CLOUDS ON THE INCREASE FOR THE SECOND HALF OF LABOR DAY WEEKEND

PREDICTABILITY OF FORECAST PERIOD: MEDIUM

 

1. After a warm, sunny Saturday, clouds will build in for Sunday through much of Tuesday before clearing works in Wednesday-Thursday.  Overall pattern will turn overcast, with fog likely at night (especially near the coast)

Intellicast Temps and Clouds through the period:

 

2. RAIN: Sunday-Monday are mostly dry, but a risk of a stray shower is possible in the afternoon. Higher Chance Monday. Then, more numerous showers Tuesday, as what remains of Isaac passes through. Rainfall totals could average around an inch area-wide, with some higher amounts.

NOAA HPC Rainfall amounts Tuesday

 

3. Another front charges in Thursday evening/Friday morning, with showers and thunderstorms a good possibility.

 

4. We’ll have to monitor the track of Leslie in the Atlantic. Seas will certainly build beginning Wednesday at the ocean; the closest pass to our coastline would come by late next week, but too much uncertainty exists to say how close at this point. Bears watching.

GFS model spray for Leslie

5. Astronomical rainfall from Isaac this past week over the Mississippi Delta Region was recorded via doppler radar estimates. Areas in pink represent over fifteen inches of rainfall!

ANOTHER STRETCH OF FAIR WEATHER RIGHT THROUGH THE HOLIDAY WEEKEND

PREDICTABILITY OF FORECAST PERIOD THROUGH SUNDAY: HIGH 
PREDICTABILITY OF FORECAST PERIOD FOR MONDAY- LOW

1. No changes to last overview regarding tomorrow (Tuesday). Rain and thunderstorms will make for a slow morning commute. Clearing by midmorning/early afternoon, then temps start to level off even more as humidity drops.

2. Wednesday-Thursday: fair skies prevail, with very comfortable nights. Temps in the outlying suburbs of NYC will see low temps solidly into the 50s!

ACCUWEATHER graphic shows widespread 50s away from the city Thursday night in green:

3. Friday/Saturday: Temps/humidity values reach their peak, with highs around 90. Sunday/Monday is cooler, with readings near normal.

INTELLICAST:

4. Best chances for numerous showers wait until Monday, as some moisture from a decayed Isaac gets pushed towards us by a front. impact expected with this rainfall should only be a nuisance, and not lead to a substantial flood threat.

5. Isaac will virtually stall over the Mississippi River Valley; potential for catastrophic inland flooding, as well as the likelihood of hardship for many of the same areas hit by Hurricane Katrina back in 2005. 

A MUGGY LATE AUGUST AIR MASS THROUGH TUESDAY...

1. Risk of a shower or storm for Saturday/Sunday, as stagnant pattern becomes unstable. Humid, and some fog at night. Clouds will dominate at times this weekend, with easterly flow off the relatively cool Atlantic Ocean.

2. Storms become more numerous Monday evening into Tuesday morning. Front will be the spark for a period of heavy rain as it cuts into the tropical regime. Action should wind down by early Tuesday afternoon. Cooler Wednesday and Thursday as fair weather takes hold again.

3. Temps: right around normal, but humidity values will drop as mentioned by Wednesday

Intellicast:

4. Tropics will remain active through the first week of September, but the overall pattern will put a clamp on widespread activity after the 10th.

ISAAC VERY LIKELY WILL BE A PROLIFIC, CLASSIC GULF HURRICANE

The latest track guidance from the various models continues to tout the idea that this storm, while still in its embryonic stages, will head for the gulf, NOT FLORIDA, in the next few days.

The ocean heat content of the Gulf is ripe for storm intensification...

All of the evidence, including the fact that the storm will be in an environment suitable for strengthening, leads me to the conclusion that a significant, perhaps destructive storm, may be in the making for the Gulf Coast come early next week. My educated guess this past Tuesday was based on twofold; the euro model's insistence on a westward path and the idea that storms don't often scrape the western coast of Florida, as was depicted in the majority of forecasts. This is not to disparage any one particular forecast or group of forecasters, because after all, this blog is about PROMOTING THE IDEA THAT STORMS AND WEATHER ARE MORE PREDICTABLE THAN EVER BEFORE AND NOT ENOUGH CREDIT IS GIVEN TO THE REAL SCIENTISTS WHO PURSUE IT, NOT HOBBYISTS LIKE MYSELF.

here was the graphic i put together using Weather.com's graphic back on Tuesday.

No matter what happens, i applaud the forecasters from all circles on this one, especially the people in the plane flying into the storm, who are tweeting from the action. I am in awe of that still.

Good luck, and godspeed to the residence in the path of Isaac, both now, and over the weekend.

11PM ISAAC RUN-DOWN ...

I'll try and do this periodically as we watch this thing unfold. But until the storm establishes a true inner core (which should happen in a day or two), there's no telling where this is going and how strong it will be. But the odds of a US miss are slim based on most sources and the overall pattern in the atlantic (see previous post, as i use TWC graphics to show what's going on in the larger sense).

ISAAC TO BECOME A HURRICANE: IMPACT TO US COAST VERY LIKELY EARLY NEXT WEEK

VIDEO: LOOKING AT THE "PROBLEMS" FOR THE WEEK

PREDICTABILITY OF FORECAST PERIOD LOWERED TO MEDIUM NOW THROUGH
WEDNESDAY, HIGH FOR WEDNESDAY THROUGH SATURDAY.




"weather overview" terms to help kick the point-and-click:

PREDICTABILITY OF FORECAST PERIODS

HIGH- most credible sources are in excellent agreement
MEDIUM: most credible sources are in fairly good agreement, with some differences
LOW: widespread differences in forecasts, AND overall low confidence from NWS Upton office

Risk of a shower/thunderstorm-probability of a shower is low. Most of the forecast period will be dry.

Numerous (heavy can be inserted) Showers/thunderstorms- probability of showers is high, and could happen multiple times during the given forecast period. Constant rain is not expected

Rainy conditions-intermittent precip; rain can vary in duration, but usually will last more than an hour. Light to moderate intensity. Less than an inch expected during the forecast period.

Heavy Rain-soaking, constant rainfall for at least an hour (duration can be much longer); amounts over a half an inch. 

Light snow-very light snowfall. Little to no accumulation. Duration depends. 

Snowy conditions-intermittent snow can last more than an hour at a time, but generally average less than 3 inches total.

Heavy Snow-heavy snowfall. Snowfall of at least 3 hours in duration. Totals can be added in

Drizzle-constant drizzle

Occasional Drizzle-intermittent drizzle