s some hint of a weak surface trough in the
vicinity of the Rio Grande as well, and with dewpoints remaining
in the lower-50s, expect scattered coverage of thunderstorms again
tomorrow, and a relatively active day. Weak steering flow will
continue, resulting in localized heavy rainfall and highly
localized flooding.
For Thursday, a shortwave trough over the Central Rockies will
skirt northern New Mexico, while down south we`ll remain in the
weakness between the subtropical ridge centers with
trapped/recycled upper level moisture remaining in place. Areas
east of the Rio Grande may be favored for thunderstorm coverage
Thursday afternoon/evening, as slightly drier air aloft looks to
push into the NW portion of the area.
Thunderstorm activity will slowly diminish Friday and Saturday,
with mostly dry conditions expected by Sunday and Monday as the
upper ridge redevelops to our west, and drier air aloft moves in
from the north. The ridge looks to slowly shift eastwards Monday
into Tuesday, suggesting continued drier conditions and
temperatures warming back up again.
&&
.AVIATION...Valid 21/00Z-22/00Z...
P6SM FEW-SCT080-100 SCT-BKN150-200 through much of the period.
Isolated to scattered VRB25G40KT 1-3SM TSRA BKN030-040 possible
through 06Z, mainly mountains and lowlands between Continental
Divide and Rio Grande. Thunderstorm coverage increases to
isolated/scattered lowlands and numerous mountains after 18Z. Winds
mainly east to southeast AOB 12KTS except near thunderstorms.
&&
.FIRE WEATHER...
Low level moisture has returned to the region with showers and
thunderstorms over area mountains this afternoon with some isolated
to scattered coverage over the lowlands into the evening. Moisture
will become a little deeper Wednesday with increasing storm
coverage, especially over the mountains. The main threat with these
storms the next couple days will be locally heavy rain as storm
motion will be very slow. Temperatures will fall to near normal and
relative humidities rising above 20 percent. An upper high will
start to build back over the area starting Friday and really gets
established for the weekend into early next week. This will bring a
return to very hot and dry conditions with highs over the lowlands
likely back near or above 100 degrees with minimum humidities back
into the teens.
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 75 97 72 95 / 20 10 30 20
Sierra Blanca 69 93 68 92 / 10 0 20 30
Las Cruces 71 95 66 94 / 40 20 50 10
Alamogordo 70 96 67 95 / 20 30 40 30
Cloudcroft 56 73 53 73 / 30 70 50 50
Truth or Consequences 70 94 67 95 / 40 40 40 20
Silver City 66 88 61 89 / 30 60 40 20
Deming 71 96 66 95 / 50 20 50 10
Lordsburg 72 97 67 95 / 10 30 40 10
West El Paso Metro 76 97 72 96 / 20 10 40 20
Dell City 71 98 71 98 / 0 0 20 30
Fort Hancock 75 100 73 99 / 0 0 20 30
Loma Linda 71 92 69 90 / 30 10 30 30
Fabens 75 97 72 95 / 10 0 30 20
Santa Teresa 73 96 69 95 / 30 10 40 10
White Sands HQ 74 96 71 95 / 40 30 40 20
Jornada Range 69 95 66 94 / 40 40 50 10
Hatch 70 96 66 96 / 40 40 50 20
Columbus 73 96 69 95 / 40 10 50 10
Orogrande 71 96 68 95 / 20 10 40 20
Mayhill 59 82 57 82 / 30 60 40 50
Mescalero 58 82 56 82 / 30 60 50 50
Timberon 58 81 57 80 / 20 50 40 50
Winston 60 85 56 87 / 30 70 40 30
Hillsboro 67 93 63 93 / 40 50 40 30
Spaceport 68 94 64 94 / 40 40 50 20
Lake Roberts 60 88 55 89 / 20 70 30 20
Hurley 65 90 61 91 / 30 50 40 20
Cliff 65 97 60 98 / 10 50 30 20
Mule Creek 67 92 63 92 / 10 50 30 10
Faywood 68 90 63 91 / 40 50 40 20
Animas 69 98 66 96 / 20 30 40 30
Hachita 70 97 65 94 / 30 20 50 10
Antelope Wells 70 95 66 93 / 30 30 50 30
Cloverdale 68 91 64 88 / 30 40 40 40
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
25-Hardiman / 26-Grzywacz
Area Forecast Discussion
National Weather Service Goodland KS
702 PM MDT Tue Aug 20 2019
.UPDATE...
Issued at 655 PM MDT Tue Aug 20 2019
Just completed an update. Coverage of storms has increased along
and south of Interstate 70 in northwest Kansas in response to a
couple of prefrontal troughs. Mesoscale interaction of storms have
also helped to move storms along. This coverage is a little more
plus further west than what was in the forecast. So have raised
pops in this area.
Also surface boundaries have sagged further south over the northern
half of the area than what was called for. This plus thunderstorms
will make for gusty and erratic winds this evening. Because of all
this further updates through the rest of the night will be
possible.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 226 PM MDT Tue Aug 20 2019
Upper ridge will be centered over the southern plains with a weak
shortwave trough currently emerging out of Wyoming and topping the
ridge axis. At the surface, radar shows a surface cold front
evident on radar has settled near the Kansas-Nebraska border
region with a wind shift to the east behind it. For the rest of
this afternoon and tonight, two areas of concern for convection.
The first is over the south central to south eastern areas, where
latest HRRR continues to show a cluster developing and moving
eastward through this evening. These storms will be south of the
front in a low shear/moderate instability environment, with the
main hazards gusty winds and perhaps marginally severe hail. Later
tonight, another thunderstorm complex will move out of northeast
Colorado into western Nebraska. These will be north of the front
in a high shear/very unstable environment. Expecting a MCS to move
across western/central Nebraska through the night, mainly
impacting areas to the north, but cannot discount development
southward along mesoscale/outflow boundaries through the night.
The main hazard with these storms will be strong/damaging winds.
Low temperatures will be near normal, mainly in the 60s.
Some storms may linger into Wednesday morning as outflow
associated with the MCS moving through eastern Nebraska may
continue to have mesoscale influences. Areas of fog may also
develop in the post frontal upslope flow in the morning. Expecting
a lull in activity around midday then new development in the
afternoon, mainly in southeastern areas. In fact, HREF members
suggest little convection through Wednesday afternoon, holding off
until the next weak shortwave comes out of Colorado Wednesday
night. Best chances will be in southern/central part of the area
south of Interstate 70. Primary hazard will be wind, with only a
marginal risk for hail due to nocturnal timing. Heavy rain threat
may stay south, but do see some HREF members hitting parts of
Cheyenne County, Colorado, during the evening with heavy rain, so
cannot totally discount it there. High temperatures on Wednesday
will be cooler behind the front and with the morning clouds/fog,
ranging from upper 70s/lower 80s in southwest Nebraska to the
lower 90s in west central Kansas.
.LONG TERM...(Thursday through Tuesday)
Issued at 224 PM MDT Tue Aug 20 2019
The extended forecast is a bit messy with daily chances for showers
and thunderstorms. Thursday morning, lingering showers will be
possible in the western part of the forecast area, mainly along and
west of the Kansas-Colorado border. A weak upper level ridge will
be in place over the western part of the Dakotas. On the underside
of the ridge, an upper level shortwave trough will move through the
Tri-State area during the day. Showers and thunderstorms will be
possible Thursday afternoon and evening. Storms will fire off along
a frontal boundary in northeastern Colorado, moving west into the
Tri-State area.
Friday into the weekend, a series of upper level shortwave troughs
will move through the Central Plains. Showers and thunderstorms,
while not widespread in coverage in the forecast area, will be
possible through Saturday.
Monday, a broadening upper level trough will extend from British
Columbia, Canada to Minnesota and south into the Dakotas. The Tri-
State area will be under northwest flow aloft as a shortwave trough
moves through the larger scale upper trough. Meanwhile, a lee
cyclone will develop Sunday night and progress eastward on Monday.
Cannot entirely rule out a chance of precipitation early Monday
morning, but am thinking we will remain dry through much of the
day.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 536 PM MDT Tue Aug 20 2019
For Kgld, at this time vfr conditions are expected through the
period. East winds near 14 knots will shift to the southeast at 19
knots with gusts to around 27 knots. From 06z to 11z, southeast
winds near 8 knots are expected with 6SM BR expected to develop
around 09z. From 11z to 15z east winds near 8 knots and the light
fog are expected. This is the time period where possible sub vfr
conditions due to ceilings. At 15z east northeast winds near 15
knots will continue until 22z. At that time the winds will become
northeast near 15 knots with gusts to around 22 knots.
For Kmck, vfr conditions are expected through the first half of
the period. Otherwise, east winds near 15 knots with gusts near
23 knots are expected until 04z. From 04z to 07z the winds will be
southeast at 6 knots. From 07z to 15z east to northeast winds of 6
to 12 knots are expected as thunderstorms will be near the site
along with fog of 6SM BR. From 09z to 12z, vfr conditions will
change mvfr and continue until 15z.
Ifr conditions are expected from 15z to 18z with northeast winds
of 15 knots with gusts to 23 knots. From 18z to the end of the
period east northeast winds near 10 knots are expected as mvfr
conditions will become vfr around 22z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...024
LONG TERM...AW
AVIATION...BULLER
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1000 PM EDT Tue Aug 20 2019
.SYNOPSIS...
Several mid/upper level disturbances will move east through the
region through Thursday, with a slow-moving surface frontal
boundary drifting south during this time period. With seasonably
warm and humid conditions persisting through Thursday night,
periods of scattered showers and storms will be possible before
drier conditions filter in area-wide for the upcoming weekend.
Slightly below normal temperatures are expected for this weekend
with generally drier and sunnier conditions. A few isolated
storms may be possible by late Sunday afternoon.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Subsidence has taken hold of the ILN CWA behind the widespread
convective activity this afternoon, with the entire forecast
area currently clear of any precipitation. In fact, much of the
CWA is clear of any low clouds. Attention overnight will turn to
a shortwave currently moving eastward along the IN/MI border,
which at the very least appears likely to produce an increase in
clouds, as satellite imagery currently supports. Earlier
NAM/GFS projections of more widespread precipitation overnight
appear unlikely to occur, but even recent HRRR runs do suggest
some scattered showers in the northern half of the forecast
area, so some PoPs will be kept in overnight.
Current conditions and recent RAP/HRRR runs also support lower
temperatures this evening, especially with the clearing that
should be observed for the first segment of the overnight
period. Min temps were lowered by a couple degrees, with values
now expected to reach the middle to upper 60s. This is still
fairly warm, and the surface Tds in the upper 60s to around 70
would suggest that temperatures will not be able to fall too
much further than that. The possibility of fog is also worth
mentioning, but for now it appears that in a general sense, this
should be limited to MVFR-type visibilities.
Previous discussion >
A corridor of isolated to scattered thunderstorms have
developed in a moderately to highly unstable environment
entrenched across the heart of the ILN FA. This activity
continues to blossom out ahead of a slowly-decaying MCS with
attendant MCV noted on mosaic radar further to the north/west in
north-central IL.
For the rest of the afternoon, the corridor of scattered storms
currently approximately coincident with the I-75 corridor will
continue to drift east-northeast as additional isolated to
scattered activity develops ahead of the decaying complex
tracking south-southeast through central/southern Indiana. While
the MCS-generated convection is generally moving into a
favorably unstable environment characterized by MLCAPE in excess
of 2500j/kg and DCAPE of 1000-1200j/kg, the leading edge
continues to push further away from the MCV itself --
essentially outrunning the source that has kept it going for
this long. Nevertheless, this activity is likely to trend a bit
further south of southeast through mid/late afternoon -- likely
grazing and impacting only the Tri-State area and points
south/west of this particular area. Elsewhere, any isolated to
scattered activity will be more pulsy/airmass-driven opposed to
along the leading edge of a cohesive line/MCS. It is the pulsy
type activity that will likely pose the greatest strong/damaging
wind risk through early evening -- especially coincident with an
environment that will support downward acceleration of healthier
cores. Even with this said -- the highly unstable environment,
with good instability aloft, will also support instances of
large hail with the better/stronger cores.
The best coverage of storms will gradually shift from western
OH/eastern IN/northern KY from mid-afternoon through central OH
and northeast KY by early this evening. There seems to be
fairly good agreement in the short-term hi-res CAMs showing a
downtick in convection near/past sunset as the environment
becomes worked over and subsidence behind the main MCS
overspreads the ILN FA. Feel pretty confident in a trend toward
drier conditions by/past sunset this evening, with just a few
isolated showers possible past this time period as some midlevel
energy continues to propagate through the mean northwest flow in
the area. However, as previously mentioned, subsidence behind
the main MCS structure diving south-southwest through central
KY could be enough to stifle additional isolated shower activity
further north in an environment that will be fairly used up by
late evening into the overnight.
Highs for today have reached into the lower 90s but have likely
already plateaued due to the overspreading of
clouds/precipitation through the remainder of the local area
over the next several hours.
Some light fog will be possible late overnight with the nearly
saturated low level environment. However, the pressure gradient
will not completely relax -- lending itself to some uncertainty
in exactly where and how widespread any fog development will be.
Therefore, have not included in the official fcst although
certainly observational trends will be monitored closely to see
if this may eventually be warranted.
Lows tonight will bottom out in the upper 60s and lower 70s
area-wide.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
After any fog/stratus lifts/dissipates by late morning on
Wednesday, anticipate some diurnally-enhanced Cu to develop in
the region.
Although the frontal boundary will still be stretched in an E-W
fashion across the northern Ohio Valley on Wednesday, the
absence of any focused mid/upper level disturbance and/or source
for forcing is likely to keep an diurnally-driven activity to
mainly isolated in nature. The approach of a disturbance by late
evening may help spread some higher chance PoPs into the far
western ILN FA by late evening into the overnight hours --
especially as we near the end of the short term period by
Thursday morning. However, with a relatively strong cap in
place, anticipate that coverage will be far less than is the
case today.
Scattered showers and isolated thunderstorms will be on the
increase from the west towards sunrise Thursday as more S/W
energy ejects east through west-central and central Ohio Valley.
Highs on Wednesday will again top out around 90 degrees near the
Ohio River and mainly mid to upper 80s near/north of the I-70
corridor. Heat indices south of the I-70 corridor will again be
in the mid/upper 90s. Lows Wednesday night will fall into the
mid/upper 60s in the north to lower 70s south of the Ohio River.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Period begins with a cold front around the Ohio River. The front
will provide convergence and lift in the southern part of the fa,
giving the best PoPs around and south of the Ohio River. Went will
likely PoPs in the far south.
The front will continue to sag south Thursday night into Friday.
This will keep chance PoPs in the region for Friday.
By Saturday, high pressure will be settling in across the Great
Lakes. This will bring cooler and drier conditions.
On Sunday, an inverted trof will bring increasing humidity back into
the region along with a chance of thunderstorms to northern Kentucky
and the Scioto Valley.
Thunderstorm chances will increase Monday and Tuesday as
heat and instability increases.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Chances for thunderstorms this evening have diminished, leaving
just a few showers left in the area. The main concern overnight
will be the development of MVFR visibilities and MVFR/IFR
ceilings. The lowered ceilings appear most likely to develop at
KDAY (where IFR is quite possible) and KILN/KCMH/KLCK (where
MVFR is most likely). Some visibility restrictions are possible
at all TAF sites, though IFR visibilities appear generally
unlikely as of now.
Any visibility or ceiling restrictions should improve by 15Z,
with quiet conditions expected heading into the afternoon, and
WSW winds generally at or below 10 knots. A chance of pop-up
showers and storms is in the forecast for late afternoon, but
this will be handled with a VCSH for now, as storm coverage
should be fairly light.
OUTLOOK...Thunderstorms will remain possible at times through
Friday afternoon.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...KC
NEAR TERM...KC/Hatzos
SHORT TERM...KC
LONG TERM...Sites
AVIATION...Hatzos
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
954 PM EDT Tue Aug 20 2019
.UPDATE...
Issued at 954 PM EDT TUE AUG 20 2019
Outflow boundary has shifted into southeast Kentucky with some
ongoing showers continuing ahead of this boundary. Activity is
starting to fade with the loss of daytime instability, but a few
showers will continue over the next hour or so before this
activity shifts southeast and weakens further. This will provide a
fairly quiet overnight period. However, CAMS continue to support
some redevelopment across a portion of east Kentucky towards 08z
or 09z. Given some MUCAPE holding its ground in southeast
Kentucky, cannot rule out some redevelopment late tonight, and
thus, will bring some low end pops back into the forecast at this
time. Most areas will stay dry through the night. Rain chances on
Wednesday look to remain fairly sparse as well based on the latest
model guidance suggesting a quieter day may be seen across the
area.
UPDATE Issued at 745 PM EDT TUE AUG 20 2019
Several boundaries continue to be the focus for showers and
storms. The first one is from Lawrence county southeast to Bell
and Knox county. Outflow from more organized earlier day
convection is spread into our western counties, but this outflow
is running into an area already worked over from earlier
convection. Thus, convection associated with this boundary has
shifted more southward and that trend will continue over the next
few hours with rain chances gradually ending from northwest to
southeast as this outflow continues to push southeast. The outflow
could stall somewhere in southeast Kentucky and could led to
redevelopment later tonight or tomorrow, but will focus more on
that later, keeping some rain chances in late tonight and tomorrow
to account for that potential. Otherwise, looks like a period of
drier weather will be seen overnight.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 431 PM EDT TUE AUG 20 2019
A closed low to our SE and incoming shortwave are both impacting the
CWA today. Once our CAP was reached, showers and thunderstorms
starting quickly popping up across the CWA early this afternoon.
However, with very little wind aloft, there is no steering flow and
storms are not moving very quickly...rather pulsing up, becoming
strong, and then collapsing near their origin. On the converse, a
strong MCS is diving SE from Illinois this afternoon, but models
continue to show a diminishing trend as the system reaches Kentucky.
The latest CAMS show the line reaching the western CWA between 23
and 0Z, and falling apart around the same time, with only isolated
to scattered showers and thunderstorms expected across the CWA
through 3Z. Since there has been good agreement between the CAMs
throughout much of the day concerning the diminishing of this line
and mostly dry conditions thereafter through 6Z, did not include
much in the way of pops during this time period.
However, after 6Z, the HRRR and NAM12 both point at another round of
showers and thunderstorms developing across the CWA heading into the
early morning hours as the above-mentioned shortwave moves across
the CWA. Coverage will increase to scattered across the CWA
throughout the day as we increase our instability with daytime
heating. Still expecting hot temperatures, with heat indexes near
100 degrees, perhaps only a few degrees cooler than today.
Wednesday night, heights will begin to lower across the state as a
closed upper level low moves SE across eastern Ontario and western
Quebec. A cold front is also forecast to shift southward towards the
state, with scattered showers and thunderstorms expected to continue
throughout this overnight as a result. A more focused east to west
oriented band may develop across the central portion of the CWA
according to the latest CAMs.
Given the cloud cover both tonight and tomorrow night, temperatures
will remain quite mild. Lows will be around 70 each night, perhaps a
2 to 3 degrees cooler in the deepest valleys.
.LONG TERM...(Thursday through Tuesday)
Issued at 420 PM EDT TUE AUG 20 2019
The models are in fair agreement with the upper level pattern
through much of the extended. A deep northern stream trough will
progress over the northeastern CONUS, with zonal flow over
Kentucky. Ridging will then take hold over the northeastern
portion of the country, as well as a trough over the north-central
CONUS, for late weekend into early next week.
At the surface, a cold front will approach the Commonwealth early
Thursday. By the afternoon, the front will slow and eventually
stall over the state. This front will linger through Friday before
moving off to the south for the start of the weekend. MUCAPE
values from GFS model soundings average about 2500 J/kg Thursday
and Friday afternoons. Therefore, the better chance for showers
and storms is expected from Thursday through Friday.
High pressure will then build over the northern portion of the
Great Lakes and northeastern CONUS through Monday. By Tuesday,
another system over the Plains will progress eastward, with a warm
front slated to move over western Kentucky early Tuesday. This
pattern will keep daily chances of showers and afternoon/evening
storms for eastern Kentucky through the end of the forecast
period.
High temperatures will be in the mid 80s Thursday, but FROPA will
cause highs to only be in the low 80s through Saturday. Highs
will then gradually increase to be in the mid 80s by Tuesday. Lows
will generally follow a similar pattern, beginning in the upper
60s Friday morning. Lows will then drop to be in the mid 60s
through Sunday before returning to the upper 60s Tuesday morning.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 745 PM EDT TUE AUG 20 2019
While the majority of the period will feature VFR conditions,
there is some small potential for a few showers or storms late
tonight or tomorrow, but confidence is low on coverage and
location to include anything in the TAFs at this time. Thus, will
run with VFR TAFs for now. Light winds will be seen through the
period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...CGAL
AVIATION...KAS
Area Forecast Discussion
National Weather Service Mobile AL
848 PM CDT Tue Aug 20 2019
.DISCUSSION...See updated information for land areas below.
&&
.UPDATE...Overall the afternoon forecast package remains on track.
Just included some patchy fog development tonight to the current
forecast. /08
&&
.PREV DISCUSSION... /issued 701 PM CDT Tue Aug 20 2019/
DISCUSSION...Updated for latest aviation discussion below.
AVIATION...
00Z issuance...Widely scattered showers and storms linger through
early evening before slowly dissipating. Winds become light and
variable overnight. Patchy light fog is possible by 06Z across
areas that received rain today with visibility dropping to IFR or
LIFR for a short period at the TAF sites near sunrise. Showers
and storms redevelop by late morning. 07/MB
PREV DISCUSSION... /issued 337 PM CDT Tue Aug 20 2019/
NEAR TERM /Now Through Wednesday/...20.12Z upper air analysis
shows a trof axis at multiple levels from the Appalachians
stretching southwest over the central Gulf coast. At the surface,
a weakly defined pressure trof has migrated slowly northward over
the I-65 corridor today where visible satellite imagery animations
and radar loops continue to show a cyclonic motion to
cloud/precipitation elements around the trof axis. Meso-analysis
shows deepest Gulf moisture (PWATs 1.9 to 2.2 inches) along and
southeast of I-65. Scattered to numerous showers and storms have
used up instability with mixed layer CAPE values in areas where it
hasn`t rained ranging 1000-1500 J/KG over the land zones. Storm
cores have had a hard time maturing this afternoon, with over-all
core heights staying below -20C height at ~ 26.2 KFT per RAP BUFR
soundings. Although storm growth has been lacking, deep layer shear
being non-existent and mid level lapse rates ~ 5.5C/KM, forecasters
still cannot rule out a few afternoon perhaps early evening storms
becoming briefly strong. Deep layer environmental moisture supports
some storms being efficient heavy rain producers. Going into the
evening, ensembles of the high resolution models show a rapid
decrease in coverage. Some patchy fog possible late in the night in
those areas that received heavier rains today. Overnight lows mostly
in the lower to mid 70s.
A weak shear axis aloft remains positioned over the southeast
US and central Gulf coast on Wednesday. With deep layer moisture
holding and with onset of daytime instability, scattered to
perhaps numerous showers and storms are expected. Daytime highs
range from 88 to 93. /10
SHORT TERM /Wednesday night Through Friday night/...An unsettled
weather pattern will remain in place through the short term. A
very moist airmass with precipitable water values around 2 inches
combined with an upper level weakness will continue to generate
scattered to locally numerous showers and thunderstorms each day.
Showers and thunderstorms will start near the coast in the
morning and spread inland through the late morning. Convective
coverage will be most numerous over the land areas during peak
daytime heating. The upside to the additional rain and associated
clouds will be temps that will be at or slightly below normal. /13
LONG TERM /Saturday Through Tuesday/...Very little change in the
pattern through the extended range as plenty of deep layer
moisture will continue across the Gulf coast with precipitable
water values over 2 inches. This will continue the pattern of
diurnally driven scattered to locally numerous showers and
thunderstorms each day. /13
MARINE...A light mostly onshore flow continues over the marine
area as a ridge of surface high pressure continues to stretch
from the western Atlantic to the north central Gulf. Winds, waves,
and seas will be locally higher near thunderstorms through the
forecast period. Conditions will also remain favorable for
isolated waterspouts, especially during the morning and early
afternoon hours. /10
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...None.
FL...None.
MS...None.
GM...None.
&&
$$
This product is also available on the web at:
http://weather.gov/mob
Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
946 PM CDT Tue Aug 20 2019
.UPDATE...
Issued at 946 PM CDT Tue Aug 20 2019
Updated grids to warm overnight temps several degrees. Drier air
has been slow to advect in due to the light winds. Dew points
have fallen into the 50s from the Brainerd Lakes region and north,
but remain in the mid to upper 60s, and even some low 70s, across
central and southern MN into WI. The forecast now calls for mid
50s to lower 60s, warmest in the metro and southeast where the
drier air will be slowest to arrive.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 323 PM CDT Tue Aug 20 2019
No significant redevelopment of thunderstorms is expected ahead of
the cold front through this evening, thanks in large part to storms
that tracked across the area this morning. Although SPC meso
analysis shows mlCAPE values have built back up to the 1500-3500
j/kg range ahead of the cold front. Forecast soundings from the RAP
and NAM show a strong subsidence inversion in place at h8.
Convergence along the front is weak and there`s no discernible upper
wave, so this lack of forcing will allow this cap to hold. You can`t
completely rule out a stray shower developing along the front north
of I-94 from central MN into western WI, but it looks unlikely given
the lack of forcing. Already this afternoon on radar on satellite,
we`ve seen a few attempts at initiating convection along the front
from central MN into the Arrowhead, but nothing has ever been able
to sustain itself and expect this trend to continue.
For tonight through Wednesday night, high pressure centered to the
west of Hudson Bay will be nosing into the upper MS Valley. This
will result in some of the best weather you can cook up in MN during
the summer. The one thing to watch both Wednesday and Thursday is we
will see very deep mixing and will be tapping into a very dry
airmass as we mix deeper. So afternoon dewpoints and humidities will
likely be lower than what we currently have. During the overnights,
the airmass will be too dry to support any widespread fog. Winds
will help make sure we don`t see fog tonight, but Wednesday night,
we`ll have light/calm winds, so some valley fog will be possible in
the the valleys along the MS south of the St. Croix and up the
Chippewa Valley into WI, other than that, it`s windows open weather
for the next couple of days.
.LONG TERM...(Thursday through Tuesday)
Issued at 323 PM CDT Tue Aug 20 2019
Pleasant, early fall-like, weather continues into Friday as
troughing extending south from eastern Canada keeps cool
temperatures aloft over the Upper Midwest, and high pressure over
Ontario keeps any systems away from the region. Highs are only
expected to reach into the low to mid 70s Thursday afternoon and
cool, dry NE winds off of lake Superior will keep dewpoints in the
40s and low 50s. Southeasterly flow picks up on Friday as the high
slides off to the east, with temperatures warming a few degrees and
more humid air working into the area.
Precipitation still looks likely this weekend, but trough and
surface front driving the chance for showers and thunderstorms has
slowed by a day or so as the ridge over eastern North America slows
its progress. Friday evening now looks dry across the area and
precipitation may even hold off through most of Saturday across
eastern Minnesota/western Wisconsin as the front slowly
approaches from the Dakotas. Best chance for precipitation now
looks like it will occur from overnight Saturday into Monday,
although timing differences still exist among the models during
this timeframe. Models have trended stronger with the trough and
linger it longer over the region, as the eastern ridge continues
to stall its progress. Models show some pretty heavy QPF amounts
Sunday into Monday as showers and thunderstorms linger over the
area and show PW values approaching 2 inches. Will have to monitor
the heavy rain/flooding potential over the second half of the
weekend. Drier weather looks possible Tuesday after the front
passes, as high pressure briefly moves into the region.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 629 PM CDT Tue Aug 20 2019
VFR conditions and northwest winds 5-10 kts expected through the
period. Clouds will dissipate this evening, with high clouds
returning to southern MN Wednesday.
KMSP...No concerns.
/OUTLOOK FOR KMSP/
Thu...VFR. Wind NE 5 kts.
Fri...VFR. Wind SE 5-10 kts.
Sat...VFR. Chc -TSRA/MVFR. Wind SE 10G20 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...MPG
LONG TERM...ETA
AVIATION...BORGHOFF
Area Forecast Discussion
National Weather Service Mount Holly NJ
908 PM EDT Tue Aug 20 2019
.SYNOPSIS...
A nearby front will lift slowly northward into New York and New
England tonight and on Wednesday. A slow moving cold front is
forecast to approach from the northwest on Wednesday night and
Thursday. The boundary is expected to pass through our region on
Thursday night. High pressure is anticipated to follow for the
coming weekend and for the early part of next week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
The earlier convection across the lower Susqu Valley has
diminished for the most part with one or two surviving cells
escaping into the southern Poconos attm. Other dying tstms
across Delmarva has morphed into a large area of showers across
srn DE/NE MD. Going forward, the models are all over the place
with the HRRR showing a dry night and the 18Z NAM showing more
tstms developing after 6Z. The the nearby front, it seems that
some activity should be expected, so I have just refined the
Pops a bit mostly N/W and adjusted for present conditions.
Patchy fog will probably develop, but with the drier air today,
likely not that widespread.
With decent cloud cover overnight, temperatures will remain
warm and in the 70s through much of the region, with some mid to
upper 60s across the southern Poconos and northwestern New
Jersey.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
Heat Advisory remains in effect through Wednesday.
Another active day is in store for Wednesday as the
aforementioned frontal boundary pushes north of the region,
placing us firmly in the warm sector. Winds that have been more
southeasterly through today will turn more to the southwest and
we will see moisture increase across the region once again with
dew points rising into the low to mid 70s.
Hot and humid conditions will prevail with little relief
expected until showers and thunderstorms start to develop and
move through the forecast area. A pre-frontal trough will
develop ahead of the main front (which arrives Thursday) and
will be a focus for thunderstorm development across the region.
The main concern will be the potential for severe weather. The
SPC has placed portions of our area in the slight risk category,
with damaging winds being the main threat. Shear is modest
(only around 20- 30 kts) but with CAPE increasing through the
day to around 1000-2000 J/KG and plenty of moisture and lift
available, we could see some strong to severe storms develop,
mainly during the afternoon and evening and primarily to the
north and west of the I-95 corridor. Once again, PWATs are
running high (up to 2.00") so heavy rainfall will be likely and
may result in some flooding concerns.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
We should be solidly in the warm and humid air on Wednesday
evening, with ongoing showers and thunderstorms. The warm front
is expected to be well up into New England at that time with an
approaching cold front extending across the eastern Great Lakes
and the lower Ohio River Valley.
The showers and thunderstorms are expected to weaken gradually
on Wednesday evening with the loss of daytime heating. Partly
cloudy and muggy conditions are anticipated for late Wednesday
night.
The cold front is forecast to extend from northern New England
to the Ohio River Valley on Thursday morning. The boundary will
likely sink slowly to the south, passing through our region from
late Thursday into Thursday night. We are expecting another hot
humid day. Heat index values may again approach 100 from the
Philadelphia metropolitan area southward. However, conditions
seem borderline and we will not extend the Heat Advisory at this
point although it may need to be done as we get closer in time.
Another round of showers and thunderstorms is forecast ahead of
and with the cold front from Thursday afternoon into Thursday
evening.
Some improvement is expected on Friday as high pressure begins
to build down into our region from Ontario. There is a chance of
showers and thunderstorms from northeastern Maryland and
Delaware into southern New Jersey as the departing front remains
nearby to our south.
The center of the high is anticipated to shift from Ontario to
Canada`s Maritime Provinces over the weekend. This pattern will
keep our region in dry conditions with a developing northeast to
east flow. Temperatures will be cooler than what we are
currently experiencing and humidity levels will be noticeably
lower.
The onshore flow may bring a return of some moisture early in
the new week. We have included a slight chance of showers and
thunderstorms at that time.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Tonight...Isolated showers and thunderstorms this evening. Then
more activity N/W after midnight psbl. Otherwise, expect mostly
VFR conditions across the region. Some patchy fog psbl and some
low clouds S/E. Light and variable winds overnight.
Wednesday...Lingering MVFR/IFR conditions (mainly at KACY/KMIV)
in the morning should clear by 15Z and then VFR is expected
through much of the day. Showers and thunderstorms will again
develop across the region and there will be the potential for
MVFR or lower conditions to occur during the afternoon and
evening, especially from KPHL and northward. South to southwest
winds around 5 to 10 knots early will strengthen into the
afternoon, with some gusts around 15 to 20 knots possible.
OUTLOOK...
Wednesday night...MVFR and IFR conditions with a chance of
showers and thunderstorms. Southwest wind 5 to 10 knots.
Thursday...Conditions improving to VFR. However, there will
continue to be a chance of showers and thunderstorms with
locally MVFR and IFR conditions. West wind 5 to 10 knots.
Thursday night...Mainly VFR. A chance of showers and
thunderstorms with locally MVFR and IFR conditions. Northwest
wind 5 to 10 knots.
Friday...Mainly VFR. A chance of showers. Northwest wind 5 to
10 knots.
Friday night...Mainly VFR. Variable wind 6 knots or less.
Saturday...Mainly VFR. North to northeast wind 5 to 10 knots.
Saturday night...Mainly VFR. Variable wind 6 knots or less.
Sunday...Mainly VFR. Northeast to east wind around 10 knots.
&&
.MARINE...
Sub-advisory conditions are expected to continue through
Wednesday. Seas will generally be around 2 to 4 feet. Winds are
expected to pick up from the southwest Wednesday afternoon and
gusts may approach 25 knots, especially later in the day. For
now, keep winds just below SCA criteria but cannot rule out a
few gusts around 25 knots.
Isolated showers and thunderstorms may lead to locally higher
winds and waves.
OUTLOOK...
Wednesday night through Sunday...No marine headlines are
anticipated.
RIP CURRENTS...
With waves forecast at 2-3 foot and a 6-7 second period, along
with southerly winds 5-10 knots, the risk for dangerous rip
currents is low into tonight. Waves in the surf zone will likely
remain around 2-3 feet.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 8 PM EDT Wednesday for PAZ070-071-102-104-
106.
NJ...Heat Advisory until 8 PM EDT Wednesday for NJZ015-017>019.
DE...Heat Advisory until 8 PM EDT Wednesday for DEZ001.
MD...None.
MARINE...None.
&&
$$
Synopsis...Iovino
Near Term...Meola/PO
Short Term...Meola
Long Term...Iovino
Aviation...Iovino/Meola/PO
Marine...Iovino/Meola