Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/11/17

Area Forecast Discussion
National Weather Service Taunton MA
1028 PM EDT Mon Jul 10 2017 .SYNOPSIS... An approaching cold front will trigger a couple round of scattered showers and thunderstorms from early Tuesday morning through early evening. This front lingers nearby Wednesday into Friday, resulting in unsettled weather at times. Weak high pressure builds in for Saturday, then another cold front is expected to move through the area next Sunday or Sunday night. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Clouds moving over the region during the night, with radar showing a few light showers, mostly to our west. The shortwave driving these showers will move over New England toward 12Z bringing a chance of showers moving in from the west a few hours before that. The 01Z HRRR maps from SPC show a few light showers moving in from PA toward midnight and crossing CT and Western/Central Mass through 06Z/2AM. Somewhat stronger showers than move into these western areas 2-4AM and across RI and Eastern Mass 5-8AM. It is tricky to read too much into the details of this output, except to expect a few showers during the overnight hours moving in from the west and lingering through the morning commute. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... ***Scattered thunderstorms with localized heavy rainfall and an isolated wind damage Tuesday morning into early Tuesday evening*** Tuesday morning... The shortwave that was driving the current complex of showers and thunderstorms over the eastern Great Lakes will track eastward overnight. A developing modest low level jet coupled with ample forcing from the shortwave and elevated instability will trigger scattered showers and probably embedded thunderstorms after midnight into Tuesday morning. While this activity is possible across most locations, highest risk is north and west of a Boston to Providence corridor and especially across western MA. This is where the strongest forcing will likely reside. Timing of the showers and embedded thunderstorm threat after midnight into Tuesday morning remains uncertain, although models have been trending faster. The main threat will any thunderstorms through that time will be heavy rainfall and a brief localized urban street flooding threat as Pwats climb to between 1.5 and 2 inches. The overall severe weather threat is low through Tuesday morning, as weak mid level lapse rates and limited surface instability. However, we can not rule out an isolated strong to severe thunderstorm or two given 0 to 6 km shear on the order of 35 knots and a decent shortwave. In addition, 0 to 1 km helicity looks to be between 100 and 200 units. Most likely will not be an issue given elevated nature of morning activity, but still need to keep a close eye on the radar for the very low risk of some mesoscale intervention that can sometimes make things go surface based earlier than expected. Tuesday afternoon and early evening... Probably will see some sort of break in the main activity for a time Tuesday afternoon, but still may see a few showers/t-storms given deep moisture and warm advection. Another shortwave will be approaching from the west later in the day. This will probably trigger additional scattered showers and thunderstorms that will persist into early evening. Given Pwats close to 2 inches, heavy rain and a brief localized urban street flooding threat will be a concern. There is an isolated strong to severe thunderstorm potential Tuesday afternoon and early evening. This will depend on how quickly the atmosphere can recover from the morning convection and timing of the second shortwave. High temps may be able to recover into the lower to middle 80s and it will be humid. As is often the case in our region, weak mid level lapse rates will likely prevent a widespread severe weather outbreak. 0 to 6 km shear is also rather marginal and even diminishes a bit during the afternoon. Nonetheless, enough instability may develop with MLCapes near or above 1000 J/KG for a few strong to severe thunderstorms. The main threat would be locally strong to damaging wind gusts, but hail can not be ruled out. The bulk of the activity should wind down by the early evening hours on Tuesday. However, frontal boundary stalling near the south coast and low level jet persisting may allow some activity to last longer in that region. Low temps mainly in the upper 60s to around 70. Will have to watch for some patchy ground fog developing late in the typically prone locations. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Highlights... * Showers/t-storms possible at times Wed-Fri * Warm and humid Wed/Thu then turning cooler Fri * Mainly dry Sat but shower/t-storm risk returns next Sun Overview... Zonal flow dominates northern CONUS mid to late week with series of fast moving shortwaves which will keep an unsettled pattern across SNE. Mid level trof eventually amplifies a bit across the Gt Lakes and New Eng next weekend as anomalous subtropical ridge builds across the western CONUS. Will follow a blend of available guidance to smooth the less predictable details. Details... Wednesday... Cold front will be moving south across the region but there is uncertainty with how far south the front gets before stalling. This will affect how much drier air advects in from the north and the extent of instability and resulting shower/t-storm activity if front stalls further north across SNE. ECMWF keeps threat of showers/t- storms across the region while GFS dries it out. We will have slight chc PoPs during the day. Still humid near the south coast but somewhat drier air may work into northern MA. Highs in the 80s. The front is expected to lift back to the north Wed night and there may be an MCS that develops across northern New Eng at the nose of the low level jet. Some of the guidance has convection spilling into northern MA late Wed night. Still much uncertainty. Thursday into Friday... Unsettled period expected. May be dealing with remnants of an MCS across northern MA Thu morning, then front is expected to move back south across the region with a period of showers/t-storms possible. High PWAT airmass suggests potential for locally heavy rainfall. The position and timing of the front is uncertain and its location will be critical to temps and timing of showers/t-storms. Big temp bust potential for Thu as slower timing means very warm but if front is faster and further south temps will fall sharply. Warmest temps across CT/RI and SE MA. The front pushes south of New Eng Thu night into Fri, but SNE will be on the leading edge of higher theta-e air with continued risk of showers/t-storms, with greatest risk across SW half of New Eng. Cooler Fri with E/NE flow expected and temps upper 60s to lower 70s and it is possible all SNE remains in the 60s on Fri. Saturday... This potentially looks to be the driest day as weak high pres builds south into the region with some drying of the column. Temps likely still below normal with onshore winds. Sunday and Monday... Low confidence forecast at this time range with timing of shortwaves and cold front. Another risk of showers/t-storms as the mid level trof swings through but timing is uncertain. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/... Overnight...Moderate to high confidence. Mainly VFR. However, a band of showers and isolated thunderstorms with brief heavy rainfall may impact the region after 6z. Highest risk will be to the north and west of a Boston to Providence corridor, particularly in western MA. Lastly, will have to watch for some low clouds/fog patches across the Cape and Islands but confidence on whether they develop is low. Tuesday...Moderate confidence. Scattered showers and embedded thunderstorms are expected into early Tuesday evening with locally heavy rainfall. Timing and areal coverage a bit uncertain, but may come in two main rounds in the morning and later in the afternoon/early evening. A few of the thunderstorms may produce locally strong wind gusts. Outside of any showers and embedded thunderstorms, mainly VFR conditions will probably prevail but southwest wind gusts up to 25 knots. Tuesday night...Moderate confidence. Most of the lingering scattered showers and embedded thunderstorms should come to an end early Tuesday evening, but may linger a bit longer near the south coast. Otherwise mainly VFR, but will have to watch for areas of patchy ground fog developing late that could result in localized MVFR to IFR conditions. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Wednesday through Saturday/... Wednesday...Moderate confidence. Some early morning MVFR/IFR stratus possible, otherwise mainly VFR. Low risk for a few showers/t-storms with brief lower conditions. Thursday and Friday...Low confidence. MVFR/IFR conditions possible but timing and details uncertain. Showers/t-storms possible at times both days. Saturday...Moderate confidence. VFR/MVFR cigs. && .MARINE... FORECASTER CONFIDENCE LEVELS... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday Night/... Overnight...Moderate to high confidence. Weak pressure gradient will keep winds/seas below small craft advisory thresholds. Some fog may develop across our southern waters late, but confidence in that is low. Tuesday and Tuesday night...Moderate to high confidence. Modest low level jet coupled with diurnal heating should result in southwest wind gusts up to 25 knots developing by afternoon, especially near shore. In addition, persistent southwest fetch should allow seas to build to between 3 and 6 feet across our southern waters. Therefore, have hoisted small craft headlines for all our waters on Tuesday. Near shore 25 knot wind gusts should diminish Tuesday evening with the loss of daytime heating. In addition, a few strong thunderstorms with gusty winds are possible. Outlook /Wednesday through Saturday/...Moderate confidence. Wednesday...Light winds expected but 5 ft seas may linger over the southern waters. Thursday...Variable winds, becoming NE across eastern MA waters with southerly winds south coastal waters, becoming easterly Thu night. Seas may build to 5 ft over eastern MA waters late Thu/Thu night. Sct showers/t-storms. Friday...Easterly winds less than SCA with diminishing seas. Saturday...Winds and seas below SCA. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 10 AM to 8 PM EDT Tuesday for ANZ230>234-236-250-251. Small Craft Advisory from 10 AM Tuesday to 8 AM EDT Wednesday for ANZ235-237-254>256. && $$ SYNOPSIS...KJC/Frank NEAR TERM...WTB/KJC/Frank SHORT TERM...Frank LONG TERM...KJC AVIATION...KJC/Frank MARINE...WTB/KJC/Frank
Area Forecast Discussion
National Weather Service State College PA
1127 PM EDT Mon Jul 10 2017 .SYNOPSIS... A dying cold front will approach from the Great Lakes this evening, then stall out just north of Pennsylvania for the next few days. This boundary is likely to push south of the region by next weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Radar showing a dwindling band of showers moving into the Susq Valley late this evening ahead of shortwave moving over the state. The back edge of remaining showers should be exiting the eastern part of the forecast area around 05Z-06Z. However, regional radar showing a new area of convection developing at nose of low level jet over Ohio. This feature is progged by near term models to overspread the area late tonight, with focus of associated convection expected to be across the Laurel Highlands and I-80 corridor per latest HRRR runs and 00Z NAM. Will reintroduce the chance of thunder with this new batch of convection late tonight, given the increasing forcing and marginally unstable soundings. Much higher humidity, along with cloud cover, will result in a warmer night than recent ones, with min temps mostly between 65-70F. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/... Focus for scattered showers Tuesday morning is likely to be across the southern half of the forecast area associated with passage of another weak shortwave. However, expect the best chance of precip to come during the afternoon hours, as brightening skies and resulting heating of high PWAT air mass leads to development of more widespread diurnal convection. 18Z GEFS and superblend continue to support POPs in the 50-60pct range for most of central Pa. The region remains within a marginal threat risk area for severe weather Tue PM. Model soundings indicating moderate CAPEs but fairly weak 0-6km unidirectional shear, suggesting the potential for isolated large hail with the damaging wind gusts originating from the strongest updrafts. Dewpoints will be pushing 70F in most places Tuesday, likely resulting in heat indices reaching as high as the mid 90s across the Lower Susq Valley. A ridge of a high pressure will briefly push the mugginess and most of the convection south of the Mason/Dixon line late Tuesday night through Wednesday morning, before the boundary returns north into the CWA Wednesday afternoon and stays situated near or right over our region through Thursday. Convective development along this front and the potential for one or more MCSs tracking in from the WNW will maintain a fairly active weather period Wednesday afternoon/evening with the potential for a few STG to SVR TSRA given the presence of the sfc boundary and moderately strong mid level west-nwrly shear. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Guidance remains consistent in depicting the summertime pattern evolution this period featuring strong upper level ridge rebuilding over the Western U.S. with corresponding mean troughing downstream over the Eastern U.S. The wavy front pushing southeast from the Great Lakes will provide a focus for thunderstorms with heavy rainfall Thursday-Friday. A trailing front progressing from southern Canada may generate some convection on Sunday. Above normal temperatures are likely ahead of the front at the start of the period. As the pattern evolves toward more troughing aloft, expect a gradual cooling trend with near to slightly below normal temperatures during the latter half of the period. Dangerous heat conditions are possible Thursday afternoon with fcst max heat index values around 100 degrees across portions of the mid/lower Susquehanna Valley into far s-central PA. An area of strong/severe storm potential could occur along/ahead of the wavy front late this week given strong buoyancy and moderate mid level flow between the ridge/trough pattern. However, model detail differences render a low confidence/predictability in severe storm risk at this time. By next Monday, cool high pressure may make an eastward push into the region, providing at least a temporary reprieve after a warm and stormy week. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... Band of showers now falling apart, updates done. Small area of storms over far SW PA. Should stay south of JST. Low CIGS at BFD at times. For Tuesday, went with VCSH. Most of the day should be VFR. .OUTLOOK... Wed-Fri...Periods of localized sub-VFR in sct showers/Tstorms. Sat...Improving conditions. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Fitzgerald NEAR TERM...Fitzgerald SHORT TERM...Fitzgerald/La Corte LONG TERM...Gartner/Steinbugl AVIATION...Martin
Area Forecast Discussion
National Weather Service Quad Cities IA IL
800 PM CDT Mon Jul 10 2017 .UPDATE... Issued at 754 PM CDT Mon Jul 10 2017 Focus of marginal severe threat this evening has shifted far south and possibly far east into Bureau/Putnam counties. Marginally severe hail, isolated downburst winds and heavy rain are main issues. Had a funnel cloud and possible brief tornado during Roseville earlier, so cannot completely discount that threat as well. && .SYNOPSIS... Issued at 305 PM CDT Mon Jul 10 2017 Heat Advisory in effect in the counties approximately to the south of a Cedar Rapids to Quad Cities line through 7 PM this evening. After widespread rainfall last night, the atmosphere has become very humid with dewpoints rising into the middle to upper 70s. Expect peak heat indices between the upper 90s to lower 100s. && .SHORT TERM...(This Evening through Tuesday) ISSUED AT 305 PM CDT Mon Jul 10 2017 Late this Afternoon through Tonight Very humid conditions with dewpoints in the mid and even upper 70s at some locations will be the main story. Threat for convection is fairly low but continued the lower 20-30% PoPs roughly in the counties along and south of I-80 to account for isolated activity. However, latest thinking is that most locations will stay dry overnight due to absence of low-level jet impinging into E Iowa/NW Illinois. Visible satellite shows a low-level cyclonic circulation within the CU field moving into the NW forecast area. It appears the mid/upper level cirrus streaming over the top are inhibiting more substantial CU development. However, a few storms may form downstream of this circulation in a localized zone of enhanced ascent and low-level convergence. The past several runs of the HRRR has developed a few storms mostly E/NE of the Quad Cities. The Storm Prediction Center has a slight risk for severe storms across Bureau and Putnam Counties which is in line with this thinking. If a few storms form, the primary threats would be damaging winds and large hail. Tuesday Shortwave or mid-level vorticity max currently analyzed over the Central Rockies, is forecast to traverse the Plains and reach the Upper Mississippi Valley by the late morning or early afternoon on Tuesday. This is probably our next decent chance for scattered showers and storms. It`s a return flow setup - there is a signal for lower tropospheric isentropic lift and WAA, which could kick off a broken band of convection that moves to the ENE. Models indicate enough instability and shear for a few strong storms, but do not see much of a potential for organized severe weather through Tuesday afternoon. In fact, models are in pretty good agreement breaking out the strongest convection to the north across Minnesota and Wisconsin later Tuesday into Tuesday night on the nose of the 850mb jet. Heat Indices: The highest dewpoints, in the mid 70s, are forecast to reside in the counties along and south of highway 34 west of Galesburg, Illinois for Tuesday afternoon. In this area, peak heat indices are forecast in the upper 90s to around 100 F. If skies clear out for several hours, it is likely values reach heat advisory criteria (~100 F). Uttech .LONG TERM...(Tuesday Night through Monday) ISSUED AT 305 PM CDT Mon Jul 10 2017 A hot and humid air mas will continue to remain in place across the region through the day Thursday. Wednesday looks to be the hottest day of the period, as high temperatures will climb into the upper 80s across the north, the middle 90s along and south of Interstate 80. With forecast dewpoints expected to reach the lower to middle 70s, this will produce afternoon humidity in the upper 50s and lower 60s, allowing heat index values to climb into the upper 90s to lower 100s. A heat advisory is possible depending on convective trends. A better chance for showers and thunderstorms will come late Wednesday through Thursday as an upper level shortwave and cool front moves the middle Mississippi River Valley. Should storms develop, an extremely moist atmosphere will allow for heavy rainfall leading to localized flash flooding as the primary threat. Other severe weather threats are low confidence at this time. Behind this front, weak high pressure will build south over Great Lakes for Friday and Saturday, providing a temporary break from the precipitation and higher humidity. High temperatures for Friday are expected to climb into the lower and middle 80s, before a return to the 90s for the weekend. Past Sunday, models begin to diverge on possible solutions, with a predominantly dry and high pressure filled ECMWF vs. a more potent and shortwave aggressive GFS. Temperatures for the period are forecast to remain in the middle to upper 80s, with dewpoints in the lower to middle 60s. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) ISSUED AT 754 PM CDT Mon Jul 10 2017 Evening storms have pushed south of KBRL, so low chances of additional storms impacting TAF sites through the overnight. Fog development is expected overnight with lingering low level moisture and slackening winds, especially at KDBQ/KCID, where at least 1-2SM visibilities are possible along with low stratus. A warm front will lift north into the area Tuesday, with the best chance of additional storms at KBRL/KMLI. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...RP Kinney SYNOPSIS...Uttech SHORT TERM...Uttech LONG TERM...Speck AVIATION...RP Kinney
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1035 PM EDT Mon Jul 10 2017 .SYNOPSIS... A weak frontal boundary over northern New England will lift north tonight. A cold front will approach from the northwest on Tuesday and will push south through the region Tuesday night. High pressure will build in from the northwest on Wednesday and will shift east Wednesday night as low pressure moves in from the west. Several waves of weak low pressure will pass south of the region Thursday through Friday. A cold front will drop southeast from Canada Saturday and will push east through the area Saturday night. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Update...Radar to the west looks like it may have more bark than bite at the moment. ASOS/AWOS sites across NY have shown mainly trace to a couple hundredths precip out of the leftover stratiform rain shield. This will continue to drift E thru the night. Latest HRRR seems overly aggressive with QPF amounts in the near term so far. However...a SWly LLJ is forecast to approach late tonight/early Tue and will likely provide some enhancement or redevelopment of rain/convection. This looks fairly well covered with the likely PoP I have in thru mid morning Tue across the Srn half of the forecast area. Attention tonight will be on a well developed MCS in progress in OH. CAPE axis trails off quickly to the E...and the strongest part of the line...evident by lightning and cloud top already starting to turn more Swd. The stratiform rain moving off the NE of the complex is forecast by mesoscale models to get into Srn zones late I will continue to monitor its progress. Also not seeing much in the way of marine fog at the backed off this in the forecast. But skies are mainly clear to the S where it would develop first...and it will be a nice test run with new GOES-16 fog imagery. Previous discussion...Remains of Midwest MCS will move east tonight, bringing showers into the region later tonight. Models have had a challenging time picking up on this feature. Have upped pops for after midnight tonight. Prior to the clouds and precipitation, patchy fog will form across the inland valleys. There may be late night fog rolling in off the Gulf of Maine as well. Overnight lows will drop down into the upper 50s in the north, with 60s elsewhere. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Timing and strength of the convection tomorrow will be dependent on the amount of cloud cover and the exiting of the remains of the MCS during the early morning hours. After plenty of cloudiness and patchy fog early, subsidence after this passage of the exiting complex should allow for some sunshine during the day, allowing the atmosphere to destabilize ahead of an approaching cold front. CAPE values increase during the day with precipitable water values approaching 2 inches in some areas. This may allow for a few storms to produce damaging wind gusts and locally heavy rainfall. Freezing levels will be high so any hail should be relatively small. SPC continues to keep the forecast area in a marginal risk for severe weather tomorrow. Most areas will be in the 70s for highs Tuesday, with lower 80s over far southern areas away from the coast. Showers and any remaining storms should diminish and weaken around sunset tomorrow evening, with a few stray showers continue for a good portion of the night over the far south. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... The long term outlook period will be featured with a fast moving west to northwest flow aloft that will drive several short waves through the flow into northern New England. This will cause several bouts of convection, the first being Wed night and Thu. Due to the fast flow aloft, this system will be quick to exit, so by Thu night the system will have exited the region. On Fri and again Sat the next few systems move rapidly across the region spreading scattered showers back into the region. Timing of the systems will be difficult, and combined with some differences on model consensus, mean more of a broader brush needed to be used for the chance of showers Fri and through the weekend. Temps will be comfortably mild Wed but cooler Thu and Fri. A return to warmer temps expected for the weekend into next week as warmer southwest flow develops. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Short Term...VFR conditions tonight. VFR Tuesday with areas of MVFR/IFR ceilings/vsby in Thunderstorms. Long Term...VFR Wed. Conditions becoming MVFR/IFR in showers and scattered thunderstorms late Wed night and Thu. Conditions improve to VFR Thu night into Fri although widely scattered showers possible. Variable conditions to MVFR into the weekend in scattered showers as another system approaches from the west. && .MARINE... Short Term...Seas and winds will reach SCA levels tonight over the outer waters and all areas by Tuesday as a southerly gradient increases. Long Term...No flags. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory from 6 AM to 6 PM EDT Tuesday for ANZ151- 153. Small Craft Advisory until 6 AM EDT Wednesday for ANZ150-152- 154. && $$ NEAR TERM...Legro
Area Forecast Discussion
National Weather Service Lincoln IL
905 PM CDT Mon Jul 10 2017 .UPDATE... Issued at 900 PM CDT Mon Jul 10 2017 Updated the forecast for handling convection trends tonight as highest chances of showers/thunderstorms have shifted south of I-74 with an MCS. Severe thunderstorm watch continues through 11 pm north of a Jacksonville to Springfield to Decatur to Tuscola and Paris line. In addition to severe wx, heavy rains and frequent lightning will also occur with these storms as they track se at 55 mph toward I-72. Still have unstable airmass over parts of central IL especially where storms have not occurred yet, with pockets of CAPE as high as 2-3k J/kg. Also have 30-40 kt bulk shear over central and ne CWA (highest over northeast CWA). The HRRR model shows convection shifting southeast toward I-70 toward midnight as it weakens by that time, then convection is more isolated over area overnight as airmass stabilizes. Muggy lows overnight in the lower 70s look on track and no changes there. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 318 PM CDT Mon Jul 10 2017 Clearing across central IL this afternoon is taking place as the remnants of last night`s thunderstorm complex have moved east of the area in to Indiana. Return of south-southwesterly winds have allowed temperatures to rise into the upper 80s at most locations with a few readings over 90 degrees, while dewpoints in the low to mid 70s are predominant. Strong instability of 2000-3500 J/kg has built across the area as a result, and sfc-6 km bulk shear 35-45 kt, combined with an approaching shortwave and cold front from the north should be able to initiate strong to potentially severe thunderstorms later this afternoon especially in the I-74 corridor northward. This activity should sink southward overnight, although weakening with the upper level forcing moving east and instability decreasing. The frontal boundary stalled out over central IL should keep a chance for thunderstorms going over much of the area Tuesday. Southern portions of the area may see highs over 90 with heat index around 100, but areas north of the front a less hot with upper 80s/upper 90s heat index. .LONG TERM...(Tuesday night through Monday) ISSUED AT 318 PM CDT Mon Jul 10 2017 The warmest day of the week should be Wednesday as the frontal boundary lifts well north of the area resulting in high temps in the low to mid 90s across the area, with heat index around 100 with perhaps a few spots of 105. Dry conditions look to occur much of the day before chances of thunderstorms develop in the evening through Thursday as a wave moving through the Great Lakes region pushing the front back through central IL. SPC has a marginal risk for severe thunderstorms from around I-74 northward with this feature. This should also result in slightly cooler temperatures by Thursday. As the front gradually shifts southward into the weekend, the focus for thunderstorm chances should shift south of the area by Saturday morning, and temperatures should remain slightly cooler with highs mainly upper 80s into Monday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 658 PM CDT Mon Jul 10 2017 A band of thunderstorms north of a Rushville to Bloomington line was tracking slowly south this evening and will affect the PIA and BMI TAF sites in the immediate future with strong gusty winds and hail. Still a question as to how far south these storms will get later this evening as models suggest a gradual weakening of the storms, but brief MVFR or IFR cigs possible with the stronger cells will be possible. Outside any storms, we look for mainly VFR conditions although there is the potential for some fog by Tuesday morning in the areas that see the rainfall tonight. We expect some cumulus to reform tomorrow with mainly scattered coverage with bases of 3500 to 4500 feet expected. Winds tonight will be light southwesterly and then west southwest winds expected on Tuesday at 10 kts or less. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...37 LONG TERM...37 AVIATION...Smith
Area Forecast Discussion
National Weather Service Indianapolis IN
1149 PM EDT Mon Jul 10 2017 .UPDATE... The AVIATION section has been updated below. && .SYNOPSIS... Issued at 327 PM EDT Mon Jul 10 2017 Upper waves and a few surface fronts will continue to bring chances for rain to the area for much of the work week. High pressure will bring dry conditions early next week. Hot and humid conditions through the work week will give way to average conditions for the weekend. && .NEAR TERM.../Overnight/ Issued at 1030 PM EDT Mon Jul 10 2017 Current forecast looks on track. Storms over north central Indiana should drop southeast over the area overnight. More storms could also develop and central Illinois storms could hold together and effect southwestern parts of the forecast area as well. Previous discussion follows... Issued at 327 PM EDT Mon Jul 10 2017 Scattered showers and thunderstorms have continued to develop in the area with instability being fed into the area on decent 850mb winds. The current round of showers and a few storms should move out of the area in a couple of hours. Pop-up convection will still be possible though as instability increases with decreasing clouds. Late this afternoon and early this evening more convection will develop to our north with some additional upper energy moving in and a cold front to the north. This convection will sink south through the area during the evening hours, before weakening as instability wanes and with the cold front remaining to the north of the area. Went likely PoPs across the north this evening with lower PoPs south, diminishing to just chance or lower PoPs overnight as convection weakens. With the instability building upstream this afternoon, could still see some severe storms later this afternoon and this evening. High precipitable water values will make heavy rain/flooding an additional threat. The model blend looks ok for low temperatures. && .SHORT TERM.../Tuesday through Thursday/ Issued at 327 PM EDT Mon Jul 10 2017 Models are close enough that the model blend initialization was accepted for most items. A leftover boundary from overnight convection should be across the forecast area on Tuesday. This boundary plus still decent flow at 850mb will lead to the redevelopment of convection during the day as instability builds once again. Will go high chance category to low likely category PoPs across central parts of the area where boundary is expected to be. Again heavy rain is a possibility with high moisture content. Chances for rain will diminish Tuesday night as the upper ridge to our south begins to exert its influence into the area. On Wednesday, enough of the ridge should be in control to go with a dry forecast. However, isolated convection (with PoPs below the threshold for mentioning) cannot be ruled out. Rain chances return Wednesday night and Thursday as another upper wave and surface front moves into the area. Heat indices will be near 100 degrees at some locations by Wednesday with high low level moisture content and the upper ridge nosing into the area. && .LONG TERM /Thursday Night through Monday/... Issued at 309 PM EDT Mon Jul 10 2017 A gradual shift to a quieter weather pattern should take hold through much of the extended as the upper ridge retrogrades into the Intermountain West. This will enable the frontal boundary to finally shift south of the Ohio Valley Friday with more widespread convective threats ending as high pressure settles into the region on Saturday. Dry weather is expected to persist through much of the rest of the period with the exception of a small threat for storms late Saturday into Saturday night as an upper wave rapidly tracks through the lower Great Lakes. While highs will remain in the 80s through the extended...humidity levels will lower from the muggy conditions expected for much of the work week. Some hints in the long range data at the upper ridge expanding back east into the Plains early next week...which conceivably would thrust central Indiana back into a more active pattern with ridge rider potential as the region sits on the edge of the heat dome. && .AVIATION (Discussion for the 110600Z TAF Issiance)... Issued at 1149 PM EDT Mon Jul 10 2017 The storms have been slow to develop and spread south this evening compared to HRRR runs. Thus, will only go VCTS through 10z. Then, should see more storms develop after 16z as another wave approaches and the atmosphere becomes moderately to strongly unstable. Good confidence that flying conditions should be mostly VFR away from thunderstorms. Winds will be southwest 10 knots or less but with high gusts possible in thunderstorms. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...50/MK SHORT TERM...50 LONG TERM....Ryan AVIATION...MK
National Weather Service Jackson KY
949 PM EDT Mon Jul 10 2017 .UPDATE... Issued at 949 PM EDT MON JUL 10 2017 Forecast is still in good shape with only minor adjustments needed to make sure the near term grids were on track with current observations. A few high clouds are continuing to move into eastern KY from ongoing convective systems to our north and northwest. Latest satellite trends are showing a rapid expansion and cooling of cloud tops with the convective complex taking shape across southern Illinois over the last hour. As this system continues to track eastward overnight, these high clouds look like they may be on track to move across portions of the CWA, especially the northern half. Will continue to monitor this as it may have an impact on temperatures in this area, however should not pose any other threats. All updates were sent to NDFD/web, with no major changes expected to impact the ongoing ZFP/HWO. UPDATE Issued at 624 PM EDT MON JUL 10 2017 Forecast continues to be in good shape early this evening. Just freshened up the near term grids for temps, dew points and winds to make sure they were on track with current observations. No updates to the forecast package will be needed at this time. && .SHORT TERM...(This evening through Tuesday night) Issued at 415 PM EDT MON JUL 10 2017 19z sfc analysis shows high pressure off to the southeast of Kentucky with enough of an influence to keep skies mostly sunny today for the bulk of the area. On satellite, a small to moderate cu field is diminishing in the face of thin and higher clouds arriving as blow off from the storms well off to the northwest. Temperatures are running in the mid 80s through the area as they top out while dewpoints are in the mid to upper 60s making for a warm and humid afternoon. Winds have been occasionally gusty out of the southwest across the Bluegrass counties and near Lake Cumberland. The models remain in good agreement aloft through the short term portion of the forecast. They all depict a strengthening ridge through the Southern Plains and across into the Tennessee Valley. This will help push the eastern trough out of Kentucky while leaving the west to east track of energy impulses nearby and just to the north of the state through Wednesday morning. Given the good model agreement will favor a blended solution but lean heaviest on the higher resolution HRRR and NAM12 given the small scale nature of the features affecting the forecast. Sensible weather will likely entail a quiet and mild night with partly cloudy to mostly clear skies and some patchy valley fog by dawn. Still expect a small ridge to valley temperature split tonight on the order of 3 to 5 degrees. The caveat is that the models are right and any convection stays well north of the area - this will have to be monitored through thr night. Tuesday will be a repeat of today with temperatures and humidity a notch higher. We will even have a repeat of concerns about convection tracking east just north of the CWA for late tonight into Tuesday. We will need to watch out for any outflow boundaries that could trigger some convection in the northern tip of the JKL CWA despite the rising heights aloft. For this have carried small chance PoPs north of Interstate 64. Tuesday night into Wednesday morning will be quite similar to tonight but with less concern for any convective intrusions. Again used the CONSShort as the starting point for all the grids with adjustments tonight and Tuesday night for a small ridge and valley temperature distinction. Also, tweaked the blended guidance PoP grids to allow for more of a lingering threat of convection through the day Tuesday in the north. .LONG TERM...(Wednesday through Monday) Issued at 415 PM EDT MON JUL 10 2017 The models are in good agreement with a stagnant long wave pattern to rule across the CONUS initially, with ridging in place from the mid-Atlantic to the Desert Southwest. A little more amplification then takes place towards the weekend, as passing short wave energy along the Great Lakes and New England, eventually re-establishes a trough in the eastern CONUS by the weekend. Heat and humidity will be the main weather story for eastern Kentucky to start out, as highs on Wednesday look to be in the low 90s, with dew points on the rise. Capping from the nearby ridge axis should keep a lid on convection. As the ridge breaks down through Friday, rain and storm chances will be on the increase. The highest chances will occur on Friday, as a cold front moves through the area, with some modest upper level support accompanying it. The lingering trough and moisture still in place will allow for chance POPs into Saturday, before some temporary dry weather ensues Saturday evening. Another weaker cold front and modest pocket of short wave energy will pass through the area on Sunday, maintaining the threat of at least a few storms. Dry weather then returns for Monday, as the trough axis works east of the area. Highs will gradually cool to the mid 80s by Friday, thanks to increasing cloud cover and storm chances; however, the humidity will continue to be very high, as lows average around the 70 degree mark each night. A more noticeable change in humidity will occur by the end of the week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 732 PM EDT MON JUL 10 2017 Expect VFR conditions through the period as sfc high pressure will remain just to the SE. A series of passing mid level waves just to the north of Kentucky will bring some high clouds throughout the overnight. Otherwise, the only other concern will be the moisture return into the south where some patchy valley fog could develop late tonight. However, not expecting impacts to make it into the TAF sites. Light winds are forecast out of the southwest through the overnight and into the day tomorrow. However, still can`t rule out a brief period of wind shear late tonight/just before daybreak in northern KY (potentially including KSYM) at 2k feet from the southwest at 35 kts. Have kept this in the KSYM TAF as a result. Tomorrow, a few fair weather VFR CU clouds may appear during the afternoon, but otherwise mostly clear conditions and light SW winds will persist. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...GREIF LONG TERM...GEOGERIAN AVIATION...JMW
Area Forecast Discussion
National Weather Service Louisville KY
616 PM EDT Mon Jul 10 2017 ...Updated Aviation Discussion... .Short Term...(This evening through Tuesday night) Issued at 245 PM EDT Mon Jul 10 2017 Surface analysis this afternoon shows low pressure over Iowa with broad southwesterly flow ahead of it across the mid-Mississippi and lower Ohio River Valleys. A weak surface trough associated with an earlier complex of storms lies across central Indiana. This southwest flow has pushed dewpoints up into the 60s to lower 70s across southwest Indiana while temperatures are running in the mid to upper 80s. For the remainder of this afternoon and evening, the main forecast challenge is whether any storms will brush parts of southern Indiana. As of mid afternoon, recent HRRR and RAP soundings show a mid-level capping inversion holding in place, keeping a lid on storm development across our area. While to the north, the cap is weaker and diurnally driven convection has blossomed across central Indiana. Forecast soundings across southern Indiana show this cap weakening some which might allow an isolated shower or storm to develop through early evening, so have introduced 10-15 percent chances across our far northern areas. Otherwise, the remainder of the area will stay warm and dry with breezy southwesterly flow. Readings will be slow to fall and overall a very mild and somewhat muggy night is on tap. Plan on lows in the lower to middle 70s, warmest in the urban centers. For tomorrow, the latest guidance suggests outflow or effective boundaries will be draped east/west across central Indiana, a bit further south compared to today. With maximum daytime heating and a passing shortwave to the north, another complex of storms may initiate over central Indiana and drop east/southeast into parts of southern Indiana. Will continue to show 20-30 percent chances, mainly north of the Ohio River during the day. It will be another seasonably warm day with highs in the upper 80s to lower 90s. Lows Tuesday night are expected to fall into the 70s. .Long Term...(Wednesday through Monday) Issued at 255 PM EDT Mon Jul 10 2017 Broad upper level ridging across the southern US is likely to suppress convection across central Kentucky and most of southern Indiana Wednesday and Wednesday night. Plan on very warm high temperatures in the upper 80s to lower 90s and morning lows in the 70s. By Thursday into Friday the upper ridge breaks down somewhat and more northwesterly flow sets up across the Great Lakes, bringing a better chance for showers and thunderstorms across portions of the area. A more pronounced shortwave trough is forecast to drop through on Friday which will enhance thunderstorm coverage across the lower Ohio Valley. A few stronger showers and storms could be possible during this time frame. 10.12z models then show high pressure building back into the area from the Great Lakes next weekend, bringing lower humidity with near normal temperatures. && .Aviation...(00Z TAF Issuance) Issued at 613 PM EDT Mon Jul 10 2017 VFR conditions are expected through the TAF period. Weak LLJ will develop overnight but should be below LLWS criteria for mention in TAF. Southwesterly winds will pick up again tomorrow morning and afternoon and could be gusty at times. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Short Term...ZT Long Term...ZT Aviation...DM
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
958 PM CDT Mon Jul 10 2017 .MESOSCALE DISCUSSION... 958 PM CDT Isolated strong/severe thunderstorms are currently approaching the southwest Chicago suburbs at 945 pm. This small cluster of storms may be somewhat elevated, within a region of warm/moist isentropically forced ascent provided by 25-30 kt westerly low level jet. SPC RAP mesoanalysis depicts roughly 2000 J/kg MUCAPE axis across this region, and 35-40 kts of effective bulk shear, sufficient for producing organized updrafts. Trends over the past hour or so have indicated some healthy cores aloft at times with this cluster of storms (ping pong ball size hail in Peru IL), and currently noting wind signature with 45+ kt inbounds per MDW TDWR and LOT 88-D data. Magnitude of wind at the surface is of some question as these storms may be rooted slightly above the boundary layer, though warm/moist low levels and analyzed DCAPE pocket of 1000-1500 J/kg in ahead of storms suggests that some severe threat persists. Based on these trends have elected to hold onto current watch counties at this time. Overall though, will likely see a gradual decrease in intensity with time further east. Ratzer && .SHORT TERM... 200 PM CDT Through tonight... Meso discussion to follow closer to initiation... We get into lighter north winds once the surface low spreads along the southern CWA tonight. With some clearing expected and no real dry advection occurring, it appears some fog and or stratus will form overnight into the early morning hours on Tuesday. Will need to hang onto some pops overnight as the boundary does not clear the area and some weak energy slides southeast across it, though most of the activity will shift south before daybreak. MTF/KMD && .LONG TERM... 224 PM CDT Tuesday night through Monday... Active weather looks to continue into Thursday as a low amplitude upper flow remains in place with a number of waves rippling through it. A surface frontal boundary will be just south of the area Tuesday morning with high pressure settling in early but then shifting to the east into the afternoon. Low pressure will be across the plains with a southerly low level flow trying to become re- established across the area. Warm and humid conditions will continue. Upper level energy which is currently across the northern Rockies and is helping to break down the ridging over the plains will cross the local area later Tuesday. This will likely generate scattered showers and thunderstorms which will work east across the area through the evening. Instability is not notably strong and forecast soundings do show some inhibition. Severe threat is on the low end but cannot rule out something isolated. Best chances will be across the south closer to the boundary where instability will also be greater. Surface low pressure will better organize across the northern plains Wednesday. The upper flow will become a bit more cyclonic with another shortwave expected to cross the region. The surface low will move eastward across central Lake Michigan and work in conjunction with the upper flow to generate convection. Much stronger low level southwesterly flow will have developed over the area by Wednesday afternoon resulting in a push of warmer and much more unstable air. This should result in quite a bit of instability as well as precipitable water values pushing 2 inches. The combination of instability and forcing point to a decent severe potential. Tough to pin down any specifics at this time frame given several rounds of convection locally and nearby between now and then but will need to keep an eye on a potentially greater severe threat. Also have some initial heavy rain concerns as the surface low will pass north of the area allowing its attendant surface boundary to stretch out parallel to the westerly mean flow which may lead to training storms. Temp-wise, should see highs in the lower 90s for most areas combining with mid 70s dewpoints leading to heat index values in the 97 to 103 or so range. The boundary will hang up to the south on Thursday with the active upper flow continuing so storm chances will linger, especially south where instability will likely be greatest. Should see a range in temps as well with highs near 80 north and in the upper 80s south. The upper flow buckles to the east into Friday with broad ringing developing to the west. Surface high pressure is expected to settle into the local area leading to a quiet period and a modest break in the warm and humid conditions. The northwest flow aloft may become somewhat active as we have seen on several occasions in recent weeks so may see several windows for isolated to scattered showers and storms over the weekend. MDB && .AVIATION... For the 00Z TAFs... 638 pm...Main forecast concern this period is potential for low clouds and fog overnight into Tuesday morning. A boundary is moving south toward mdw and gyy and will shift winds northerly shortly. Winds will eventually become light northeast this evening and then possibly light/variable overnight into Tuesday morning. A weak gradient will likely lead to light east/ northeast winds for the Chicago terminals Tuesday with the potential for a lake breeze. Further west...including at rfd winds may remain light for much of the day with a west/southwest direction by mid/late afternoon. Other than a few showers in the next hour or two...the rest of tonight into Tuesday afternoon looks dry for the terminals. Additional thunderstorm development is possible Tuesday afternoon into Tuesday evening...likely well south of the terminals but confidence decreases by late Tuesday night with the possibility of thunderstorms developing over the terminals by early Wednesday morning...but this would be beyond the end of this forecast. With the light winds and moist low levels...some fog is expected overnight and as a weak surface low moves across the area...some low cloud development is also expected. Confidence on specifics is still rather low but some period of ifr cigs/vis are possible overnight through sunrise. cms && .MARINE... 224 PM CDT Low pressure will move from eastern Iowa to southern Lake Michigan this evening before weakening as it continues east. The associated frontal boundary will push south of the lake this evening before re- developing across northern Lake Michigan Tuesday night as low pressure moves across central and northern Wisconsin. This low will push the front back south down the lake later Wednesday into Thursday. High pressure will spread across the lake Friday keeping northerly winds in place. An active pattern returns for the weekend bringing a series of lows across the lake which will result in winds oscillating between northerly and southerly with the passage of associated frontal boundaries. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lubbock TX
629 PM CDT Mon Jul 10 2017 .AVIATION... VFR conditions continue through this forecast. Low level jet intensifies overnight enough to add LLWS to KCDS TAF. Otherwise, gusty south winds on tap for Tuesday afternoon. && .PREV DISCUSSION... /issued 227 PM CDT Mon Jul 10 2017/ DISCUSSION... Anti-cyclonic motion was quite evident on visible satellite today. RAP analysis showed our forecast area to barely be under the southeast edge of the high. Low and mid-level dry air was encroaching from the east via water vapor imagery. Near the state line, a cu field was developing, as well as across the TX Panhandle. Though one or two random showers may pop up across the forecast area this afternoon or evening, the vast majority will stay dry. Models show a wobbling ridge starting Tuesday, and that trend continues for most of the week. We never end up squarely under the high, which means highs will only reach a few degrees above normal, at the most. A weak wave will pass westward to our south in Mexico over the course of Wednesday and Thursday. Models show the moisture with this wave making it as far north as the southern Permian Basin, but the strength of the ridge will be too much to allow it to pass northward into our area. Temperatures on Tuesday and Wednesday should be fairly similar to Monday, varying by a degree or so, as thickness will be roughly the same. By Thursday, thicknesses fall, so Thursday temps should be slightly cooler. For the weekend, a slight disturbance may develop in the flow about the high over Colorado. May is the word of focus as the models have yet to agree on this feature. Moisture return by the weekend looks to be meager to the slight end of modest at best. We also return to northeast flow, which tends to hose our thunderstorm chances. With all of these negating factors, have chosen to keep PoPs out of this forecast package for the weekend. This will certainly be something to watch over the coming days as models hone in on the finer details. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 74/74/24
Area Forecast Discussion
National Weather Service Spokane WA
445 PM PDT Mon Jul 10 2017 .SYNOPSIS... Breezy and dry conditions will raise wildfire concerns in central Washington through this evening. There will be a slight chance of thunderstorms along the Canadian border through the evening as well. Winds will decrease on Tuesday with near average temperatures. Look for another round of hot and dry weather for late next week and the weekend. && .DISCUSSION... Tonight: Scattered showers and thunderstorms are expected to develop in the 3 PM to 5 PM time frame over the high terrain Ferry, Stevens, Pend Orielle, Boundary, and northern Okanogan counties. Growing cumulus over the mountains suggest that our convective temperature has been reached. RAP analysis as of 2 PM, suggests 400 J/KG to as much as 1000 J/KG of surface based CAPE along the Canadian border in the vicinity of a surface low pressure trough. Shear profiles are weak. Cells will likely form over mountain ridges and weaken as they move off the high terrain with a cell motion of northeast at 15 to 20 mph. Brief heavy rain, gusts up to 30 mph, and cloud to ground lightning will accompany the strongest cells through 9 PM. There may be enough mid-level instability through the night to produce ongoing, high-based showers into the early morning hours around Laurier, Northport, Porthill, and Bonners Ferry. Gusty west or northwest winds will raise wildfire concerns for the remainder of the afternoon into this evening along the East Slopes of the Cascades, the Waterville Plateau, and the Moses Lake area. On-shore flow will produce our typical late day "gap winds" as marine air spills over the Cascades. Gusts as high as 25 to 30 mph are expected around Wenatchee, Chelan, Vantage and portions of the Waterville Plateau through mid evening. Further east, winds in the Spokane, Coeur d`Alene, Pullman, and Colville areas will subside prior at or around sunset. Tuesday and Wednesday: The weather Tuesday and Wednesday will be relatively quiet and dry. Today`s weak shortwave will exit the region by Tuesday morning leaving the region in a dry westerly flow for Tuesday afternoon. High temperatures on Tuesday will be about average with most lowland areas in the 80s. Readings will rebound into the mid 80s and low 90s on Wednesday as a hot high pressure ridge rebounds over the Northern Rockies. /GKoch Thursday through Monday: Synoptic weather pattern shows a strong upper level ridge near the 4 corners region and a low pressure system in the gulf of Alaska. This will provide southwest flow into our region and keep us quite warm. the 12Z model runs have come in similar to the 00Z runs of yesterday evening, which is trending quite a bit cooler than what was forecasted in yesterday`s afternoon forecast package. Have continued the trend of lowering daytime high temperatures...about another 2-5 degrees cooler for Fri-Sun. Around 100 is possible for the deep Basin and Snake river valley with 90s for all other valley locations. Mostly clear skies are expected through the week. Saturday we may start to see an increase in cirrus across extreme eastern WA and north ID, but our forecast will remain dry. /Nisbet && .AVIATION... 00Z TAFS: Breezy west winds will be the main focus for aviation. Wenatchee will experience the strongest winds but occasional gusts near 20 mph could impact all other terminals through 03z. Winds slacken this evening then look to increase slightly again overnight with the passage of a cold front. Look for a general decreasing trend in winds Tue afternoon with most terminals decreasing toward 10kts or less after 21z. && .PRELIMINARY POINT TEMPS/POPS... Spokane 58 82 58 87 60 90 / 0 0 0 0 0 0 Coeur d`Alene 55 81 54 85 55 89 / 0 0 0 0 0 0 Pullman 54 81 48 86 56 89 / 0 0 0 0 0 0 Lewiston 60 88 59 94 63 97 / 0 0 0 0 0 0 Colville 54 86 53 90 53 91 / 20 0 0 0 0 0 Sandpoint 50 79 48 83 49 87 / 10 0 0 0 0 0 Kellogg 52 79 52 84 53 89 / 0 0 0 0 0 0 Moses Lake 55 88 56 92 57 94 / 0 0 0 0 0 0 Wenatchee 60 88 62 91 61 91 / 0 0 0 0 0 0 Omak 58 89 57 91 57 93 / 10 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...Red Flag Warning until 9 PM PDT this evening for East Washington Central Cascade Valleys (Zone 677)-East Washington Northern Columbia Basin (Zone 673). && $$
Area Forecast Discussion
National Weather Service Raleigh NC
941 PM EDT Mon Jul 10 2017 .SYNOPSIS... A positively-tilted mid level shear axis stretching from the eastern Carolinas to the lower MS Valley will become increasingly diffuse through mid-week, as a sup-tropical ridge centered over the central N. Atlantic expands west across the southeastern U.S. At the surface, a trough will remain anchored in the lee of the central and southern Appalachians. && .NEAR TERM /THROUGH TONIGHT/... As of 940 PM EDT Monday... Earlier multi-cellular convection has propagated (along outflow) to the southeast of the RAH CWFA, with now just a lingering canopy of convective mid-high level blow-off streaming northeast across the eastern half of NC, including all but the RAH nw Piedmont. There does remain a lingering axis of weak instability centered over the Piedmont, which will gradually lessen with further nocturnal cooling; and satellite data indicates cumulus continues to bubble from the SC upstate to the nw NC Piedmont, within/invof an Appalachian-lee trough. A few showers have tried to percolate within that area of cumulus in recent hours, including over Durham and nrn Guilford counties within the last couple of hours. However, the associated shallow cores quickly collapsed (within a few volume scans of initial reflectivity development), presumably as a result of tropospheric-deep dryness - characterized by precipitable water values of a mere half to three quarters of an inch centered over wrn NC- sampled by both the RNK RAOB and Blended Total Precipitable Water data. As such, a dry night is expected, aside from perhaps a very brief shower over the Piedmont that may yet briefly percolate in the next few hours, before instability further wanes. Relatively abundant low level moisture, characterized by surface dewpoints in the 70s over all but the nw Piedmont, where 60s reside, will probably result in patches to areas of low stratus late tonight- early Tue, centered from the Sandhills to the ne Piedmont. This idea is supported by a common signal in both SREF and HRRR model data. Persistence lows in the upper 60s to middle 70s. && .SHORT TERM /Tuesday and Tuesday night/... As of 200 PM Monday... The big story for Tuesday will be the increase in temperatures as the subtropical ridge takes over and thickness values climb to near 1440 meters. The surface frontal boundary will still be draped over our southern tier and this will once again be the most likely area for diurnal convection. An isolated severe thunderstorm cant be ruled out in these areas but most of the activity should remain sub- severe and as a result the SPC has the area in general thunder at this time. With highs in the low 90s and some dewpoints in the low 70s heat indices should remain in the upper 90s but a few 100 degree readings are possible. Low temperatures in the low 70s. && .LONG TERM /Wednesday through Monday/... As of 130 PM Monday... The weather pattern for Wednesday and Thursday will feature high pressure extending across the Carolinas from the western Atlantic with ridging aloft. With limited forcing across our CWA, most of the WDLY sct tstm activity should develop on the sea breeze to our east and/or higher terrain to our west. But nevertheless, we can`t rule out isolated showers/tstms across our area as outflows move into our area. PoPs at or below climo during this time. The main story will be the heat and humidity, with heat index values approaching 100 both afternoons. On Friday, rain chances will increase as a short wave moves across the Great Lakes and Ohio Valley region then across the Mid Atlantic region by afternoon. Additional cloud cover should keep temps a few degrees cooler than Wed/Thu, but with no substantial airmass change, readings once again should climb into the 90s. Over the weekend, another short wave within the longwave trough developing over the East, will approach from the NW and it`s attendant sfc cold front will subsequently stall out over the Carolinas as the southern extent of the midlevel trough weakens and its axis stalls over the East. At this point it appears that rain chances will be at or above climo over the weekend and perhaps into Monday. Clouds and rain will keep temps closer to normal. && .AVIATION /00Z Tuesday through Saturday/... As of 840 PM EDT Monday... 24 hour TAF period: VFR conditions are expected to continue this evening. Some patchy sub-VFR conditions will be possible at KFAY/KRWI (and possibly even KRDU) during the early morning hours of Tuesday. Generally light and variable winds tonight will become south to southwesterly Tuesday afternoon in the 6 to 10 kt range. Isolated to widely scattered showers and storms are expected Tuesday afternoon, with the greatest coverage expected across the southeastern/far eastern reaches of central NC. Thus, have included a prob30 at KFAY and KRWI for storms from 18Z Tuesday onward. Outlook: Scattered convection across the southern counties will be possible for the next several days but otherwise VFR conditions should be prevalent through much of the period. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...MWS SHORT TERM...Ellis LONG AVIATION...BSD/Ellis
Area Forecast Discussion
National Weather Service Riverton WY
330 PM MDT Mon Jul 10 2017 .SHORT TERM...(Tonight through Thursday) Issued at 130 MDT Mon Jul 10 2017 Afternoon convection will continue into the evening hours tonight, with some strong storms possible, particularly across northern WY and Sweetwater County. Wind gusts over 40 mph are certainly possible along with small hail and brief heavy rain. In advance of a shortwave trough moving through MT, Early afternoon SB CAPE values across NW WY were above 2000 J/kg and LIs in the -2 to -4C range. Interesting that the HRRR continues to keep convection to the north in MT though. Thunderstorms and showers should diminish by midnight as a weak dry slot pushes through central WY from the west. A weak boundary appears to set up tonight across the WY/MT border, and will continue Tuesday for some weak showers and storms before pushing southward east of the divide Tuesday evening. The mid-level moisture and instability with the high pressure should remain more south into CO as well for only a slight chance of convection across the southern half of Sweetwater County.Some west wind with gusts over 20 mph should push into west central WY Tuesday afternoon for mostly clear skies. Wednesday should be the least active day this weak as drier air with weak flow moves in from the west under a flattening ridge. Still above normal temperatures and mostly clear skies. Thursday continues the Wednesday trend with weak northerly flow, and only a slight chance of mountain thunderstorms over southwest WY. .LONG TERM...(Thursday night through Monday) Issued at 130 MDT Mon Jul 10 2017 Persistence appears to be the pattern for the medium range forecast today, as the upper level ridge axis over the Rockies remains fairly stationary through the period. GFS and ECMWF are suggesting a slight strengthening and northwest movement of the upper level high over the southern portion of the UT/CO border. Friday and Monday look to be the more active of the four days for convective action during the afternoon and evenings with some instability impacting the area, although mainly diurnal terrain- initiated convection should dominate. Temperatures will continue to be above normal with 90+F and around 60F east of the divide for afternoon highs and morning lows. Winds appear to be fairly light, although thunderstorm outflow is always a concern. Models are suggesting some easterly flow from the plains at times for the eastern portions of the forecast area. A slight transition to a monsoon type flow from the Southwest US may develop Tuesday into Wednesday next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 330 MDT Mon Jul 10 2017 Convection has developed across the area, and is expected to continue through at least 03Z/Tue, as a shortwave trough moves through MT, and the northern edge of a monsoon like patter affects the southern part of the state. Wind gusts over 40 kts along with small hail and brief heavy rain are possible with the storms. VFR generally expected with MVFR possible under and around storms. Strong storms could develop across the northern part of the area due to more favorable conditions. Some showers could remain until just after 06Z/Tue, with clearing expected overnight. Tuesday will see breezy westerly flow push into the central area with gusts over 20 kts. Some showers and thunderstorms are possible along both the northern and southern borders of the state. After 00z/Wed, a northerly push is expected east of the divide with a slight chance of showers. && .FIRE WEATHER... Issued AT 130 MDT Mon Jul 10 2017 Isolated to scattered thunderstorms will continue this afternoon into the evening hours, and bring gusty outflow over 40 mph as well as some small hail and brief heavy rain. The storminess should continue through 9 pm, moving from west to east. The storms may be stronger across northern WY then produce gusty NW wind around Buffalo this evening. Tuesday through Thursday look to be less active across the area in terms of showers and thunderstorms. Conditions should dry out gradually as well with RHs dipping down to the 13-16% range in some of the lower elevations. Tuesday looks to be the breeziest of the three days as well with a westerly flow with gusts over 20 mph pushing in from the west. A somewhat moister boundary from MT will push down wast of the divide on Wednesday. Thursday will continue with light flow and drying. Temperatures are all expected to be above normal for the next few days. && .RIW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...McDonald LONG TERM...McDonald AVIATION...McDonald FIRE WEATHER...McDonald
Area Forecast Discussion
National Weather Service Tucson AZ
226 PM MST Mon Jul 10 2017 .SYNOPSIS...Plenty of moisture for afternoon and evening thunderstorms with a favorable pattern for storm development most days this week. Some storms this afternoon and evening will generate heavy rainfall, especially in the mountains. The increase in moisture and rain chances will also result in more seasonable temperature readings. && .DISCUSSION...Deep moisture is in place with precipitable water values around 1.4 to 1.5 inches on sounding and satellite estimate data. Our weak flow this morning is giving way to a very modest northerly flow which has enhanced outflow from the rim a little more than earlier HRRR resolutions suggested. The main concern is still heavy rain, especially in the mountains. FFW earlier for Mt Graham and portions of the Frye fire area. Valleys will still be at the mercy of outflows, and those outflows are doing pretty well with several cell mergers and the Rim activity. Good potential of better shower and thunderstorm coverage this evening and even overnight as outflows try to merge over Pima and Pinal counties. A strong complex developing in northern Sonora just south of Nogales may end up playing a big part in that. Beyond today and tonight, we will maintain enough moisture and a favorable pattern for daily thunderstorm chances. Nothing special, with mountains favored until later in the week when we will watch an easterly wave currently developing on the southeast periphery of the high move across central to northern Mexico. There`s going to be a busy day or two as a result but timing is difficult. At this point Wednesday night and Saturday night into Sunday are looking interesting. && .AVIATION...Valid thru 12/00Z. Isolated to scattered -TSRA/-SHRA mainly E and S of KTUS this into this evening with SCT-BKN clouds 7-11k ft AGL. MVFR conditions and gusts near 40 kts possible with the stronger TSRA. Otherwise, VFR conditions with SFC wind wly/nwly 8-14 kts. A few SHRA may persist overnight with SCT SHRA/TSRA occurring again Tuesday afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered mainly afternoon and evening thunderstorms will prevail this week, with better chances in the mountains. Expect brief strong, gusty and erratic winds due to thunderstorm outflows. Otherwise, 20-foot winds will generally be terrain driven at less than 15 mph. Occasional gusts will occur during the afternoon hours due to daytime heating. High temperatures will be close to seasonal normals this week and increased moisture will help moderate relative humidity levels. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Meyer/French Visit us on Facebook...Twitter...YouTube...and at
Area Forecast Discussion
National Weather Service Las Vegas NV
815 PM PDT Mon Jul 10 2017 .SYNOPSIS...Increasingly dry southwest flow will reduce thunderstorm chances across the region Tuesday and Wednesday. A slight warming trend is possible through the end of the week before another possible push of monsoonal moisture surges northwest back over the area, bringing with it another slight cool down and more precipitation chances for the weekend. && .NEAR TERM...800 PM to 200 AM. OUTLOOK: Widespread thunderstorm activity is expected to diminish with the loss of daytime heating this afternoon. The two main threat areas are across southeast San Bernardino/southern Mohave counties as well as southern Nye, Lincoln, and northeast Clark counties over the next few hours. The overall threat of flash flooding is becoming more isolated this evening, with outflow winds and lightning becoming the main threats. CURRENT ANALYSIS: Moderate-grade monsoon moisture remains across nearly the entire forecast area this evening with 850-500mb mixing ratios of 6-8 g/kg exist in all but San Bernardino County. Across southern Nevada and northwest Arizona MLCAPE of 500+ J/kg exists, with local maxima over Lincoln, southern Nye and northeast Clark counties. Convection has worked over much of the atmosphere across much of Clark and northern and central Mohave counties, resulting in downward trends in those areas. The best lift is located over the NNSS and is progressing east. This is where the bulk of the activity is likely over the next 1-2 hours as the region of lift tracks into Lincoln County. To the south, outflow was pushing south in a line extending from Baker to Wikieup. Storms are primarily discrete, forming small clusters on outflow boundaries. Storm motion has increased to around 10-15 mph, which has resulted in a decreased flash flood threat. DCAPE values are generally less than 1000 j/kg leading to a primarily sub-severe wind threat, with a local maxima near Lake Havasu City. If storms make it that far south (which is a low probability outcome), they have a higher potential of producing isolated severe wind gusts. -Wolcott- && .SHORT TERM...through Wednesday morning. An active afternoon for thunderstorms is underway over the forecast area but a drying trend will lead to less thunderstorm coverage the next couple days. The most extensive thunderstorms were developing over central and northern Mohave County on the western periphery of a well defined circulation lifting up over northwest Arizona. Another hot spot is the McCullough range south of Las Vegas where cells were developing and expanding then moving north into the southern and southeast Vegas Valley. Also, thunderstorms were developing under a deformation axis extending across Inyo county and central Nevada, along with a jet entrance region over eastern Nevada. These will be the areas to watch through the afternoon and early evening. Storm movement will be generally toward the north- northeast around 10 mph. There will be the potential for heavy rain and possible flash flooding with a few storms. The HRRR indicates thunderstorms will continue across Lincoln and northeast Mohave Counties until a little after midnight. A drying trend will develop Tuesday due to a broad weak trough dropping down over northern California and northwest Nevada. This will lead to increasingly dry southwest flow going into Wednesday. Thunderstorm coverage will diminish Tuesday but isolated storms will still be possible over the southern Sierra, Spring Mountains and parts of Lincoln and Mohave counties. Temperatures will trend upward slightly as dewpoints and cloud cover decrease. && .LONG TERM...Wednesday through Monday. Mid level high center will be suppressed to our southeast Wednesday allowing for slightly drier air associated with Pacific Northwest trough to penetrate in southeast California and southern Nevada. This will bring a decrease in thunderstorm coverage to that area by Thursday and Friday. Moisture never really gets scoured out of Mohave County with low grade monsoon persisting with isolated thunderstorms possible each day primarily over the higher terrain. With the lack of significant low level moisture in place gusty winds and lightning will be of concern. Easterly flow increases across Arizona and into southern California over the weekend as mid level high center circulation becomes established over the Great Basin. Position of the high initially looks to keep deeper monsoon moisture confined to southern Mohave County, lower Colorado River valley and southern San Bernardino County Saturday and Sunday. Models have been consistent showing a well defined easterly wave moving across northwest Mexico over the weekend. Outflow pushing north from large thunderstorm complexes could quickly change the atmospheric parameters so something to keep an eye on. Otherwise, as inverted trough pushes east off the Baja Peninsula early next week a more favorable southeast flow develops with moisture surging north in the rest of the Mojave Desert and southern Great Basin. && .AVIATION...For McCarran...Showers and thunderstorms have developed south of Las Vegas and will continue to push into the southern portions of the valley this afternoon. Some of these storms may cause sudden and gusty wind shifts associated with thunderstorm outflow. Will continue watching storm development and motion through the afternoon and evening. As storms settle down later this evening, winds will favor a southwest/west direction with speeds around 10-15 kts. Winds will become light and variable overnight and will begin to favor an easterly component after sunrise. Otherwise, VFR scattered clouds are expected through evening and overnight. For the rest of southern Nevada, northwest Arizona and southeast California...South to southwest winds around 10-20 kts are expected to develop this afternoon and continue into the evening across the Mojave Desert and southern Great Basin sites. There will be a lull in the wind overnight before setting up again tomorrow in the late morning/early afternoon. A few areas of thunderstorms are expected this afternoon and evening, mainly across Clark, Mohave, Lincoln and Inyo Counties. Thunderstorms may produce strong wind gust and sudden changes in wind direction. Thunderstorm activity should begin to decrease later this evening. Skies will be mostly scattered to broken this evening, however VFR conditions are expected. && .HYDROLOGY...Not at the magnitude of runoff in late June, but creeks, streams and rivers in northern Inyo County continue to run higher than normal and fast from snow melt. Some road closures continue in the area. Bishop Creek Bypass and Big Pine Creek Bypass continue to be utilized to minimize flows through Bishop and Big Pine. Over the past week, streamflows on Independence Creek have stabilized with peak flows comparable to 1969 and 1983. Isolated thunderstorms over the mountains may aid snowmelt runoff and keep some drainages elevated over the coming days as well. Remember, never drive through flooded roadways or around barricades. Also, pastureland or farmland adjacent to creeks, streams or rivers could experience areas of standing water. && .FIRE WEATHER...Isolated to scattered thunderstorms with the potential for wetting rains will persist into the early evening then dissipate late this evening and overnight. Humidity values and thunderstorm coverage will decrease Tuesday and Wednesday as a dry southwest flow aloft begins to develop over the region. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Adair LONG TERM/HYDROLOGY....Pierce AVIATION...Boothe For more forecast information...see us on our webpage: or follow us on Facebook and Twitter