Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/19/17

Area Forecast Discussion
National Weather Service Taunton MA
1037 PM EDT Wed Oct 18 2017 .SYNOPSIS... High pressure will maintain dry weather and warmer than normal temperatures through the weekend. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 1035 PM Update... corrected SREF to HRRR. At 10 PM, skies were crystal clear across southern New England. Temperatures had dropped to the mid 40s to lower 50s except mid 50s at the coast. Have lowered temperatures a tad to fit with current trends. Lows should range from the lower 40s to lower 50s in the larger cities. Some patchy frost possible in northwest MA. As noted by previous forecaster, the 23Z North America Rapid Refresh Ensemble System (NARRE) has continued to emphatically show development of low cloudiness beginning in eastern CT around 06Z and then expanding everywhere south of the Mass Pike by 11Z. The HRRR has the same trend, only later and farther east, only across RI and southeast MA, mainly after daybreak. Have decided to increase sky cover grids to 60-70 percent across eastern CT and RI late tonight and around daybreak, since the NARRE is often quite good at picking up on these trends. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Tomorrow... Upper lvl shortwave continues opening trend as it moves across S New England during the late afternoon/evening hours. The attendant cold front loses its baroclinicity and is associated with little to no moisture increase so aside from a few more SCT clouds are possible, but this fropa passes with little fanfare. SFC pres gradient response yields an increase, so S-SW flow will be breezy with a few wind gusts around 25 mph during the afternoon. Temps a bit milder in spite of the SCT clouds thanks to weak warm advection aloft ahead of the wave. Looking at widespread low 70s. Tomorrow night... Weak front shifts E. Gradient winds shift to the W but weaken inland as pres gradient weakens rapidly with the core of a stronger high pres shifting E. Winds may remain elevated near shore. The slight increase in moisture thanks to S gradient flow during the day will limit overnight mins further still, suggesting more widespread upper 40s to low 50s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... * Above average temps and dry conditions lasting into Monday * Precipitation chances are increasing for mid-next week. Pattern Overview/Confidence... 12z guidance is in good agreement for the long term. Passing frontal system an associated trough will push offshore by Friday morning. Anomalous ridging will develop across the East Coast pushing heights and temperatures 2 STD above normal. This strong ridge will last into early next week before a pattern change appears to take hold of the area. Digging trough will dip into the Gulf states with the potential for a closed low peeling off. Another wave will begin to dive into the Ohio Valley which could result in phasing to a negatively tilted trough putting much of the East Coast near 3-4 STD below normal in heights fields. This pattern change will result in cooler conditions and unsettled weather. Details... Temperature Forecast... Overall trend in the forecast is for above average temperatures through the period. Cool front will sweep through the region Thursday night leading to a cooler day on Friday, but still above average. Anomalous ridge will begin to build for the weekend into Monday resulting in high temps into the mid 70s. Tuesday`s and even Wednesday`s temperature forecast is a bit trickier as it is dependent on the timing of the front. Thus will trend towards a model consensus until guidance gets a better handling on the FROPA. Precipitation Forecast... High pressure will take over the area on Friday through Monday leading to dry weather. Next chance or precipitation will be around the Tuesday timeframe when a potent trough will dig into the Ohio Valley and towards the East Coast. Ensemble guidance is trending towards a very wet pattern with high PWAT values and strong southerly LLJ. This is in conjunction with the several waves of low pressure that will ride along the trough both Tuesday and Wednesday. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Thursday Night/...Generally high confidence. VFR through 06Z. Confidence is increasing in the development of some IFR ceilings developing especially 08-13Z across northern CT, RI, and southeast MA. Patchy MVFR-IFR in fog in a portion of those areas. VFR then returns tomorrow and most of tomorrow night. SW flow expected today through the daylight tomorrow, then gradual shift to the W is expected tomorrow evening/overnight. KBOS Terminal...High confidence in TAF. KBDL Terminal...Moderate confidence in TAF. Although VFR dominates there is a moderate risk for some IFR ceilings developing late tonight into early tomorrow morning. Outlook /Friday through Monday/... High Confidence. VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Thursday Night/...High confidence. Overnight... Quiet boating weather into tomorrow morning. Tomorrow and tomorrow night... S-SW winds increase tomorrow afternoon with gusts to around 25 kt likely over all waters by late afternoon and a slight increase in outer seas to near 5 ft. These winds persist into the overnight but slowly diminish as they shift to the W late tomorrow night. Small Craft Advisories will be issued for all waters. Outlook /Friday through Monday/...High confidence. Great boating weather as high pressure prevails through the upcoming weekend with sub SCA conditions. && .FIRE WEATHER... Ahead of a very weak cold front tomorrow (with which no precipitation is expected) S-SW winds will gust 20-25 mph across much of the region. Relatively mild conditions (highs in the low-mid 70s) and continued dry dewpoints in the mid 40s to low 50s will yield min RH values near 30 percent. With an overall lack of precipitation of late this suggests elevated fire weather for the day tomorrow. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 2 PM Thursday to 6 AM EDT Friday for ANZ231>234. Small Craft Advisory from 2 PM Thursday to midnight EDT Thursday night for ANZ230-236. Small Craft Advisory from 4 PM Thursday to 6 AM EDT Friday for ANZ235-237-255-256. Small Craft Advisory from 2 PM Thursday to 8 AM EDT Friday for ANZ250-251-254. && $$ SYNOPSIS...Doody/Dunten NEAR TERM...Field SHORT TERM...Doody LONG TERM...Dunten AVIATION...Field/Doody/Dunten MARINE...Field/Doody/Dunten FIRE WEATHER...Doody
Area Forecast Discussion
National Weather Service Burlington VT
742 PM EDT Wed Oct 18 2017 .SYNOPSIS... High pressure along the east coast of the United States will maintain dry conditions across the North Country through Sunday. With south to southwest winds in place, temperatures will warm well above seasonal levels for mid to late October beginning today, and continue through the upcoming weekend. The next chance of appreciable precipitation occurs by Monday into Tuesday of next week as a cold front crosses the area from west to east. && .NEAR TERM /THROUGH THURSDAY/... As of 707 PM EDT Wednesday...Forecast in great shape with another mild evening across the north country. Surface high pres is shifting east...while surface boundary approaches the central Great Lakes. The gradient between these two features will help to increase sfc winds overnight...especially in the wider cpv/slv. Meanwhile...early this evening...skies are clear and winds have decoupled in the deeper valleys...along with very dry air mass has allowed temps to fall quickly. Have updated to capture rate of fall in hourly grids...but have only made minor tweaks to overall low temp forecast. Expecting lows upper 30s/lower 40s slk/nek to l/m 50s cpv/slv with mostly clear skies. Previous discussion below: Going forecast on track. 925mb temps around 12C at BTV per RAP this afternoon which should yield max temps in the mid 60s in the valleys lower 60s in the hills this afternoon which is well covered in the going forecast. Very quiet wx through the near-term. Generally looking at clear skies otherwise through tonight. The sfc ridge axis extending along the east coast of the U.S. and building shortwave ridging aloft will bring dry weather, but southerly pressure gradient increases overnight especially west of the Greens with light south to southwest winds and moderating temperatures. Only a very small chance for any radiation fog east of the Greens so left it out. Lows mainly in the 40s for tonight except near 50 in the St. Lawrence and Champlain valleys. Temperatures moderate further on Thursday under a rather strong west southwest flow with 850-mb winds 30 to 50 kts leading to breezy surface winds of around 15 kt with gusts to 25 to 30 kt. With 925-mb temps around 14C for looking for max temps reaching the upper 60s to lower 70s. Another mid-upr level shortwave trough is progged to pass along the intl border Thursday afternoon. This feature should bring an increase in mid-upr level clouds, but dry low-level conditions should preclude any precipitation. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 334 PM EDT Wednesday...A rather dry cold front will pass through the region Thursday night with some clouds especially in the northern Green mountains where a sprinkle can`t be ruled out. 925mb temps drop to about 8C near BTV on Friday for "cooler" high temps in the mid 50s to lower 60s, still a bit above normal. High pressure will slide across the mid-Atlantic states and off the coast lead to quiet weather conditions with mostly clear skies under broad subsidence. Return SW flow around the high with warm advection over the weekend will will bring warming temps each day with upper 60s Saturday to 70 by Sunday. Each night we`ll radiatively cool and should see temps in the upper 30s to low 40s. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 352 PM EDT Wednesday...High pressure will be the dominant feature over the weekend. Surface ridge axis will slide eastward over the Atlantic seaboard, increasing warm southwesterly flow. This will result in daytime max temperatures in the mid 60s to low 70s to close out the weekend. Min temperatures will see a warming trend heading into the work week, from mid 40s to mid 50s. The beginning of the work week will see a pattern change as a cold front associated with a mid-upper level longwave trough approaches from the west. The North Country will see an increase in clouds and potential for rain some time late Monday into Tuesday. Potential for rain showers will be reinforced, especially on Tuesday at the mid-upper level trough digs southward into the Mississippi valley. At the surface, ECMWF and GFS show closed low pressure system develop and move over SE Ontario/NW NY by late Tuesday. Increased pressure gradient at the surface should lead to fairly gusty winds with the potential for 15-25 mph with gust to 35mph Tuesday into Wednesday. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... Through 00Z Friday...VFR conditions expected to persist as low level southwesterly jet of 20-35kts developing overnight due to increasing pressure gradient with surface high pressure settled over the mid-Atlantic states and approaching strong Canadian low entering Hudsons Bay increases the pressure gradient. Jet should hinder any fog development under clear skies into Thursday morning, but also produce some LLWS (23035kt at 020) overnight at KMSS and KSLK. There`s a chance some intermittent fog may develop at KSLK before the jet develops...mainly btwn 02Z-04Z as T-Td spread is very narrow to start the night. Winds will mix to the ground throughout the daytime with S-SW sustained winds of 10-15kts and gusts 20-35kts expected. Can`t rule out funneling up the St Lawrence to have isolated higher gusts. A cold front associated with the low will bring some high to mid level clouds toward 18z with a wind shift to west northwest toward 00Z Fri. Outlook... Thursday Night: VFR. Breezy. NO SIG WX. Friday - Sunday: VFR. NO SIG WX. Sunday Night: VFR. Slight Chance SHRA. Monday: VFR. Chance SHRA. && .MARINE... Southerly winds will increase overnight reaching 15 to 25 kts by dawn Thursday as a moderately strong pressure gradient develops. Relatively mild water temps in the upper 50s may mix winds of 30 knots just above the surface early Thursday morning, so could be a bit higher than 25 knot for a few hours from sunrise to noon. Winds should slowly diminish late in the afternoon and then shift to the west northwest 10 to 15 knots Thursday night. && .EQUIPMENT... KTYX radar at Fort Drum, New York will remain down for scheduled maintenance through tonight (10/18) and tomorrow (10/19) as technicians repaint the radome. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Sisson NEAR TERM...Taber/Sisson SHORT TERM...Sisson LONG TERM...KGM AVIATION...KGM MARINE... EQUIPMENT...BTV
Area Forecast Discussion
National Weather Service Marquette MI
727 PM EDT Wed Oct 18 2017 .SHORT TERM...(This evening through Thursday) Issued at 345 PM EDT WED OCT 18 2017 ...Windy into this evening then again on Thu... Surface low over northern Manitoba down to 973mb at 19z/4-5 standard deviations below mid October mean is resulting in warm and windy day across much of Upper Michigan. Temps over portions of western U.P. have reached over 20F above normal in the middle 70s. Warm spot as of 3 pm in Upper Michigan is on the Keweenaw near the Upper Entrance of the Portage Canal. Houghton Co Airport not far behind at 75F. Pretty warm for mid to late October. Should note the record high for today in the Houghton area is 80F set in 1910. Dry airmass ahead of the low and associated cold front is leading to just a batch of mid clouds over northern Ontario into western Upper Michigan. Cold front crosses region late tonight with winds shifting from southwest to west. Based on RAP soundings showing mixed layer winds over 35 kts/40 mph, current obs and pressure falls crossing north of Lk Superior into early this evening, expect wind gusts over 40 mph from north central into eastern forecast area. Issued special weather statement into early evening to cover the strong winds. West winds ramp back up on Thursday behind the cold front. Strongest wind gusts 30-40 mph will be across Lk Superior and Keweenaw Peninsula but 15-30 mph gusts could also occur over rest of forecast area. Even with cooler airmass compared to today, temps on Thursday will top out in the low to mid 60s, which is still well above normal. Min RH values will bottom out in the 20-25 percent range so fire weather concerns may be elevated especially given the recent stretch of warm/dry weather. .LONG TERM...(Thursday night through Wednesday) Issued at 404 PM EDT WED OCT 18 2017 Thursday night through Friday night: Fairly quiet weather is expected through this time period as high pressure will remain in control. Aloft, upper level ridging in place will keep temperatures above normal through this time period, in fact, many places will be around 15 to 20 degrees above normal through this time period. For perspective, average temperatures this time of year area right around the low 50s. Saturday into Sunday: An upper level trough is expected to slide from the Plains eastward through the Upper Great Lakes region through this time period. At the surface, the associated stroung surface low is expected to slide north of the area, and remain mainly over Canada. This will drag a cold front through the Upper Peninsula Saturday afternoon and night and then to the east of the area by Sunday evening. Increased moisture and forcing and moisture ahead of the front will allow for widespread rain showers to spread across the U.P. Current model trends have roughly a half inch of precip across the area by the time the precipitation ends Sunday afternoon. There may be just enough instability around for Saturday afternoon and Saturday evening ahead of the front for a few thunderstorms; however, thunderstorm potential does look to be fairly marginal overall. Temperatures will be about 10 to 15 degrees above normal through this time period. The rest of the extended: There will likely be a brief break in the precipitation Sunday night as a brief ridge builds into the area; however, another slow moving low pressure system is expected to slide through for Monday through Wednesday. Aloft, a much deeper trough will dig into the Upper Great Lakes region. This will allow enough cold air to slide into the region to cause some snow to mix in with the rain over the higher terrain of the west. The ground is still warm and overall QPF is not expected to be that impressive, so not expecting too much in the way of accumulation. 850mb temperatures are progged to drop into the -5C to -7C range, creating delta-T values in the 17 to 19C range. This will be prime for lake enhancement. The favored areas will have to be pinned down as models come into better agreement, but it looks like the northwest wind lake effect prone areas would have the best chance at this point. Model consnesus was used and appeard to work well for this time period. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 726 PM EDT WED OCT 18 2017 VFR conditions are expected to prevail over the next 24 hours. A cold front will push east across all terminals tonight veering winds to the west at KSAW. Breezy winds will likely persist behind the front. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 345 PM EDT WED OCT 18 2017 South to southwest winds to 30 kts with a few gale gusts to 35 kts over eastern sections will continue into the evening. Cold front crossing tonight will shift winds to west and these may gust to 30 kts late tonight into early Thu aftn and once again there may be gale gusts to 35 kts over east half. Overall, expect winds to stay 25 kts or less Thu night into early next week. Winds could increase to 30 kts late Fri night into Sat though as pressure gradient briefly tightens up ahead of low pressure tracking across south central Canada. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Gale Warning until 11 PM EDT this evening for LSZ250-251. Gale Warning until 8 PM EDT this evening for LSZ248-249. Lake Michigan... Gale Warning until 11 PM EDT this evening for LMZ248-250. && $$ SHORT TERM...JLA LONG TERM...KEC AVIATION...JLB MARINE...JLA