textproduct: Burlington

WHAT HAS CHANGED

As of 627 AM EDT Monday...

A quick update to the forecast was made to better reflect the current showers and thunderstorms moving across the area this morning.

KEY MESSAGES

As of 300 AM EDT Monday...

1. Unseasonably warm temperatures will continue for the first half of the week, with high temperatures climbing into the upper 70s and 80s. Meanwhile, lake and river water temperatures remain dangerously cold across the region, and breezes on Lake Champlain may result in rough lake conditions.

2. Above normal temperatures are expected for the first half of the week ahead.

3. Cooler and drier conditions are favored Thursday through Friday before a transition back to seasonable temperatures and a wetter pattern.

DISCUSSION

As of 300 AM EDT Monday...

KEY MESSAGE 1: Building high pressure across the region will allow for unseasonable warmth to continue for the first portion of the week. A warm front lifting across the region this morning may bring a few chances of showers this morning, but as the day progresses drier conditions are expected to prevail. High temperatures this afternoon are expected to climb into the upper 70s and 80s areawide. Despite the extremely warm air temperatures, water temperatures are still quite frigid, so any recreators should be sure to take the proper precautions, including wearing a life jacket. In addition to the warm temperatures, southerly winds will continue to be a bit breezy throughout the day, especially in the Champlain Valley and along the lake due to channeled flow. A Lake Wind Advisory is in effect, with additional details in the Marine section below

Tuesday looks to be the hottest day of the week, with high temperatures climbing into the 80s and near 90 under southwesterly flow. These temperatures will be the warmest of the year so far, especially after a cool start to the month, so it is important to remember to stay safe in warmer temperatures by staying hydrated and take frequent breaks if working outside. Dewpoints will also be trending upwards going into Tuesday, making it feel quite humid especially for this time of year. The warmth and humidity will result in increasing instability, which will support the development of showers and possible thunderstorms for Tuesday, which could impact how warm temperatures climb during the day Tuesday. A cold front is expected to cross the region on Wednesday, which will impact how warm we can get that day. At the moment, highs in the upper 60s to mid 80s look likely, with central and southern Vermont getting the warmest before the cold front and associated precipitation arrive. In addition to warmth during the days, our lows likely won't fall below the upper 50s and 60s until the cold front arrives, providing only some relief from heat overnight.

KEY MESSAGE 2: The warm and humidity environment ahead of an approaching cold front will allow for increased chances of thunderstorm develop Tuesday and Wednesday. Latest CAM guidance shows plenty of instability across the region, with surface CAPE values anywhere from 500 to 1500 J/kg, with temperatures in the 80s to near 90 and dewpoints in the 60s. Forcing will be mainly from an upper level weak wave and its potential interactions with topography, while surface forcing looks minimal Tuesday afternoon into the overnight period, and mid level lapse rates don't look overly impressive. The primary hazard with any strong to severe storms that do develop look to be damaging winds. SPC has placed much of the region a Slight Risk for severe weather, so be sure to monitor the forecast especially if you have any outdoor plans.

The main cold front looks to drop across the region on Wednesday, bringing higher chances of precipitation with it. As we get closer to the event, the timing of the cold front or fronts should become more set. Should the front be delayed, the potential for stronger storms would increase during the day on Wednesday with more time to destabilize.

KEY MESSAGE 3: Temperatures trend much cooler Thursday behind Wednesday's front with northwest flow resulting in cold air advection and a return to highs in the 50s to around 60 degrees. Winds slow overnight with skies clearing; this may be a period of concern for some frost outside the Champlain Valley with lows in the mid/upper 30s for many locations, and low 40s for the Champlain Valley. Conditions are favored to remain dry into Friday with temperatures rising back to seasonal averages in the mid/upper 60s to around 70 degrees.

Models begin to split on precipitation timing heading into the weekend. Consensus maintains some chances of showers increasing Saturday with more widespread rain Sunday. However, a number of models are beginning to hold onto the ridge longer delaying precipitation onset until the late weekend. Either way, a pattern shift to deep return flow from the Gulf Coast northeastward into the Northeast is appearing probable. This flow pattern would result in multiple days of rain potential once it sets up.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Through 12Z Tuesday...Showers and isolated thunderstorms are moving through northern New York and Vermont this morning bringing periods of MVFR/IFR VIS during burst of rainfall. SLK may be tapering off first by 12-13Z. Otherwise, these showers will continue through 15Z, but possibly longer for EFK. A lljet will sweep through in the same time frame promoting some LLWS for MSS/SLK/PBG/EFK. Surface winds at PBG could gust 20-30kts at times with favorable off- lake, channeled flow while most other terminals see gusts around 20kts. Gusts drop by 00Z with clouds thickening late in the period as a diffluent flow pattern moves over the region with some increasing elevated instability. A few showers will be possible after 06Z, but widespread LLWS will return as the next lljet moves into the region 00-12Z.

Outlook...

Tuesday: VFR. Chance SHRA, Slight chance TSRA. Tuesday Night: Mainly VFR, with local MVFR possible. Slight chance SHRA, Slight chance TSRA. Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX.

MARINE

As of 300 AM EDT Monday...

A Lake Wind Advisory is in effect for the Broad Waters of Lake Champlain. Channel southerly flow will result in winds increasing to 15 to 25 knots this afternoon, with even higher gusts possible.

BTV WATCHES/WARNINGS/ADVISORIES

VT...None. NY...None.