Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/09/22

Area Forecast Discussion
National Weather Service La Crosse WI
1030 PM CDT Mon Aug 8 2022 .DISCUSSION...(This evening through Monday) Issued at 239 PM CDT Mon Aug 8 2022 Key Messages: - Potential For Valley Fog Tonight - Next Rain Chances End Of The Week Into The Weekend Tonight...Fog potential With an area of high pressure moving in overhead tonight, the setup for a valley fog event looks pretty good. Winds looks to be under 10 knots for a pretty deep layer with calm to nearly calm at the surface. Forecast soundings show saturation occurring at the surface and slowly deepening toward sunrise. Some caveats for dense fog forming tonight are that the saturated layer does not look to be all the deep and with the north winds occurring today as the high moves in, that should produce some general drying of the dew point. Expect to see some fog in the morning, the question is just how dense it will be. End Of The Week Into The Weekend...small rain chances Through the middle of the week, ridging aloft and at the surface will be the dominant feature with seasonable and quiet weather. The upper level ridge looks to retrograde to the west just enough for the end of the week to allow some ridge runner short wave troughs to start dropping across the Great Lakes and Upper Midwest regions. The first of these potentially could drop across the area Thursday night and Friday bringing a chance of rain with it. A couple more may then slide through over the weekend with another chance for some rain both Saturday and Sunday. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1030 PM CDT Mon Aug 8 2022 CIGS: generally SKC conditions expected through much of Wed as high pressure influences the TAF sites. That said, with fog/stratus favored in the river valleys, likely LIFR BKN cigs at KLSE for a few hours around 12z Tue. WX/vsby: river valley fog a concern for KLSE Tue morning. 03z T/Td spread only 5 F while RAP soundings show a deepening light wind layer in the veritical (upwards of 4 kft by 12z). Both very favorable for 1/4SM at KLSE. Sfc wind gives pause to that threat, with current light north winds generally an inhibitor to fog flowing onto the airfield from the river system. If winds can swing southeast, a prolonged period of 1/4SM likely. With these sfc winds the only really deterent - going to trend downward with the fog. Winds: light and variable overnight with light but more southerly for Tue into Tue night. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ DISCUSSION...04 AVIATION.....Rieck
Area Forecast Discussion
National Weather Service Boston/Norton MA
1037 PM EDT Mon Aug 8 2022 .SYNOPSIS... The oppressive heat persists into Tuesday. A slow moving cold front brings the better shot for more widespread showers and storms. Isolated strong to severe storms are possible with the main threat of damaging winds and locally heavy downpours. This front will linger nearby bringing additional opportunities for showers and thunderstorms through Thursday. Cooler temperatures, but still quite humid until this front clears. Seasonable, with much lower humidity Friday into next weekend, with dry weather returning. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 1030 PM update... A broken line of storms is crossing western into central MA late this evening. While the main front remains stalled well to our north, there is a surface trough hung up across our region. With a few hundred joules of MLCAPE left and around 10-15 kt of shear, the storms actually picked up slightly in intensity as shown in the cooling of cloud tops per the sandwich satellite product and uptick in GLM flashes. Radar velocity product shows that there could have been isolated 30 kt gusts across the high terrain out west, but we did not receive any damage reports from our amateur radio or public. With the line continuing to weaken, expect shower coverage to diminish for the remainder of overnight hours. Did bump up PoPs a little for the next few hours but current forecast remains largely on track. Previous Discussion... Highlights * Any lingering shower/storm activity tapers off during the evening. Should be dry and quiet for most, but will see stratus move into parts of the south coast. Subtle shortwave trough lifts into northern New England this evening. The surface prefrontal trough slides through, but unfortunately we remain within the warm sector as the cold front begins to sag southeastward from northern New England. Anticipating that the shower/storm activity will dissipate this evening due to the loss of daytime heating and there really isn`t much of a lifting mechanism with the shortwave ejecting out of the region. As has been the case the past couple of days still cannot rule out locally heavy downpours and gusty winds given the anomalously tropical environment. Still have roughly 1000-1500 J/kg of MLCAPE before the MLCIN rises after sunset. Lapse rates remain between 7-9 degrees Celsius with poor mid level lapse rates and PWATS approaching 2 inches along with warm cloud layer depths greater than 10 kft. Given the relatively weak forcing models are really struggling with the coverage. For most will be a miss, but think chances are greatest across the interior. Once the shower/storm activity diminishes will see an increase in stratus and perhaps some fog across the south coast. Not overly confident in widespread fog given the 30-40 kt SW low level jet swinging through. May not completely mix down gusts especially across the Islands as they remain inverted per forecast soundings, but the pressure gradient appears tight enough to keep winds above 10 kts. Will be tough to cool down with W flow and the 30-40 kt low level jet swinging through. Low temps remaining in the mid to upper 70s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Highlights * Oppressive heat persists for much of southern New England on Tuesday. * Slow moving cold front brings more widespread showers and storms on Tuesday. Isolated severe storms possible with the main threat of damaging wind gusts and locally heavy downpours. A more amplified trough/shortwave slides from the eastern Great Lakes/Quebec through New England by Tuesday evening. May have a shortwave lifting into the central/eastern Great Lakes by early Wednesday. A slow moving cold front slides into and potentially through much of southern New England on Tuesday and Tuesday night. Main concerns for Tuesday are the persistent oppressive heat and risk for strong/severe thunderstorms. Until the cold front slides in will still be under a low/mid 70 degree dew point airmass. Aloft will have W flow with 850 hPa temps around 18-20 degrees Celsius. Do have some uncertainty with how warm we get due to cloud cover across northern portions of the CWA, but still will be quite close to Heat Advisory criteria, so have left as is at this point. Most confident in the temp/dewpoint forecast for CT, RI and eastern MA especially during the morning. Highs top out in the mid 80s to mid 90s. As the cold front slides through there will be a risk of strong/severe thunderstorms. Will be located within the RRQ of a 500 hPa jet streak lifting into northern New England. Still quite the tropical airmass with PWATS between 2-2.25 inches for most with warm cloud layer depths between 10-15 kft. On top of this with the jet streak lifting through will have deep layer shear increasing to 25-30 kts. Expecting MLCAPE values to range from a few hundred to 1500 J/kg with 7-9 degree Celsius low level lapse rates and the typical poor mid level lapse rates. Thinking that the main risk with any stronger storms that develop are damaging wind gusts and locally heavy downpours. CAMs show a broken line sliding through. Will note the NCAR HRRR Neural Network Convective Hazard forecast shows roughly 15-30 percent probabilities for a severe hazard over our area. Given the environment reached out to SPC to introduce a marginal risk for severe storms on Day 2. Lastly, have put a mention of heavy rain and gusty winds into the forecast. Timing wise think the risk is highest for severe storms from roughly noon to 10 PM. Will see any lingering showers and storms coming to an end for most of the interior, but still may linger into early Wednesday for the south coast depending on how quickly the front swings through. Anticipate the strong/severe storm risk to diminish during the evening as the instability wanes. Low temps falling into the 60s across the interior, but remain in the upper 60s to low 70s for the south coast. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * Quasi-stationary front Tue night thru Thurs will focus periods of cloudiness and a few opportunities for welcomed rains. Best chance at widespread rains Wed night into early Thu. Temps cooler than normal but still quite humid. * Cooler and much more comfortable humidity levels Fri into the weekend. * Need to track position of surface cold front offshore but odds favor dry weather for the weekend. Details: Tuesday Night through Thursday: Quasi-stationary, slowly-southward-sagging frontal boundary in vicinity of SNE will combine with roughly front-parallel 700-500 mb flow and continued influx of tropical moisture to focus several opportunities for welcomed rains through showers and embedded t- storms. Though it`s likely it won`t be raining for the whole stretch, continued differences in frontal position and more specifically its southward egress through SNE supported PoP of at least lower Chance level for most of this period. Overall severe weather risk appears low to nil given abundant cloud cover, some onshore wind component and cooler surface temps. It looks like the period which harbors the best chance at welcomed rains is later Wed/Wed night into the early Thurs AM period, as subtle vort maxima induces weak surface low development on the frontal boundary and bringing with it a slug of beneficial rain, especially near/south of the Mass Pike into southeast New England. Seems to be reasonably good consensus in this outcome, in spite of how dry we`ve been, and also supported by EPS, GEFS and GEPS 24-hour QPF probs of at least 0.5 inches that are as much as 70% in the EPS. Lower probs of 24-hr QPF in the 1" range in this same corridor. In a convective pattern and given the coarser horizontal res of these global models can`t take QPF at face value but nonetheless favorable probs for welcomed rains exist. Given the above, and synoptic pattern recognition looking similar to that of the Maddox frontal rain regime, opted to increase PoP into the higher Likely to Categorical range for Wed night into early Thurs, with PoP then diminishing a bit into Thurs aftn. Elevated PWAT values could support local downpours. Anticipate seasonable to cooler than normal high temps in this period, with lows around seasonable levels as well. Highs mainly mid/upper 70s to lower 80s, lows in the 60s to near 70. However it still will be quite muggy until the front sags southward into the coastal waters. Friday into the Weekend: Amplification of the western CONUS mid-level ridge is expected to dig a longwave trough southward from east-central Canada into the Ohio Valley/northern Appalachians vicinity. This should bring a much more refreshing air mass to SNE with lower humidity levels and temperatures around seasonable levels. PoP/rain chances continue to carry some level of uncertainty, but did note a rather remarkable flip-flop back towards drier weather for this period in both global ensemble means and the 00z deterministic guidance. Though it really didn`t have much 12z ensemble membership support, the 12z ECMWF/GFS counterparts showed a closing-off mid-level trough with developing low pressure on the front near Bermuda then pivoting NNW toward coastal New England Fri- Sat with a decent slug of rain. The 00z suite of guidance however came in with a weaker and more progressive trough, which shifts the front well offshore into the western Atlc and keeps SNE dry with NWly flow. Something to monitor, but as NBM is too slow in reducing PoP given what`s transpired in the 00z guidance, lowered PoP toward borderline slight chance/sub- mentionable levels in case today`s 12z guidance comes back in wetter. Key in that evolution is the strength of the trough and if it closes off. Keeping outcomes open but given lack of ensemble support for a wetter outcome, thinking odds favor drier weather for this weekend. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. 00Z update... Tonight...High confidence. VFR for most with any lingering shower/storm activity coming to an end during the evening. Could see some MVFR/IFR stratus/fog spread into the Cape/Islands late. May be a case where it is just stratus given how strong winds are. Will have LLWS concerns especially across the Islands with a SW jet overhead. SW winds 10-15 kts. Tuesday...High confidence in trends, moderate in timing. VFR for most with increasing chances for showers/storms especially after 17-19Z. If any showers/storms pass over a terminal then conditions are likely to lower to MVFR/IFR conditions and bring locally heavy downpours along with gusty winds. SW/W winds at 10-15 kts with gusts of 20-25 kts. Tuesday night...Moderate confidence. Conditions lowering to MVFR to IFR in wake of the cold front. Still have may some lingering showers/storms with the front moving through, but confidence highest across the south coast. Winds shifting to the N/NE at 5-10 kts. KBOS...Moderate confidence in TAF due to pop up shower/storm activity this afternoon. KBDL...Moderate confidence in TAF due to pop up shower/storm activity this afternoon. Outlook /Wednesday through Saturday/... Wednesday: Mainly VFR, with local IFR possible. Slight chance SHRA, isolated TSRA. Wednesday Night: Mainly VFR, with local IFR possible. Chance SHRA. Thursday: Mainly VFR, with local MVFR possible. Chance SHRA, isolated TSRA. Thursday Night through Friday: VFR. Slight chance SHRA. Friday Night through Saturday: VFR. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight...High confidence. Could see a few isolated showers/storms leak into eastern areas this evening. Overall dry and quiet tonight, but will see increasing low clouds across portions of the south coast late. SW winds between 15-20 kts with gusts between 20-30 kts. Small Craft Advisories remain in effect for much of the waters. Tuesday and Tuesday night...High confidence in trends, moderate in exact wind shift timing as a cold front slides through. Risk of showers and thunderstorms as a cold front slides into and through southern New England. Risk highest during the afternoon an into the evening. Any of these showers/storms could produce strong winds gusts at times. Will see SW winds at 10-20 kts with gusts of 20-25 kts. Winds shifting to the N/NE once the front passes through with speeds of 10-15 kts. Outlook /Wednesday through Saturday/... Wednesday: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers, isolated thunderstorms. Wednesday Night through Thursday: Winds less than 25 kt. Chance of rain showers, isolated thunderstorms. Thursday Night: Winds less than 25 kt. Slight chance of rain showers, isolated thunderstorms. Friday: Winds less than 25 kt. Slight chance of rain showers. Friday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers. Saturday: Winds less than 25 kt. Seas locally approaching 5 ft. && .CLIMATE... Record Maximum Temperatures August 8th: BOS 96F [1983] ORH 94F [1916] PVD 95F [1909] BDL 98F [2001] && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Heat Advisory until 8 PM EDT Tuesday for CTZ002>004. MA...Heat Advisory until 8 PM EDT Tuesday for MAZ002>023-026. RI...Heat Advisory until 8 PM EDT Tuesday for RIZ001>007. MARINE...Small Craft Advisory until 11 AM EDT Tuesday for ANZ231>234- 250. Small Craft Advisory until 8 PM EDT Tuesday for ANZ235-237- 254>256. Small Craft Advisory until 7 AM EDT Tuesday for ANZ236. && $$ SYNOPSIS...BL/BW NEAR TERM...BL/BW/Chai SHORT TERM...BL LONG TERM...Loconto AVIATION...BL/BW MARINE...BL/BW CLIMATE...
Area Forecast Discussion
National Weather Service Caribou ME
957 PM EDT Mon Aug 8 2022 .SYNOPSIS... A cold front will remain stalled over the northern Gulf of Maine tonight. A low pressure from the Great Lakes will approach overnight and cross the Downeast coast Tuesday. Weak high pressure builds in Tuesday night through Wednesday night. A cold front approaching from Canada Thursday and crosses the area Thursday night. Stronger high pressure will build in from the Great Lakes Friday and Saturday. && .NEAR TERM /THROUGH TUESDAY/... 9:57PM Update...Continue to make adjustments to the POPs based on latest radar trends. New area of moderate to potentially heavy rain is moving into the North Woods from Quebec and will track across the Flood Watch area. There is rapidly weakening convection over southern Maine that may be robbing the best southerly moisture advection. So far, QPF forecast hasn`t played out well given a break in precip with just scattered showers has been occurring in the Flood Watch. 00z RAOB from CAR showed an incredibly moist atmosphere from 860-200mb resulting in a PWAT of 1.60 inches. This is more than 0.20 inches above the 90th percentile. Therefore, continue to be concerned with areas of heavy rainfall and will continue the Flood Watch as is for the approaching rain from Quebec. Temperatures continue to remain nearly steady so minor tweaks but overall looking good there. Previous Discussion... Models are in good agreement that a last s/wv alf and sfc low from the Great Lks tracks ENE alg a stationary front near the Downeast coast toward the Can Maritimes ovrngt. Rnfl at this tm still looks to be more stratiform Mon Ngt into Tue Morn, with heavier downpours with meso-beta elements within the rn shield where we mentioned isold tstms with lmtd elevated CAPE and the best 6hrly QPFs in across the 8pm-2am and 2am to 8am tm frames. One potential spoiler with regard to distribution of heaviest QPF across the FA is the possibility of high cnvctn from NW New Eng tracking further S ovr Cntrl ptns of the FA later tngt, potentially intercepting the moisture transport from S of the stationary front from reaching far Nrn ptns of the FA as per latest HRRR model runs. Rn will then taper to sct to isold shwrs NW to SE across the FA late Tue morn thru Tue aftn with progressively lesser 6 hrly totals. Temps will remain below avg thru Tue due rn and or cld cvr. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... Northern stream shortwave ridging transits the area Tuesday night. Other than possibly some lingering showers near short early Tuesday evening, it should be dry as a result. Lows Tuesday night should be within a few degrees of either side of normal. Patchy fog is possible by late Tuesday night. A weak northern stream shortwave passes Wednesday, with a slight chance of showers across far western zones and a few mid to high clouds elsewhere. Highs on Wednesday should be a few degrees below normal. Another weak northern stream shortwaves moves through Wednesday night, with a slight chance of showers. These should be far more miss than hit in nature, with the possible exception of far western zones. Lows Wednesday night should be a few degrees above normal. With onshore flow, there is the potential of patches to areas of fog by late at night. A northern stream trough approaches Thursday is it strengthens and stretches down into the Central Appalachians from Northern Quebec. It`s associated cold front should be close enough by late Thursday afternoon to bring some isolated to scattered showers and thunderstorms to far western zones. IT this point CAPES appear to be fairly low, generally less than 500 J/kg, but with Showalter indices in the 0 to 3 range, there should be enough low to mid level instabilty to support some elevated storms. The GFS has a progressive bias so sided with the idea of a slower cold front passage than it has, something similar to the CMC- Regional and NAM for timing. Highs on Thursday should be near normal. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A northern stream trough builds into the region Thursday night- Saturday. Differential positive vorticity advection, coupled with support from the right entrance region to the 300 hPa jet should support some showers and thunderstorms Thursday evening. At this time, the severe threat appears to be very low, but a few stronger storms early Thursday evening cannot be ruled out, especially across northern zones. It should then be dry Friday- Saturday. A closed low should develop near the Gulf of Maine Saturday night, then lift northeast into the Canadian Maritimes through Sunday night. Depending on the exact track of this system, there could be some isolated to scattered showers across mainly eastern zones, however, most if not all locations should be mainly, if not completely, dry Saturday night through Sunday night. Another northern stream shortwave approaches on Monday, brining with it a slight chance of showers, mainly across the North, Temperatures should generally be within a few degrees of either side of normal Thursday night-Sunday night. Highs should be above normal on Monday. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... NEAR TERM: 00z TAFs continue to amend as needed. Overall IFR cigs in southern zones but seeing occasional SCT IFR cigs at BGR making for MVFR. Across the Northern Sites generally VFR cigs with SCT IFR but cigs continue to lower. Expecting IFR with next batch of rain approaching from the west. Wind Shear is possible into tomorrow at BHB. Previous Discussion... MVFR clgs/vsbys in rain/patchy fog this eve lowering to IFR ovrngt. Lgt ENE winds. Tue...IFR clgs/vsbys in rn and patchy fog Tue Morn, then MVFR/low VFR clgs/vsbys in shwrs durg the aftn. Light ENE winds SHORT TERM: Tuesday night-Thursday morning...VFR, except MVFR or lower possible late at night/early in the morning in any fog. NE winds G15-20KT possible Tuesday evening. Thursday afternoon-evening...VFR, except brief MVFR possible in any stronger thunderstorms. Late Thursday night-Saturday...VFR. && .MARINE... NEAR TERM: Winds and seas are expected to be below SCA conditions for these ptns of the fcst. Visibilities will be reduced in at least patchy fog Tngt thru Tue with patchy fog becmg areas late Tngt into erly Tue Morn with patchy fog ending by Tue Aftn. Kept close to blended wv model guidance for fcst wv hts with the main spectral wv group propagating S to N with pds of 6 to 8 sec. SHORT TERM: Sub-SCA conditions are expected on the waters Tuesday night-Saturday. The pressure gradient should be sufficiently relaxed to limit winds to 10 kt or less from Wednesday afternoon-Saturday. && .HYDROLOGY... A Flood Watch has been issued for the N ptn of the Rgn through Tuesday morning. Models are in good agreement with the timing of the highest rainfall amounts after sunset, where they indicate a band of QPF of around 1 to 2” and lcly more moving across the northern half of the region by Tue Morn. Flash flooding is not the main concern attm due to the low soil moisture, normal river levels, and guidance showing a need for over 1” per hour in order for flash flooding to occur, which is a relatively low probability with this system. However, minor flooding of streams and any urban areas that are traversed by core of best banding of rnfl rates is definitely more probable. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...Flood Watch through Tuesday morning for MEZ001>006-010. MARINE...None. && $$ Near Term...Sinko/VJN Short Term...Maloit Long Term...Maloit Aviation...Sinko/VJN/Maloit Marine...Sinko/VJN/Maloit Hydrology...
Area Forecast Discussion
National Weather Service Cleveland OH
1122 PM EDT Mon Aug 8 2022 .SYNOPSIS... A cold front will slowly move southeast across the area tonight into Tuesday morning. Behind the front, high pressure will build southeast across the Great Lakes, persisting into Wednesday. Another cold front will move south across the Great Lakes on Thursday, with high pressure building in behind it for the weekend. && .NEAR TERM /THROUGH TUESDAY NIGHT/... Moisture rich airmass with PW`s over 2 inches continues to stream northeast, interacting with the approaching cold front and leading to pockets of heavy rain. Rainfall has been very efficient tonight with a deep warm layer. Cooling cloud tops and high lightning rates have been good indicators of heavy rain producing storms and a new Flood Advisory has been issued for high rainfall rates and ponding of water on roads in Ashland and Wayne counties. Overall trend for convection tonight is for the heavier rain to shift east with a gradual weakening trend with waning instability. Previous discussion... Mid-level trough and upper-level trough are located across the northern Great Lakes with surface low near Lake Huron extending a cold front southwest across lower Michigan and northern Indiana towards the central Mississippi Valley, all of which are providing weak synoptic-scale lift across the area. Anomalous moisture content is residing over the area with surface dew points as high as 78 being observed (at KFDY) and RAP mesoanalysis placing PWAT values over 2" across much of the area, which is near the max moving average for the area, according to the SPC sounding climatology. This environment, in combination with weak synoptic lift, is more than sufficient for the development of thunderstorms. Convective initiation has already across across portions of northern Indiana, southern Michigan and northwest Ohio. High moisture content and daytime heating from earlier has allowed for MUCAPE of up to 3500 J/kg, sufficient for strong updrafts despite the weak forcing and mid-level lapse rates. Theta-e differences of near 25 C suggest the potential for strong to perhaps near severe wind gusts within the strongest storms this afternoon into early this evening, mainly for northwest Ohio and perhaps into north- central Ohio. This is despite weak deep layer wind shear of only ~20 knots. Storms will move east into a much weaker environment located over central Ohio, northeast Ohio and northwest Pennsylvania, so storms should evolve into a weakening state by late evening into tonight. With a degree of mean cloud layer wind near parallel to the forcing mechanism (cold front), somewhat slow storm motions, and very high moisture content, locally heavy rain could produce localized flash flooding, if we are to observe training of thunderstorms. This may be hard to do as weak advection should limit training of storms. Best potential for flooding would be northwest Ohio where the greatest instability is. Rain showers overspread the area tonight, though thunderstorm potential is limited due to limited and weakening instability overnight. Rain showers end from north to south Tuesday through Tuesday night as the cold front moves through. Significantly cooler temperatures are ushered in with the cold front as we go from heat indices in the 90s this afternoon to high temperatures in the mid to upper 70s on Tuesday. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... The cold front will slowly push south of the region Wednesday morning as 1020 mb surface high pressure attempts to build in from the northern Great Lakes. A few showers lingering along and south of the US 30 corridor in the morning will end by afternoon with increasing sunshine as drier air and subsidence work into the region. Dew points will be lower, falling into the low 60s, but the real airmass change will wait for the passage of a second front which will come Thursday. As the surface high weakens and shifts east Wednesday night, a strong mid/upper shortwave will drop into the central Great Lakes while deepening the longwave mid/upper troughing over the Great Lakes and NE CONUS in the process. This shortwave will push the aforementioned second cold front south across the region Thursday morning and early afternoon. Moisture return ahead of the boundary is very limited due to an already northwesterly boundary layer flow, but upper forcing from the left exit of a 70-90 knot H3 jet streak should induce sufficient low- level convergence to generate a broken line of showers along and ahead of the front, so blended in higher PoPs compared to NBM for Thursday morning into the afternoon. Surface heating ahead of the front will also lead to at least weak instability, so isolated thunderstorms are possible as well. Behind the front, strong surface high pressure (Canadian high) will build into the Great Lakes and Ohio Valley Thursday night. This will filter in a refreshing airmass with dew points dropping into the 50s Thursday evening and Thursday night. Highs Wednesday will range from the upper 70s to mid 80s (warmest in NW Ohio) cooling into the mid 70s to low 80s Thursday. Lows Wednesday night will range from the upper 50s to mid 60s (coolest in far NE Ohio and NW PA) with widespread mid 50s to low 60s Thursday night. && .LONG TERM /FRIDAY THROUGH MONDAY/... The strong surface high will remain in control Friday through Sunday while gradually shifting from the central Great Lakes and Ohio Valley into the Northeast US and central Appalachians by Sunday. This along with a highly amplified pattern characterized by deep longwave troughing over the eastern CONUS downstream from a massive ridge (heat dome) over the Rockies and Plains will keep our region in cool, dry NW flow leading to picture perfect summer weather. Highs Friday and Saturday will generally be in the mid/upper 70s with crisp overnight lows in the low/mid 50s. It will feel more like a fall airmass! Return flow starting to develop behind the departing high Sunday will increase high temperatures into the upper 70s/low 80s, but dew points will remain pleasant. The upstream mid/upper ridge tries to build a bit farther east into the Mississippi Valley late Sunday and Monday while meeting resistance from the continued deep troughing in the eastern CONUS. The resultant warm air advection/theta e advection combined with weak shortwaves rippling through the NW flow will ignite convection in the Mississippi Valley, and several models try and bring showers into the region from this activity Sunday afternoon. However, with the surface high slow to move away and very dry airmass in place, feel this is way too far east, so kept conditions dry through Sunday. However, kept slight chance PoPs from NBM Sunday night and Monday as a more defined shortwave drops through the Great Lakes and interacts with what will probably be a tight baroclinic zone draped from NW to SE near the western Great Lakes. Highs Monday will warm more solidly into the low 80s with gradually increasing humidity. && .AVIATION /00Z Tuesday THROUGH Saturday/... Thunderstorms producing heavy rainfall continue to move northeast across the area with thunder possible at all terminals. IFR conditions in heavy rain expected with most thunderstorms, with a weakening trend as activity continues east overnight. As a cold front settles south across the area tonight, widespread IFR conditions with low ceilings are expected to develop. These will persist into Tuesday morning before starting to lift. Southwest winds will shift to the north with the passage of the front. Erratic wind shifts are possible with thunderstorms although most of the higher gusts above 30 knots are done for tonight. Outlook...Non-VFR with patchy fog possible Tuesday night into Wednesday morning. Non-VFR also possible with isolated rain showers on Thursday. && .MARINE... Continued the Small Craft Advisory for the nearshore zones from Geneva to Ripley as W to SW winds nearing 20 knots at times generate 3 to 5 foot waves ahead of a cold front which will cross the lake late tonight. It is a marginal Small Craft advisory since the strongest winds are in the open waters, but recent observations and the latest model data support a continued threat for the aforementioned winds and waves. Farther west across the central basin, winds do get into the 15-20 knot range early tonight, but waves should stay 2 to 4 feet. The highest risk of rip currents will continue to be at the lakeshores of Ashtabula and Erie Counties with more of a moderate risk offshore of Lake County. Winds switch to N behind the cold front late tonight while decreasing to 10-15 knots, and N winds of 5-10 knots will continue Tuesday and Tuesday night becoming W Wednesday into Wednesday night. Another cold front will cross the lake Thursday morning, and NW winds behind it will increase to 10-15 knots before becoming N and increasing to 15-20 knots Thursday night. The Thursday and Thursday night time period could approach Small Craft Advisory criteria again along with at least moderate risks for rip currents. N winds will generally decrease to 5-10 knots Friday through Saturday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...Beach Hazards Statement until 4 AM EDT Tuesday for PAZ001. MARINE...Small Craft Advisory until 4 AM EDT Tuesday for LEZ148-149. && $$ SYNOPSIS...Saunders NEAR TERM...KEC/Saunders SHORT TERM...Garuckas LONG TERM...Garuckas AVIATION...KEC MARINE...Garuckas
National Weather Service Hastings NE
640 PM CDT Mon Aug 8 2022 .DISCUSSION...(This evening through Monday) Issued at 226 PM CDT Mon Aug 8 2022 A few clouds are lingering across north central Kansas this afternoon as the front that brought the much cooler air to the region is currently extended across southern Kansas. This has resulted in a seasonably cool afternoon across the local area...with most locations currently in the mid to upper 70s...and expected to top out just above 80 degrees later this afternoon. For tonight...inherited some small pops for southern portions of the forecast area where models are hinting at some weak lift late in the night. The latest NAMnest and RAP are both indicating some weak convection across this area straddling daybreak...with less noticeable signals in the HRRR. While confidence is not high in much developing...anything that does develop should be on the weak side...and kept this mention going in the current forecast as it seems reasonable. With nearly full sunshine and a moderating high pressure builds to our west and heights aloft begin to rise...a return to more seasonal temperatures is expected for Tuesday afternoon...which will be the start of a warming trend through the end of the week. With the responsible upper level ridge not showing any weakness as it shifts east by the upcoming weekend...dry weather is also anticipated to accompany the warm temps...with the current 7 day QPF forecast from WPC indicating most of the local area will be dry through next weekend. While not as oppressive as the heat of late...heat index values will likely top out in the upper 90s to near 100 by next weekend. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday) Issued at 637 PM CDT Mon Aug 8 2022 VFR conditions persist through the forecast period at both terminals. Winds will be light and variable this evening and through the overnight hours, becoming southerly around 5-10kts around mid-morning. A few passing clouds remain possible this evening and again tomorrow. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ DISCUSSION...Rossi AVIATION...Wekesser
Area Forecast Discussion
National Weather Service Northern Indiana
612 PM EDT Mon Aug 8 2022 .SYNOPSIS... Issued at 606 PM EDT Mon Aug 8 2022 Scattered to numerous showers and thunderstorms will continue this evening and decrease in coverage overnight as a cold frontal boundary moves through. A few of the storms could produce gusty winds and localized heavy rainfall. Most of the area will be dry beginning Tuesday with conditions turning less humid through the end of the work week. && .SHORT TERM...(This Evening through Tuesday) Issued at 345 PM EDT Mon Aug 8 2022 Convective development through early evening and potential of isolated gusty winds/heavy rain will be the main forecast concerns for the near term. Earlier convection this morning over northern Illinois has complicated mesoscale details a bit for the local area. A remnant weak MCV may still emerge from decaying northern Illinois convection into local area this evening that should aid in prefrontal/frontal convection. MSAS analysis/sfc observations indicate a couple of boundaries of interest, the first from near Valparaiso to Elkhart to north of Angola, with primary sfc cold front and sharper low level convergence approaching the IN/IL border. Initial convection this afternoon appears to be favoring the lead remnant outflow/marine reinforced boundary north of the US Route 6 corridor, but would expect with continued destabilization over next few hours and increase in stronger low level convergence with the cold front, storm coverage will increase in the 20-22Z timeframe. RAP analysis from 19Z indicates a few pockets of enhanced instability, one across far northeast Illinois into far northern Indiana near the aforementioned lead boundary. Pre-frontal confluence in this area is also accompanied with some pooling of low level moisture and PWATS in excess of 2 inches. Another MLCAPE axis extends from southern Illinois noising into east central Illinois. Instability should increase across central portions of CWA next few hours, and main pre-frontal instability axis across east central Illinois should nose into west central Indiana. This should support continued expanding coverage of showers and thunderstorms, but this will be in an overall poorly sheared environment. Some locally modest increase in shear is possible with remnant convectively enhanced short wave moving out of NE Illinois, but confidence is low that this feature would have a notable effect on convective organization locally. Given combination of moderate instability and weak shear, multi-cell mode is favored through early evening with quick preference to outflow dominance with any more robust cells. SPC has placed much of area in Day 1 Marginal Risk for severe, mainly for any isolated wet microbursts that would occur. The greatest risk for this isolated threat appears to be fairly limited in time, more to the 20Z-00Z window. The other concern through early evening will be on potential of some localized heavy rain amounts given the 2+ inch PWAT pre-frontal pooling and moderate westerly low level jet of similar magnitude to deep layer mean wind supporting some upwind/backbuilding propagation. The orientation of primary instability axis working in from east central IL could also set up an environment favorable for upwind development. Not expecting widespread hydro issues at this time, but could see some localized issues in some areas given what should be efficient rain rates this evening, and recent localized heavy rainfall in some spots over past day and a half. With mid/upper short wave shearing out across Great Lakes/eastern Ontario, front should slow its southeast progress later this evening across southeast third of the area which could allow for some training potential into early evening. A few showers may linger into Tuesday across the south/southeast but will maintain idea from previous forecast in dry conditions for the afternoon with better shower potential south of the area. && .LONG TERM...(Tuesday Night through Monday) Issued at 345 PM EDT Mon Aug 8 2022 Cooler and less humid conditions will be in store Tuesday night through much of rest of work week as a stable longwave pattern becomes entrenched (western CONUS ridging/eastern CONUS troughing). This pattern will keep low level anticyclone positioned across the region for much of this period. A more vigorous upper level trough dropping across eastern Great Lakes on Thursday should drive reinforcing cool front into region on Thursday. Front for our area will be somewhat divorced from stronger mid/upper level support so at this forecast distance will just maintain slight chance PoPs Thursday PM. Eventually this pattern should exhibit some slight progression into the weekend that could allow for some renewed convective chances late in the period at the nose of better advective forcing. Overall temps for the extended look to remain below normal, particularly with min temps given dry nature to low levels and weak flow allowing for cool nights. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) Issued at 606 PM EDT Mon Aug 8 2022 Cool frontal boundary passage will continue to bring increased chances for moderate to heavy rainfall and even a few embedded thunderstorms through this evening with some VISBY decreases within the heaviest rain also being possible. Chances will decrease through the overnight period from the north to the south as the boundary moves through. Behind the boundary, periods of stratus will be possible and lowered vsbys could occur into Tuesday with flight conditions dropping into MVFR and IFR as cold air advection take over tonight. Localized patchy fog will be possible however at this time not expected to become dense. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Beach Hazards Statement through Tuesday afternoon for INZ003. MI...Beach Hazards Statement through Tuesday afternoon for MIZ077. OH...NONE. LM...Small Craft Advisory until 11 AM EDT Tuesday for LMZ043-046. && $$ SYNOPSIS...Andersen SHORT TERM...Marsili LONG TERM...Marsili AVIATION...Andersen Visit us at Follow us on Facebook...Twitter...and YouTube at:
Area Forecast Discussion
National Weather Service North Platte NE
646 PM CDT Mon Aug 8 2022 .SHORT TERM...(This evening through Tuesday night) Issued at 324 PM CDT Mon Aug 8 2022 One more cool night for wrn and ncntl Nebraska. Sfc high pressure across the Midwest will drift slowly east and the temperature forecast leans on the coolest guidance data set- the NAM, for lows in the 50s to lower 60s. This is a few degrees cooler than the short term model blend and the 50th NBM. The temperature forecast will compete with south winds aloft at 850mb. An isolated thunderstorm chance is in place across the Sandhills and swrn Nebraska Tuesday afternoon and evening. The models are in good agreement suggesting a warm front will be draped across the southwest and ncntl area. The cap is still weak and the moisture very modest, less than 1.25 inches of PWAT. Winds aloft are weak also, less than 20 kts at h500mb, but the models including the GFS suggest a weak UA disturbance will drift east southeast off the nrn Rockies as a trigger. The temperature forecast Tuesday leans on the short term model blend for highs in the 90s. This is the middle road, slightly warmer than the guidance blend but very close to the 50th NBM and the RAP model. .LONG TERM...(Wednesday through Monday) Issued at 324 PM CDT Mon Aug 8 2022 Another protracted period of dry weather Wednesday through Sunday appears imminent across wrn and ncntl Nebraska. An upper level ridge high pressure across the Four Corners region this morning will build very slowly north into Colorado and then east into KS by next weekend. The associated subtropical plume of upper level moisture will remain mostly north of Nebraska through Saturday and then drop south Sunday as the ridge moves into KS. The forecast concern is how warm temperatures will get this week before a cold front drops into Nebraska next weekend. The very warm GFS guidance suggested 5 days of 100+F degree temperatures Wednesday Sunday but bias correction lowers these temperatures into the upper 90s to around 100. The operational GFS shows h700mb temperatures of 14C-18C supporting it`s heat- much warmer than the ECM or GEM. The forecast follows the 50th percentile NBM which is close to the guidance blend. This suggested highs in the 90s to around 100 with the warmest temperatures Friday and Saturday. It is during this time that sfc low pressure will migrate east off the high plains into SD. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 645 PM CDT Mon Aug 8 2022 Quiet aviation conditions are expected over the next day. Winds remain near or under 10 knots with mostly clear skies. Some increasing clouds can be expected tomorrow afternoon, but ceilings should remain in VFR. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Kulik
Area Forecast Discussion
National Weather Service Phoenix AZ
539 PM MST Mon Aug 8 2022 .SYNOPSIS... The main storm chances for today will begin in the eastern Arizona high terrain and parts of the western deserts this afternoon before possibly spreading into the lower deserts and Phoenix this evening and tonight. Storm chances will increase noticeably tomorrow and then remain elevated through next weekend and into early next week due to abundant moisture and an active Monsoon pattern in place. Occasionally heavy rainfall, localized flash flooding, gusty winds and localized blowing dust remain likely through early next week. High temperatures will also remain slightly below to near normal through early next week. && .DISCUSSION... The H5 Monsoon ridge is ideally positioned near the 4-Corners with moist E flow through the mid-upper levels aloft. GOES WV imagery indicated a very moist airmass across the region with inverted disturbances pushing W into SE CA where GOES imagery and radar also indicated an area of scattered showers and storms/MCS where localized flash flooding is happening this afternoon including near I-10 and JTNP. Early afternoon radar also showed widely isolated to scattered distant thunderstorms across the high terrain of N, E and S AZ. The E AZ storms were associated with additional E wave vort clusters advancing from NM. The latest ACARS soundings shows an increasingly moist airmass with PW having climbed to 1.7->1.9" while mesoscale analysis indicated PW >2" across SW AZ and into SE CA. MU and SB CAPE had also increased to >2-3K j/kg. Some HREF members still favor pronounced convection with locally heavy rainfall developing this afternoon across the across S Gila Cty and near Globe and burn scar areas before descending into the lower deserts and parts of the Phoenix Metro around 04Z. The HRRR however is an outlier and has recently backed off on that notion by both delaying and weakening the convection coming off of the high terrain this evening. However all members continue to favor a gusty E outflow this evening pushing into the Phoenix metro and N Pinal. The potential for patchy blowing dust moving west remains possible, although most likely for N Pinal Cty and the SE-E Phx Metro Valley For tomorrow the HREF and ensembles are in agreement on an uptick in storm chances and coverage from E to W across the region with POPs increasing to near 50% for Phoenix and the lower deserts, to 60-70% for the E AZ high country, and 20-30% for SW AZ and SE CA. WPC Day 2 ERO also features a "slight risk" over much of the region for tomorrow. Some HREF members start with some shower activity W of Phoenix in the Tue morning hours moving in from in S-SE AZ. However the main convection will likely start in E-SE AZ associated with the next E wave(S) and will push into the Phoenix Metro and the lower deserts Tue evening. Good (>50% for >35 mph gusts) chances of strong gusty winds, from both the S-SW and E and locally dense blowing dust will likely be followed by locally heavy rainfall and localized flash flooding in the high country and the lower deserts. Going through the rest of the week and possibly beyond, ensembles continue to be in very good agreement that the subtropical high pressure will remain situated northeast of the four corners region. This overall positioning of the high will be favorable for continuous moisture advection into the desert southwest with PWAT values across the lower elevations ranging between 1.7 and 2.0 inches. In addition to the continuous moisture advection, there will be periodic easterly waves that will migrate into the region, which will aid in increasing the storm coverage. However, determining the timing of each individual wave as it approaches the region is difficult this far in advance. NBM PoPs through the period range between 25-50% in the lower elevations and between 40-70% across the higher terrain. With the increased moisture and potential cloud cover from convective debris, high temperatures during the next several days will remain near to slightly below normal. && .AVIATION...Updated 0039Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: The environment over Phoenix is still capped this afternoon with FEW to SCT small cumulus. There are storms surrounding the area with storm motion to the west. There are a couple outflows moving toward the metro area with the closest one to the northwest that could provide a light northwest wind shift at KDVT. The more favorable outflow(s) will be from showers and storms moving toward the metro from the east this evening. Most favorable timing of an outflow is still around 4-6Z. Probability of outflow gusts exceeding 30 kts is around 30-40%, which could also generate blowing dust at these magnitudes. There is also a 30% for showers and storms to survive into or redevelop in the metro this evening with the outflow(s), although most hi-res models weaken the activity the further west they push. Storm chances in the metro will be higher Tuesday afternoon and evening. Lowest cloud bases will mostly be around 10 kft, but could dip to 7-8 kft with a storm. Greatest cloud coverage will be during the evening and overnight. Southeast California/Southwest Arizona including KIPL and KBLH: Westerly winds at KBLH now are expected to eventually shift back southerly or become variable this evening and overnight. East to southeast winds at KIPL will prevail for at least the next hour or so, but storms over the mountains to the west may eventually push a gusty outflow through the Imperial Valley with winds shifting to the west. There is a low chance (10-15%) for VCSH or VCTS at KIPL with an outflow this afternoon and evening. Winds should eventually turn back easterly tonight after any outflow. There will be another chance for VCSH and VCTS Tuesday morning, better at KBLH (10-20%), as hi-res models suggest elevated convection moving through SW AZ. FEW to SCT clouds based around 10 kft will be common, with SCT to BKN higher clouds, through the period. && .FIRE WEATHER... Active monsoon storm conditions are expected during the next several days as moisture levels remain elevated across the area. With the elevated moisture levels in place, MinRHs will range between 25-40% with excellent overnight recoveries. Therefore, the fire danger threat is expected to remain low for the foreseeable future. Winds for the most part will remain light, with the exception of thunderstorm outflows generating stronger gusts. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Sawtelle/Lojero AVIATION...Benedict FIRE WEATHER...Lojero
Area Forecast Discussion
National Weather Service Springfield MO
635 PM CDT Mon Aug 8 2022 Key Messages: 1. Scattered showers and thunderstorms today. Isolated gusty downburst winds and flash flooding will be the main hazards through tonight. Flood Watch northeast of Springfield. 2. Scattered showers and thunderstorms again Tuesday, mainly along and south of Interstate 44. 3. Slightly less hot the first half of the work week with cloud cover and precipitation overhead. 4. Mostly dry forecast the second half of the week with near to slightly above normal temperatures. .SHORT TERM...(This evening through Tuesday) Issued at 200 PM CDT Mon Aug 8 2022 Synoptic Pattern and Current Conditions: Water Vapor imagery revealed an upper level low across southern Missouri-northern Arkansas. This low was slowly drifting west ahead of an incoming shortwave trough across the central/northern Plains. A surface front was now moving into the far northern portion of the CWA with temps in the 90s ahead of the front with temps in the 70s-80s back behind the front. The airmass across the area was moist and unstable with ML cape values in the 2000-3000j/kg range. PW values have increased from this morning and are now likely in the 1.7-2.0in range. Wind shear was very weak with 850mb-300mb mean winds around 5-10kts. Low level lapse rates were very steep (9C/km). Theta E diffs were in the 25-35C range therefore the environment is conducive to localized severe downdrafts. Areas of showers and thunderstorms have developed this afternoon east and south of Springfield in a unstable and a uncapped environment. These storms will continue to be pulse storms with a few severe downbursts and localized flash flooding possible. Of greater concern will be later this evening and tonight as the cold front continues to move closer to Interstate 44 and interacts with a unstable airmass and the lift from the upper level low. The 12z HREF data supports a very high probability (>70%) of thunderstorms developing along the Interstate 44 corridor from Springfield northeast to Rolla/Lake of the Ozarks. These storms could develop/train over the same areas and with the high moisture content/instability, both severe pulse storms and flash flooding is possible. HREF local probability matched mean data is showing 2-5 inches pockets northeast of Springfield, within a greater area of smaller amounts of 1 inch or less. This area has also seen more rain recently versus other areas therefore we will issue a Flood Watch for this area northeast of Springfield for this evening and tonight. Other areas further west will see less amounts of rainfall. The cold front will slow overnight and additional showers and thunderstorms will be likely across the area, especially east of Springfield. The front will likely move just south of I-44 during the day Tuesday therefore chances of rain Tuesday will mainly be across the southern CWA. The latest RAP does indicate 2000j/kg of ML cape south of I-44 Tuesday afternoon therefore will need to monitor for more pulse storms and isolated flash flooding. .LONG TERM...(Tuesday Night through Monday) Issued at 200 PM CDT Mon Aug 8 2022 Overall Synoptic Pattern: The Ensemble Cluster Analysis reveals pretty high confidence that the area will remain just to the east of the upper level high across the plains. Temperatures: Ensemble guidance and NBM data supports temperatures generally at or slightly above average. NBM spreads are only 5-6 degrees with highs ranging from the upper 80s to lower 90s expected from mid week into the weekend. Precipitation Chances: The ensemble means indicate very low probabilities (less than 20%) of seeing precip in this pattern. Therefore most areas will likely remain dry through the rest of the week into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Pilots flying in and out of the southwest Missouri airports will need to monitor radar trends throughout the entire 24 hour taf period. A slow moving frontal system will be a focus for showers and thunderstorms through tonight and tomorrow. A few of the storms will be capable of producing some downburst wind gusts, along with heavy rain and lightning. Therefore, visibilities could drop at any airfield experiencing this activity. Safe Travels. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch through Tuesday morning for MOZ057-058-069>071- 080>083-091-092. KS...NONE. && $$ SHORT TERM...Burchfield LONG TERM...Burchfield AVIATION...Cramer