textproduct: Caribou

WHAT HAS CHANGED

- Increased areal coverage of the isolated POPs for diurnally driven showers today but limited thunder.

KEY MESSAGES

1) Isolated to scattered showers and thunderstorms this afternoon, mainly over the North.

2) A couple rounds of showers and thunderstorms for late week may produce a strong storm or two. Rainfall will be limited to where convection forms, allowing for some worsening of ongoing dry conditions.

DISCUSSION

KEY MESSAGE 1...Scattered showers and thunderstorms this afternoon, mainly over the North.

KEY MESSAGE 1 DESCRIPTION... Lift from upper level shortwave energy should help continue to drive isolated to scattered afternoon shower and thunderstorm development over the North. Much of the convection will be showers as models are showing poor mid-level lapse rates as a result of a mid-level inversion generated by last nights MCS that crossed the region. Confidence remains low on showers and any storms developing downslope of the Longfellow Mtns due to the position of upper level forcing but cannot rule out an late afternoon to early evening shower in the Bangor Region to along the Airline (Route 9).

KEY MESSAGE 2...A couple rounds of showers and thunderstorms for late week may produce a strong storm or two. Rainfall will be limited to where convection forms, allowing for some worsening of ongoing dry conditions.

KEY MESSAGE 2 DESCRIPTION... On Thursday the large 500mb high over the Deep South begins to push a large ridge over the Central US. At the same time a trof begins to dig south over the Great Lakes and Eastern Canada. A surface warm front will be lifting thru the CWA during the day. Showers move in from the west in the afternoon with thunderstorms possible during the afternoon SBCAPE between 500-1000 J/kg, 0-6km shear >30kts, strong low level lapse rates and modest mid level lapse rates. This may bring strong storms to the area with decent dynamics working into the area but confidence is low at this point.

GFS/ECMWF/Canadian models differ significantly on timing of the trof and cold front but expecting showers into the night. The upper level trof remains progged to move thru during the day on Friday, along with the cold pool. This will result in another round of diurnally driven storms. PWATs are pretty meager, ranging from 1-1.50 inches, highest over Downeast so not seeing the potential for heavy rain at this point.

Convection will result in limited precipitation in most locations which will continue to worsening the ongoing dry/drought conditions. D0-D1 conditions are present in southern and eastern areas of the CWA. Much of the streamflows across the CWA are Below to Much Below Normal for this time of year along with Groundwater wells rapidly falling to below normal to low end normal conditions. Lack of significant widespread rainfall will result in worsening conditions in terms of the drought.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

This afternoon: Mainly VFR, with brief MVFR possible in the afternoon at northern terminals due to scattered showers. Possible -TSRA this afternoon for northern terminals. NW winds 5 to 15 kts with gusts 20 to 25 kts.

Tonight-Wednesday: VFR. Winds W at 5-10 kt.

Wednesday night...Mainly VFR. Light W winds.

Thursday-Friday---MVFR/IFR in showers and storms. SW winds 5-15kts, becoming NW 5-15kts on Friday with gusts 20-25kts in the afternoon.

Friday night-Saturday...VFR. NW winds 10-20kts.

MARINE

Winds and seas below small craft advisory criteria through Wednesday on all waters. Seas 3 ft or less with wind gusts 15 kts or less.

Winds remain aob 25kts Wednesday night through Friday before increasing in CAA Friday night. Waters from 25-60NM will see gusts over 25kts on Friday night before diminishing as high pressure builds in. Seas remain between 1-3 feet into Thursday night before building toward 5ft Friday night over waters from 25-60NM.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...None.