Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/03/19
AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
1015 PM EDT Tue Jul 2 2019
.SYNOPSIS...
High pressure settles off the Southeast coast for the remainder
of the week, resulting in increasingly hot and humid conditions
with a potential for afternoon and evening showers and
thunderstorms.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 1015 PM EDT Tuesday...
Narrow line of convection has managed to hang on across the
upper eastern shore and is in the process of dropping across
lower eastern shore of MD late this evening. Past few runs of
HRRR have gotten a better handle on this activity and as a
result, maintained a chc pop/sct tsra through midnight, tapering
off into early Wed morning. Otherwise, clearing sky over the
southern 2/3 of the CWA with partly to mostly clear and a bit
more humid conditions with lows mainly in the 70s.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
As of 350 PM EDT Tuesday...
By Wednesday and Independence Day the mid-upper ridge becomes
centered in vicinity of the nrn Gulf coast, and somewhat of a
split flow pattern develops as the primary jet will be located
well N of the local area in vicinity of the international
border. Numerical models suggest a series of weak shortwave
troughs will rotate around the nrn periphery of the ridge, and
this will result in a chc of mainly aftn/evening showers/tstms
Wednesday and Thursday. Pulse storms should be the primary mode
given a weak wind field aloft. 02/12z models suggest more areal
coverage of showers/tstms on Thursday.
Hot and even more humid Wednesday as surface high pressure
settles well offshore. 850mb temperatures near 20C should
support highs in the low/mid 90s (upper 80s at the immediate
coast). Dewpoints around 70F and into the low 70s will support
heat indices of 100-104F for central/SE VA and NE NC. Warm and
humid Wednesday night with lows in the low/mid 70s. High
temperatures Thursday may be a few degrees lower than Wednesday.
However, dewpoints will still be in the low/mid 70s, so heat
indices will approach 100F. An exception will be the MD Ern
Shore where a weak backdoor front could result in highs in the
low/mid 80s.
The ridge aloft builds Friday. However, some semblance of a
mid- level trough will remain, and hence there will be a chc of
aftn showers/tstms again. Seasonably hot and humid with highs in
the upper 80s to low 90s, and dewpoints in the low/mid 70s.
This will result in heat indices near 100F.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 410 PM EDT Tuesday...
A very moist/humid airmass combined with an upper level trough
over the area, followed by a cold front pushing thru the region
Sun into Mon morning, will result in chcs for sctd showers/tstms
Fri night into at least the first part of Mon. High pressure
will then build in from the NE for later Mon thru Tue. High
temps will be in the upper 80s to lower 90s Sat and Sun, and in
the mid to upper 80s Mon and Tue. Heat indices will be in the
mid to upper 90s on Sun. Morning low temps will generally be
70-75 Sat, Sun, and Mon morning, and in the upper 60s to lower
70s Tue morning.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
As of 920 PM EDT Tuesday...
VFR conditions across area terminals looks to persist through
the 00z TAF period. Latest analysis reveals sct showers/T-Storms
just NW of KSBY as of 01z. Have updated to vicinity thunder
wording at KSBY with line of showers moving through over the
next couple of hours. Otherwise, partly cloudy to mostly clear
overnight into Wednesday morning. Iso- sct showers/tstms are
expected to develop Wednesday aftn, with a 30-40% chc at
RIC/ECG, 20-30% PHF/ORF, and 20% at SBY. VCTS has not yet been
mentioned, as timing appears to be within the last few hours of
the TAF period after 20z/4pm Wed aftn.
High pressure remains off the Southeast coast Thursday through
Sunday, with a chc of aftn/evening showers/tstms each day.
&&
.MARINE...
As of 350 PM EDT Tuesday...
Afternoon check of surface/buoy observations shows winds generally
from the southwest 5-15 knots with surface high pressure off the
Southeast coast and a weak trough over Pennsylvania and Maryland.
Waves in the Bay are 1-2 ft with seas offshore ~2 ft.
High resolution guidance continues to show a ribbon of enhanced SSE
flow across the Bay late this afternoon into the overnight hours as
the pressure gradient tightens with the weak trough/low dropping
southeast. Winds in this time period are between 10-15 knots with a
few gusts nearing 20 knots in the Bay. Winds will be slightly
stronger offshore overnight but both areas are expected to remain
below SCA thresholds. Waves in the Bay will increase to around 2 ft
with seas increasing briefly to 3-4 ft overnight. Thereafter, marine
conditions will be relatively tranquil through the Independence Day
holiday as ridging aloft strengthens.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/MAM
SHORT TERM...AJZ
LONG TERM...TMG
AVIATION...AJZ/MAM
MARINE...RHR
Area Forecast Discussion
National Weather Service La Crosse WI
1055 PM CDT Tue Jul 2 2019
.SHORT TERM...(This evening through Wednesday)
Issued at 331 PM CDT Tue Jul 2 2019
At 3 PM, a weak convergent boundary extended from the
Minnesota/Iowa border east to Lake Michigan. A few showers and
storms have developed in our area. Meanwhile, further east, a more
robust area of showers and storms has developed in south central
and southeast Wisconsin and east central Iowa. This precipitation
is associated with a mid level shortwave moving through this area.
For the remainder of this afternoon and evening, we will have to
continue to watch the aforementioned boundary for additional
development in our area. ML CAPES are already in the 1500 to 3000
J/kg, so there is enough instability for further development of
showers and storms. The only question is whether the convergence
will become strong enough for them to develop. With very weak
shear, not anticipating organized severe weather. However, could
not rule out a pulse severe storm.
On Wednesday, a shortwave trough will move east into the region.
ML CAPES once again climb into the 2 to 3K range. Surprisingly,
the shear looks weak. This would greatly limit the potential for
organized convection. The latest HRRR has been trending toward a
bit less convection than earlier, so kept the precipitation
chances in the 30 to 50 percent range mainly south of Interstate
94. With precipitable water values near 2 inches and warm cloud
layer depths of 4 km, any showers and thunderstorms which form
will be efficient rain producers.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 331 PM CDT Tue Jul 2 2019
From Wednesday night through Friday night, the frontal boundary
will remain located over the region. As waves move through the
region, there will scattered showers and storms. Overall, the
shear looks weak, so organized severe convection is not
anticipated. However, a pulse severe storm will be a possibility.
With precipitable water values above normal, heavy rain will
continue to be a possibility.
For the upcoming weekend, there are indications that a Canadian
high will build across the region. This could provide us with a
few dry days before a return of showers and storms as the ridge
builds and pushes the front back into the region.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1055 PM CDT Tue Jul 2 2019
Main concern through this TAF period will be potential for MVFR to
IFR visibilities and ceilings overnight as high pressure passes by
to the north. There is plenty of residual low level moisture in
place, and with calm winds and only some cirrus overhead, the
setup will be favorable for fog development overnight. Already
seeing a couple regional fog observations at this hour. That being
said, some of the latest guidance is not quite as aggressive as it
was earlier with visibility reductions. Have still kept LSE going
to IFR for a time and RST to MVFR with conditions improving
shortly after 12Z. Light winds during the day on Wednesday with
potential for some afternoon pop up showers and storms as a weak
disturbance moves through. Confidence remains low in timing and
location of this convection, but it should diminish after 00Z
Thursday.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Boyne
LONG TERM...Boyne
AVIATION...Kurz
Area Forecast Discussion
National Weather Service Cheyenne WY
437 PM MDT Tue Jul 2 2019
.SHORT TERM...(This evening through Wednesday night)
Issued at 230 PM MDT Tue Jul 2 2019
Expect sctd showers and tstms currently around the mtns to
progress east and northeast through early this evening but may
have some difficulty progressing much across the Neb Panhandle.
Shear and instability not impressive but once again a few strong
storms possible, most likely up north. Activity should dissipate
late this evening.
Should see pretty much a repeat for Weds with convection firing
again initially over the mtns then moving over the plains. Best
area looks to be over northern parts of the CWA closer to a
shortwave that will clip that area. A weak sfc boundary may also
help to enhance activity a bit.
.LONG TERM...(Thursday through Tuesday)
Issued at 230 PM MDT Tue Jul 2 2019
Looks like pretty much a persistence fcst through early next week
as the upper pattern changes very little. Expect sctd mainly
afternoon and evening showers and tstms most days as weak impulses
lift across the region. The airmass may dry out some early next
week as some drier air from the desert sw may advect over the
region. Otherwise a cool front looks to pass across early Friday
bringing a cool down for Friday and Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 430 PM MDT Tue Jul 2 2019
Thunderstorms expected once again this evening for a few airports.
Nailing down specific airports...used the latest short term
guidance...namely HRRR and HIRES. Looks like KBFF and KAIA look to
be the two locations that could see storms moving over the
airports. Have TEMPO groups in for both TAFs this evening.
&&
.FIRE WEATHER...
Issued at 230 PM MDT Tue Jul 2 2019
No significant changes are expected for the rest of the week
with warm temperatures and pretty much daily chances for mainly
afternoon and evening showers and thunderstorms. A cool front will
move across Thursday night bringing cooler conditions Friday and
Saturday. Fire weather concerns remaining quite low.
&&
.HYDROLOGY...
Issued at 310 AM MDT Tue Jul 2 2019
Additional rainfall and snowmelt over the next several days could
bring levels back to action stage, but the heaviest rain looks to
stay to the east of the mountain ranges.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...RE
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...RE
HYDROLOGY...RUBIN
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
625 PM CDT Tue Jul 2 2019
.Discussion...
Issued at 257 PM CDT TUE JUL 2 2019
Regional radar mosaic showing an increase in shwr/isolated storm
activity this afternoon, likely in response to an approaching
weak shortwave disturbance and diurnal heating effects. Fcst
soundings from across the region this afternoon show a deeply
mixed boundary layer with nearly dry adiabatic lapse rates
extending up through roughly 7 kft. Moreover, soundings further
show very weak wind fields aloft, suggesting that storms will move
very slowly once they form this afternoon. With all this said,
shear values are obviously non-existent for organized severe
storms, however MLCAPE values in excess of 3000 J/kg combined with
the previously mentioned steep low-level lapse rates, may support
an isolated strong wind gust or two when storms collapse in this
shearless environment. Latest HRRR fcsts suggest coverage will be
rather sparse, and because of this, have elected to keep coverage
in the isolated category this afternoon. Storms should gradually
come to an end early this evening with loss of daytime heating.
Another sound of shwrs/storms will possible during the predawn
hours as a weak shortwave seen over the southern Plains this
afternoon gradually lifts northeast with time. Again though,
coverage looks pretty sparse in nature, but operational models
seem fairly insistent on its occurrence. For now, have capped
pops in the low-end chance category, under the assumption that
pops can be increased once trends become better established this
evening. For now, the most concentrated activity looks like it
will remain south of the Route 50 corridor, and the evening shift
will have a better idea as additional high-res model runs are
received.
Lingering shwr/storms will be possible through the morning and
early afternoon hours on Wednesday before gradual clearing occurs
later in the day. Another warm day is expected with highs again
topping out in the upper 80s across much of the area. Much of the
same can be expected right through the end of the week with
afternoon shwrs/storms again being possible both Thurs and Fri
afternoons as the main jet stream remains well north of our area.
As mentioned yesterday, trying to pindown any one specific
focusing mechanism is difficult with such a weakly forced and
convoluted weather pattern. Many of the storms over the next few
days will be a direct result of very minor shortwave disturbances
and daytime heating effects. It does continue to look as though
the upcoming weekend will have better forcing as a disturbance
ejects out of the central Rockies. This combined with a frontal
boundary that is still expected to reach our area Saturday/early
Sunday should result in the best chance for organized shwrs/storms
over the next several days.
&&
.Aviation...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 613 PM CDT TUE JUL 2 2019
VFR conditions are expected to continue. Pattern continues to
feature chances for isolated showers/thunderstorms, but
predictability of timing and coverage is low. Best chances appear
to be early morning and again later Wednesday afternoon.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
Discussion...32
Aviation...Blair
Area Forecast Discussion
National Weather Service Green Bay WI
1035 PM CDT Tue Jul 2 2019
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Wednesday
Issued at 223 PM CDT Tue Jul 2 2019
The latest RAP analysis and satellite/radar imagery show a weak
cold front positioned from southern Minnesota and across central
Wisconsin to lower Michigan early this afternoon. After morning
showers exited the lakeshore by around the noon hour, mixed layer
instability has been slowly building over the Fox Valley into
northeast Wisconsin into the 600-800 j/kg range. Cu has also
gradually become more agitated early this afternoon. With
convective inhibition eroding, think will see scattered shower and
storm redevelopment. A strong storm cannot be ruled out, but deep
layer shear around 25 kts will limit storm organization, thereby
making severe potential rather low. Clearing skies are occurring
behind the front over northwest WI, due to an influx of dry air.
Besides the thunderstorm potential this afternoon, forecast
concerns also revolve around dense fog potential late tonight.
Tonight...It is possible that a few showers and storms will linger
over east-central WI for the first hour or two in the evening
until the front gets pushed south of the area. Otherwise, should
see the clearing trend shift south across central and northeast WI
this evening. The clearing skies, light winds, and high boundary
layer moisture will set the stage for fog development later
tonight. Models indicate that eastern WI will have a higher threat
of fog, where the moisture will have limited opportunity of
mixing out, unlike over north-central WI where dewpoints have
fallen into the 50s. Patchy dense fog appears possible,
particularly near the Bay and Lake where surface winds may turn
onshore for a brief time. Lows will range from the upper 50s in
the north to the mid 60s south.
Wednesday...With the front stalling over northern Illinois and
southern Minnesota, weak high pressure and dry air will lead to
quiet Summer weather for a change. It will still feel humid over
central and northeast WI, where dewpoints will remain in the
middle to upper 60s. It will be a warm day with fair weather
clouds popping in the heating of the day once the fog/stratus
burns off early in the morning. Highs ranging from the mid to
upper 80s away from Lake Michigan.
.LONG TERM...Wednesday Night Through Tuesday
Issued at 223 PM CDT Tue Jul 2 2019
Precipitation trends for the 4th of July holiday will be the main
forecast concern.
After a brief reprieve during the midweek period, a warm and humid
air mass will return to the region Wednesday night into Thursday.
The leading edge of elevated instability should move into roughly
the southwest third of the forecast area late Wednesday night,
leading to a chance of showers and thunderstorms. The unstable air
mass will overspread the entire forecast on the 4th of July, but
the best chance of storms should occur near a cold front over
north central WI and a warm front in central WI, during the
afternoon and early evening. The strongest instability (SBCAPE of
2k-3k j/kg) is also focused in these areas. Deep layer shear is
fairly weak, except in far north central WI, where values around
30 kts are forecast. Could see a few strong to severe storms near
the aforementioned frontal boundaries, but especially over north
central WI, given the more favorable shear. Models suggest a
general weakening trend in convection overnight, but isolated
showers and storms may persist along the cold frontal boundary.
Precipitation chances should persist over at least part of the
region Friday into Friday evening, with the best chances over our
southern counties.
Canadian high pressure is expected bring relatively dry conditions
from Saturday into Monday. A cold front will arrive sometime in
the first half of the work week, and bring the next significant
chance of thunderstorms. However, timing varies greatly between
the faster GFS and slower ECMWF. Will split the difference, and
bring chance pops back into the region Monday night into Tuesday.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1029 PM CDT Tue Jul 2 2019
Main concern overnight will be the low clouds and fog, which were
already developing along the the Lake Michigan shoreline into
Door County and portions of eastern Kewaunee County. The low
clouds and fog are expected across the remainder of northeast
Wisconsin overnight. Have decided to take the KGRB/KATW/KMTW
taf sites down to a quarter of a mile for period of time
towards sunrise. Patchy or areas of fog are expected over the
remainder of the region overnight. The KMTW taf site will
be difficult forecast Wednesday into Wednesday evening.
Current thinking is there will be fog over the lake during
this time frame. With easterly flow, the low clouds and fog
may come and go at the KMTW site through the afternoon.
However, after sunset Wednesday evening, CIGS/VSBYs may
drop quickly into the IFR or lower category. The same would
be true if flying into KSUE. Otherwise fair weather cumulus
clouds between 2,500 and 5,000 feet are expected late Wednesday
morning and afternoon.
.GRB WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 9 AM CDT Wednesday for WIZ022.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kieckbusch
AVIATION.......Eckberg
Area Forecast Discussion
National Weather Service Wichita KS
947 PM CDT Tue Jul 2 2019
.UPDATE...
Issued at 947 PM CDT Tue Jul 2 2019
Storms continue to fester over portions of southern KS, ahead of a
weak mid level shortwave moving across wrn KS into Central KS. Low
level moisture transport ahead of this shortwave continues to
support the cluster of storms over the Flint Hills/SE KS and south
central KS. Latest RAP shows initial moisture transport waning some
as midnight approaches. So expect the SE KS cluster of storms to
wane as it wanders east. Another area of storms over south central
KS may maintain itself until after midnight, as it moves into south
central KS for areas along and SW of ICT, as the RAP also shows
another area of moisture transport increasing into southern KS after
midnight. So will keep pops going into the overnight hours for
southern KS.
Ketcham
&&
.SHORT TERM...(This evening through Friday night)
Issued at 236 PM CDT Tue Jul 2 2019
Unstable airmass in weak flow regime with weak capping should
continue to allow for mainly isolated/widely scattered convection
through Friday. Mesoscale vorticity center drifting over western
Kansas this afternoon and other sub-synoptic features will likely
remain foci for loosely organized, slow moving convection. As
previous forecaster alluded to, a gradual increase in the daily
heat is expected with heat indices flirting with advisory criteria
again late in the week. A southward sagging weak cold front by
Friday evening into Friday night may provide a better focus for
scattered storms across the area.
Darmofal
.LONG TERM...(Saturday through Tuesday)
Issued at 236 PM CDT Tue Jul 2 2019
Weak migratory perturbations just north of the upper ridge axis
trying to build north again into the central Plains will continue
to ripple east over the meandering surface boundary through the
weekend. So will continue to show modest chance PoPs. The GFS
continues to show a more progressive upper flow regime across the
northern tier of states through early next week which evolves
into eventual troughing over the Upper Midwest into the Great
Lakes by mid-week. If so, this may allow modest cooling just
beyond the seven day forecast.
KED
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 713 PM CDT Tue Jul 2 2019
Widely scattered diurnally driven showers/storms will continue over
portions of central and south central KS for a few more hours until
sunset. So will go with a VCTS for the KRSL/KGBD and KICT tafs.
Will also put some variable gusty winds for a tempo group, as the
slow moving storms have a microburst threat with gusts to 35-40 kts.
After sunset expect most of the convection to wane or end, as
daytime heating is lost. So expect VFR conditions for the next 18
hours or so, until Wed afternoon.
Could see a repeat of the diurnally driven storm chance for Wed
afternoon. But will let later taf issuances try to figure out
where. For now will go with a VCTS near KCNU, where chances seem a
little higher, albeit small.
Ketcham
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 72 92 72 93 / 20 20 20 20
Hutchinson 71 93 71 94 / 20 20 20 20
Newton 71 92 71 93 / 20 20 20 20
ElDorado 71 90 71 91 / 20 20 20 20
Winfield-KWLD 70 90 71 91 / 20 20 20 20
Russell 70 94 71 95 / 40 10 20 20
Great Bend 70 93 71 94 / 40 10 20 20
Salina 72 94 73 95 / 20 20 20 20
McPherson 70 93 71 94 / 20 20 20 20
Coffeyville 72 89 72 90 / 20 20 20 20
Chanute 71 90 71 91 / 20 20 20 20
Iola 71 89 71 90 / 20 20 20 20
Parsons-KPPF 71 89 72 90 / 20 20 20 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Ketcham
SHORT TERM...KED
LONG TERM...KED
AVIATION...Ketcham
Area Forecast Discussion
National Weather Service Lincoln IL
935 PM CDT Tue Jul 2 2019
.UPDATE...
Issued at 935 PM CDT Tue Jul 2 2019
Most of forecast looks ok, but need to make some tweaks to pops/wx
across the north given current radar trends. Update will be out
shortly.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 149 PM CDT Tue Jul 2 2019
Hot and humid conditions continue throughout the near term along
with the possibility of scattered afternoon/evening pop-up
thunderstorms. A broad upper level ridge will remain over the
eastern 2/3 of the country into midweek, centered along the
Mississippi River Valley. Meanwhile, at the surface, a frontal
boundary is noted from southern Minnesota east across central
Wisconsin and northern Michigan while a prefrontal trough is noted
from far NE Illinois into SE Iowa, marked by a subtle wind shift
and a more organized area of tower cumulus/developing storms.
These features will serve as the focus for afternoon and evening
thunderstorms, though cannot rule out more isolated development
further south across the entire CWA as we near convective temps
this afternoon. Temperatures in the low 90s with dew points in the
low to mid 70s are contributing to moderately strong instability
of 2000-2500 J/kg, greatest over the northern CWA where low/mid
level lapse rates are steepest. Deep layer shear over the area is
very weak (10-15kt) limiting the risk of organized storm
development; however, a number of factors are favorable for
damaging winds from pulse storms through the day today, mainly for
the northern tier of counties in the forecast area. Near the
aforementioned prefrontal trough and per latest RAP guidance,
steep 0-3 km lapse rates to around 8.5 C/km, marginally high LCLs
around 1250-1300 m, and DCAPE values in excess of 1400 J/kg are
all supportive of wet microbursts into this evening.
Trough/effective frontal boundary is progged to sag south into
central Illinois, aided by convective outflow this evening and
tonight. How far south and how quickly remain big question marks,
but the chance for it entering northern portions of the CWA with
accompanying precip chances increases late this evening and
overnight, while further south precip chances will diminish as the
boundary layer stabilizes.
By Wednesday, we pretty much lose any definition in the synoptic
boundary but will be dealing with another hot and humid day with
diurnally favored precip chances along any lingering outflow
boundaries from overnight convection. Similar conditions will
remain in place thermodynamically supporting yet again another
threat for some isolated to scattered thunderstorms, some of which
could be severe with a pulse microburst threat. Temperatures may
be tempered a few degrees compared to today with increased PoPs
and cloud cover, but still anticipate temps near the 90F mark with
dew points in the low to mid 70s which will contribute to
moderately strong instability to around 2500 J/kg.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 212 PM CDT Tue Jul 2 2019
Much of the same throughout the long term forecast as the pattern
remains largely unchanged into the middle of next week. Upper
ridge will remain centered across the mid section of the country
with open flow from the Gulf of Mexico keeping humid conditions
across the Midwest, and supporting diurnal convective chances on
a daily basis. Of note, though, there is a buckle in the upper
ridge projected by the GFS and ECMWF associated with the tail end
of a wave pivoting over Hudson Bay this weekend. There is a weak
surface reflection that will move across the local area, likely on
Saturday with an associated increase in precip chances. In its
wake, high pressure building into the upper midwest should help
moderate temperatures locally with northerly flow, and will bring
in lower dewpoints at least briefly on Sunday and perhaps Monday
which will limit diurnal PoPs relative to the remainder of the
week`s forecast. Upper ridge quickly recovers and amplifies in
the wake of this system, and anticipate a return to hot and humid
conditions Tuesday into Wednesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 642 PM CDT Tue Jul 2 2019
VFR conditions will prevail next 24hrs at all TAF sites.
Thunderstorms that did develop this afternoon have stayed south of
the all TAF sites and expect this to continue this evening. So,
all sites are seeing sct to bkn cirrus due to high cirrus blow off
from storms to south. These scattered clouds will likely continue
into the overnight hours so keeping sct clouds all night. Then CU
will develop around 4kft tomorrow morning and then thicken at
around 5kft in the afternoon as a weak boundary drops into the
area. Expecting scattered storms to develop along this boundary
early afternoon. So will have VCTS at all sites for mid afternoon
through end of TAF period. Winds will become light and variable
for tonight and then become southwest tomorrow at under 10kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...Deubelbeiss
LONG TERM...Deubelbeiss
AVIATION...Auten
Area Forecast Discussion
National Weather Service North Platte NE
1107 PM CDT Tue Jul 2 2019
.SYNOPSIS...
Issued at 308 PM CDT Tue Jul 2 2019
H5 analysis from earlier this morning was highlighted by
a strong closed low over northern Saskatchewan and a second, much
weaker low over western Washington state. A low amplitude pattern
existed across the western CONUS west southwesterly flow extended
from California into the central and northern Rockies. East of the
Rockies, a zonal pattern extended from the northern plains east to
the Mid Atlantic. High pressure was anchored over southern Florida
with a low amplitude ridge extending north into the Tennessee
Valley. Within the west southwesterly flow, a shortwave was located
from east central Colorado into south central Nebraska. Cloudiness
in association with this feature, extended from far sw Nebraska into
east central Nebraska and northern Iowa. At the surface...a decent
cold front extended from southern Montana into northeastern North
Dakota. Temperatures north of this front were in the 50s this
afternoon with readings in the 70s/80s south of the front. A
secondary, stationary front extended from far sern Wyoming into far
sw Nebraska, then northeast into northeastern Iowa. Skies were
generally cloudy INVOF the stationary front in Nebraska with
overcast conditions noted from Imperial to Broken Bow and O`Neill.
Further west, skies were mainly clear. Readings as of 2 PM CDT
ranged from 79 at O`Neill to 86 at Ogallala.
&&
.UPDATE...
Issued at 1107 PM CDT Tue Jul 2 2019
The HRRR model suggest fog across parts of the Sandhills and
Platte valley tonight. A forecast update is in place for this
feature.
UPDATE Issued at 906 PM CDT Tue Jul 2 2019
A forecast update is in place using the RAP, HRRR, HREF and NAM
models. This suggests just an isolated thunderstorm chance
overnight across northwest Nebraska and north central Nebraska.
Earlier thunderstorm activity across Lake McConaughy quickly
diminished after the storms became mature. The atmosphere appears
to be fairly stable.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 308 PM CDT Tue Jul 2 2019
Thunderstorm chances in the near term is the main forecast
challenge. For tonight: Thunderstorms are expected to develop
INVOF the before mentioned frontal boundaries. The first well off
to the north in northwestern South Dakota, and the second from
extreme sw Nebraska into east central Nebraska. As for
precipitation chances tonight, they were lowered from the pvs
forecast particularly across north central into northeastern
portions of the forecast area. Low pops were held onto in the
western forecast area this evening to capture any convection which
lifts east of the Cheyenne Ridge and along and INVOF the
stationary boundary from far SW Nebraska into the sern forecast
area. As for the severe threat, it will be very minimal for
tonight. Deep layer shear is very weak across the forecast area
tonight and mid level flow is weak. That being said, the main
threat from any strong storm is some gusty winds and heavy rain.
With the absence of a low level jet tonight, the threat for storms
should end during the evening hours. Lows tonight will be mild
with readings ranging from the lower 60s west of highway 83 to
near 70 in the northeastern forecast area. On Wednesday, the cold
front, currently over North Dakota, will be forced south into
northwestern Nebraska by overnight convection in South Dakota. The
front will then stall across northwestern Nebraska Wednesday
afternoon. Mid level forcing will increase Wednesday afternoon
over Wyoming, leading to thunderstorm initiation in eastern
Wyoming. This activity will track northeast along the H5 flow
ending up in northwestern Nebraska late Wednesday
afternoon/evening. Deep layer shear increases to 30 to 40 KTS
Wednesday afternoon across northwestern Nebraska and with fcst
capes of 2500 to 3500 J/KG late Wednesday afternoon, there is some
threat for severe storms especially INVOF the surface front
across NW Nebraska. Pops were trended higher in the northwest for
Weds afternoon. The models generate a low level jet Wednesday
night across central Nebraska, so convection is expected to
persist into the overnight hours with the greatest threat over the
northern half of Nebraska.
.LONG TERM...(Thursday through Tuesday)
Issued at 308 PM CDT Tue Jul 2 2019
The frontal boundary, will be driven south by storms Wednesday
night, becoming anchored across the Sandhills Thursday morning.
The models then lift this north as a warm front, stalling it
across northwestern Nebraska by Thursday afternoon. Another round
of thunderstorms will develop INVOF the front late Thursday
afternoon with activity lifting east Thursday night. Based on the
latest NAM12 soln, the front will be located in NW Nebraska
Thursday afternoon, while the GFS has this feature across the
Sandhills. Regardless of model solution, am expecting storms to
fire INVOF the front Thursday afternoon. Some of these may be on
the strong to severe side as deep layer shear is on the order of
40 to 50 KTS and SB CAPES are above 4000 J/KG Thursday afternoon.
This area is covered under a marginal day 3 risk for severe storms
and wouldn`t be surprised if this is upgraded to a slight with
the new day 2 outlook to be issued later tonight. Since this is
Independence Day, we sent out a sit report to partners about the
severe potential Thursday. The threat for storms will persist into
the weekend as low level moisture remains entrenched across the
central plains and a low amplitude zonal pattern persists.
Temperatures will be somewhat cooler, but still in the 80s which
is slightly below normal for this time of year.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 625 PM CDT Tue Jul 2 2019
Over the next 24 hours expect scattered high cloudiness across
western and north central Nebraska. Ceilings at the KLBF and KVTN
terminals will range from 20000 to 25000 FT AGL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...CDC
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...Buttler
Area Forecast Discussion
National Weather Service Omaha/Valley NE
621 PM CDT Tue Jul 2 2019
.SHORT TERM...(Tonight through Friday)
Issued at 310 PM CDT Tue Jul 2 2019
Surface frontal boundary remains stalled in the area today, from
south of Columbus, to north of Omaha and and Harlan. Isolated
thunderstorms have bubbled up along the boundary through the day,
with the latest attempt between Columbus and Wahoo a little more
vigorous with daytime heating. Nevertheless, while there is
extreme instability, with up to 3500-4000 J/kg of surface based
cape, wind shear is quite light, only 10 or 15 knots. SPC earlier
in the day removed our area from the Marginal Risk, and maintained
that with the 20z update. Various CAM solutions suggest scattered
storms will continue to bubble along along the frontal corridor
this evening, with likely not much if anything across our far
northern and southern forecast area fringes. The HRRR model
suggests that storms diminish by 11pm-midnight, but other models
suggest that scattered storm chances continue along the boundary
overnight, which is the preferred solution.
Not much changes on Wednesday. The aforementioned boundary
essentially washes out, but there will likely be another very
subtle upper wave moving through the mid Missouri valley,
resulting in scattered thunderstorm chances. Highs Wednesday in
the upper 80s to near 90s.
Even though the original boundary washes out, the models seem to
want to focus convection again Wednesday night along and just
north of I80, where the highest Pops will be placed. This is also
likely the nose of the developing low level jet, although to be
honest, confidence is somewhat low since other models may try to
focus the low level jet just a little farther south.
The overnight convection could set up a new boundary across the
region on Independence Day, as depicted by the Nam, or not, as
depicted by the GFS. Either way, it will be another typical
summertime day, highs in the upper 80s to lower 90s, with a 20-30%
chance of thunderstorms.
A wetter pattern continues Thursday night and Friday with no
substantial change to the overall pattern. Typical summer weather
with at least a chance of storms.
.LONG TERM...(Friday night through Tuesday)
Issued at 310 PM CDT Tue Jul 2 2019
The extended period will have the same overall pattern, with a
daily chance for rain. It should be slightly cooler for the
weekend, highs in the lower to mid 80s, but back to 85 to 90 for
Monday and Tuesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 620 PM CDT Tue Jul 2 2019
Thunderstorms affecting KOMA through 01z, with some gusty winds up
to 30 knots possible. Can`t rule out small hail, but did not
include in the TAF at this time. Otherwise, VFR, with probability
too small to include any thunder mentions at any other time.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
SHORT TERM...DeWald
LONG TERM...DeWald
AVIATION...DeWald
Area Forecast Discussion
National Weather Service Nashville TN
1037 PM CDT Tue Jul 2 2019
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
Cold pools/outflow boundary initiated convection continuing past
10 AM CDT (03/03Z), and thus suite of forecast products updated
accordingly. With this convection being cold pool/outflow boundary
based, short term models not picking it up on it that overall
well, with the latest HRRR solution at least hinting at it.
Although strength of convection has weakened over the last hour.
Still with this typical summertime unstable wx pattern along with
one not being able to rule out weak disturbance(s) aloft
transversing mid state region thru overnight hrs too per riding
over this unorganized quasi upper level riding pattern aloft
aiding to continued convective development potential, will
continue mention of iso shwrs/tstms across mid state region thru
4 AM CDT (03/09Z) mainly along and north of I-40 Corridor, before
eventually dissipating. Per agreement with surrounding offices,
mentioned patchy fog across Cumberland Plateau Region and near
bodies of water late tonight. Tweaked hrly temp, dewpoint, and
wind speed/direction grids. Current temp trends generally in line
with overnight forecasted low temps values. Remainder of forecast
continues to be on track.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR conditions are expected overnight with BR included for a few
hours during sunrise. VIS may be marginally impacted by BR
through 13-14z at the terminals. Otherwise, expect VCTS to be
around during the afternoon and early evening...with possible TS
lowering VIS/CIGs at a terminal or two.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......31
AVIATION........Schaper
Area Forecast Discussion
National Weather Service Pocatello ID
223 PM MDT Tue Jul 2 2019
.SHORT TERM...Tonight through Thu night. A portion of a coastal
upper level trough is expected to move across the Idaho panhandle.
This action will bring a weak cold front through central and
eastern Idaho, which should trigger some showers and
thunderstorms in greater coverage than what has been lately
occurring. So thunderstorm threat is highest on Wed, but decreases
for Thu. Guidance has backed off on the strength of the wind with
this feature, which is good news for fireworks displays on Thu
night, Independence Day. The thunderstorm threat for tonight and
Wed is more prevalent. The greater cloud cover is keeping
conditions cool, and there is also an expected increase in
humidity, with dewpoints rising into the 40s from the 30s. Messick
.LONG TERM...Friday through next Tuesday. An upper trough will be
exiting around mid-day Friday, and will bring some morning showers
to the Bear Lake area. Drier conditions will move in behind the
trough as another trough deepens over the PAC NW. A couple
shortwaves will lift out of the trough over the weekend, but models
still place impacts in the Panhandle area, possibly extending into
the northern reaches of the Central Mountains on Saturday. As we
head into Sunday, the GFS is pushing some convection further south
as far as Ketchum extending into Custer County and the Montana
border. As we head back into the work week, upper ridging will
become more pronounced and temperatures should begin to hit that 90
degree mark across southeast Idaho. Weather in the extended periods
looks dry except for a few afternoon/evening showers/thunderstorms
up around the Island Park area. Hinsberger
&&
.AVIATION...Models are keeping convection away from the terminals
today, but hint at bringing showers in late tonight, similar to last
night. NAM 3km is more widespread with shower activity across the
Upper Snake Plain and Eastern Highlands in the morning. HRRR is
pointing showers more over Stanley and Challis. Strong southwest
winds expected across the Snake Plain today, and will taper off this
evening. Hinsberger
&&
.FIRE WEATHER...Portions of a coastal low will be moving into the
Idaho panhandle during this period. This will bring in more
unstable conditions and so thunderstorms on Wed will be greater in
coverage. A shift to westerly flow aloft will bring drier
conditions for Independence Day. Earlier this week it appeared as
thought the holiday would be breezy or even windy, but general
wind forecast wind speeds are down and expect most areas to stay
below 15 mph except for ridges. Humidity will be on the increase
because the dewpoint is rising and temperatures are cooling.
Temperatures will dive to as much as 8 deg F below normal for the
time of year. The shift to westerly wind will start a drying out
after Thu. The trough does not entirely leave the Pacific
Northwest, so flow eventually returns to southwest and it really
is a more of the same pattern with most thunderstorms developing
in the northern half of the forecast area, mainly in the Salmon-
Challis NF, Targhee NF, and nearby BLM land. By next Tue, the
southwest upper level ridge may build enough to push the
thunderstorm activity farther north and out of eastern Idaho. This
would also allow some significant warming and drying if the
forecast continues. Messick
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
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