Aggregator

000
ABPZ20 KNHC 011733
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Tue Aug 1 2023

For the eastern North Pacific...east of 140 degrees west longitude:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Dora, located several hundred miles off the southwestern coast
of Mexico.

Off the coast of Southwestern Mexico:
An area of low pressure is forecast to form towards the latter part
of this week a few hundred miles south of the coast of southwestern
Mexico. Thereafter, some gradual development of this system is
possible, and a tropical depression could form by early next week
while it moves west-northwestward or northwestward, roughly parallel
to the southwestern coast of Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

&&
Public Advisories on Tropical Storm Dora are issued under WMO
header WTPZ35 KNHC and under AWIPS header MIATCPEP5.
Forecast/Advisories on Tropical Storm Dora are issued under
WMO header WTPZ25 KNHC and under AWIPS header MIATCMEP5.

$$
Forecaster Papin

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1226 PM CDT Tue Aug 01 2023 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL MISSOURI INTO SOUTHERN ILLINOIS... ...SUMMARY... Thunderstorms capable of damaging gusts are possible from central Missouri into southern Illinois Wednesday afternoon through evening. Isolated strong to severe thunderstorms capable of producing damaging gusts and hail are also possible across the Upper Great Lakes region and central High Plains. ...Synopsis... Upper ridging is forecast to remain in place over the southern Plains and Lower MS Valley, keeping that region hot and dry. Some modestly enhanced mid-level flow will exist from the northern Plains/Upper Midwest through the Mid-Atlantic, between the southern Plains ridge and an upper low over the Hudson Bay. A shortwave trough and associated surface low will likely move through this enhanced flow across Ontario. An attendant cold front is expected to move into the northern Plains, Upper Midwest, and Upper Great Lakes, with some thunderstorms possible along the front during afternoon and evening. Additionally, a convectively induced vorticity maximum will likely track eastward over the central Plains and into the Mid/Lower MO Valley. Some thunderstorms are possible from the Mid MO Valley into the Mid MS Valley as this vorticity maximum interacts with the moist and buoyant air mass over the region. ...Mid MO Valley into the Mid MS Valley... Numerous showers and thunderstorms will likely be ongoing Wednesday morning in an arc from far eastern NE to southeast MO/southern IL/far western KY, remnant from overnight storms from the Mid MO Valley into the Mid MS Valley. These storms will likely dissipate by late morning/early afternoon, but residual cloud cover and resulting differential heating will help induce a warm-front-like boundary across MO. Dewpoints are expected to be in the mid 70s in the vicinity of this boundary Wednesday afternoon, contributing to moderate/strong buoyancy. Even with strong daytime heating south/west of the boundary, some convective inhibition will likely persist, particularly with southwestward extent, where mixing will be greatest. However, convergence along this differential heating zone, combined with slightly higher dewpoints and less overall mixing, as well as ascent from the approaching vorticity maximum, is expected to result in convective initiation. Strong buoyancy will support a risk for hail within the first hour or so of development, before cell interactions and outflow-dominant structures influence a more linear storm mode. Additionally, given the presence of a surface boundary and some more southeasterly surface winds, a tornado or two cannot be entirely ruled out. However, a somewhat quick transition to a predominantly linear mode is anticipated, with at least some chance for cold pool organization into a coherent linear convective system. This system should then track southeastward along the buoyancy gradient into southeast MO, southern IL, and potentially even far western KY. ...Upper Midwest into the Upper Great Lakes... Moderate buoyancy is anticipated ahead of the approaching cold front mentioned in the synopsis. Convergence along the boundary will be modest, with higher storm coverage expected across Upper MI versus farther west across northern WI and northeast MN. Even so, expected moderate buoyancy will combine with 30-40 kt of effective bulk shear to support organized thunderstorms. Forecast soundings show modestly steep midlevel lapse rates and elongated/straight hodographs above around 1-2 km. This suggests isolated hail potential with the strongest storms. Where stronger heating occurs, steep low-level lapse rates will foster isolated strong/damaging gusts as well. ...Central High Plains... Afternoon thunderstorms across the higher terrain are forecast to progress eastward into the lower elevations of the central High Plains during the late afternoon/early evening. Steep low-level lapse rates and high cloud bases will likely support a few stronger gusts as this activity moves eastward into western KS. ..Mosier.. 08/01/2023 Read more

000
ABNT20 KNHC 011728
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
Issued by the NWS Weather Prediction Center College Park MD
200 PM EDT Tue Aug 1 2023

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Central Subtropical Atlantic (AL96):
Showers and thunderstorms remain disorganized in association with
a low pressure area located about 800 miles north-northeast of the
northern Leeward Islands. Environmental conditions are becoming
less favorable for tropical cyclone formation, and the low
is expected to merge with a frontal system over the north
central Atlantic in about two to three days.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...low...30 percent.

$$
Forecaster Beven/Jackson

No watches are valid as of Mon Jul 31 22:16:01 UTC 2023.

MD 1800 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF CENTRAL/NORTH ND
Mesoscale Discussion 1800 NWS Storm Prediction Center Norman OK 0511 PM CDT Mon Jul 31 2023 Areas affected...Parts of central/north ND Concerning...Severe potential...Watch unlikely Valid 312211Z - 312345Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe storms will be possible this evening, with a threat of large hail and localized severe gusts. Watch issuance is currently considered unlikely, but will become possible if storm coverage becomes greater than expected. DISCUSSION...A small cluster of storms has recently developed over southwest Manitoba, with attempts at convective initiation noted across far northeast Bottineau County, ND, and increasing cumulus across north-central ND. Modest diurnal heating amid relatively rich low-level moisture is supporting moderate buoyancy (MLCAPE of 1500-3000 J/kg), while northwesterly midlevel flow is supporting effective shear of 35-45 kt across the region. As a result, the environment is conditionally favorable for supercell development. The primary uncertainty this evening is storm coverage. While multiple mid/upper-level shortwave troughs are moving across the Canadian Prairies, most of ND is under the influence of an upper ridge, and large-scale ascent will likely remain limited. However, a weak warm-advection regime may continue to support isolated storm development, with any mature storms tending to propagate southeastward along the primary instability gradient. As a result, a supercell or two may develop and move across parts of north and central ND this evening, with a threat of large hail and localized severe gusts. Watch issuance is currently considered unlikely due to the expectation for the threat to remain isolated, but will become possible if short-term trends support a greater coverage of storms than currently anticipated. ..Dean/Grams.. 07/31/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...BIS... LAT...LON 48990147 48989982 48299952 47629936 47379944 47120011 47250081 47710124 48100147 48660158 48990147 Read more

Issued at 400 PM CDT Mon Jul 31 2023 224 WTPZ45 KNHC 312041 TCDEP5 Tropical Depression Five-E Discussion Number 1 NWS National Hurricane Center Miami FL EP052023 400 PM CDT Mon Jul 31 2023 Through this morning and afternoon, the system we have been monitoring several hundred miles offshore to the south of the coast of Mexico has improved in organization on satellite imagery, with plenty of curved convective bands along its northern semicircle. A couple of bulls-eye ASCAT passes earlier this afternoon indicated that a closed circulation had formed at the surface, with believable 25-30 kt winds on its northern flank. We also received a subjective Dvorak intensity estimate of T2.0/30-kt from TAFB this afternoon. The aforementioned data supports initiating advisories on the system as a tropical depression, with maximum sustained winds of 30 kt. The initial motion of the depression is north of due west at 280/12 kt. A prominent mid-level subtropical ridge is located poleward of the cyclone and is expected to move westward with the system throughout the forecast period. The orientation of the ridge ahead of the system may even result in a west-southwestward motion by the middle to latter part of this week. The track guidance is in fairly good agreement, especially for a system that has only recently formed, though some speed differences exist towards the end of the forecast period. The initial NHC track forecast has opted to remain close to the reliable consensus aids, roughly in between the faster HCCA and slower TVCE guidance. Environmental conditions appear quite favorable for intensification over the next few days. Both the GFS- and EC-based SHIPS guidance shows deep-layer vertical wind shear remaining 10 kt or below throughout the forecast period as sea-surface temperatures underneath the system remain above 28 C for the next 3 days. While there will likely be some mid-level dry air lurking near the system during this time-span, this may not harm the cyclone as much as just keeping its convective core small. In fact, most of the hurricane-regional models show the system significantly intensifying as a small tropical cyclone during the forecast period. The NHC intensity forecast follows this evolution, with significant intensification expected, especially between 36-72 h after the system has an opportunity to develop an inner core that takes better advantage of the favorable conditions. A period of rapid intensification during this time frame is also possible. This initial intensity forecast is in best agreement with the SHIPS guidance this cycle, and is roughly a split between the higher HWRF/HMON and lower HAFS-A/B runs. FORECAST POSITIONS AND MAX WINDS INIT 31/2100Z 14.8N 104.4W 30 KT 35 MPH 12H 01/0600Z 15.5N 106.4W 35 KT 40 MPH 24H 01/1800Z 15.8N 109.0W 40 KT 45 MPH 36H 02/0600Z 15.5N 111.7W 50 KT 60 MPH 48H 02/1800Z 15.1N 114.3W 65 KT 75 MPH 60H 03/0600Z 14.7N 116.7W 75 KT 85 MPH 72H 03/1800Z 14.3N 119.3W 85 KT 100 MPH 96H 04/1800Z 13.3N 125.1W 90 KT 105 MPH 120H 05/1800Z 12.7N 130.9W 90 KT 105 MPH $$ Forecaster Papin

5-Day Uncertainty Track last updated Mon, 31 Jul 2023 20:40:03 GMT


Wind Speed Probabilities last updated Mon, 31 Jul 2023 21:23:07 GMT

Issued at 2100 UTC MON JUL 31 2023 000 FOPZ15 KNHC 312038 PWSEP5 TROPICAL DEPRESSION FIVE-E WIND SPEED PROBABILITIES NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP052023 2100 UTC MON JUL 31 2023 AT 2100Z THE CENTER OF TROPICAL DEPRESSION FIVE-E WAS LOCATED NEAR LATITUDE 14.8 NORTH...LONGITUDE 104.4 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 30 KTS...35 MPH...55 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 18Z MON AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 18Z MON 06Z TUE 18Z TUE 06Z WED 18Z WED 18Z THU 18Z FRI PERIODS TO TO TO TO TO TO TO 06Z TUE 18Z TUE 06Z WED 18Z WED 18Z THU 18Z FRI 18Z SAT FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 15N 105W 34 29 X(29) X(29) X(29) X(29) X(29) X(29) 15N 110W 34 X 11(11) 30(41) 1(42) X(42) X(42) X(42) 15N 110W 50 X X( X) 8( 8) X( 8) X( 8) X( 8) X( 8) 15N 110W 64 X X( X) 2( 2) X( 2) X( 2) X( 2) X( 2) ISLA SOCORRO 34 X 1( 1) 2( 3) 2( 5) X( 5) X( 5) X( 5) ISLA CLARION 34 X X( X) 2( 2) 6( 8) 3(11) X(11) X(11) 10N 115W 34 X X( X) X( X) 1( 1) 2( 3) X( 3) X( 3) 15N 115W 34 X X( X) 2( 2) 55(57) 26(83) X(83) X(83) 15N 115W 50 X X( X) X( X) 21(21) 23(44) 1(45) X(45) 15N 115W 64 X X( X) X( X) 7( 7) 13(20) X(20) X(20) 20N 115W 34 X X( X) X( X) 2( 2) 1( 3) 1( 4) X( 4) 10N 120W 34 X X( X) X( X) X( X) 3( 3) 5( 8) X( 8) 15N 120W 34 X X( X) X( X) 1( 1) 61(62) 15(77) 1(78) 15N 120W 50 X X( X) X( X) X( X) 28(28) 16(44) 1(45) 15N 120W 64 X X( X) X( X) X( X) 12(12) 12(24) X(24) 10N 125W 34 X X( X) X( X) X( X) X( X) 12(12) 4(16) 10N 125W 50 X X( X) X( X) X( X) X( X) 2( 2) 2( 4) 10N 125W 64 X X( X) X( X) X( X) X( X) 1( 1) X( 1) 15N 125W 34 X X( X) X( X) X( X) 1( 1) 49(50) 6(56) 15N 125W 50 X X( X) X( X) X( X) X( X) 21(21) 5(26) 15N 125W 64 X X( X) X( X) X( X) X( X) 9( 9) 3(12) 10N 130W 34 X X( X) X( X) X( X) X( X) 1( 1) 19(20) 10N 130W 50 X X( X) X( X) X( X) X( X) X( X) 6( 6) 10N 130W 64 X X( X) X( X) X( X) X( X) X( X) 2( 2) 15N 130W 34 X X( X) X( X) X( X) X( X) 3( 3) 39(42) 15N 130W 50 X X( X) X( X) X( X) X( X) X( X) 16(16) 15N 130W 64 X X( X) X( X) X( X) X( X) X( X) 8( 8) 10N 135W 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) 15N 135W 34 X X( X) X( X) X( X) X( X) X( X) 7( 7) $$ FORECASTER PAPIN

Issued at 400 PM CDT Mon Jul 31 2023 000 WTPZ35 KNHC 312038 TCPEP5 BULLETIN Tropical Depression Five-E Advisory Number 1 NWS National Hurricane Center Miami FL EP052023 400 PM CDT Mon Jul 31 2023 ...NEW TROPICAL DEPRESSION FORMS IN THE EAST PACIFIC... ...FORECAST TO INTENSIFY SIGNIFICANTLY... SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...14.8N 104.4W ABOUT 290 MI...465 KM S OF MANZANILLO MEXICO MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 400 PM CDT (2100 UTC), the center of Tropical Depression Five-E was located near latitude 14.8 North, longitude 104.4 West. The depression is moving toward the west near 14 mph (22 km/h) and this motion is expected to continue with a gradual turn to west-southwestward by the middle portion of this week. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is forecast during the next several days, and the system could become a hurricane by the middle part of this week. The estimated minimum central pressure is 1008 mb (29.77 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 1000 PM CDT. $$ Forecaster Papin

...NEW TROPICAL DEPRESSION FORMS IN THE EAST PACIFIC... ...FORECAST TO INTENSIFY SIGNIFICANTLY... As of 4:00 PM CDT Mon Jul 31 the center of Five-E was located near 14.8, -104.4 with movement W at 14 mph. The minimum central pressure was 1008 mb with maximum sustained winds of about 35 mph.

Issued at 2100 UTC MON JUL 31 2023 015 WTPZ25 KNHC 312036 TCMEP5 TROPICAL DEPRESSION FIVE-E FORECAST/ADVISORY NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP052023 2100 UTC MON JUL 31 2023 NOTICE... LAND-BASED TROPICAL CYCLONE WATCHES AND WARNINGS ARE NO LONGER INCLUDED IN THE TROPICAL CYCLONE FORECAST/ADVISORY...(TCM). CURRENT LAND-BASED COASTAL WATCHES AND WARNINGS CAN BE FOUND IN THE MOST RECENTLY ISSUED TROPICAL CYCLONE PUBLIC ADVISORY...(TCP). TROPICAL DEPRESSION CENTER LOCATED NEAR 14.8N 104.4W AT 31/2100Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 12 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1008 MB MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 14.8N 104.4W AT 31/2100Z AT 31/1800Z CENTER WAS LOCATED NEAR 14.6N 103.8W FORECAST VALID 01/0600Z 15.5N 106.4W MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 30NE 0SE 0SW 0NW. FORECAST VALID 01/1800Z 15.8N 109.0W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 30NE 0SE 0SW 30NW. FORECAST VALID 02/0600Z 15.5N 111.7W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 20NE 0SE 0SW 0NW. 34 KT... 40NE 30SE 30SW 40NW. FORECAST VALID 02/1800Z 15.1N 114.3W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 10NE 0SE 0SW 0NW. 50 KT... 30NE 20SE 10SW 20NW. 34 KT... 40NE 30SE 30SW 50NW. FORECAST VALID 03/0600Z 14.7N 116.7W MAX WIND 75 KT...GUSTS 90 KT. 50 KT... 30NE 20SE 20SW 30NW. 34 KT... 50NE 50SE 40SW 60NW. FORECAST VALID 03/1800Z 14.3N 119.3W MAX WIND 85 KT...GUSTS 105 KT. 50 KT... 40NE 30SE 30SW 40NW. 34 KT... 60NE 50SE 50SW 60NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 125 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 04/1800Z 13.3N 125.1W MAX WIND 90 KT...GUSTS 110 KT. OUTLOOK VALID 05/1800Z 12.7N 130.9W MAX WIND 90 KT...GUSTS 110 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.8N 104.4W NEXT ADVISORY AT 01/0300Z $$ FORECASTER PAPIN

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Mon Jul 31 2023 Valid 011200Z - 021200Z There were two primary changes to the outlook with this update. 1) The Elevated highlights in central TX were expanded eastward to the I-35 corridor and northward into far southwest OK. Despite slightly weaker sustained southerly surface winds (around 10-15 mph) closer to the I-35 corridor, continued 100 deg surface temperatures, breezy/gusty afternoon winds, and critically dry fuels (above the 90th percentile ERCs) will still support elevated to spotty critical fire-weather conditions. Upon collaboration with TX Predictive Services, the western portion of the Elevated highlights were trimmed slightly -- as fine fuels (grasses) here will generally be less receptive to large-fire spread compared to the timber/brush fuels farther east owing to a lack of stronger sustained surface winds. 2) A small Elevated area was added over far northeast CA, northwest NV, and far southeast/south-central OR. A continuation of moderate southwesterly midlevel flow across the northern Sierra/southern Cascades will promote 15 mph sustained southwesterly surface winds and around 10 percent minimum RH over dry fuels. For additional details, see the previous discussion below. ..Weinman.. 07/31/2023 .PREV DISCUSSION... /ISSUED 0148 AM CDT Mon Jul 31 2023/ ...Synopsis... A weak lee cyclone is forecast to develop across Kansas on Tuesday as a mid-level shortwave trough crosses the central Plains. This will result in a tightening pressure gradient across the southern Plains with sustained winds around 15 mph. For now, the Elevated delineation covers portions of the Permian Basin into Northwest Texas where winds are expected to be 15 to 20 mph with relative humidity of 20 to 25 percent and critically dry fuels. Dry and breezy conditions may also exist northward into the TX/OK Panhandles, much of western Texas, and southern Kansas. However, fuels remain green across this region due to the significant rainfall in early July. Dry and breezy conditions are expected Tuesday across portions of northeast Montana. However, wetting rain across the region early this morning should moisten fuels in the region and alleviate significant fire weather concerns. Finally, some locally elevated fire weather conditions are possible across portions of northwest Nevada into southwest Idaho, but the threat appears too localized for an Elevated area at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Mon Jul 31 2023 Valid 312000Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS...LOWER/MID MISSISSIPPI VALLEY...COASTAL SOUTHEAST...AND ARIZONA... ...SUMMARY... Isolated severe thunderstorms remain possible over portions of the northern/central Plains, coastal Southeast, lower Missouri Valley to west-central Gulf Coast, and Arizona. ...20Z Update... No changes have been made to the prior outlook. ..Gleason.. 07/31/2023 .PREV DISCUSSION... /ISSUED 1121 AM CDT Mon Jul 31 2023/ ...MO to LA this afternoon into tonight... Multiple thunderstorm clusters occurred overnight, and the remnants of convection with outflow and debris clouds persist from southern AR into LA, and across northwest MO. The relatively widespread convective overturning/modification suggests the environment will not have sufficient time to recover by this afternoon. There will be some potential for additional development along the outflow boundary moving southward into southern LA this afternoon, where isolated downbursts may occur. Otherwise, the more probable scenario is for slightly elevated storms to form again tonight in the strengthening warm advection zone across MO. Lapse rates will not be as steep as prior days and midlevel temperatures will be relatively warm in proximity to the southern Plains ridge, so any hail/wind threat should remain marginal. ...Dakotas to northeast CO this afternoon into tonight... Lingering low-level moisture in a weak upslope flow regime will support scattered thunderstorm development this afternoon/evening from the Front Range in northeast CO northward into eastern WY. Midlevel lapse rates will not be as steep as prior days as a result of the monsoonal moisture plume spreading northeastward across UT/CO/WY, and flow aloft will also be relatively weak. Thus, primarily multicell clusters with isolated strong-severe outflow gusts will be the main threat as convection spreads eastward toward western NE and vicinity by tonight. Farther north into ND, the focus for storm development will be nebulous at best. There will be a small chance for diurnal storms in the differential heating zone across far southwest ND by late afternoon, and a storm or two could approach the international border from SK tonight. However, confidence in either scenario is low. ...Fl to Carolinas this afternoon/evening... A weak midlevel trough over the southeast Atlantic states and daytime heating in cloud breaks will drive diurnal convection this afternoon. The primary wind shift/front extends across north FL and off the coasts of the Carolinas, leaving terrain influences and a weak outflow boundary to focus thunderstorm development this afternoon. Lapse rates aloft are poor and buoyancy will be rather modest by summer standards - both of which suggest today is a low-end downburst day (at best) into the Carolinas. Stronger surface heating and destabilization will occur farther south into FL, where a few pulse severe storms with downburst winds will be possible this afternoon. ...AZ this afternoon/evening... With prior convection and the approach of a weak wave from northwest Mexico, there's been an increase in low-level moisture and a decrease in low-midlevel lapse rates since yesterday across southern AZ. Still, isolated strong outflow gusts will be possible with convection from southeast AZ northwestward in the vicinity of the Mogollon Rim, which is where the weaker convective inhibition is expected this afternoon/evening. Read more

000
ABPZ20 KNHC 311751
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Mon Jul 31 2023

For the eastern North Pacific...east of 140 degrees west longitude:

Offshore of Southern Mexico (EP96):
Showers and thunderstorms are gradually becoming better organized in
association with an area of low pressure located a couple hundred
miles to the south of the southern coast of Mexico. In addition,
recent satellite wind data indicate its circulation is also becoming
better defined. If these trends continue, a tropical depression
could form as soon as later this afternoon. The system is forecast
to move generally westward near 15 mph over the next few days,
moving farther away from the Mexican coast. Additional information
on this system, including gale warnings, can be found in High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 7 days...high...90 percent.

Central East Pacific:
A small area of low pressure located about 1100 miles southwest of
the southern tip of the Baja California Peninsula continues to
produce an area of disorganized showers and thunderstorms. The
proximity of nearby dry air is likely to prevent significant
development of this system while it moves westward at 5 to 10 mph
during the next couple of days.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

South of Southwestern Mexico:
An area of low pressure could form towards the end of this week a
few hundred miles south of the coast of southwestern Mexico. Some
gradual development of this system is possible by the weekend while
it moves west-northwestward or northwestward, roughly parallel to
the southwestern coast of Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...30 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php

$$
Forecaster Papin

000
ABNT20 KNHC 311750
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Mon Jul 31 2023

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Central Tropical Atlantic (AL96):
Showers and thunderstorms associated with an area of low pressure
located about 650 miles northeast of the northern Leeward Islands
have become less organized since last night. However, the system is
producing a small area of gale-force winds well to the east of the
center. Environmental conditions still appear somewhat conducive
for a tropical depression or tropical storm to develop during the
next couple of days while the system moves northwestward and then
northward at 10 to 15 mph over the central subtropical Atlantic.
Additional information on this system, including gale warnings, can
be found in High Seas Forecasts issued by the National Weather
Service.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...high...70 percent.

Western Atlantic (AL97):
Shower and thunderstorm activity continues in association a
gale-force low pressure system located over the western Atlantic
several hundred miles south of Nova Scotia. However, recent
satellite data indicate that the low is attached to frontal
boundaries, and it is forecast to move quickly toward the
east-northeast at 30 to 35 mph, reaching colder waters by tonight.
As a result, the likelihood of this system becoming a tropical
storm is diminishing. Additional information on the low, including
gale warnings, can be found in High Seas Forecasts issued by the
National Weather Service.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

&&
For more information about marine hazards associated with AL96
and AL97, please see High Seas Forecasts issued by the National
Weather Service found under AWIPS header NFDHSFAT1, WMO header
FZNT01 KWBC, and online at
ocean.weather.gov/shtml/NFDHSFAT1.php

$$
Forecaster Berg

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Jul 31 2023 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH DAKOTA AND NORTHWESTERN MINNESOTA... ...SUMMARY... Severe thunderstorms capable of producing large hail and damaging winds appear possible Tuesday across parts of North Dakota into northern Minnesota, and the central High Plains into the mid Missouri Valley. Thunderstorms capable of producing occasional damaging winds may also occur over parts of the coastal Southeast. ...Synopsis... An expansive upper ridge will remain anchored over the central CONUS on Tuesday. Multiple weak mid-level disturbances are forecast to rotate around the apex of the upper ridge across the northern/central Plains and Upper Midwest. Upper troughing is expected to persist across the eastern states. Between these features, a belt of modestly enhanced mid-level west-northwesterly flow will extend from the northern Plains and Upper Midwest to parts of the Southeast. ...Northern Plains/Upper Midwest... A weak mid-level shortwave trough should dampen the northern extent of upper ridging over central Canada and the northern Plains on Tuesday. At the surface, a cold front is forecast to move east-southeastward across these areas through the period. Rich low-level moisture, characterized by mid 60s to perhaps low 70s surface dewpoints, should be in place ahead of the front across ND into northern MN. Thunderstorms should develop along/ahead of the front by Tuesday afternoon in a moderately to strongly unstable airmass. The presence of steep mid-level lapse rates and around 30-40 kt of effective bulk shear should aid in some threat for supercells capable of producing large hail. Otherwise, one or more clusters may eventually develop along the length of the cold front and pose more of a severe wind threat as convection develops south-southeastward through Tuesday evening. Given a greater signal for supercells and multicells across this area, have introduced a Slight Risk. This activity should eventually weaken with eastward and southward extent into the northern Plains and Upper Midwest as it encounters a less unstable airmass. ...Central High Plains into the Mid Missouri Valley... Scattered to numerous thunderstorms should once again develop over the higher terrain of the central Rockies early Tuesday afternoon, and eventually spread eastward into the adjacent central High Plains through Tuesday evening. One or more weak mid-level vorticity maxima may aid in this convective development. While deep-layer shear appears fairly modest, generally 30 kt or less, convection should gradually strengthen as it encounters a more unstable airmass across eastern CO and vicinity. Most high-resolution guidance suggests that a small cluster will eventually consolidate and spread eastward across the central Plains Tuesday evening and possible continuing overnight. Isolated hail may occur with the initially more cellular convection, while severe/damaging winds appear more of a concern with eastward extent if a cluster does develop. Have therefore expanded the Marginal Risk eastward to account for this possibility. Farther east into the mid MO Valley, thunderstorms may be ongoing at the beginning of the period in a low-level warm advection regime. While most of this activity will probably remain sub-severe, some threat for hail and gusty winds may exist with the more robust cores through Tuesday morning. The potential for additional convective development Tuesday afternoon appears highly uncertain given weak large-scale forcing. But, there appears to be a signal for renewed thunderstorms in another low-level warm advection regime Tuesday night through early Wednesday morning. With ample MUCAPE and strong deep-layer shear forecast, any elevated supercells which can develop may pose an isolated threat for large hail and strong/gusty winds. ...Coastal Southeast... Isolated to scattered thunderstorms should develop Tuesday afternoon along and east of a weak lee surface trough, with additional convective development possible along the Atlantic sea breeze. Weak to locally moderate instability should develop with daytime heating of a moist low-level airmass. But, poor mid-level lapse rates will probably tend to limit updraft intensity to some extent. Still, around 20-30 kt of deep-layer shear should prove adequate for modest convective organization. An isolated threat for damaging winds may exist with the stronger clusters that form and spread eastward through Tuesday evening, before they eventually weaken and/or move offshore. ..Gleason.. 07/31/2023 Read more

Residents of Wrangell were urged to voluntarily conserve water as July precipitation was about 70% of normal. Water consumption has also been higher than usual, which, combined with the low rainfall, has pushed the community nearer to mandatory water restrictions. As of Monday, July 24, a little more than two months’ worth of water were stored in the two reservoirs. KSTK-FM 101.7 Public Radio (Wrangell, Alaska), July 26, 2023

MD 1790 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR CENTRAL AND EASTERN MONTANA
Mesoscale Discussion 1790 NWS Storm Prediction Center Norman OK 0442 PM CDT Sun Jul 30 2023 Areas affected...Central and Eastern Montana Concerning...Severe potential...Watch possible Valid 302142Z - 302315Z Probability of Watch Issuance...60 percent SUMMARY...A severe thunderstorm watch is possible this afternoon/evening across eastern Montana. DISCUSSION...Elevated thunderstorms are ongoing this afternoon across northeast Montana. 12Z CAM guidance was split whether this elevated convection would be strong/severe, however, current radar trends suggest a supercell or two, similar to the 12Z WRF-ARW/NSSL may be the most likely evolution. If this activity continues to intensify, it could eventually become surface based as heating and low-level moisture advection destabilizes the airmass ahead of it. Similarly, thunderstorms across southeast Montana are also likely somewhat elevated, but are moving into an airmass with increasing surface based instability and reducing inhibition. If one or both of these regions appear to "turn the corner", a watch may be needed in the next 1 to 2 hours. Regardless of this early activity across eastern Montana, a severe thunderstorm watch is more likely later this evening for supercells which are expected to form in central Montana and move east. At this time, inhibition appears to be limiting more robust convective development, but with a few more hours of heating and upslope flow, expect an uncapped airmass and a few mature supercells to develop and move off of the higher terrain. A strengthening southeasterly low-level jet later this evening and increasing moisture advection should maintain this threat into the early morning hours on Monday. ..Bentley/Grams.. 07/30/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BIS...UNR...BYZ...GGW...TFX... LAT...LON 47000977 48290987 48740966 49100794 49130567 49100434 48520378 46910360 45690350 44990401 44830531 44990688 45160811 47000977 Read more

MD 1789 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN NEBRASKA...FAR WESTERN IOWA...FAR NORTHWEST MISSOURI...FAR NORTHEAST KANSAS
Mesoscale Discussion 1789 NWS Storm Prediction Center Norman OK 0326 PM CDT Sun Jul 30 2023 Areas affected...Eastern Nebraska...far western Iowa...far northwest Missouri...far northeast Kansas Concerning...Severe potential...Watch possible Valid 302026Z - 302230Z Probability of Watch Issuance...40 percent SUMMARY...Storms capable of occasional large hail are possible this afternoon. Overall coverage and intensify of storms is not certain. The necessity of a watch will depend on convective trends. DISCUSSION...Storms have continued to form in association with a subtle shortwave/weak warm-advection regime. These storms have occasionally produced large hail this afternoon in South Dakota. Additional thunderstorms have formed in eastern Nebraska, west of Omaha. MLCAPE of around 1500 J/kg and effective shear of 40-50 kts would support some continued risk of large hail. Storms, however, have not appeared overly organized on regional radar imagery and have tended to pulse intensity. The 12Z observed OAX and TOP soundings did show some dry air at low levels which appears to be reflected in objective MLCIN fields. That being said, these storms may be slightly elevated in nature. The need for a watch will be conditional on trends in storm coverage and intensity. ..Wendt/Thompson.. 07/30/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EAX...FSD...OAX...TOP...GID... LAT...LON 41709808 42609822 43109821 43409758 42789655 41919585 40989503 40219511 39919562 39979641 41709808 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Sun Jul 30 2023 Valid 302000Z - 311200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHEASTERN WYOMING AND WESTERN SOUTH DAKOTA... ...SUMMARY... Severe thunderstorms should be most organized over parts of the northern/central Plains through tonight, with the greatest threat for very large hail and severe outflow gusts centered near the Black Hills. ...20Z Update... No changes have been made to severe probabilities across the northern/central Plains. See Mesoscale Discussion 1786 and recently issued Severe Thunderstorm Watch 573 for more details on the potential for very large hail and severe wind gusts with developing thunderstorms over the Black Hills of SD. Wind probabilities have generally been adjusted southward across parts of the Southeast based on the progression of loosely organized clusters ongoing across AL/GA. Reference Mesoscale Discussion 1787 for additional information on the threat for strong to damaging winds associated with this convection. ..Gleason.. 07/30/2023 .PREV DISCUSSION... /ISSUED 1125 AM CDT Sun Jul 30 2023/ ...Northern Plains/MO Valley through tonight... Around the northern periphery of the central Rockies midlevel high, embedded speed maxima will continue to move eastward over MT and southeastward from the Dakotas to the upper MS Valley. Elevated convection is ongoing in a band of frontogenesis/warm advection from southern ND into northern SD, along the east edge of the steeper midlevel lapse rate plume. MUCAPE near 1500 J/kg and long hodographs with effective bulk shear in excess of 50 kt will continue to support the potential for elevated supercells capable of producing large hail and isolated strong outflow gusts as the storms spread southeastward through the afternoon. Farther west this afternoon/evening, additional storm development is likely across the northern High Plains in the zone of low-level upslope flow, and isolated storms may also form with daytime heating over the Black Hills. Very steep midlevel lapse rates noted in the 12z UNR sounding and relatively strong mid-upper flow/long hodographs will initially favor supercells capable of producing very large hail of 2-3 inches in diameter or greater. Some upscale growth is expected this evening as the storms move east of the higher terrain, with an increase in the potential for severe outflow gusts. The convection will likely persist overnight and develop southeastward toward middle/lower MO Valley as warm advection increases with a nocturnal low-level jet, with isolated large hail/damaging winds possible. ...Southeast this afternoon... A weak midlevel trough is moving slowly southeastward over northern MS/AL and the southern Appalachians. Isolated thunderstorms are ongoing along the wind shift across northern MS/AL, and this convection will likely increase through the afternoon as the low levels warm/destabilize to the south of the wind shift. Deep-layer flow/vertical shear will remain rather weak, so the primary threat will be downburst winds with multicell clusters through the afternoon. ...Southern AZ/southeast CA this afternoon/evening... Easterly flow aloft is established over AZ to the south of the Four Corners high, and on the northern periphery of a weak wave moving westward over northwest Mexico. Despite some moistening, 12z soundings still revealed steep lapse rates and the potential for deep inverted-V profiles across southern AZ this afternoon. Storms that form over the higher terrain will have the potential to spread westward over the lower deserts and produce isolated strong-severe outflow gusts. Read more