Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/25/18


Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
526 PM MDT Thu May 24 2018 .AVIATION... 00Z TAF CYCLE A ridge of high pressure aloft will continue to slowly build over the American Southwest through Friday, keeping mostly clear and tranquil conditions over northern and central New Mexico. VFR condtions expected at all TAF sites through the next 24 hours. && .PREV DISCUSSION...256 PM MDT Thu May 24 2018... .SYNOPSIS... A few thunderstorms remain possible through mid evening near and just east of the Sacramento mountains. If storms shift eastward off the higher terrain, they will have the potential to become strong or severe with hail and gusty winds. Otherwise, smoke from the Buzzard fire will be the main concern through the evening from areas near Aragon toward Pie Town. After this evening, the next potential for storms exists on Sunday afternoon and evening along the Texas border where a dryline will sharpen. Otherwise, near to above normal temperatures are expected for the next week. Breezy afternoon southwest winds will become common Saturday through at least Monday. This will cause critical fire weather concerns, especially for portions of northeast New Mexico. && .DISCUSSION... A few thunderstorms have developed over the Sacramento Mountains this afternoon, but are struggling to make it off the higher terrain. If they do manage to shift eastward into the higher dewpoints and better instability, we could see a severe storm or two. The HRRR has been suggesting that one or two storms move into eastern Lincoln County this afternoon. Shear is lacking today as the upper level ridge builds overhead so no storms should last for very long. Otherwise, the moisture across the plains is slowing mixing out this afternoon, though it will likely slosh back, mainly south of I-40, overnight. On Friday, the upper level ridge will remain over NM, though the moisture over eastern NM will mix out even further eastward. As a result, the potential for additional storms on Friday aftn/eve is next to nil. Instead, look for temperatures to continue to rise, with most areas around 5 to 15 degrees above normal. By Saturday, the ridge will slide eastward and southwest flow will increase over western NM as an upper level low pressure system slowly shifts over the Great Basin. This low will very slowly meander toward the northeast through Monday. This will mean continue dry, southwest flow over much of NM. One exception may be near the Texas border on Sunday aftn/eve where the dryline will sharpen and a few storms may develop. However, these storms will quickly move into Texas if they form. Otherwise, Saturday through Monday will feature near to above normal temperatures, and increasingly breezy conditions (at least thru Sunday). Generally quiet conditions will persist through the mid and latter half of next week. Temperatures will soar though as height rises continue to increase. In fact, high temperatures in Roswell may reach or break the century mark starting tomorrow through the end of next week. 34 && .FIRE WEATHER... ...RETURN OF CRITICAL FIRE WEATHER CONDITIONS THIS WEEKEND... As is typical for late May, western NM remains quite dry with surface level moisture sloshing around eastern NM. Currently, the higher dewpoints are struggling to hold their ground over east central to northeastern parts of the state, but should see some short-lived recovery overnight. Into the daytime Friday, the moisture will abruptly scour out and the entire forecast area will be plagued by RH less than 10 percent by late afternoon with temperatures rising a few more degrees. Fortunately, through this time frame wind speeds will remain relatively light due to an absence of stronger flow aloft. Into Saturday, the Pacific trough will be moving inland as an upper low, bringing a bit of stronger momentum aloft toward NM. To complement this, the lee side surface trough will also deepen, imposing a slightly stronger surface gradient with breezy to windy surface/20ft winds by Saturday afternoon, mostly in northwestern and northeastern areas of the state. While not overly strong, marginally critical wind speeds in these northwestern and northeastern areas will be juxtaposed over single digit RH, high Haines indices, and well above average temperatures. The coverage of these stronger winds is just persuasive enough that a Fire Weather Watch will be issued for the northeast highlands for Saturday with winds being the lower confidence element. The pattern will be slow to evolve into Sunday with the upper low slowly working from NV to UT while lee side surface troughing persists. This would steer breezy to windy conditions over the eastern half of NM with the strongest speeds over the northeast corner where another round of critical conditions is expected. Winds could slacken a bit into Monday as the low weakens over northern UT, and should drop off much more into Tuesday as the low is sheared out. This will limit critical conditions in the mid week period, but no precipitation is foreseen through this time either. 52 && .ABQ WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday afternoon through Saturday evening for the following zones... NMZ103. && $$
Area Forecast Discussion
National Weather Service Boston/Norton MA
959 PM EDT Thu May 24 2018 .SYNOPSIS... High pressure moves offshore tonight and Friday, bringing warmer weather on gusty southwest winds. A cold front drops south across the region late Saturday into Saturday evening and will bring scattered showers and thunderstorms followed by much cooler and unsettled weather Sunday with some improvement by Monday. Mainly dry and warmer weather returns for Tuesday through Thursday as high pressure moves in. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 10 pm update... */ Highlights... - Areas of dense fog for S/SE coastal RI and MA - Visibility as low as a quarter of a mile - Associated fog bank, expanding across the region towards midnight, pushing E and offshore by daybreak */ Discussion... GOES-16 nighttime microphysics tells the story, as does the 0z Chatham sounding. An area of pooled moisture trapped beneath a stout inversion just off the deck is lending to low clouds and/or fog. Moving with the mean wind flow, this deck pushed through late last night with NE winds pushing out towards Long Island as high pressure built across the Gulf of Maine. Now with the high S/E, seeing the start of return S flow and the mean wind shifting out of the W. Progressing towards morning, will see the associated fog bank expand and then begin to push off to the E towards daybreak. SPECIAL WEATHER STATEMENT for lower visibility, but given residency time and visibility holding for the most part above a quarter of a mile, will hold off on any dense fog advisories. A combination of high-res guidance including the NBM and HRRR has modeled the fog bank quite well, the basis for the going forecast. Otherwise, clear conditions expected tonight with light S/SW winds. Airmass remains dry enough to preclude valley fog. Lows should drop back into upper 40s to mid 50s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... * Some locations make a run at 90 degrees Friday * High pressure moves offshore Friday and Friday night with prevailing W/SW flow. Forecast soundings show deep mixing with decent 30-40kt low level jet, strongest near Cape Cod and Islands where strong inversion will be present. Thus, we should see 25-35 mph gusts across much of SNE with perhaps a few 40kt gusts across SE MA. Model 2-meter temperatures suggest highs easily reach into 80s inland, if not 90 degrees in lower CT valley, Merrimack Valley, and greater Boston, especially given gusty W/SW winds. Dewpoints drop into 40s (or even upper 30s) during the afternoon so it will just be a "dry heat" this time. Certainly not humid. Winds diminish Friday night but airmass remains warm in advance of frontal boundary still well to our north. Lows should drop back into 60s along with some mid and high clouds. Less confident on low clouds/fog returning to South Coast so this may need to be added in later forecasts. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Highlights... * Very warm and humid Sat with sct afternoon showers/t-storms * Much cooler with occasional showers Sun * Some improvement Mon but below normal temps * Mainly dry and warmer weather returns Tue through Thu Saturday into Saturday night... Very warm airmass in place Sat ahead of approaching backdoor cold front. 925 mb temps 22-23C supports highs upper 80s to perhaps some lower 90s interior, but cooler near the south coast due to SW flow. Dewpoints will be climbing into the 60s so it will be increasingly humid. This front will move south into SNE during mid/late afternoon reaching the south coast toward evening. Much cooler air will follow with ENE winds and sharply falling temps. Locations in NE MA may drop into the 60s by late afternoon and there could be some gusty winds here as well Sat evening as the cooler air rushes in. Environment destabilizes ahead of the front with MLCAPES approaching 1000 J/kg with moderate deep layer shear. However, mid level lapse rates are unfavorable and will likely by a limiting factor to widespread convection. Still expect sct showers/t-storms developing in the afternoon and lingering into Sat evening. Sunday into Monday... Much cooler airmass Sunday as high pres builds south from the Maritimes with NE flow. Models are also indicating a wave developing on the frontal boundary south of New Eng which will likely bring some rain at times with cool NE winds and temps potentially remaining in the 50s. Some improvement expected Monday with mainly dry weather but still cool with lots of clouds and onshore winds. Tuesday through Thursday... Mainly dry and warmer weather returns as mid level ridge builds into the region with rising heights. Weak fropa Tue but it should come through dry then high pres builds into the region Wed/Thu. Temps should warm back well into the 70s and some 80s. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday Night/...High confidence. Tonight... IFR-VLIFR FG bank over SE RI and MA, expanding towards 6z, will gradually push E with increasing W flow towards daybreak. Expect towards 12z only ACK may see some lingering lower VSBYs. Friday... Increasing SW winds immediately with sunrise. Gusts up to 25-30 kts through much of the day, sustained around 15 kts. SCT mid- decks. Friday night... SW winds taper but remain brisk over S/SE coast with sustained flow around 10 kts and gusts up to 20 kts. KBOS Terminal...High confidence in TAF. Will hold the fog bank just S of the terminal. It is possible it may edge in tonight close to 04-05z. KBDL Terminal...High confidence in TAF. Outlook /Saturday through Tuesday/...Moderate confidence. Sunday: Mainly MVFR, with areas IFR possible. Breezy. Chance SHRA. Sunday Night: Mainly MVFR, with areas IFR possible. Slight chance SHRA. Memorial Day: Mainly MVFR, with local IFR possible. Slight chance SHRA. Monday Night: Mainly VFR, with local MVFR possible. Slight chance SHRA. Tuesday through Tuesday Night: VFR. Wednesday: && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Friday Night/...High confidence. 10 pm update... Low clouds and/or fog will remain an issue for the S/SE waters overnight. Expanding towards midnight, the associated fog bank will push E towards daybreak with increasing, steering W flow, the last traces over the SE outer waters by 8 am, exiting. Previous discussion... Small Craft Advisories posted for all waters for increasing SW winds tonight (NE MA waters) and Friday (remainder of MA/RI waters). S/SE flow this afternoon with local sea breezes. Should see some 15-20kt gusts along south coastal near shore waters with locally choppy seas due to incoming high tide. Fog and low clouds linger on waters south of islands. High pressure moving off the coast will bring increasing SW winds tonight and Friday. Enough of a low level jet tonight to bring marginal SCA conditions to NE MA waters, otherwise winds increase during day Friday across all waters with strongest gusts (30kt) near shore. Winds and seas gradually subside Friday night. Outlook /Saturday through Tuesday/...Moderate confidence. Sunday through Sunday Night: Winds less than 25 kt. Areas of rough seas. Chance of rain showers. Memorial Day: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers. Monday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday Night through Wednesday: Winds less than 25 kt. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...Air Quality Alert from 11 AM to 11 PM EDT Friday for RIZ001>008. MARINE...Small Craft Advisory from 10 AM Friday to 2 AM EDT Saturday for ANZ231>234. Small Craft Advisory from 11 AM to 8 PM EDT Friday for ANZ230- 236-251. Small Craft Advisory from 11 AM Friday to 2 AM EDT Saturday for ANZ235-237. Small Craft Advisory until 8 PM EDT Friday for ANZ250. Small Craft Advisory from 8 AM to 8 PM EDT Friday for ANZ254>256. && $$ SYNOPSIS...KJC/JWD NEAR TERM...KJC/Sipprell/JWD SHORT TERM...JWD LONG TERM...JWD AVIATION...KJC/Sipprell/JWD MARINE...KJC/Sipprell/JWD
Area Forecast Discussion
National Weather Service Columbia SC
1035 PM EDT Thu May 24 2018 .SYNOPSIS... The region will remain moist and unstable the next few days between a ridge offshore and weak low pressure to the west. Scattered to numerous showers and thunderstorms, mainly during the afternoon and evening, are expected. Periods of heavy rain are possible Sunday and Monday as a plume of tropical moisture is directed into the area. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... The high moisture will continue through tonight. Much of the instability has been released and shower coverage and intensity has diminished. There will be a continued chance of showers overnight because of the high moisture and weak mid-level shortwave trough caught in the ridging but expect little coverage based on radar trends and the loss of heating. The HRRR displayed little coverage overnight. The high moisture will limit the temperature drop. Expect lows in the upper 60s to around 70. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Friday, deep moisture will remain over the forecast area allowing diurnally driven convection in the afternoon. There will be little in the way of surface forcing with the cold front that moved into the area becoming ill-defined. Therefore thunderstorms should be scattered in nature but favored to the west, further from the ridge. PWAT values near 2 inches and slow storm motion will again favor moderate or heavy rain rates. Localized flooding will be possible, particularly in low lying or poor drainage areas. Saturday, the deeper moisture will shift northward and allow for drier air to move over the forecast area. Drier air and synoptic scale subsidence will limit the extent of convection compared to previous days. Therefore will keep lower pops across the area on Saturday and Saturday night. High temperatures during this period will be in the mid to upper 80s with lows in the upper 60s to around 70 degrees. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Troughing to our west and the Bermuda High to the east will direct tropical moisture into the Southeast. The models have been consistently streaming a plume of high theta E air into the area Sunday and Monday. Strong moisture advection over ridging to our north will likely result in moderate rainfall with periods of heavy rainfall at times. Flooding issues may arise, particularly for areas with saturated soils from the antecedent wet pattern. The remainder of the long term is less certain but the potential exists for periods of heavy rain through Thursday. Expecting mostly cloudy skies through the long term so temperatures should be mild with lows above normal and highs near normal. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... Showers have mostly tapered off, but due to abundant moisture, considerable cloudiness remains. Ceilings are expected to lower to IFR tonight, and stratus will persist through Friday morning. Fog now looks less certain due to a 20 to 25 kt low level jet that has developed. However, the NAM has the jet weakening by morning, so patchy fog is still possible. Another round of thunderstorms can be expected Friday afternoon and evening, with heavy rain the primary threat. Winds will remain light and generally out of the southeast, except gusty and erratic in the vicinity of convection. EXTENDED AVIATION OUTLOOK...Late night and early morning IFR to MVFR ceilings and visibilities with fog and stratus, along with mainly diurnal showers and thunderstorms through early next week as a very moist air mass remains over the region. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Hastings NE
755 PM CDT Thu May 24 2018 .UPDATE... Issued at 659 PM CDT Thu May 24 2018 Regarding evening-overnight storm chances: Refreshed our Hazardous Weather Outlook (HWOGID) a little bit ago, mainly in an "attempt" to highlight that the primary focus for possible severe storms this evening should be within the southwest quadrant of our coverage area (CWA). Would normally hesitate getting too "cute" trying to pinpoint areal details in this rather uncertain/murky pattern, but now that we are within a few hours of potentially dealing with a few severe storms (primary window of opportunity will be 7PM- midnight), it appears via satellite/radar trends and also very short term models such as the HRRR that our primary shot at severe storms will hinge on whether or not the activity currently blossoming just southwest of our CWA over northwest KS maintains its intensity as it expands/evolves eastward. Like last night, seasonably-weak deep layer shear averaging only 20-25kt will be a limiting factor in more widespread/organized severe storms, but with a corridor of healthy mixed-layer CAPE well into the 1000-2000 J/kg range in place primarily over our western zones for several more hours, at least some marginally-severe multicell storms are possible. Outside roughly the southwest quadrant of our CWA, at least small (20-30 percent) storm chances/PoPs exist for later tonight, but the odds of severe storms appear fairly low. && .SHORT TERM...(This evening through Friday) Issued at 256 PM CDT Thu May 24 2018 Short term is a tough call. Numerical models point toward convection erupting along a dry-line near the Kansas/Colorado border, especially near where a surface low should develop in northwestern Kansas. Convection has already developed along a boundary over the Sandhills, but CIN is tamping down on these cells for the time being this afternoon. If convection develops, it will likely form into an MCS and head east, being supported by an increasing low-level jet this evening, with the best low-level convergence expected to be just southwest of the CWA. I would expect damaging wind gusts and maybe up to golf ball hail to be primary threats. Deep layer shear will be relatively weak, but lapse rates could be at least moderate. There is a shot at some severe weather, especially in north central Kansas where there is a stronger signal near a surface low, but pretty convection may very well pop up just about anywhere as a low-amplitude perturbation moves by tonight and could be severe on the Nebraska side as well. Primary time of focus will be between 6 or 7 pm and midnight. .LONG TERM...(Friday night through Thursday) Issued at 256 PM CDT Thu May 24 2018 The upper ridge will keep the heat on for the foreseeable weekend with highs in the 90s. Still going with a dry forecast with intermittent chances of showers/t-storms creeping back in Monday night as the ridge axis shifts east. Highs for the rest of the forecast will be well into the 80s/90s past the weekend,behind the ridge axis. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday) Issued at 659 PM CDT Thu May 24 2018 VFR ceiling/visibility is expected to prevail, with only fairly limited passing mid-high clouds. There will be a LOW chance of thunderstorm activity later this evening-tonight (probably most favored 03-06Z), but with better thunderstorm potential likely to focus 75+ miles south-southwest of both KGRI/KEAR, we cannot even justify a generic "vicinity thunderstorm" (VCTS) at this time in the TAFs. Wind-wise, aside from any possible thunderstorm influences, surface winds are actually expected to be relatively light through the period, with sustained speeds at-or-below 11kt the vast majority of the time. Direction will transition from southerly this evening to generally westerly during the latter half of the period Friday. && .CLIMATE... Issued at 755 PM CDT Thu May 24 2018 ..Warmest final week of May on record at Grand Island/Hastings?.. Although it`s obviously not a "sure thing" yet, our latest forecast for May 25-31 indicates that both Grand Island and Hastings (our two primary long-term climate data sites) will experience the overall-hottest last week of May on record! Listed below is the projected May 25-31 average temperature (average of the daily highs/lows) for this year, and the current warmest on record for that week: - Grand Island airport (records date back 122 years to 1896) 1) 2018...76.9 degrees (PROJECTED from current forecast!) 2) 1926...75.9 degrees 1921...75.9 degrees 4) 2014...75.6 degrees 5) 1934...75.3 degrees - Hastings airport (records include 109 years dating to 1907) 1) 2018...77.0 degrees (PROJECTED from current forecast!) 2) 1926...75.1 degrees 3) 2014...74.6 degrees 4) 1913...74.5 degrees 5) 2006...73.7 degrees && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ UPDATE...Pfannkuch SHORT TERM...Heinlein LONG TERM...Heinlein AVIATION...Pfannkuch CLIMATE...Pfannkuch
Area Forecast Discussion
National Weather Service Huntsville AL
910 PM CDT Thu May 24 2018 .NEAR TERM...(Tonight) Issued at 910 PM CDT Thu May 24 2018 The area stayed for the most part shower/storm free today as the result of a surface high to our north and a rather dry profile, which is evident in the 00z OHX sounding. To our NE there are a few storms still going but those are stuck to the terrain and with weak flow aloft don`t believe these will move towards the area. Latest RAP analysis shows a region of higher MUCAPE and Theta-E over areas E/SE of Huntsville. A weakening line of storms moving just north of ATL does appear to be moving towards the better Theta-E and they could hold together long enough to clip portions of DeKalb and Marshall counties this evening. Made some adjustments to PoPs to account for those storms. In terms of temps, nudged values down in the typical cool spots but didn`t make any other changes to the overall forecast for tonight. Lows in the mid to upper 60s. .SHORT TERM...(Friday through Saturday Night) Issued at 224 PM CDT Thu May 24 2018 The MCV in GA is forecast to lift back northeast on Friday as shortwave troughs in the central Plains move into the lower MO valley and Ozark plateau. This will enable weak southerly flow to develop in low levels and lift the convergence zone (albeit weakening) northeastward through the TN valley on Friday afternoon and evening. This along will be enough to bring greater chances of thunderstorms during peak heating. The elevated terrain along the Cumberland Plateau may also aid development as well. Exact timing and locations of precipitation will largely be impacted by mesoscale features which the NAM and GFS are showing with convectively enhanced vorticity centers moving through both Friday night into Saturday. The NAM in particular shows a wave forming over southeast MS that lifts north and merges somewhat with the incoming 5h trough axis which should lie from central KY through northern MS. This may keep more widespread activity to our NW on Friday night into Saturday. Nevertheless, will keep PoPs in the chance range from Friday night through Saturday night (highest during peak heating Saturday). .LONG TERM...(Sunday through Wednesday) Issued at 224 PM CDT Thu May 24 2018 Much like yesterday, the extended portion of the forecast looks to be a soggy one, as we welcome the unofficial start of Summer with Memorial Day. Daily chances for showers and storms will be the rule, with the exception being slightly less coverage during the late evening/overnight hours. The higher-than-normal rain/storm chances are thanks to a developing upper low, currently over the Yucatan Peninsula, that will meander N over the open GOMEX. Whereas yesterday the GFS was the outlier with the furthest `track` to the E, making landfall in the Ern Panhandle of FL, today it joins the rest of the model consensus with a more Wwrd track. Model consensus this afternoon has a general `landfall` near Biloxi ~12Z Monday, with a few members skirting SErn LA. Either way, with a more Wwrd track, confidence is increasing in higher rainfall amounts compared to a more Erly track (keeping much of the heavy rainfall locked further S/E of the local CWFA). That said, the highest rainfall totals with wherever this sub/tropical feature ends up will definitely be greater along the coast, lessening as you move inland. This feature looks to meander/wobble across the region for much of the week as it gradually weakens, though higher-than-normal moisture will remain, making for a muggy week ahead. While confidence is high that tropical moisture streaming into the area will provide near-daily-max PWat values through the week (1.8-2.1"), torrential rainfall will be the primary hazard of concern. This may lead to hydrologic concerns (flash and river flooding) toward the end of the week if several heavy rounds of rainfall traverse the region. In addition to the rainfall/flooding threat, gusty winds ~40mph will be the secondary hazard (thanks to a couple hundred Joules of DCAPE present each aftn), especially within any stronger storms that can develop during the week ahead. Again, the forecast for the extended heavily depends on exactly where this feature tracks, so stay tuned for further forecast updates. Temperatures during this timeframe will be generally in the lower/middle 80s for daytime highs, with morning lows only falling into the upper 60s to around 70 degrees. Only late in the period will temperatures approach 90 degrees, and it`s when the remnants of this sub/tropical feature finally get picked up in H5 flow by Thu/Fri that this occurs. This will clear things out perhaps in time for the weekend as an H5 ridge building across the Central Plains finally shift E over our area, though models diverge regarding a disturbance in NW flow by Sat. This would bring yet more rainfall to the region, but details are too murky to buy this solution just yet. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 636 PM CDT Thu May 24 2018 VFR conditions prevailed again today and should continue through much of the period. Winds become more southerly after 14Z Friday and this will trigger an increase in low level moisture. Added a Prob30 group for Friday afternoon as coverage of storms should be higher but still unable to narrow a time down for moving over the terminals. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...Stumpf SHORT TERM...17 LONG TERM...12 AVIATION...Stumpf For more information please visit our website at weather.gov/huntsville.
Area Forecast Discussion
National Weather Service Marquette MI
636 PM EDT Thu May 24 2018 .SHORT TERM...(This evening through Friday) Issued at 437 PM EDT THU MAY 24 2018 Forecast concerns in the short term will focus on chances and timing of convection and potential for any strong to severe storms. Remnant outflow boundary as noted on sfc obs has become the focus for another round of convection this afternoon over central MN and northern WI along 1000-2000 j/kg MLCAPE gradient and area of strong 850 mb moisture transport and 25 kt 850 mb jet. Isolated t-storm ahead of area of convection has moved into central MNM county in past hour. RAP model indicates MLCAPE values increasing to 500-1000 j/kg range into the western half of Upper MI this evening with effective shear values increasing to 25-30 knots as a weak shortwave rotates across the area. Believe this will support redevelopment of shra/tsra into western half of Upper MI this evening and a few stronger storms could produce dime-sized hail with wet-bulb-zero heights 9.5-11kft. SPC has included the western U.P. in a marginal risk for svr storms mainly this evening. As shortwave moves east overnight and evening/overnight and warmer 8h temps of 16-18C move in later tonight believe atmosphere will become more capped leading to a lull in convection later tonight into Fri morning. Arrival of another shortwave from the west could lead to another round of scattered to numerous showers/t-storms Fri mid-afternoon into early evening as MLCAPE values increase to 1500-2000 j/kg. These higher CAPE values combined with fcst deep layer shear of 25-35 knots and WB zero heights 9.5-10.5 kft could yield isolated severe storms over the interior western two-thirds of Upper Mi with damaging winds and large hail. SPC has this area of Upper Mi in a marginal risk for severe storms on Fri. .LONG TERM...(Friday night through Thursday) Issued at 333 PM EDT THU MAY 24 2018 Above normal temperatures expected to continue through the extended forecast along with scattered showers and thunderstorms through much of the Memorial Day weekend. Saturday: A shortwave is set to slide across the area Saturday morning into the early afternoon hours, helping mlcape values reach to around 1000J/kg. Models are showing that 0-6km deep layer shear may be up to around 30 knots; however, with the shortwave set to slide east of the area by the late afternoon hours. If enough sunshine breaks out during the morning hours, then instability could be enhanced enough to allow for some organization in the thunderstorm activity across the area. There will be a conditional risk for at least some isolated severe thunderstorms for late Saturday morning into the afternoon for the central and eastern U.P.with the increased shear values. Sunday: There may be a few rain showers and possibly a thunderstorm on Sunday morning; however, coverage and intensity will likely be much more muted as the lingering shortwave will continue to slide to the east. During the afternoon hours, under very weak pressure gradient, convergent lake breeze boundaries may touch off a few showers and a remote chance of an afternoon thunderstorm across the area. Overall coverage will be minimal and mainly confined to the central and eastern U.P. Monday: There is a hint that a subtle shortwave may try to slide through the Upper Great Lakes by Monday afternoon. This will help to increase CAPE values a bit, probably in the 500 - 1000 J/kg range by Monday afternoon. The instability along with lake breeze boundaries under light flow, will lead to a few pop up afternoon showers across the area, with a couple rumbles of thunder possible. Tuesday through early Wednesday: Fairly quiet weather will be in place for Tuesday and early Wednesday as high pressure slides through the area and temperatures will continue to be above normal for this time of year, by about 15 to 20 degrees. Wednesday afternoon through Thursday: A deepening upper-level trough is progged to approach the Upper Great Lakes region Wednesday afternoon and slide through the area Wednesday night into Thursday. This will be basically the same time frame that the associated low pressure system and cold front slides through the area. Instability is progged to be increased with the moisture advection into the area and steepening lapse rates; therefore, there will likely be thunderstorms ahead of the cold front. Shear looks marginally favorable for severe weather; however, exact details will be ironed out as we get closer to this time period and models converge on the details. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 636 PM EDT THU MAY 24 2018 Scattered showers will move back into the area this evening, although VFR conditions should prevail. LLWS will develop at IWD and CMX by late evening/overnight. By late evening/overnight another round of shra/t-storms should push over all the TAF sites and then be off and on through the forecast period. Timing these will be difficult. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 437 PM EDT THU MAY 24 2018 Winds less than 20 kts are expected into next week. Expect areas of fog to develop late tonight into the weekend as some rainfall occurs over the lake and a humid air mass arrives. May have dense fog at times with best chance setting up Fri night and Sat as a trough slides across the lake. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Voss LONG TERM...KEC AVIATION...07 MARINE...Voss
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
1007 PM EDT Thu May 24 2018 .DISCUSSION... The update will extend PoPs across the southern and central Valley through most of the night as ongoing convection is showing little signs of dissipating despite the loss of heating. An inverted surface trough appears to be creating weak convergence that is maintaining the showers. The RAP shows this trough weakening around 06Z. Slight tweaks to temps and dewpoints will be made, but the forecast lows in the 60s appear on track. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$ DGS
Area Forecast Discussion
National Weather Service Norman OK
959 PM CDT Thu May 24 2018 .DISCUSSION... Have updated the forecast for tonight and early Friday to account for the latest expected trends, mainly in precipitation (along with its effects on temperature, etc.). Short-range models show convection in various configurations moving into parts of northern, and maybe even central, Oklahoma overnight. This makes sense, given the forecast of the low-level jet, which should focus convergence in southwest Kansas around midnight, then shift into northwest Oklahoma toward morning. The nocturnal inversion is the main limiting factor, which is why we have--for now-- maintained PoPs of about 40 percent or less. The MCV indicated by Kansas radars should remain over Kansas, along with its immediate area of convection. CmS && .PREV DISCUSSION... /issued 641 PM CDT Thu May 24 2018/ DISCUSSION... 00Z TAFs. AVIATION... The current showers and storms across northern and central Oklahoma should stay between the TAF stations, primarily between KPNC and KOKC. One thing we will have to watch closely is the storms in Colorado moving into Kansas. The HRRR model brings those into Oklahoma late tonight, a bit earlier than when we have the storm chances in the current TAFs based on the synoptic models (mainly the NAM). Have not gone with this timing yet as the RAP dissipates the current convection before reaching Oklahoma, so the signal is still rather mixed. But if it does look like the storms will roll in earlier or be more widespread based on radar and satellite trends or updated runs of the high-res models, we will update the TAFs with this scenario. PREV DISCUSSION... /issued 400 PM CDT Thu May 24 2018/ DISCUSSION... Primary forecast issues are the chance of thunderstorms on Friday and hot temperatures toward the end of the forecast period. For this afternoon/evening, a remnant MCV is resulting in scattered to numerous thunderstorms across north central Oklahoma. These thunderstorms are expected to continue through at least the mid-evening hours with hail and gusty winds possible. For Friday, there continues to be a risk of strong to severe thunderstorms, but the location of the greatest risk will be modulated by any remnant outflow boundary/MCV from tonight. Various convective-allowing models (e.g., NAM NEST/HRW NSSL) indicate an MCS and its attendant outflow boundary and/or MCV will develop and move southward somewhere across northern Oklahoma. The uncertainty is how far south will any remnant feature reach before the potential for redevelopment in the afternoon. Currently, the highest chance of redevelopment is somewhere from northern central into west-central Oklahoma. Environmental conditions tomorrow afternoon will be more than sufficient for strong to severe thunderstorms. Forecast soundings indicate large downdraft CAPE (~1500 J/kg) and steep low-level lapse rates in the subcloud layer, so damaging wind gusts from downbursts will be possible. In addition, effective bulk layer shear and large/wide CAPE in the hail-growth zone suggest large hail will be possible as well (especially with initial, single- cellular development that could have embedded supercellular characteristics). Organization/cold pool generation may result convection to eventually grow upscale into an MCS. If an MCS develops, it would likely propagate southward through the evening hours with a continued damaging wind gust threat. For Sunday through Tuesday, northwest Oklahoma will maintain a low to moderate chance of showers and thunderstorms to account for any remnant High Plains convection and/or influence from shortwave troughs embedded in the stronger mid-level flow. This area will on the western periphery of the mid-level ridge and closer to a western U.S. trough. Otherwise, the forecast looks hot and dry for most locations. Beyond Tuesday, both the 24/12Z GFS and ECMWF indicate that a very hot pattern may develop toward and just beyond the forecast period with a strengthening mid-level ridge across the Southern Plains. Forecast mid-level heights ~596 dam (more typical for July or August) and 850 mb temperatures in the upper 20Cs to low-30Cs would result in widespread temperatures in the upper 90Fs and low 100F. These temperatures would be near record high temperatures. Mahale && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 68 89 67 93 / 30 30 20 10 Hobart OK 69 97 67 98 / 20 30 20 0 Wichita Falls TX 71 96 70 98 / 10 20 30 0 Gage OK 66 97 65 98 / 20 20 10 0 Ponca City OK 67 87 66 94 / 50 30 20 10 Durant OK 70 91 69 92 / 10 20 30 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ 23/26
Area Forecast Discussion
National Weather Service Pueblo CO
250 PM MDT Thu May 24 2018 .SHORT TERM...(This evening through Friday) Issued at 249 PM MDT Thu May 24 2018 Tstms popped up in El Paso county around midday and have been moving east. It looks like the best chances for tstms this evening will probably be over Kiowa county, but the NAM and HRRR also show activity in Baca county, with a slight chance that something will also pop up in Prowers county. There could be one or two storms that reach severe limits. After midnight conditions should be dry. Friday, an upper level ridge will be over the state and both the NAM and the GFS show dry conditions across southeast and south central CO, along with above average temps. Highs acrs the southeast plains will mostly be in the upper 80s to lower 90s, with 80s in the Upper Arkansas and San Luis Valleys. .LONG TERM...(Friday night through Thursday) Issued at 249 PM MDT Thu May 24 2018 Friday night through Sunday...Upper closed low over northern CA Fri night will slide into the Great Basin for Sat and Sun, producing strong deep southwest flow across the Four Corners. This will serve to continue warm and dry conditions across the state, and coupled with increasing winds, fire danger will be the main concern for both Sat and Sun. Decided to issue a Fire Weather Watch for much of the area for Sat, with the eastern plains left out due to fuels info indicating green up. Look for high temps in the upper 70s to lower 80s for the high valleys, and upper 80s to upper 90s for the plains. Monday through Wednesday...The upper low weakens Mon and begins to eject to the east-northeast across the Rockies through Wed. Exact timing is still questionable and Mon may end up being another potential fire weather day, but at some time during Mon a weak cold front pushes south across the Palmer Divide, cooling temps slightly and raising humidity levels. Winds should ease as well, with isolated diurnal showers and storms each day for the higher terrain and far eastern plains. Temps will warm into the 70s for the high valleys, and 80s to around 90F for the plains. Thursday...Another upper trough develops over the West Coast late Wed, producing brisk w-sw flow across the Four Corners and western Colorado once again. Temps will again warm to near 80F for the high valleys, and 80s to lower 90s for the plains. Depending on how much pcpn is received through mid-week, the forecast area might be right back into enhanced fire danger. Stay tuned. Moore && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 249 PM MDT Thu May 24 2018 VFR conditions are expected the next 24 hrs at KCOS, KPUB and KALS, with an upper level ridge over the area. Winds should mostly be 12 kts or less. && .PUB WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday morning through Saturday evening for COZ220>230. && $$ SHORT TERM...28 LONG TERM...MOORE AVIATION...28
Area Forecast Discussion
National Weather Service Springfield MO
648 PM CDT Thu May 24 2018 ...Update Aviation for 00z Tafs... .SHORT TERM...(This evening through Friday) Issued at 153 PM CDT Thu May 24 2018 Storms have taken a bit longer to get going today, but we are now starting to see updrafts take shape. We will see scattered storms for the remainder of the afternoon into the early evening with convective outflows kicking up additional storms. Convection should then simmer down from mid to late evening. By late tonight, short wave energy will track east across eastern Kansas and western Missouri. A low level jet stream will veer into the region ahead of this feature and induce isentropic upglide. Looking at RAP data between 08 and 15 UTC, parcels only look weakly capped between 900 and 825 mb. We therefore think that elevated convection will be possible during this time frame across southeastern Kansas and western Missouri. Convective chances by Friday afternoon are then heavily dependent on the coverage of morning convection and any remaining outflow boundaries. If morning convection throws outflow towards the east, the eastern Ozarks may see the best chance for afternoon storms. If coverage is more limited in the morning, scattered afternoon convection will be possible across the entire area. Inspection of forecast soundings does reveal potential for downbursts and perhaps some large hail with afternoon convection. As for temperatures, lows tonight and highs on Friday look pretty similar to what we have been seeing. Lows should range from the lower to middle 60s over the eastern Ozarks to the middle and upper 60s over western Missouri and southeastern Kansas. Highs on Friday will range from the lower and middle 80s across the eastern Ozarks to the middle and upper 80s across western Missouri and southeastern Kansas. .LONG TERM...(Friday Night through Thursday) Issued at 153 PM CDT Thu May 24 2018 The potential for isolated storms will then persist into Saturday. Coverage will be more limited as weak upper level height rises will be overspreading the region. We should tack on a few degrees for highs on Saturday as mid-level temperatures begin to warm. The Sunday through Tuesday time frame then look dry as an upper level ridge shifts east and builds into the region. Temperatures also look rather warm with highs warming into the upper 80s and lower 90s. Global models then vary as we get into the last half of next week. The ECMWF and Canadian models knock down the ridge and keep us in a weak west or southwest flow aloft. This would give us a low-end threat for a few storms, although we will have to watch the remnants of the tropical system in the Gulf of Mexico. The GFS actually puts us in a pseudo northwest flow aloft. This would open the door for mesoscale convective systems (MCSs) and afternoon pop-up storms. Regardless, temperatures should remain well above normal to finish next work week. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 647 PM CDT Thu May 24 2018 Isolated storms will continue early this evening and will dissipate by the late evening hours. Coverage will again be limited with this activity and a lot of locations will not be affected. South to southeasterly winds will occur this evening and tonight, then winds will become more southwesterly on Friday. An upper level disturbance will track through the area late tonight into Friday morning and may trigger scattered storms across the area. Isolated storms may then be possible again Friday afternoon into the early evening hours. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Schaumann LONG TERM...Schaumann AVIATION...Wise