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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu Aug 17 2023 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NEW ENGLAND AND ARIZONA... ...SUMMARY... Isolated severe thunderstorms with a risk for damaging gusts and perhaps a tornado or two will be possible during the day across portions of New England on Friday. Storms capable of isolated severe gusts will also be possible across parts of Arizona. ...Synopsis... A seasonably deep/strong upper-level trough will move across the Northeast and Mid Atlantic regions on Friday. An associated surface low will move eastward across Quebec, as a trailing cold front moves from the upper Great Lakes into New England through the day. Farther west, a mid/upper-level low will remain nearly stationary off of the California coast. A mid/upper-level shortwave trough and associated surface low will move across the Canadian Prairies, as an attendant cold front moves into the northern Plains. ...Northeast... Multiple rounds of convection are possible across parts of the Northeast/New England on Friday. The initial morning to early afternoon round may be capable of locally damaging gusts and perhaps a tornado or two, with a more isolated threat later Friday afternoon along/ahead of the cold front. One or more storm clusters will likely be ongoing Friday morning somewhere from northern NY into southern New England. Strong deep-layer flow associated with the approaching upper trough will support sufficient effective shear for organized convective elements within these clusters. The strongest buoyancy (with MLCAPE generally 500-1000 J/kg during the morning) is expected near/south of a northward-advancing warm front across southern New England, with weaker instability extending northward into parts of VT/NH. The morning threat will likely be maximized near/south of the warm front, where line-embedded supercells and/or shorter-lived mesovortices will support potential for locally damaging gusts and perhaps a tornado or two, within an environment of favorable low-level shear/SRH. Depending on the extent of heating/destabilization that can occur across southern New England prior to storm arrival, higher severe probabilities may eventually be needed. In the wake of early-day convection, redevelopment along/ahead of the cold front will be possible during the afternoon. Coverage and intensity of convection associated with the cold front remain uncertain, with storms potentially struggling to mature due to generally weak instability and a midlevel dry slot overspreading the region. However, a few strong to locally severe storms will be possible within this frontal regime, with a threat of locally damaging gusts and small to marginally severe hail. ...Arizona... Scattered to numerous thunderstorms are expected Friday from AZ into southern NV/UT, as moisture continues to increase east of the nearly stationary upper-level trough off of the CA coast. Modest southerly midlevel flow will support the potential for loosely organized, north to northwesterly moving clusters during the afternoon and evening. Localized severe gusts will be possible where somewhat stronger preconvective heating/destabilization occurs, which currently appears most likely across the lower elevations of southern/central AZ. Small hail and gusty winds will also be possible into northern AZ, though coverage of any severe threat remains more uncertain across this area. ...Montana... Widely scattered high-based convection is expected across parts of MT Friday afternoon and evening. Hot, deeply mixed boundary layers will support the potential for localized severe gusts, though the threat appears too disorganized and unfocused for severe-wind probabilities at this time. ..Dean.. 08/17/2023 Read more

Wisconsin has had about 250 more wildfires than usual since the start of the year due to persistent drought, according to the Wisconsin Department of Natural Resources. There have been 871 fires that have consumed nearly 4,400 acres to date, compared to the 10-year average of 614 fires and roughly 1,800 acres burned. Wisconsin Public Radio (Madison), Aug 11, 2023

Water was not flowing at Headwaters at the Comal. Water that used to be flowing and clear had become cloudy and filled with algae as extreme heat and drought depleted the flow. Fewer birds, butterflies and dragonflies can be found at the Headwaters riverside grassland ecosystem. Native grasses and plants were brown and dry. At Landa Lake, the Landa Lake Boathouse was closed early for the season due to low water levels. Launching boats was not safe. A burn ban was reinstated in early July and remained in effect. Open flames were prohibited. The extreme fire risk led the county to issue a disaster declaration due to the ongoing heat wave and intensifying drought conditions. New Braunfels Herald-Zeitung (Texas), Aug 14, 2023

Some fishing spots in Bell County have gone dry, due to drought, leaving fewer fishing opportunities. Winkler Park Campsite and Own Creek near Gatesville were dry. Lake Belton was 60% full, compared to 62% two weeks ago. The lake was at 77.7% at this time last year. KWTX TV 10 (Waco, Texas), Aug 16, 2023

5-Day Uncertainty Track last updated Thu, 17 Aug 2023 14:51:52 GMT


Wind Speed Probabilities last updated Thu, 17 Aug 2023 15:22:49 GMT

Issued at 500 AM HST Thu Aug 17 2023 190 WTPZ42 KNHC 171450 TCDEP2 Post-Tropical Cyclone Fernanda Discussion Number 20 NWS National Hurricane Center Miami FL EP072023 500 AM HST Thu Aug 17 2023 Fernanda has lacked convective activity since yesterday evening and is therefore considered a post-tropical cyclone. With no convective activity, Dvorak estimates are no longer a reliable source for intensity guidance. The initial intensity is lowered to 30 kt for this advisory largely based on the trend in geostationary satellite imagery. An occasional burst of convection is still possible given 25-26 degrees C sea surface temperatures along the forecast track of Fernanda. Model guidance indicates the cyclone will continue to weaken in an increasingly dry and stable environment for the next few days and is likely to dissipate by day 3. The remnant low is moving westward at 13 kt. This general motion is expected to continue for the next few days as the system is steered by the low-level flow around a ridge to its north. For additional information on the remnant low please see High Seas Forecasts issued by the National Weather Service. Those forecasts can be found under AWIPS header NFDHSFEPI and WMO header FZPN02 KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php. FORECAST POSITIONS AND MAX WINDS INIT 17/1500Z 16.4N 132.2W 30 KT 35 MPH...POST-TROPICAL 12H 18/0000Z 16.4N 134.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 24H 18/1200Z 16.4N 136.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 19/0000Z 16.4N 139.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 19/1200Z 16.3N 141.7W 20 KT 25 MPH...POST-TROP/REMNT LOW 60H 20/0000Z 16.4N 144.4W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 20/1200Z...DISSIPATED $$ Forecaster Bucci

Issued at 1500 UTC THU AUG 17 2023 000 FOPZ12 KNHC 171450 PWSEP2 POST-TROPICAL CYCLONE FERNANDA WIND SPEED PROBABILITIES NUMBER 20 NWS NATIONAL HURRICANE CENTER MIAMI FL EP072023 1500 UTC THU AUG 17 2023 AT 1500Z THE CENTER OF POST-TROPICAL CYCLONE FERNANDA WAS LOCATED NEAR LATITUDE 16.4 NORTH...LONGITUDE 132.2 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 12Z THU 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 12Z THU 00Z FRI 12Z FRI 00Z SAT 12Z SAT 12Z SUN 12Z MON PERIODS TO TO TO TO TO TO TO 00Z FRI 12Z FRI 00Z SAT 12Z SAT 12Z SUN 12Z MON 12Z TUE FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT $$ FORECASTER BUCCI

Issued at 500 AM HST Thu Aug 17 2023 000 WTPZ32 KNHC 171450 TCPEP2 BULLETIN Post-Tropical Cyclone Fernanda Advisory Number 20 NWS National Hurricane Center Miami FL EP072023 500 AM HST Thu Aug 17 2023 ...FERNANDA BECOMES A REMNANT LOW... ...THIS IS THE LAST NHC ADVISORY... SUMMARY OF 500 AM HST...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...16.4N 132.2W ABOUT 1515 MI...2440 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...W OR 270 DEGREES AT 15 MPH...24 KM/H MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 500 AM HST (1500 UTC), the center of Post-Tropical Cyclone Fernanda was located near latitude 16.4 North, longitude 132.2 West. The post-tropical cyclone is moving toward the west near 15 mph (24 km/h) and this general motion is expected to continue for the next few days. Maximum sustained winds have decreased to near 35 mph (55 km/h) with higher gusts. Continued weakening is forecast during the next couple of days, and Fernanda is likely to dissipate by the weekend. The estimated minimum central pressure is 1005 mb (29.68 inches). HAZARDS AFFECTING LAND ---------------------- None NEXT ADVISORY ------------- This is the last public advisory issued by the National Hurricane Center on this system. $$ Forecaster Bucci

...FERNANDA BECOMES A REMNANT LOW... ...THIS IS THE LAST NHC ADVISORY... As of 5:00 AM HST Thu Aug 17 the center of Fernanda was located near 16.4, -132.2 with movement W at 15 mph. The minimum central pressure was 1005 mb with maximum sustained winds of about 35 mph.

Issued at 1500 UTC THU AUG 17 2023 000 WTPZ22 KNHC 171449 TCMEP2 POST-TROPICAL CYCLONE FERNANDA FORECAST/ADVISORY NUMBER 20 NWS NATIONAL HURRICANE CENTER MIAMI FL EP072023 1500 UTC THU AUG 17 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). POST-TROPICAL CYCLONE CENTER LOCATED NEAR 16.4N 132.2W AT 17/1500Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT 13 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1005 MB MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT. 12 FT SEAS.. 90NE 30SE 30SW 90NW. 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 16.4N 132.2W AT 17/1500Z AT 17/1200Z CENTER WAS LOCATED NEAR 16.4N 131.5W FORECAST VALID 18/0000Z 16.4N 134.1W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 18/1200Z 16.4N 136.6W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 19/0000Z 16.4N 139.2W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 19/1200Z 16.3N 141.7W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 20/0000Z 16.4N 144.4W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 20/1200Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 16.4N 132.2W THIS IS THE LAST FORECAST/ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON THIS SYSTEM. FOR ADDITIONAL INFORMATION ON THE REMNANT LOW PLEASE SEE HIGH SEAS FORECASTS ISSUED BY THE NATION WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFEPI AND WMO HEADER FZPN02 KWBC. $$ FORECASTER BUCCI

The City of Lampasas entered Stage 4 Drought Response, or critical water shortage conditions, on Aug. 15, due to the low level of Stillhouse Hollow Reservoir. Lawn watering is permitted once weekly. Water may not be used to wash motor vehicles, except in the immediate interest of public health, safety and welfare. Pools may not be filled or refilled. KWTX-TV 10 News Waco (Texas), Aug 16, 2023

A Vermilion Parish rice farmer stated that he has kept the wells pumping for the past two and a half to three months since no rain has fallen. KATC (Lafayette, La.), Aug 16, 2023

Kittitas County residents were urged to conserve water amid ongoing drought. Water rights have been secured for junior groundwater uses associated with small-scale and individual well use, offering more security during droughts. KNDU-TV NBC 5 Kennewick (Wash.), Aug 16, 2023

The City of Beaumont was experiencing so many water main breaks that they were considering hiring contractors to assist with water main repairs as extreme heat and drought continued to take a toll. Water conservation was mandatory under the stage 3 restrictions. 12 News KBMT (Beaumont, Texas), Aug 16, 2023

Algae in Lake Manatee caused drinking water to taste unpleasant last month, but the peculiar taste should be gone. The algae continued to bloom amid drought conditions and was expected to persist until the drought ends. Sarasota Herald-Tribune (Fla.), Aug 16, 2023

Pasture grasses in Osceola County mostly dried up in May and June amid the hot, dry weather. Many area beef farmers had to feed hay supplies intended to be used in the winter months, meaning that more hay will have to be purchased for the winter. Some cattle may also be sold before winter. Drought hurt the hay crop. Yields from the first cutting were 20% to 40% less than normal. Drought also decreased the size of the second cutting of hay. Christmas trees were affected by the dry weather, too. Growers lost 10% to 40% of the seedlings planted this year. Christmas tree prices will not be impacted immediately, but may show up years from now if there is a shortage of trees. Cadillac News (Mich.), Aug 16, 2023

No watches are valid as of Wed Aug 16 22:12:01 UTC 2023.

5-Day Uncertainty Track last updated Wed, 16 Aug 2023 20:46:55 GMT


Wind Speed Probabilities last updated Wed, 16 Aug 2023 21:35:57 GMT

Issued at 400 PM CDT Wed Aug 16 2023 000 WTPZ44 KNHC 162044 TCDEP4 Tropical Storm Hilary Discussion Number 2 NWS National Hurricane Center Miami FL EP092023 400 PM CDT Wed Aug 16 2023 Hilary has not changed much this afternoon. A large burst of convection, with cloud top temperatures colder than -85 degrees C, continues to obscure the low-level circulation and some outflow has developed on the southern semicircle of the storm. Subjective and objective satellite intensity estimates range from 30 to 43 kt and the initial intensity is remains at 35 kt. The storm is moving to the west-northwest at 13 kt. Hilary is forecast to gradually turn, first to the northwest by day 2 and then to the north-northwest by day 3 with the same general forward motion. This is likely driven by a building ridge over the United States and a trough off the coast of California. The short-term track prediction has shifted to the right of the previous forecast, largely due to an adjustment in the rather uncertain initial position. It is closest to the simple consensus aid, TVCE. Strengthening is still expected due to the conducive atmospheric conditions and warm sea surface temperatures. Hilary is forecast to be in an area of weak vertical wind shear through 72-96 hours and remain over warm waters through 72 hours. Therefore, steady to rapid intensification is anticipated and the official forecast shows Hilary becoming a hurricane in 24 hours. However, the system is broad and it could take slightly longer to initially consolidate and strengthen. Beyond day 3, Hilary is forecast to cross over a gradient of cooling ocean waters which should induce a weakening trend. The system is still expected to be post-tropical by the end of the forecast period. It is important to remind users to not focus on the exact forecast track and intensity of Hilary, especially in the latter parts of the forecast period. Due to the nearly parallel angle of approach to the Baja California peninsula, small changes in the cross track position may result in large changes to when and where the system ultimately approaches the coast. Regardless, wind and rainfall impacts are likely to extend far from the center of Hilary. KEY MESSAGES: 1. Hilary has the potential to bring impacts to the Baja California Peninsula and portions of the southwestern United States this weekend. Although it is too soon to determine the location and magnitude of rainfall and wind impacts, interests in these areas should monitor the progress of Hilary and updates to the forecast. 2. Large swells from Hilary will spread northward along the coast of southwestern Mexico and the Baja California Peninsula during the next days. FORECAST POSITIONS AND MAX WINDS INIT 16/2100Z 13.7N 103.7W 35 KT 40 MPH 12H 17/0600Z 14.5N 105.4W 50 KT 60 MPH 24H 17/1800Z 15.6N 107.6W 65 KT 75 MPH 36H 18/0600Z 16.8N 109.6W 75 KT 85 MPH 48H 18/1800Z 18.2N 111.3W 90 KT 105 MPH 60H 19/0600Z 20.0N 112.8W 105 KT 120 MPH 72H 19/1800Z 22.3N 113.7W 105 KT 120 MPH 96H 20/1800Z 27.8N 115.2W 70 KT 80 MPH 120H 21/1800Z 34.3N 118.3W 40 KT 45 MPH...POST-TROP/INLAND $$ Forecaster Bucci