Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/27/18
remains on track and the previous forecast discussion and an
updated aviation discussion are below. STP
&&
.SHORT TERM...valid for Fri and Sat...
Scattered showers and thunderstorms are ongoing over southern MT
and northern WY this afternoon. These showers and thunderstorms
should move southeastward for the rest of this afternoon and
evening thanks to strong northwesterly flow aloft. Over south
central MT and north central WY, RAP guidance shows 0-6 km bulk
shear values of 40 to 50 knots and NUCAPS soundings from earlier
this afternoon showed a few pockets of appreciable instability
under mostly sunny skies. These ingredients support a few strong
to severe thunderstorms over those same areas through this
evening.
Upper-air disturbances will continue to move over the region
tonight through Saturday, bringing additional periods of showers
and thunderstorms. There is a low risk of a strong to severe
thunderstorm Friday afternoon-evening over far southeastern
Montana and Sheridan County...but cloud cover from morning
convection could limit convective development in the afternoon.
However, if skies can clear during the day Friday, sufficient
shear would be in place to produce strong thunderstorms.
High temperatures on Friday and Saturday will be below normal,
generally in the middle 70s to near 80 degrees. RMS/borsum
.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...
Transition in the extended period as heights begin to build
bringing a period of much warmer weather. Sunday through Wednesday
a ridge of high pressure dominates bringing mainly dry weather and
temperatures in the 90s. Normally this time of year humidity in
the teens would be expected but with still green vegetation in
many areas and a prevailing easterly surface flow this could keep
humidities from falling below 20 percent.
Ridge breaks down on Thursday but the time of this breakdown has
been slipping consistently each run so the heat spell may last
longer than currently depicted. The front breaking down the ridge
could bring a round of thunderstorms Thursday. A consistent
period of lower heights follows for Friday into Saturday as a weak
wave moves through the area for of cooler temperatures and a
chance for thunderstorms. borsum
&&
.AVIATION...
Isolated to scattered showers and thunderstorms will continue
overnight into Friday across portions of the area. In general,
VFR will prevail with MVFR possible under the heaviest
shower/thunderstorm activity. Mountains may occasionally be
obscured. STP
&&
.PRELIMINARY POINT TEMP/POPS...
Fri Sat Sun Mon Tue Wed Thu
-----------------------------------------------------------
BIL 057/077 056/078 056/084 057/091 061/094 063/090 059/084
34/T 43/T 21/U 00/U 01/U 11/U 11/U
LVM 050/078 048/077 047/080 048/088 053/089 054/085 051/080
33/T 43/T 21/U 00/U 11/U 11/U 10/U
HDN 056/080 054/081 055/083 054/091 059/094 062/090 059/085
44/T 43/T 22/T 00/U 01/U 11/U 11/U
MLS 057/078 054/080 056/081 056/088 060/093 064/090 060/083
34/T 42/T 22/T 00/U 00/U 01/B 11/U
4BQ 055/079 054/079 055/079 055/087 059/092 064/092 061/085
44/T 43/T 23/T 00/U 00/U 01/U 11/U
BHK 053/075 051/076 052/079 054/086 057/090 061/088 057/081
13/T 32/T 22/T 01/U 00/U 01/B 11/B
SHR 054/078 051/077 051/079 049/086 055/091 058/088 055/083
45/T 45/T 23/T 00/U 11/U 11/U 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Cheyenne WY
420 PM MDT Thu Jul 26 2018
.SHORT TERM...(This evening through Friday)
Issued at 300 PM MDT Thu Jul 26 2018
Severe weather ongoing across southeast Wyoming as we get an early
start today. Forecast challenges deal with severe convection and
possibility of heavy rain both today and Friday.
Currently...Water vapor imagery showing an upper level shortwave
tracking into the CWFA that has kicked off convection. SPC
Mesoanalysis page showing an uncapped environment with surface
based CAPE around 2000-2500J/KG already this afternoon at 2PM.
Bulk shear around 40-45kts as well. Both CAPE and shear are
expected to continue increasing through the rest of the afternoon.
CAPE expected to peak out around 3000-3500 J/KG at 6PM and bulk
shear increases to 50-55kts. Large hail, damaging winds and a few
tornadoes can not be ruled out. PWATs in excess of 1 inch continue
across our eastern counties through the afternoon, so existing
Flash Flood Watch will remain in effect. HRRR continues to show
pretty strong cells across the area through roughly 03Z before
beginning to ease.
Forecast still on track for severe weather Friday as another
shortwave tracks into the Nebraska Panhandle. ECMWF continues to
show the best area for severe storms Friday to be over the
Panhandle where SPC has an Enhanced Risk for severe storms. Heavy
rainfall expected out there Friday, so later shifts will need to
consider another Flash Flood Watch once again.
.LONG TERM...(Friday night through Thursday)
Issued at 307 AM MDT Thu Jul 26 2018
The wet and unsettled conditions will remain over the area
Saturday through Sunday with a pretty good push of cool air for
late July arriving Sunday. Scattered to numerous showers and
storms will continue both days. Drying should then ensue late
Sunday in the wake of a stronger shortwave that will move south
from the northern plains and cut off the monsoonal moisture for a
time. Monday through Weds should see warming temperatures back to
near seasonal averages along with mainly dry conditions under a
persistent northwesterly flow aloft.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 417 PM MDT Thu Jul 26 2018
Round #2 of thunderstorms beginning to develop along the Laramie
Range late this afternoon. Using latest HRRR guidance shows the
storms impacting KCYS and Nebraska Panhandle airports through the
03-04Z timeframe. Could see stratus redevelop tonight for those
airfields that receive heavy rainfall this evening. More
widespread showers and thunderstorms expected for the Panhandle
airports Friday afternoon.
&&
.FIRE WEATHER...
Issued at 300 PM MDT Thu Jul 26 2018
Minimal fire weather concerns over the next few days as monsoon
moisture remains in place. Widespread wetting rains expected with
well above critical humidity in the afternoon. Expect showers and
thunderstorms to continue through Sunday, before drying commences
next week. Until then, fire weather threats will remain low.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Flash Flood Watch until 10 PM MDT this evening for WYZ108-118-
119.
NE...Flash Flood Watch until 10 PM MDT this evening for NEZ003-
019>021-054-055-096.
&&
$$
SHORT TERM...GCC
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
304 PM MDT Thu Jul 26 2018
.SYNOPSIS...
A weak backdoor cold front located just west of the Rio Grande
will help increase moisture over the area, leading to scattered
thunderstorms this evening over much of the desert lowlands,
especially east of El Paso. Another preferred area for
thunderstorms this evening will be in southern Grant, Luna, and
western Dona Ana Counties. A few showers and thunderstorms will
linger after midnight across the region. Thunderstorm chances
will begin to wane again Friday and Saturday, with the focus
shifting to the Gila Region and the lowlands closer to the
Arizona border. Another backdoor front will enhance precipitation
chances Monday afternoon and through at least the middle of the
week.
&&
.DISCUSSION...
Backdoor cold front, or at least the wind shift preceding it, has
pushed just west of the Rio Grande (roughly). RAP analysis shows
CAPE values of 2000-3000 J/Kg behind the front, though this is
likely overdone, with weakening CIN. Modifying the 12Z RAOB for
current surface conditions yields SBCAPE of 1035 J/Kg, with a
capping inversion around 600 mb (CIN of just -2), assuming no
mid-level warming or cooling since 12Z.
Cu is still mostly flat in the lowlands, though it is expanding
in coverage east of the Franklins. Will keep the afternoon/evening
PoPs unchanged, and suspect storms will fire in Eastern EP County
as outflow from Hudspeth County moves west.
Some isolated stronger storms have produced impressive rain rates
in parts of the Gila, with a recent spotter call from Pinos Altos
reporting 0.40" of rain in ten minutes, mixed with pea-sized hail.
These storms have been on a weakening trend, but additional storms
will likely pulse up-and-down through the remainder of the
afternoon. Instability is much weaker in SW New Mexico, with CAPEs
generally around 400-600 J/Kg per the RAP, and a little higher
over the Bootheel. Conditions should modify some as the front
tries to push west towards the divide this afternoon/evening, and
we`ll have to watch for outflow interactions this evening in the
southern Grant/Luna/Western Dona Ana County area. By early
evening, I expect the backdoor front will be pretty well ill-
defined with not enough convergence itself to initiate convection
unless or until it is enhanced by outflow coming in from the east.
Locally heavy rainfall will continue to be the main concern with
these storms, with a secondary risk of strong wind gusts (50-60
mph) in a few storms as they develop or move into the lowland
deserts.
Expect at least isolated showers/thunderstorms lingering after
midnight given the northerly flow continuing like the past few
nights, and weak upstream disturbances dropping in.
For tomorrow, some low-level drier air tries to work in from the
SE (an unusual direction for drying). This, coupled with warming
aloft will limit instability east of the Rio Grande. The best
chance for thunderstorms will be in the Gila Region in the
afternoon, dropping south to southwest towards the Bootheel in
the evening. Scattered thunderstorms also are a good bet in the
Sacramento Mountains, but they will struggle to work into the
lowland deserts.
Saturday looks much like Sunday, except with the stable air
continuing to work westward, and slight veering in the steering
winds shifting the risk of lowland storms in SW New Mexico a
little closer to the Arizona line. Coverage over the Sacramentos
looks to become limited as well.
For the longer range, GFS, its ensembles, and the ECMWF are in
good agreement on the overall pattern, keeping the subtropical
ridge stuck over the Lower Colorado basin with continued troughing
over the Mississippi Valley. New Mexico and Far West Texas will
stay in a northerly flow aloft. This will invite another backdoor
front to push into the area Monday afternoon or evening,
increasing precip chances through at least the first half of next
week.
&&
.AVIATION...
Valid 27/00Z-28/00Z...
Scattered to numerous 1-3SM TSRA BKN030-050 expected across the
area to start the period under prevailing SCT-BKN080-100 BKN120-150.
Activity should generally move south of border by 06Z with just some
light rain showers and isolated thunder possible through overnight.
After 12Z expect SCT080-100 SCT-BKN200-250 for remainder of period
with scattered 3-5SM -TSRA BKN040-060 mountains and isolated over
the lowlands. Winds mainly E to SE AOB 12KTS except near
thunderstorms where gusts to 40KTS possible.
&&
.FIRE WEATHER...
This afternoon and evening looks to be the most active one until at
least Monday. Plenty of moisture has moved into the area and a weak
frontal boundary is moving westward across the Borderland this
afternoon/evening. Greatest activity will occur over area mountains
with locally heavy rain and flooding possible. Drier more stable air
will be entering in for Friday into the weekend with any activity
mainly confined to area mountains and locations near the Arizona
border. Moisture surge comes back Monday with more widespread
thunderstorm activity expected through midweek. Temperatures will
remain near to slightly above average with winds light except near
thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 74 95 73 97 / 20 0 10 0
Sierra Blanca 68 92 69 94 / 20 0 0 0
Las Cruces 71 93 68 95 / 50 10 10 0
Alamogordo 69 91 70 94 / 30 20 20 0
Cloudcroft 53 70 54 73 / 30 60 30 20
Truth or Consequences 70 89 69 94 / 60 10 30 10
Silver City 65 85 63 87 / 50 50 50 40
Deming 70 92 68 95 / 60 20 30 10
Lordsburg 71 92 69 94 / 50 20 50 20
West El Paso Metro 73 93 73 96 / 30 0 10 0
Dell City 70 96 70 97 / 20 0 0 0
Fort Hancock 71 96 72 98 / 20 0 0 0
Loma Linda 68 91 68 93 / 20 0 10 0
Fabens 70 95 71 97 / 20 0 10 0
Santa Teresa 71 94 71 95 / 30 0 10 0
White Sands HQ 71 92 70 95 / 30 0 10 0
Jornada Range 69 92 68 95 / 40 10 20 0
Hatch 70 93 69 96 / 60 10 20 0
Columbus 73 94 71 96 / 60 10 20 10
Orogrande 71 93 71 95 / 30 0 10 0
Mayhill 57 78 58 82 / 30 50 20 20
Mescalero 58 78 58 82 / 30 60 40 20
Timberon 58 78 58 81 / 30 30 10 10
Winston 60 83 59 87 / 60 40 60 30
Hillsboro 66 89 65 91 / 60 30 30 20
Spaceport 68 91 68 94 / 40 10 20 0
Lake Roberts 58 83 57 86 / 50 60 50 50
Hurley 65 86 64 88 / 50 40 40 30
Cliff 63 90 63 92 / 40 60 50 30
Mule Creek 65 91 64 90 / 30 50 60 40
Faywood 67 88 65 89 / 60 20 30 20
Animas 71 93 69 94 / 50 20 50 20
Hachita 70 93 68 94 / 60 20 30 20
Antelope Wells 69 92 68 92 / 40 30 50 30
Cloverdale 66 89 65 88 / 40 30 60 30
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
25-Hardiman / 26-Grzywacz
Area Forecast Discussion
National Weather Service Goodland KS
528 PM MDT Thu Jul 26 2018
.SHORT TERM...(This evening through Friday)
Issued at 234 PM MDT Thu Jul 26 2018
Northwest flow continues over the High Plains over a broad, but
weak, southeasterly low level flow. The directional shear is
resulting in rather large deep layer shear values of 50kts this
afternoon, which combined with weak to moderate instability has
resulted in an environment favorable for rotating updrafts.
Moisture is also plentiful, with precipitable water values of
1-1.5 inches and surface dew points in the 60s. Perhaps the one
lacking ingredient for more widespread convection is lift, with
only the hint of shortwave trough embedded in the northwest flow.
There is the tail end of an old front/outflow boundary located
north to south in northwest Colorado which may be a focus for
convection. Expect storms to continue to increase in coverage this
afternoon and evening as the upper shortwave moves across. HRRR
continues to suggest an MCS/thunderstorm cluster moving south out
of Nebraska and along the Colorado/Kansas border area late tonight
and during the overnight, possible posing a damaging wind gust
threat in those areas. Storm motions are rather fast at around
15kt and any right movers at 20-30kts, so despite the high
moisture not anticipating a flash flood threat tonight. As has
been the case the last few mornings, patchy dense fog will develop
overnight and persist into early Friday morning before
dissipating.
Not much changes for the general set up on Friday afternoon.
Another weak shortwave trough comes through in the northwest flow,
with impressive deep layer shear and even more instability than
today. Scattered afternoon storms will develop, some severe, with
large hail and damaging winds the main threats. Better chances
will occur Friday evening with SPC upgrading to an enhanced risk
(see Long Term section). High temperatures on Friday will be in
the lower 80s.
.LONG TERM...(Friday night through Thursday)
Issued at 151 PM MDT Thu Jul 26 2018
At the start of the long term, an upper high continues over the
desert southwest with troughing and an upper low pressure system
extending from southeastern Canada into the eastern CONUS. Between
these two features, fast northwest flow aloft is expected over
the tri-state region.
Friday evening and overnight appears to be an interesting period. A
weak shortwave passing through the northwest flow and a surface
boundary coming down from Nebraska will aid in the development of
thunderstorms. With near 2500 J/kg of CAPE, ample shear of 50 knots
or greater, steep lapse rates and good moisture in place, severe
thunderstorms are expected. Exact locations are still in question.
However, it appears that storms should fire over higher terrain west-
northwest of the CWA during the afternoon hours, with shear
supporting supercell development. Heading into the evening and
overnight, storms should congeal into a line, traveling
southeastward across the region. The main threats will be damaging
winds and large hail. Guidance including PWATS of 1 to 2 inches
suggest that heavy rainfall will be a concern as well.
A similar pattern remains in place through the weekend and unsettled
weather is anticipated to continue. Additional disturbances will
pass through the northwest flow (including a strong shortwave late
Sunday), generating storm chances through Monday morning. Severe
storms cannot be ruled out on Saturday and Sunday depending on how
well the lower levels recover from the previous day`s convection.
Will continue to monitor in the coming days. Drier air and
surface high pressure move into the area on Monday, resulting in a
dry forecast through Thursday.
High temperatures decrease from the 80s on Saturday to the mid 70s
to low 80s on Sunday and Monday. Temperatures increase thereafter,
reaching the low 90s on Thursday. Low temperatures range from the
mid 50s to mid 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 519 PM MDT Thu Jul 26 2018
Thunderstorm complexes will be affecting both Kgld and Kmck in the
first few hours of the period. Mvfr conditions with occasional ifr
conditions can be expected with variable wind gusts to around 45
knots. After that both sites will have vcts to account for
continued thunderstorm activity. Kmck should see activity through
the evening. However, thunderstorms could be near Kgld until 11z.
Outside of thunderstorms, the winds will be variable in direction
from the south to southeast at 5 to 15 mph.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...024
LONG TERM...JBH
AVIATION...BULLER
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
430 PM PDT Thu Jul 26 2018
.UPDATE...Updated air quality issues section.
&&
.SYNOPSIS...
A ridge of high pressure will persist for the next several days.
Excessive heat continues through the end of the week. A bit
cooler starting this weekend but temperatures remaining above
normal.
&&
.DISCUSSION...
Thunderstorms formed earlier today over the high sierra.
Storms activity more widespread due to an increase in mid to
upper level moisture coming off pacific on a SSW flow. Thus far
smoke from the Ferguson fire remains limited towards the Mariposa
area. Smoke starting to move northward this afternoon. HRRR
model progs smoke coming down the foothills and east side of the
valley tonight as the night time inversion sets up. Little change
in the short term with a ridge centered over the Colorado river
persisting and keeping excessive heat across the central CA
interior into the weekend. The ridge shifts a bit inland Saturday
so not as hot on Saturday with temperatures bit cooler in the San
Joaquin Valley. However guidance shows excessive heat conditions
continuing across the Mojave desert area into the weekend. Hence
the heat warming for E Kern County has been extended through
Saturday.
The ridge of high pressure has been keeping us several degrees
above average for weeks now, and it look like it will remain
anchored over the area and not let up very much any time soon.
Some moisture from Mexico will move around the south and west
side of the ridge early next week and bring a threat of convective
storms mainly over sierra mountains.
&&
.AVIATION...
Areas of MVFR visibility in smoke will continue in the vicinity of
the Ferguson Fire in Mariposa County for at least the next 24 hours.
Isolated thunderstorms will be possible near the southern Sierra
crest through 04Z Fri. Otherwise, VFR conditions will prevail over
the central CA interior during the next 24 hours.
&&
.AIR QUALITY ISSUES...
SFOAQAHNX for an Air Quality Alerts
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
Heat Advisory until 9 PM PDT Friday CAZ089>095.
Excessive Heat Warning until 8 PM PDT Saturday CAZ098-099.
&&
$$
public...MV
avn/fw...JEB
synopsis...MV
weather.gov/hanford
Area Forecast Discussion
National Weather Service Northern Indiana
812 PM EDT Thu Jul 26 2018
.SYNOPSIS...
Issued at 649 PM EDT Thu Jul 26 2018
Cooler and less humid air will spread across the region tonight
and last into the weekend. A few clouds will form along and south
of Lake Michigan during the day Friday, however no precipiation
is expected. Lows tonight will drop into the upper 50s to around
60. Cooler and less humid conditions can be expected for Friday
with highs only reaching into the mid 70s.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 341 PM EDT Thu Jul 26 2018
The next upstream short wave across the western Great Lakes continues
to impinge on the frontal zone across northern Indiana/northwest
Ohio this afternoon. Approach of this wave and favorable upper
jet dynamics have been enough to initiate storms this afternoon.
Shear profiles are robust with mid/upper level jet streak
impinging on the area, and 35-45 knots of effective shear. Earlier
mid level cloud deck has dissipated across the area allowing sfc
temperatures to recover into the lower 80s. Narrow frontal/pre-
frontal instability axis noted per RAP analyses with axis of
1500-2000 MLCAPES from MZZ to DFI, and DCAPES on the order of 1000
J/kg. Sharp mid level theta-e minimum, steep low level lapse
rates, and precip loading still argue for isolated damaging wind
gusts as the primary severe threat generally along/east of I-69
and south of US Route 30. However, cannot completely rule out
isolated large hail given relatively low wet bulbs and periodic
better mid level rotation with a few of the cores promoting hail
growth. Lack of strong frontal low level convergence fields and
modest instability should keep threat more isolated in nature at
best however. Still expecting isolated severe threat to exit far
southeast portions of the area by the 23Z timeframe. Otherwise,
mainly quiet conditions for the remainder of the night as cool/dry
advection occurs allowing mins to bottom out around 60 or the
upper 50s.
Friday will feature much below normal temperatures in the 70s with
partly sunny skies. Large negative height anomaly across the Upper
MS Valley this afternoon will settle across the Great Lakes region
on Friday with a very low probability of diurnally driven isolated
showers. Moisture looks to be quite limited and will not include
any mentionable PoPs at this time for Friday, although may need to
eventually add an isolated mention.
&&
.LONG TERM...(Friday Night through Thursday)
Issued at 341 PM EDT Thu Jul 26 2018
Upper low level will lift across eastern Ontario/western Quebec
early Saturday as next upper level trough begins to dig across
southern Alberta/Montana. Local area should be situated in break
between better precip chances for Saturday. By Sunday-Monday,
southward digging upstream wave across the Rockies should begin to
induce a broad downstream isentropic lift/fgen response across
southern Great Lakes/Ohio Valley for additional shower/storm
chances. This wave will be slow to dampen as it eventually gets
absorbed by the northern stream late work week. Slow progression
of this pattern will result in several periods of rain chances for
next week with continued below normal temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 649 PM EDT Thu Jul 26 2018
NW flow has spread over the forecast area. VFR conditions to
prevail through 15Z. Cu and strato-cu formation lee of Lake
Michigan will be thickest near KSBN with isold MVFR CIGS -
significantly less coverage toward KFWA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...Beach Hazards Statement until 7 PM EDT this evening for MIZ077.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Lewis
SHORT TERM...Marsili
LONG TERM...Marsili
AVIATION...Lewis
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Area Forecast Discussion
National Weather Service Jacksonville FL
839 PM EDT Thu Jul 26 2018
.UPDATE...
Remaining convection over southeast Georgia should diminish
before midnight. HRRR is trying to bring some convection over
metro Jacksonville overnight but not seeing any indications that
the model is onto something here so will not bite on it. Overall
might see some light ground fog in inland locations toward
sunrise.
&&
.AVIATION...Only issue at the fields tonight might be some light
ground fog/mist at Cecil Airport/VQQ and Gainesville Regional/GNV.
Otherwise VFR conditions expected overnight.
&&
.MARINE...Surface ridge will build south of the waters the next
couple of days then build over the waters over the weekend. Winds
generally south southwest 10 to 15 knots except southeast near the
coast in the afternoon. Seas 2 to 4 feet. Scattered mainly afternoon
and evening showers and thunderstorms.
Rip Currents: Moderate risk of rip currents for Georgia and a
high risk for Florida on Friday. The rip current risk will remain
elevated over the weekend due to a long fetch of SSE winds and
persistent long period swell.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 74 92 73 91 / 30 40 30 40
SSI 78 90 76 89 / 20 30 40 40
JAX 74 93 74 92 / 20 30 20 40
SGJ 76 91 74 89 / 20 40 20 40
GNV 73 92 73 91 / 20 30 10 40
OCF 73 92 73 91 / 20 30 10 50
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Sandrik/Nelson/McGinnis
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
959 PM EDT Thu Jul 26 2018
.SYNOPSIS...
A stationary boundary will linger over the middle of the state
into this weekend, lifting to the north early next week.
Bermuda high pressure will remain anchored over the SW Atlantic
into next week while a broad trough of low pressure sits over
the lower MS River Valley.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 955 PM Thursday...For the first time in awhile, we have a
quiet radar across eastern NC at late evening as earlier
isolated convection has dissipate with loss of daytime heating.
High-resolution models such as the HRRR and 3km NAM continue to
indicate showers/storms will develop after 2 or 3 AM and skirt
the coastal counties. Will continue previous forecast of a
slight chance PoP in these areas. Seasonal lows mainly in the
lower to mid 70s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
As of 320 pm Thu...Offshore showers/storms early will migrate
inland through the day, first along the coast in the morning
then transitioning to afternoon convection for interior zones in
the afternoon. Activity should be scattered in nature so no
higher than 30% PoPs at this time. Highs more typical for the
peak of the summer in the upper 80s interior to mid 80s coast.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
As of 345 AM Thu...Models remain in good agreement with the
typical summertime pattern with scattered shower and storm
chances each day as fairly active regime sets in again across
Eastern NC.
Friday night through Monday...26/00Z med range model suite in
fairly good agreement with synoptic regime this time period.
Broad upr trough will amplify across the Great Lakes region and
dig into the lower MS River Valley this weekend, with sfc front
sagging south into the Mid Atlantic to Southeast states. It
appears front will remain north and west of E NC which is
typical for the peak of the summer, though hts fall enough to
warrant somewhat better chances of showers/storms for the
weekend into early next week as convective coverage will be a
bit more widespread than typical, esp for interior zones.
Relatively deep moisture in the column will be present and mean
that precip will be a threat even during the evening and
overnight as low lvl flow is off the Atlantic and GOM. Afternoon
highs near avg in the mid/upr 80s. Overnight lows also
seasonably warm in the 70s.
Tuesday through Wednesday...The mid week period may finally
return to a drier than avg regime as strong subtropical ridge
builds westward towards the eastern seaboard and forces stagnant
upper trough to the west to retreat. More typical
afternoon/early evening iso to sct convection with best chances
along inland moving sea breeze each afternoon. Temps remain
near seasonable vals in the upper 80s inland to mid 80s coast
and lows in the 70s.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Short Term /through Fri/
As of 620 pm Thu...VFR should continue through midnight with
dry conditions forecast overnight. Some IFR/MVFR ceilings could
be possible early tomorrow morning with low level stratus or
isolated fog. VFR should continue Fri with brief Sub-VFR in
scattered convection possible at any of the 4 terminals during
the afternoon. Light SSW surface winds around 5 knots through
the short term.
Long Term /Fri through Monday/...
As of 345 AM Thu...A return to mainly VFR Friday as typical
summertime pattern returns with just scattered to isolated
showers/storms in the afternoon. Perhaps better chance of
lowered vsbys/cigs this weekend into early next week as better
chances for showers/storms moves in.
&&
.MARINE...
Short Term /through Fri/
As of 10 PM Thursday...Only minor changes needed to the current
marine forecast. Winds are S/SW 5-15 knots with seas 3-4 feet
with a few 5-footers over the outer waters. These conditions
should linger overnight and on Friday.
Long Term /Fri through Monday/...
As of 345 AM Thu...Winds and seas typical of mid-summer Bermuda
high pattern with SW winds 5-15 kt through the period, highest
outer waters. Seas will generally be 3-5 ft through Sat central
and southern waters, with 2-4 ft north of Oregon Inlet, then
2-4 ft all waters by Sunday and into Monday.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement through Friday evening for NCZ095-098-
103-104.
MARINE...None.
&&
$$
SYNOPSIS...HSA
NEAR TERM...CTC/BAB
SHORT TERM...HSA
LONG TERM...TL
AVIATION...CTC/HSA/TL/BAB
MARINE...CTC/HSA/TL/BAB
Area Forecast Discussion
National Weather Service Phoenix AZ
858 PM MST Thu Jul 26 2018
.SYNOPSIS...
Excessively hot weather will continue across southeast California
through Friday and across portions of southwest Arizona through
this evening. Moisture will slowly move back into the region over
the next few days allowing temperatures to eventually retreat
back to near normal levels by the weekend. In addition, more
expansive thunderstorms will begin over higher terrain areas of
Arizona, then gradually spread towards lower elevation communities
during the weekend and early next week.
&&
.DISCUSSION...
Thunderstorm activity has largely been confined to the fringes of
the lower deserts, especially to the north of the Phoenix area.
Isolated thunderstorm development continues to occur south of
Florence this evening, but the primary effect across the lower
deserts remains a multitude of outflow boundaries. The 00Z and 03Z
soundings from Phoenix continue to show steep mid-level lapse
rates in place. However, two capping inversions are notable, one
near 3 km AGL and another above 6 km AGL, that are likely
inhibiting convective development across the lower deserts. Thus,
potential for thunderstorms will remain quite low. Various
versions of the HRRR do try to paint some potential for isolated
shower/thunderstorm development overnight into southwest Arizona,
but with poor run-to-run consistency and lack of any coherent
signal, confidence remains quite low in this scenario.
&&
.PREVIOUS DISCUSSION...
Model guidance shows some cooling into Friday, but not enough across
southeast California, so we have extended the warning another day
for that area. Eventually moisture will overspread the entire region
starting this weekend and the high pressure ridge weakens further
allowing highs to fall back within a few degrees of normals.
Moisture levels are expected to begin to gradually increase on
Friday. This moisture increase, along with steep mid level lapse
rates and the very hot conditions will likely lead at least slight
chances for showers and thunderstorms over the lower deserts of
south-central AZ, with better chances over the higher terrain north
and east of Phoenix. The main threat from these storms will be
strong outflow winds and brief heavy rains.
As the upper level high center shifts a bit northward into
northern Arizona this weekend, deeper easterly flow will advect in
more substantial moisture. This should bring widespread
1000-700mb mixing ratios of 10-13 g/kg by Saturday afternoon which
will boost CAPES to above 1000 J/kg. There are no large inverted
troughs seen in the models, but the GFS does bring a minor IT into
southern Arizona on Saturday while the European keeps it mostly
over Sonora Mexico. Storm chances improve greatly starting
Saturday with the higher moisture levels and instability, but
steering flow will continue to be very weak. The main threats from
thunderstorms this weekend will be strong wind gusts, blowing dust
and localized flooding. Little change is seen going into next week
with moisture levels remaining modestly high and the upper high
center situated just to our north. The flow around the high should
continue to bring moisture out of the east/northeast and the
occasional inverted trough while providing day to day storm
chances over much of the region.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
South-Central Arizona including KPHX, KIWA, and KSDL...
Primary concern will surround the uncertainty of outflow boundary
motions and maintenance across the Phoenix metro area this
evening. A strong outflow boundary moved southward earlier from
northern Maricopa County, while additional weaker boundaries have
since been detected. The potential for an earlier switch out of
the east remains in association with these boundaries, but
confidence in wind direction will remain low through around 10Z.
Otherwise, a more predominant easterly wind should take hold with
typical diurnal wind shifts occurring. The potential for any
thunderstorms across the Phoenix area will remain low overnight.
Southeast California/Southwest Arizona including KIPL and KBLH:
Terminals will remain dry for the next 24 hours as there is little
to no chance of thunderstorms over the area. Only FEW to BKN high
clouds are expected as surface winds follow typical diurnal
patterns.
Aviation Discussion not updated for amended TAFs.
&&
FIRE WEATHER...
Sunday through Thursday:
Isolated to scattered showers and thunderstorms are expected to
develop on Sunday afternoon and evening over the higher terrain
north and east of Phoenix before pushing into the lower deserts.
Although rain chances will decrease slightly for Monday into the
middle of next week, moisture levels should easily support at least
isolated convective activity over the higher terrain which may push
into the lower deserts. Minimum relative humidity values will remain
above 20 percent overnight with winds generally remaining below 15
mph aside from thunderstorm outflows and westerly 20-25 mph wind
gusts.
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Excessive Heat Warning until 8 PM MST Friday for AZZ530.
CA...Excessive Heat Warning until 8 PM PDT Friday for CAZ560>563-
566>570.
&&
$$
DISCUSSION...Rogers
PREVIOUS DISCUSSION...Kuhlman
AVIATION...Rogers/Wilson
FIRE WEATHER...Percha/Hopper
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
807 PM EDT Thu Jul 26 2018
.UPDATE...
A weak boundary is draped across central Florida and into
the eastern Gulf, with deep moisture and favorable dynamics
allowing for scattered to numerous showers and thunderstorms
to develop from around Interstate 4 north this afternoon.
South of Interstate 4, broad subsidence kept conditions
mostly dry throughout the afternoon. Thunderstorms have
largely dissipated across the area, except for a few
isolated showers off the southwest Florida coast.
HRRR and other high resolution short range models are
showing thunderstorms developing pre-sunrise over the
eastern Gulf along the weak boundary and moving into the
Tampa Bay area. Rain chances during the early morning hours
were bumped up slightly to account for these showers. The
only other significant forecast change was to increase rain
chances slightly Friday afternoon. No other changes are
planned for the evening update.
&&
.AVIATION...
VFR conditions are expected to continue to hold through
much of the evening hours. Showers and storms are expected
to develop over the Gulf and move into the Tampa Bay area
after around 08z, potentially impacting KPIE, KTPA, and
KSRQ. Other terminals could see showers or storms moving
inland after sunrise. Thunderstorms will also develop over
the land during the late morning and afternoon, largely
clearing out and moving inland by the late afternoon.
&&
.MARINE...
Light westerly winds will continue through Friday, with
early morning showers and thunderstorms expected to develop
over the easterly Gulf and move inland through the early
afternoon. The Atlantic ridge of high pressure will build
into the eastern Gulf this weekend, setting up a more
southerly flow pattern through early next week, with winds
turning onshore with the afternoon sea breeze. Wind and seas
will generally remain less than headline criteria, outside
of daily thunderstorms which will create locally hazardous
boating conditions.
&&
.Preliminary Point Temps/PoPs...
TPA 78 90 78 90 / 30 20 10 60
FMY 77 92 77 91 / 10 40 40 70
GIF 76 93 76 91 / 10 40 40 70
SRQ 78 91 79 89 / 20 20 10 50
BKV 74 91 74 90 / 20 30 10 50
SPG 79 90 79 90 / 30 30 10 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...Beach Hazards Statement through Monday evening for Coastal
Charlotte-Coastal Lee-Coastal Sarasota.
Gulf waters...None.
&&
$$
UPDATE/AVIATION/MARINE...18/Fleming
UPPER AIR...27/Shiveley
DECISION SUPPORT...13/Oglesby