Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/30/18
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1005 PM CDT Fri Jun 29 2018
.DISCUSSION...Updated for latest marine discussion below.
&&
.MARINE...Have allowed the Small Craft Advisory (SCA) for Winds
on the Laguna Madre to expire as scheduled at 10 PM. Winds appear
to be in the process of decoupling with only Rincon del San Jose
reporting winds above 20 knots at this time. Will maintain the SCA
for the Gulf waters through 7 AM Saturday, though appears it will
be lower-end with winds around 20 knots and frequents gusts to 25.
Difficult to gauge model performance with no buoys reporting w
and no recent ASCAT pass, so have just teased winds up a bit for
the first part of the night for better consistency with
headlines.
&&
.PREV DISCUSSION... /issued 637 PM CDT Fri Jun 29 2018/
DISCUSSION...Updated for latest aviation discussion below.
AVIATION...Trends identified in previous set of TAF`s expected to
continue. Breezy to gusty SE winds observed currently will
continue until around sunset but only drop to moderate levels for
the overnight period. Only real sticking point is potential for
brief drops into MVFR ceilings. Atmospheric column has dried
significantly since 12Z BRO raob measured nearly 1.9" of
precipitable water, with latest GOES-16 estimate only 1.5".
Therefore, still think VFR CIG`s will prevail, except perhaps for
a few hours later tonight at BRO, where the combination of
statistical guidance and RAP BUFKIT forecast soundings suggest
longer-lived MVFR is possible. Gusty SSE winds and VFR cumulus
decks at 030-040 return by mid-late morning on Saturday. Some haze
due to Saharan dust will likely be noted by pilots, but no
visibility restriction is expected.
PREV DISCUSSION... /issued 304 PM CDT Fri Jun 29 2018/
SHORT TERM (Now through Saturday night): Mid-level high pressure
at 500 mb will slowly drift southward across Southeast Texas and
over the lower Texas Coast, keeping us dry and subsident through
the short term period. A surface low in the Northern Plains and
high in the Central Gulf will maintain a tight pressure gradient
and strong S to SSE flow. Low-level jet of around 35 knots will
continue tonight and Saturday with wind gusts reaching 30 to 35
mph at times across the lower RGV. Temperatures this afternoon
range from around 95F across inland Cameron to around 100F in the
Upper Valley. Was worried temperatures might spike this afternoon
with surface winds out of the south and Harlingen even taking a
very slight westerly component. However, the main concern is heat
indices, which are ranging from 105 to 108 and will remain several
degrees below critical thresholds for an advisory. On Saturday,
similar conditions are expected with slightly higher temperatures
as the center of the high nudges a bit closer to the area. Highs
could reach 100F again in the McAllen area with 100 to 104 from
Starr to Zapata county.
LONG TERM (Sunday through Friday):No big changes for the long
term and persistence will rule through at least Tuesday with mid
level ridge in control. Nothing more than hot and rain free with
temperatures at or slightly above normal leading up to the 4th of
July holiday. The atmosphere continues to dry out between
850-400mb as the 500mb ridge splits into two centers one along the
Mid-Atlantic and the other over Texas.
The advertised inverted trough is still depicted by the 12Z model
package to reach the Texas coast early Wednesday morning then
tracking rather quickly over the state Wednesday and Thursday.
ECMWF remains farthest north and fastest and showing a more
compact or concentrated center of vorticity. The GFS on the other
hand is a bit slower and showing a more elongated trough/vorticity
extending into the SW Gulf. Moisture increase starts Wednesday
however better QPF signals and higher model pops are indicated as
the trough passes to the west opening the door for additional
moisture which makes for a lot of uncertainty for a confidence
forecast for the 4th of July. Still with the disturbance/trough
nearby the added lift and moisture conditions should be
sufficient to maintain the low end chance already depicted in the
forecast. As for rainfall amounts WPC keeps the QPF in the
0.1-0.25 inch range with the bulk of the heavier rain chances
remaining well north. As we move into Thursday and Friday the
Center of broad upper ridge is indicated to settle farther north
leaving our CWA and Western Gulf under a deep broad easterly flow
which with the deeper moisture in place should keep at least a
chance of rain in through the end of next week. Temperatures will
continue to be seasonal with slightly higher temperatures Monday
and Tuesday and slightly lower (but not that noticeable) numbers
Wednesday-Friday as the rain and clouds increase. Model guidance
is in good agreement with this scenario.
MARINE:(Now through Saturday night): Adverse marine conditions will
continue this afternoon with strong southerly flow keeping winds
around 20 knots through this evening over the Laguna Madre. Strong
winds will then shift offshore over the Gulf waters and range from
20 to 25 knots overnight with building seas to 4 to 7 feet. A Small
Craft Advisory will go into effect at 7 PM CDT and continue through
7 AM CDT. The pressure gradient will remain strong on Saturday, too,
with additional Small Craft Advisories for the bay waters.
Sunday through Wednesday: Surface ridge over the Eastern gulf
weakens Sunday and Monday with the pressure gradient weakening
through the period as a weak surface high pressure settles over
much of the Gulf. Winds and seas should continue to lower Sunday
with light to moderate wind and slight seas Tuesday through
Wednesday. Weather wise...rain chances are near nil Sunday-
Tuesday with increasing chance of showers and thunderstorms
Tuesday night and Wednesday. If thunderstorms become a bit more
concentrated Wednesday seas could become a bit more agitated.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory for winds until 10 PM CDT this evening for
GMZ130-132-135.
Small Craft Advisory until 7 AM CDT Saturday for GMZ150-155-170-
175.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
53-Schroeder/55
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
949 PM CDT Fri Jun 29 2018
.DISCUSSION...Low cloud satellite imagery indicates the HRRR and
NARRE-TL were correct on the timing of stratocu layer development
this evening around 02Z with broken cloud deck covering most of
the coastal plains. Adjusted winds tonight to be similar to the
SREF which showed slightly higher winds in the near shore waters.
Low level flow will increase to 40 knots overnight over the
inland Coastal Bend to the Brush Country. Expect cloud deck will
continue to advance westward into the Brush Country overnight.
Adjusted minimum temperatures up slightly along the coast. Also
adjusted wind speeds for Saturday to show windy conditions over
the Coastal Bend similar to the MAV MOS.
&&
.MARINE...Made no changes to the current SCA in effect. Adjusted
winds tonight to be similar to the SREF which showed slightly
higher winds in the near shore waters where observations show
winds slightly above 20 knots with gusts to 25 knots.
&&
.PREVIOUS DISCUSSION... /Issued 648 PM CDT Fri Jun 29 2018/
DISCUSSION...See Aviation section for 00Z TAFs.
AVIATION...Scattered to broken cumulus will continue over the
Victoria Crossroads early this evening while hazy/mostly clear
skies will dominate the rest of the region. The low level flow is
expected to increase to 40 knots overnight. Latest HRRR and North
American Rapid Refresh Ensemble Time-Lagged indicate stratus/MVFR
ceilings could form over the inland coastal plains by 02Z. Think
this may be a bit early. Will show possibility of MVFR ceilings at
coastal TAF sites around 05Z and continue until 14Z Saturday
although there will be times when the low clouds scatter out.
Stratus/MVFR ceilings will be possible overnight at LRD also but
not prevailing. Winds are expected to decouple over the inland
coastal plains overnight. Will show possible low level wind shear
at ALI due to 40 knot southerly jet from 10-14Z. Winds will become
gusty from the south by 14Z and increase as they back to
southeast by the afternoon. Expect wind gusts to 30 knots at CRP
in the afternoon. VFR conditions will exist from late morning
through the afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 79 92 77 93 77 / 0 10 10 10 0
Victoria 77 96 76 95 75 / 0 10 10 10 0
Laredo 79 104 78 104 77 / 0 10 0 0 0
Alice 77 99 76 98 75 / 0 10 10 10 0
Rockport 82 91 80 91 80 / 0 10 10 10 10
Cotulla 76 102 76 103 75 / 0 10 0 0 0
Kingsville 79 96 77 97 77 / 0 10 10 10 0
Navy Corpus 82 93 81 92 81 / 0 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory until 7 AM CDT Saturday For the following
zones: Bays and Waterways from Baffin Bay to Port Aransas...
Bays and Waterways from Port Aransas to Port O`Connor...
Coastal waters from Baffin Bay to Port Aransas out 20 NM...
Coastal waters from Port Aransas to Matagorda Ship Channel
out 20 NM...Waters from Baffin Bay to Port Aransas from 20
to 60 NM...Waters from Port Aransas to Matagorda Ship
Channel from 20 to 60 NM.
&&
$$
TMT/89...SHORT TERM
Area Forecast Discussion
National Weather Service Dodge City KS
642 PM CDT Fri Jun 29 2018
.SHORT TERM...(This afternoon through Saturday)
Issued at 1200 PM CDT Fri Jun 29 2018
Another hot and windy afternoon for SW KS. Temperatures again will
top out in the 98-100 degree range, and south winds will again
gust to near 40 mph. Models including the 12z NAM/GFS and HRRR
remain consistent developing scattered thunderstorms along the
convergent trough/dryline axis along the Colorado/Kansas border
during the 5-7 pm timeframe, and then convection subsequently
spreads eastward to the US 283 corridor by 12-2 am. Various models
latch onto a shortwave embedded in the SW flow aloft to generate
the storms, although it remains noted the ECMWF continues to
remain dry for tonight. Kept pops in the chance/scattered category
for now, but if various CAMs and the 12z GFS are correct, pops
will need to be increased to the likely category. Moderate CAPE
and modest wind shear will support mainly multicellular convective
clusters, capable primarily of outflow wind gusts of 60-70 mph.
Midlevel moisture will be healthy, overlaying a deeply mixed
boundary layer (inverted-V profiles). A conference call was
performed to address the damaging wind threat to customers and
partners, emphasizing the wind threat across the western CWA.
Some marginally severe hail is also likely with the strongest
cells, but as cold pools consolidate, strong outflow winds will be
the main concern. Latest HRRR iterations suggest showers and
thunderstorms may survive all the way to the eastern border with
Wichita`s CWA by 3 am Saturday. Otherwise, breezy S/SE winds will
continue tonight outside of convection, with again temperatures
struggling to fall through the 70s.
On Saturday, expected cold front will enter NW Kansas around
midday, ending up near the I-70 corridor around peak heating.
The frontal boundary will intersect the best instability near the
NE zones, where pop grids continue to be favored by afternoon.
This is the area most at risk for surface-based severe
thunderstorm development Saturday afternoon/evening per SPCs
Day 2 outlook, however, much of this large hail/damaging wind
risk may end up largely in Wichita`s CWA. Cold front is progged by
all models to quickly drop through SW KS Saturday evening,
accompanied by an abrupt shift to N/NE winds. 12z GFS, and to a
lesser extent 12z NAM, both suggest elevated instability in the
post-frontal environment Saturday night into Sunday morning, and
at least chance pops are warranted during this time frame.
12z GFS would suggest a fairly widespread 0.25-0.50" of rain is
possible during this timeframe. With north winds and rain-cooled
outflow, temperatures are expected to fall back to the 60s Sunday
morning.
.LONG TERM...(Saturday night through Friday)
Issued at 200 PM CDT Fri Jun 29 2018
After the opportunity for showers and thunderstorms late Saturday
and early Sunday, all indications are SW KS is in for a long
stretch of dry weather for the first week of July.
12z ECMWF continues to forecast a large MCS with heavy rain
across central Kansas Saturday night; some of this will likely
impact at least the NE zones, and its outflow will help propel
the cold front through SW KS through Sunday morning. Temperatures
will be noticeably milder on Sunday, with afternoon highs reduced
to the upper 80s (actually a few degrees below normal). Most
models push the frontal boundary well south of SW KS into the
Texas panhandle at peak heating Sunday; as such, left forecast dry
with only token pops (<15%) late Sunday.
Models including 12z ECMWF suggest high pressure aloft will remain
weak enough (or at least far enough east of SW KS) to allow for
one more chance of showers and thunderstorms in Kansas on Monday.
Any convection that can form late Monday would favor the NE zones
where instability will be greater.
Tuesday through Thursday...Models show 500 mb heights steadily
rising. Large strong anticyclone initially over the NE U.S. on
Tuesday will expand and retrograde westward through the week, such
that by Friday a sprawling 598-600 dm ridge dominates the weather
across the Rockies and the plains. It will be exceptionally
difficult to generate rainfall in this pattern, and all grids past
Monday are dry.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 634 PM CDT Fri Jun 29 2018
VFR will continue to prevail through Saturday, although there will
be some convective concerns. Line of convection developing over SE
Colorado at 22z will progress eastward to the US 283 corridor by
midnight. The HRRR iterations have been consistent with timing,
with strong support from 18z NAM and GFS, so followed the
convective TEMPO timing as seen in the 18z TAFs. Primary risk from
thunderstorms through tonight will be surface outflow wind gusts
of 50-60 kts. Outside of convection, SE winds will continue to
prevail overnight, averaging 15-25 kts. Another low level jet will
create LLWS at all airports starting around 06z Sat. After 15z
Sat, south winds will increase again, averaging 20-30 kts with
higher gusts. The strongest south winds on Saturday are expected
at DDC/HYS. Another chance of thunderstorms is evident near HYS at
the end of this TAF period, and included VCTS/CB for now.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC MMM MMM MMM MMM / MMM MMM MMM MMM
GCK MMM MMM MMM MMM / MMM MMM MMM MMM
EHA MMM MMM MMM MMM / MMM MMM MMM MMM
LBL MMM MMM MMM MMM / MMM MMM MMM MMM
HYS MMM MMM MMM MMM / MMM MMM MMM MMM
P28 MMM MMM MMM MMM / MMM MMM MMM MMM
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...99
Area Forecast Discussion
National Weather Service North Platte NE
658 PM CDT Fri Jun 29 2018
.SYNOPSIS...
Issued at 322 PM CDT Fri Jun 29 2018
Western states upper trough progressing slowly eastward with 50-60m
H5 height falls noted from MT to CO. Lead PV anomaly helped to
produce severe MCS across northern Plains into the upper midwest
overnight and mid and upper level moisture is noted streaming
northward into the High Plains on the western periphery of the
eastern states upper high pressure. At the surface a stationary
front has slowed through the morning hours across northwest NE and
low stratus overtopped by altocumulus, partially generated by
gravity waves in the preferred locations of southwest flow in steep
midlevel lapse rates ahead of the trough, found on the north side of
the surface front. Heat index values climbing through the afternoon
hours in advisory area as well with good insolation and plentiful
low level moisture in parts of north central NE. Pesky low clouds
have hindered temps in the north central part of the state.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 322 PM CDT Fri Jun 29 2018
Two areas of concern for the evening hours for thunderstorm
development. The first, a surface trough that lies across the
Sandhills into southwest NE and visible on radar adjoins a dryline
that stretched southwest into western KS. GOES satellite data
showing CU/TCU forming along this boundary in eastern CO. As upper
trough moves east would expect a response of increasing southerly
winds across western KS which should promote additional
convergence along that boundary and additional convective
development. Various CAMS also suggest that scenario although the
onset in the HRRR, for example, seems delayed an hour or two from
what would likely happen. The deep layer shear across southwest NE
is not outstanding and wouldn`t be surprised to see the first few
TCU to succumb to dry air entrainment. However if the forcing
remains across the area do believe additional development will
occur along a line from just east of IML to BBW on an isolated
basis. Further north, shear is better due to the closer proximity
to the upper PV anomaly which will also promote better forcing
along a southward moving cold front later this evening. These
areas will be favored through the evening hours with additional
development possible along any of the outflow boundaries generated
as suggested by both HRRR models as well as HREF and HRRRE.
Next PV anomaly rotating through the upper trough will likely
generate additional thunderstorm development Saturday as well,
although if frontal boundary gets pushed far enough south and east
the favored areas of convection in the post-frontal environment
would be in the eastern most areas as well as likely south and west
of the forecast area. With the uncertainty that exists will include
mainly low end chances for storms across most of the area.
High temps Saturday will be heavily influenced by residual cloud
cover associated with thunderstorms and should stay well below
seasonal averages.
.LONG TERM...(Saturday night through Friday)
Issued at 322 PM CDT Fri Jun 29 2018
Upper trough axis exits the state during the day Sunday. As it
pushes eastward it will run up against the mid atlantic upper
ridge which will hold strong and force the upper PV anomaly
northeastward leaving the ridge axis in place. As the upper low
moves into southeast Canada the upper flow turns primarily zonal
through Monday. The main jet axis drifts northward as another
upper low moves into the Pacific NW by mid week. As the mid
Atlantic ridge retrogrades westward and becomes situated over the
central and southern Plains by the end of the week the upper low
over the northwest will transition northeastward into southern
Canada by late in the week. The end result looks to be a stalled
frontal boundary across the state by late Thursday with any
further southward progression limited by the strengthening upper
ridge over the Plains. This will bring a chance for showers and
storms across the area in the latter portion of the period.
Temperatures through the period will start near seasonal on Sunday
and warm into the 90s most places by mid week. Despite the upper
ridge building across the area by week`s end, temps will be hindered
by possible thunderstorms and associated cloud cover, cooling
back toward more seasonal values.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 600 PM CDT Fri Jun 29 2018
Low-end VFR ceilings (less than 7 kft) exist across parts of
northern NEB, otherwise VFR conditions currently prevail area-
wide. Scattered strong to severe thunderstorms are anticipated
across portions of the eastern Panhandle east across northern NEB
and parts of the Sandhills this evening and overnight. Severe
storms will be capable of large hail and damaging winds up to 70
mph. Otherwise, isolated thunderstorms are possible across
southwest NEB tonight, albeit with lower confidence. Flight
categories are expected to deteriorate across much of western NEB
beginning late tonight-early tomorrow with ceilings lowering to
MVFR to low-end VFR. Cloudy skies persist tomorrow Meanwhile,
chances for showers and thunderstorms continue tomorrow across
much of western and north central NEB.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM CDT this evening for NEZ007-010-028-029-
038-071.
&&
$$
SYNOPSIS...Stoppkotte
SHORT TERM...Stoppkotte
LONG TERM...Stoppkotte
AVIATION...ET
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
928 PM CDT Fri Jun 29 2018
.UPDATE...
928 PM CDT
No real changes planned to going forecast. Chicago Midway`s heat
index is still sitting at 104 after 9 pm. It is this nighttime
heat that doesn`t allow the body to recover from the stress from
the intense daytime heat that poses the most significant danger
during heat waves. It looks as though the heart of the city of
Chicago will see heat indices at or above 100 until around
midnight and probably won`t drop below 90 all night. Anyone
without access to a/c in the city should consider spending time in
air conditioning at times this weekend to lessen the risk from
this heat wave.
- Izzi
&&
.SHORT TERM...
237 PM CDT
Tonight through Sunday...
Dangerous heat and humidity are the primary forecast focus
through Saturday. Eastward drift of upper ridge axis, and an
increasing thunderstorm threat, will help limit the magnitude of
heat by Sunday. Some strong to severe storms are possible Sunday
afternoon, with wind/locally heavy rainfall potential.
Early afternoon surface analysis places low pressure across
eastern South Dakota, with a warm front extending eastward across
Wisconsin and Lake Michigan. Beneath a building upper level ridge,
with 500 mb heights approaching 5930 meters in recent RAP
analysis, a hot and very humid low level air mass had spread
across the region. Under full sunshine, temperatures have warmed
into the low-mid 90s area wide, with heat indices approaching the
105-110 range in most spots. Warmest heat index values will top
out in the 110-115 degree range during the warmest part of the
late afternoon hours. Little change in conditions is expected into
Saturday, with a repeat of today`s oppressively hot and humid
weather expected. Even after sunset, temps will remain in the 80s
(mid-upper 80s in the core of the Chicago urban heat island)
through the evening, offering little relief into the overnight
hours. Excessive Heat Warning remains in effect through Saturday,
with no changes. Forecast soundings maintain a capping inversion
around 800 mb Saturday afternoon, which despite large CAPE should
prevent convective development with little organized convergent
focus to break the cap.
Upper ridge slowly pulls away to the east through the weekend, as
a broad upper trough translates across the Plains and into the
Upper Mississippi Valley. Associated surface low pressure is
progged to lift from the northern Lakes into Ontario through
Sunday, with a trailing cold front approaching the forecast area
from the northwest during the afternoon hours. Thunderstorms
should be ongoing along and ahead of this front to our west
Saturday night, with indication that storms could work into the
forecast area after midnight, propagating ahead of the front on an
outflow boundary. These storms would likely be in a weakening
mode heading into Sunday morning as they move into a more strongly
capped environment. While some uncertainty exists as to effect of
morning convective debris and cloudiness on later
destabilization, the potential exists for moderate to strongly
unstable condition ahead of the cold front Sunday afternoon. Thus
redevelopment of storms is expected, with some strong to severe
storms possible given 2500-3500 J/kg MLCAPE potential and deep
unidirectional shear of 30-40 kts. Area remains in SPC day 3
marginal severe outlook. Locally heavy rainfall may be an issue as
well, with very warm/moist profiles sporting PW`s approaching
2.00 inches. Lowering heights, potential for more cloud cover
and/or convective outflow, all support temperatures not quite as
warm as today and Saturday, though low 90s are not out of the
question especially east/southeast. Current forecast heat indices
range from the upper 90s to the 100-105F range, below warning
criteria.
Ratzer
&&
.LONG TERM...
Sunday night through Friday...
206 pm...Primary forecast concern is an extended period of very
warm/hot and humid conditions next week.
The cold front will continue moving southeast across the area
Sunday night into Monday morning with showers/storms ending from
northwest to southeast. The front begins to slow as it reaches the
southern cwa and there is a potential for precipitation to linger
into Monday across the far southern cwa. A ridge of high pressure
will build across the rest of the area on Monday with a lake
breeze expected in the afternoon. Temps/dewpoints expected to be
slightly cooler on Monday but could still see temps upper 80s/near
90 away from the lake.
By Tuesday...dewpoints are back in the 70s across the entire area
which look to remain in place until a stronger cold front arrives
next Friday. Until then thermal profiles support temps around 90
or in the lower 90s and with dewpoints in the 70s...heat index
values are likely to remain in the upper 90s/around 100. Though
the weaker gradient may allow lake breezes to form...especially
along the IL shore with cooler temps possible there.
There will also be at least a slight chance of showers/storms
Tuesday through Thursday. Too difficult to try to pin down which
time periods might be more favored but this activity will likely
be isolated. If more widespread precip developed that could keep
expected highs a bit lower. The best chance of precip next week
will likely be with the stronger cold front next Friday. cms
&&
.CLIMATE...
Record Temps
For the Chicago area...
Record High Max Temp
June 29: 97F (1954)
June 30: 99F (1913, 1953)
Record High Min Temp
June 29: 80F (1931)
June 30: 80F (1931)
For the Rockford area...
Record High Max Temp
June 29: 103F (1931)
June 30: 102F (1931)
Record High Min Temp
June 29: 75F (1931)
June 30: 74F (1913, 1931)
&&
.AVIATION...
For the 00Z TAFs...
No significant weather through the TAF cycle.
- Izzi
&&
.MARINE...
206 pm...A cold front over the northern and central Plains will
slowly move southeast through this weekend...as a series of low
pressures move along the front. This cold front is expected to
move across Lake Michigan Sunday evening. Southerly winds will
continue until this front arrives with 15-25kts expected. Winds
will shift west/northwest behind the front. A weak area of High
pressure will move across the region early next week with winds
turning back to light southerly.
As more humid air spreads across the cooler waters of the
lake...some fog is possible tonight through Sunday morning but
confidence is low for how widespread and how dense any fog may
become. The best chance of dense fog would likely be across the
northern portion of Lake Michigan later tonight through Saturday
night. cms
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Excessive Heat Warning...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 until 7 PM Saturday.
IN...Excessive Heat Warning...INZ001-INZ002-INZ010-INZ011-INZ019
until 7 PM Saturday.
LM...None.
&&
$$
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Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
705 PM CDT Fri Jun 29 2018
.SHORT TERM...(This evening through Saturday)
Issued at 340 PM CDT Fri Jun 29 2018
Surface analysis this afternoon shows a low pressure center over
northwest MN with a trailing cold front extending SSW into central
Nebraska and a leading warm front extending ENE through the
Arrowhead into Lake Superior. Aloft, a NW-SE oriented ridge axis
emanating from a large dome of high pressure over the southeastern
CONUS is slowly shifting off to the E. This deep ridge combined
with warm sectoring of the surface system has allowed across the
WFO MPX coverage area to soar into the low-mid 90s with dewpoints
in the mid-70s, easily creating heat index values of 100-110
degrees. Little in the way of relief will come through this
evening due to strong capping in place but there is at least
modest expectation that the atmosphere will recover in terms of
instability from the overnight to early morning activity up north
while capping influences wane to produce isolated to scattered
showers and thunderstorms in mainly western-central MN overnight
through daybreak Saturday. This activity is still highly
conditional due to a warm EML (roughly +15C at H7) but a strong
H925-H850 jet in advance of the progressing cold front may still
ably provide forcing within a still unstable environment to create
at least elevated convection. Any nocturnal activity looks to time
itself away from the area by daybreak Saturday morning, allowing
the atmosphere to restock itself with instability once again while
the cold front is more actively crossing the area. The front looks
to push into western portions of the coverage area around daybreak
then reach the MN/WI border late afternoon Saturday. More robust
convection is then expected for Saturday, mainly south and east of
the TC metro, with clusters of storms potentially organizing into
an MCS for western WI and southern MN. Less capping, stronger
lapse rates and better dynamics look to mesh to bring more storms
capable of large hail and damaging winds late Saturday afternoon
through Saturday evening.
.LONG TERM...(Saturday night through Friday)
Issued at 340 PM CDT Fri Jun 29 2018
Saturday Night-Sunday...The pattern of a large dome of high
pressure in the southeast with a trough in the southwest, keeping
southwest flow aloft our region, will promote additional
shower/t-storm development over the WFO MPX coverage area through
Sunday, but mainly for the southeastern portions of the area. The
main issue becomes more of a heavy rain hazard rather than severe
storms due to PWATs increasing to near 2" in far southern/eastern
portions of the area with storms near the front and the
progression of the front slowing with upper level support waning.
Training of storms, decent storm coverage and slow moving storms
all add up to at least an isolated flooding hazard for areas which
have already received plenty of rain and have multiple sites of
river flooding. The bulk of the rain looks to come Saturday
evening with gradually improving conditions through the day on
Sunday behind the cold front. Humidity levels will be much less
while highs on Sunday will only hit the upper 70s to around 80
degrees.
Monday-Friday...A more zonal pattern aloft will prevail to start
the week, resulting in lesser chances for precipitation with drier
air in place and little upper level support along with no nearby
surface frontal systems. Chances increase a bit Tuesday as a pre-
frontal wave in advance of a warm front to the southwest
approaches the region but not looking for anything significant. A
more organized storm system looks to slowly move through the area
Wednesday-Thursday which may bring better coverage of
showers/t-storms but prospects for any severe weather remain
rather low. There will be a small temperature swing with this
midweek system, nudging temperatures closer to 90 for Wednesday-
Thursday in its warm sector before highs drop back to the lower
80s on Friday as the system exits the area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 704 PM CDT Fri Jun 29 2018
Cold front starts out from roughly AXN to INL. Capping has
remained strong ahead of the front and cu field on VIS satellite
certainly indicates breaking of the cap is NOT imminent. The
RAP/HRRR continue to show the cap finally breaking around 3/4z out
in west central MN, but confidence is low on that happening.
However, there are enough models showing this happening with TSRA
near AXN to include a VCTS there. This front will be washing out
over eastern MN Saturday and we will maintain a very unstable
environment with less CIN. However, there`s very little forcing
noted in terms of shortwaves or frontal convergence, so confidence
on when/where storms will fire Saturday afternoon is low, though
threat for storms Saturday afternoon/evening looks much better
than what we are seeing today. Better forcing for more widespread
TSRA activity does not show up until late Saturday night as the
wave currently entering Idaho works into southern MN.
KMSP...Low confidence on wind direction forecast Saturday
afternoon with the front in the process of washing out overhead.
Could see directions anywhere from the south to the northwest.
For TSRA chances, there is a very small chance MSP could see some
activity between 8z and 12z, though confidence is to low in what
the HRRR is showing to include any precip mention then at this
point. Otherwise TSRA chances will increase after 20z as the atmo
destabilizes and forecast soundings show the cap eroding away.
/OUTLOOK FOR KMSP/
Sun...VFR. Chc TSRA in mrng. Wind WNW 5-10kt.
Mon...VFR. Chc TSRA overnight. Wind SW 10-15 kt.
Tue...VFR. Chc TSRA. Wind SSE 10-15 kt.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...Excessive Heat Warning until 10 PM CDT this evening for
WIZ014>016-023>028.
MN...Excessive Heat Warning until 10 PM CDT this evening for MNZ044-
045-049>053-057>063-065>070-073>078-082>085-091>093.
Heat Advisory until 10 PM CDT this evening for MNZ041>043-047-
048-054>056-064.
&&
$$
SHORT TERM...JPC
LONG TERM...JPC
AVIATION...MPG
Area Forecast Discussion
National Weather Service Tallahassee FL
955 PM EDT Fri Jun 29 2018
.UPDATE...
Aside from some PoP adjustments to the early evening period, the
forecast for tonight remains on track.
&&
.PREV DISCUSSION [742 PM EDT]...
.NEAR TERM [Through Tonight]...
Some convective inhibition remains across the area with the
exception of the eastern FL Big Bend. The seabreeze is developing
across the Big Bend per satellite with some convection developing
across Dixie/Taylor counties where MLCAPE is 1000-2000 J/kg. HRRR
has a decent handle on this development and depicts continued
development this afternoon and evening across the eastern half of
the area with continued destabilization. Increased PoPs to likely
this evening over the FL Big Bend and adjacent counties of SW
Georgia as the storms develop and move further inland. Storms will
decrease late in the evening as instability decreases and inhibition
increases. Skies will be mostly cloudy overnight with lows in the
mid 70s.
.SHORT TERM [Saturday Through Sunday Night]...
Numerous showers and thunderstorms are expected Saturday and Sunday,
especially in the afternoon and evening hours. A weak low will
develop along the northeastern Gulf coast tonight and slowly
drift westward this weekend. This, along with our seabreeze
circulation, will serve as a forcing mechanism for storms. PW
values will rise above 2 inches across the area by Saturday
evening, which will help storms to produce heavy rainfall.
Widespread accumulations will be around 1 to 3 inches, but
isolated areas will see closer to 3 to 6 inches. Daytime MLCAPE
will be around 1500-2000 J/kg, so some of the thunderstorms this
weekend could produce damaging wind gusts. Highs will be in the
upper 80s to low 90s and lows will be in the mid 70s.
.LONG TERM [Monday Through Friday]...
The potential for heavy rainfall will persist Monday, at least for
the western half of the area, as the low continues to drift
westward. By Tuesday, the low will be far enough west to no longer
enhance our sea-breeze circulation. PoPs will return to normal 40-
50% chances each afternoon and evening. Highs will stay in the upper
80s to low 90s and lows will be in the low to mid 70s.
.AVIATION [Through 00Z Sunday]...
VFR conditions will prevail through much of the night. Closer to
dawn, MVFR/IFR restrictions in ceilings and visibilities will be
possible from ABY to TLH and eastward. The most pessimistic TAF
is furthest east at VLD. Restrictions should clear by around 14z
with a much greater coverage of showers and storms tomorrow
afternoon.
.MARINE...
Light westerly winds will become southerly tomorrow. Seas will be
low through the weekend at 1 to 2 feet. Showers and thunderstorms
this weekend will cause isolated higher winds and seas.
.FIRE WEATHER...
Hazardous fire weather conditions are not expected over the
next few days.
.HYDROLOGY...
A wet pattern is expected Saturday through Monday evening.
Widespread accumulations will be around 1 to 3 inches, with most of
that falling this weekend. Isolated areas will see closer to 3 to 6
inches. These higher totals will be more likely in our western
zones. Area rivers remain at normal levels and are not forecast to
rise above flood stage at this time. Ponding of water on roadways
and flooding of low lying areas is likely with heavier downpours.
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 74 90 74 87 74 / 30 70 40 80 30
Panama City 76 90 77 86 77 / 30 70 40 80 70
Dothan 74 91 73 87 72 / 10 70 40 70 50
Albany 74 91 74 88 74 / 20 60 40 70 30
Valdosta 73 90 73 89 72 / 20 70 40 70 20
Cross City 74 88 74 87 73 / 40 60 50 70 20
Apalachicola 77 89 77 85 78 / 30 60 50 70 50
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...Harrigan
NEAR TERM...Scholl
SHORT TERM...Nguyen
LONG TERM...Nguyen
AVIATION...Harrigan
MARINE...Nguyen
FIRE WEATHER...Harrigan
HYDROLOGY...Nguyen