Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/25/18


Area Forecast Discussion
National Weather Service Green Bay WI
1034 PM CDT Wed Oct 24 2018 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Thursday Issued at 211 PM CDT Wed Oct 24 2018 The latest RAP analysis and satellite/radar imagery show high pressure centered across Lake Michigan and a trough of low pressure over the northwest Great Plains early this afternoon. Scattered clouds are lingering over eastern WI where there is some residual low level moisture off Lake Michigan. Meanwhile, clouds are increasing over the Plains and northern Mississippi Valley ahead of the next system. As this system moves closer to the region, cloud trends and precip chances are the main forecast concern. Tonight...The high pressure system will gradually shift east of the region as shortwave energy moves across the Dakotas. Mid and high clouds will be on the increase through night ahead of this system. Models rotate deeper lower level moisture north of the U.P. border, and progged soundings indicate that dry air will remain below about 700mb, so the threat of precip appears low. With considerable more cloudiness by morning, warmer lows ranging from the upper 20s to middle 30s at most locations. Thursday...The shortwave energy and trough of low pressure will continue to inch closer to the region. Ample mid and high clouds will be overhead for much of the day, which should result in mostly cloudy skies. However, low to mid level moisture transport axis is progged to remain west of the region through the day, with dry air positioned below 10 kft as it recycles around the exiting surface high. So continue to think most of the day will be dry, but did leave a small chance of a shower over north and west of Rhinelander late in the afternoon. Raised temps slightly based on the latest trends, with highs mainly in the lower 50s. .LONG TERM...Thursday Night Through Wednesday Issued at 211 PM CDT Wed Oct 24 2018 Pattern during first part of long term characterized by several shortwave trofs moving across the region. Latest GFS and ECMWF model runs show some discrepencies in location of weekend waves and resultant precipitation amounts, so will continue with blend of models for precip location and amounts. Ridging at surface and aloft moves in early next week before next chance of precipitation. Although there are model differences again, both the GFS and ECMWF indicate a stronger system ejecting out of the SW sometime during the second half of next week. Max temps through the period will be a couple degrees either side of late October averages. Lows will be a couple degrees above average given expected cloud cover during the period. && .AVIATION...for 06Z TAF Issuance Issued at 1030 PM CDT Wed Oct 24 2018 Moisture will gradually return to the area as high pressure departs to the east and a storm system slowly organizes over the Plains. But the initial return of the moisture will occur at middle and upper levels, so low clouds will be slow to develop across the area. As a result, VFR conditions are anticipated throughout the TAF period. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......JKL AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1010 PM CDT Wed Oct 24 2018 .DISCUSSION... The heaviest rain is now confined to the coast but additional showers continue to develop over the region in response to an upper level trough over North Texas, favorable jet dynamics and abundant moisture. SE TX will lie in a RRQ overnight so although the radar is looking more benign to the west, am hesitant to lower PoPs too significantly. Will lower PoPs to likely after 06z and reevaluate at that time. Had some flooding in Brazoria and Galveston counties this evening. Some cars were flooded in Santa Fe and several roads had high water in Dickinson. An automated gage in Santa Fe reported 5 inches of rain and the NWS office had 4.24 inches of rain. 43 && .PREV DISCUSSION... /ISSUED 701 PM CDT Wed Oct 24 2018/ AVIATION... Showers and light rain continue across most of the terminals this evening, with isolated thunder embedded south of I-10 at LBX, GLS, and HOU. Short term guidance shows a clearing line with the passing of the upper level disturbance starting in the western TAF sites around 07-09Z and clearing most terminals by 10-13Z. IFR ceilings and visibilities will be possible overnight, with some potentially lowering to LIFR criteria at our more vulnerable sites. These ceilings and visibilities will stick around through most of the morning tomorrow until the drier air begins to filter in. Winds will also back out of the NW overnight. Winds are currently out of the NE and are still gusty at times along the coastal TAF sites, but should lower in speed overnight. By the afternoon hours ceilings should begin to lift with mostly high MVFR and VFR prevailing by the early evening hours. Hathaway PREV DISCUSSION... /ISSUED 328 PM CDT Wed Oct 24 2018/ DISCUSSION... Key forecast messages: - Storms tonight should be fast moving but could still produce locally heavy rainfall. - Storms done and out of area by rush hour Thursday morning. - Next cold front Sunday night into Monday. - Dewpoints in the 40s behind the front on Monday? Yes please. - Return flow with a few showers possible for Halloween. NEAR TERM [Through Tonight and Thursday]... Overall the near term portion of the forecast has not changed much from the last day. Surface analysis of 20Z observations show the surface low developing off the coast from Matagorda Bay. The warm front swings out of it just inland from PSX to GLS with 70 dewpoints just on the coast. Water vapor imagery at the mid and low level channels picks up on the remnants of Willa or its associated vorticity. There is also a potent upper level low over New Mexico which has a strong jet streak pushing up through the Texas Panhandle. Large scale lift with the vorticity from Willa should move over the area tonight and likely deepen the surface low some. It looked like this low may stay just off the coast but with the warm front pushing just inland, this area of low pressure may follow along the front as it moves NE tonight. HRRR and a few of the WRF runs have the surface low just inland and think this is probably going to be the trend forward. This may open an opportunity for a few low topped storms to rotate as we have seen off the coast prompting special marine warnings. Still agree with SPC that the severe threat will be low since instability will be marginal at best just inland along the warm front. Any ins Luchs tability will be driven by warm advection and doubtful there will be true surface based convection that can truly take advantage of the low level shear. Nonetheless, something to monitor basically now through about midnight. Overall the threat for heavy rainfall will be fairly localized. The line of showers and storms with this system can produce a good 1 inch of rainfall across the area with maybe 2 inches being the high end. An isolated 3 inches cannot be ruled out but those areas may be where there has already been some rainfall today. Highest totals look to be along the coast with the surface low and warm front to maybe as far inland as I-10. There does look to be a second max in rainfall mainly from Brenham to Lufkin northward. Biggest impacts from the rainfall will be street/urban flooding with rapid rises on the bayous but bayous should be able to handle the rainfall. There may be some subtle rises on rivers but mainly this additional rainfall will just increase how long the rivers will take to come down from any flood/action stages. The main timing for convection looks to be basically from 6PM to 9PM with a peak in the activity 9PM to Midnight. Activity should be moving out of the area after midnight and be done Thursday morning. Overpeck SHORT/LONG TERM [Thursday Night Through Wednesday]... A cold front will push through the area on the back side of the low pressure and remnants of Willa for Thursday. This should allow for low temperatures in the 50s with offshore winds. This provides a good opportunity to open the windows and air out the house if you need. The next cold front looks to come through Sunday night into Monday morning with out any precipitation. Upper level pattern will be quite favorable for this kind of frontal passage with a ridge developing over the 4 Corners and a broad trough over the Great Lakes and eastern half of the U.S. Dewpoints should drop into the 40s behind this front for even drier conditions to start next week. The pattern then becomes more progressive with the upstream ridge moving over the Plains and a trough developing in its place over the Great Basin. As this system moves towards the Rockies lee troughing and return flow develops so there may be a few warm air advection showers for Halloween. Overpeck MARINE... Winds and seas are generally diminishing across the Gulf waters, and so the small craft advisory will be allowed to expire as scheduled. However, caution flags will remain up through at least the evening. Additionally, locally higher winds and waves can be expected, along with the potential for waterspouts, through at least this evening. On the backside of the coastal low, winds will become northwesterly, with this shift occurring overnight. There may be another brief need for caution flags late tonight into tomorrow, but conditions will improve into the end of the week as the coastal low exits the area. Tides are now running nearly two feet above astronomical tide levels, and the upcoming low tide is only expected to fall to around 2.5 feet above MLLW. This sets the stage for a high tide this evening of at least 3.5 feet above MLLW, and 4 feet is not impossible. Because of this, will keep the current setup of beach hazard statements and coastal flood advisories in place. However, if water levels begin rising more than expected, that may have to be reevaluated. At the very least, flood prone roads are expected to have water - particularly Highway 87/124, and possibly the Blue Water Highway as well - around high tide. East to northeast winds also means that rip currents will also continue to be an issue. Luchs && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 58 65 52 75 54 / 100 0 0 0 0 Houston (IAH) 61 68 53 75 55 / 90 10 0 0 0 Galveston (GLS) 67 70 60 74 63 / 100 20 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk until 4 AM CDT Thursday for the following zones: Brazoria Islands...Galveston Island and Bolivar Peninsula. Coastal Flood Advisory until 11 PM CDT this evening for the following zones: Brazoria Islands...Galveston Island and Bolivar Peninsula. GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 11 PM CDT this evening for the following zones: Galveston Bay...Matagorda Bay. SMALL CRAFT SHOULD EXERCISE CAUTION until 10 AM CDT Thursday for the following zones: Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM...Coastal waters from High Island to Freeport TX out 20 NM...Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM...Waters from High Island to Freeport TX from 20 to 60 NM. && $$ Discussion...43
Area Forecast Discussion
National Weather Service Key West FL
942 PM EDT Wed Oct 24 2018 .DISCUSSION...In the middle and upper levels( 700-200 mb), latest available GOES-R satellite imagery overlaid with model streamline analysis as of 900 pm, detail the developing NW to SE oriented negatively tilted axis of the next burgeoning trough over the spine of the Central and Southern Rocky Mountains. Just downstream of that, a full latitudinal ridge is in place from Northern Minnesota down to the Central Gulf of Mexico. And east of that, there is a full latitudinal trough from Maine south southeast to near 25N 65W. The Florida Keys are beneath deep and warm ridging on the right side of the aforementioned ridge. At the surface and in the lower to mid levels(Surface to 700 mb), latest available GOES-R satellite imagery overlaid with marine and land surface observations and surface analysis, depict a 1033 mb cool anticyclone situated over Northern Michigan. Well south of that, a weak cold front is snaking across South Florida, with the attendant frontal boundary extending westward to low pressure off of the SE Texas Coast. As as result, last evenings 00Z sounding illustrated a gentle north to northeast flow from off the surface to 800 mb, backing to between northwest and north from 800 mb back to 600 mb, then increasing. Total columnar PWAT of 1.84 inches lends to a fairly moist lower to mid troposphere. .CURRENTLY...As of 900 pm, skies are mostly clear across the islands and surrounding waters. A few showers are now developing along boundaries developing across the Nearshore Gulf waters north of the Middle Keys. Temperatures along the Florida Keys are in the upper 70s to around 80 with dewpoints in the middle to upper 60s. C-man stations along the Florida Reef are recording northeast winds and 10 to 15 knots and island sensors are recording north to northeast winds at 5 to 10 mph. .SHORT TERM...Overnight, HRRR and GFS models continue with a gentle to moderate north to northeast flow across the islands and adjoining waters,as the frontal boundary is still north of the Keys. Some weak low level confluence will provide development of isolated showers which will drift south to impact the islands or develop over some locations, but any rainfall amounts will be slight. For that reason will maintain the slight chances for showers already in the forecast. No changes attm. && .MARINE...Overnight, Light to gentle northeast flow expected, with gentle to moderate out on the Straits. No SCEC or SCA. && .AVIATION... VFR conditions expected at both terminals with light northeasterly to easterly winds through the period. && .CLIMATE... On this date, the record high temperature of 89 degrees was last set in 1990. We tied this daily record today, reaching 89 degrees at the Key West International Airport. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Futterman Aviation/Nowcasts....WLC Upper Air/Data Collection......SD Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest
Area Forecast Discussion
National Weather Service Tulsa OK
851 PM CDT Wed Oct 24 2018 ...UPDATE... .DISCUSSION... Large area of light rain continues to push off to the northeast with dry air across northeast Oklahoma and northwest Arkansas eating away at the northeast edge of the rain shield. The heaviest rain, as expected, remains across southeast Oklahoma and into portions of west central Arkansas. The dry slot is not far to the southwest of the area and will likely move into parts of southeast Oklahoma near midnight and push northeastward through sunrise. The main changes to the going forecast have been to retool the POPs according to the above thinking, generally decreasing them in far northeast Oklahoma and far northwest Arkansas through mid evening and across southeast Oklahoma after midnight. Also decreased the QPF after midnight in the south. Updates out. && .PREV DISCUSSION... /Issued 642 PM CDT Wed Oct 24 2018/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. An area of rain will cross the TAF sites from tonight through Thursday morning. Flight conditions will deteriorate in the region to IFR ceilings by late tonight. IFR ceilings are expected to persist area wide on Thursday as the rain diminishes from west to east. Winds will be light through the forecast period. PREV DISCUSSION... /Issued 329 PM CDT Wed Oct 24 2018/ DISCUSSION... The main forecast concerns are rain chances/timing/amounts tonight and Thursday, rain chances Saturday night into Sunday and winds on Sunday. Finally, rain chances on Halloween. A southern stream shortwave trough, with embedded PV max over eastern NM, is ejecting into the Plains this afternoon. Light rain is spreading northeast per radar/mesonet data across OK ahead of the system and will continue to do so this evening and overnight. The latest HRRR guidance suggests a faster progression across the region tonight than what the blended PoP guidance would suggest, and thus some tweaks were made. A faster ramp up and ramp down was made in the PoP grid trends. Rain amounts should remain light with no suggestion of any convective assistance with the instability tied up well to our south closer to the Gulf surface front. Some lingering chance PoPs were maintained across the north on Thursday as a PV anomaly rotates around the basal portion of the ejecting trough and over our area. After this system and the trough axis passes, PoPs will come to a quick end from west to east Thursday night. Lows tonight should be a bit warmer than last night in most places with widespread cloud cover, and a low diurnal variation is expected on Thursday with clouds hanging on until the second wave passes. High temps ramp up quickly with more sunshine to near normal Friday and will peak on Saturday above normal ahead of the next cold front. The upper pattern will transition from the current split flow regime to more of a consolidated and amplified western ridge- eastern trough pattern over the CONUS by the weekend, with a trend toward progressive thru next week. A strong system in the NW flow will pass by to our northeast this weekend and will bring a low chance for showers to far NE OK/NW AR Saturday night into Sunday. A concomitant cold front will knock temps back below normal Sunday, while also increasing winds. Looks like a classic deeply mixed airmass behind the front, and favorable for momentum transfer. Winds will be gusty during the day, especially across NE OK and NW AR. Went above blended guidance for winds. The next storm system will affect the region by Halloween and the first of Nov. The timing of this system still remains in question, with the GFS faster than the ECMWF. For now, will not go any higher than chance PoPs and will wait for the details to be resolved before a more aggressive approach is taken. Regardless, there is definitely a chance that Halloween evening festivities could be wet. Lacy && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...22