- 5:37 am Wednesday, May 23rd, 2018 by Kirk Mellish
A fire hose of moisture is a nice metaphor but I don’t mean to exaggerate. This is NOT some flooding everywhere disaster movie scenario.
It’s merely to point out the deep fetch of moisture coming into the Southeast U.S. with a direct connection to the the Gulf, Caribbean and points even further south which can plainly be seen in satellite imagery and computer models.
There will be decent dry breaks around the Atlanta Metro area the next 5-10 days. Rain odds will vary from 30-70%. Remember thunderstorm forecasts, unlike others, sometimes have to be updated about every 3 hours.
We don’t know yet [More]
- 6:20 am Monday, May 21st, 2018 by Kirk Mellish
A total washout it not foreseen as of now, but can’t be ruled out. Either way the chance of rain in much of the South and Southeast U.S. looks to feature above-normal odds this week and for the Memorial Day weekend Friday-Monday, and the rest of the month as well.
Some models have at times even shown a tropical storm type system or worse somewhere in the Gulf of Mexico. However, wind shear and below normal water temperatures in the Eastern Gulf plus climatology argue against a named system. But we get another extended spell of unsettled weather either way.
Over a [More]
- 8:48 am Friday, May 18th, 2018 by Kirk Mellish
Looking at the condition of the Pacific and Atlantic Ocean temperature cycles (PDO/AMO), along with ENSO, global ocean sea-surface temperature, solar cycles, and spring weather patterns thus far we come up with a list of similar years from the past to attempt to predict the future.
As the economists say about investing, past performance does not guarantee future results but it does provide a guideline.
Long-range computer models are also consulted as a factor in deciding the outlook, such as these:
I looked at many other models as well.
My thinking is less hot in the Southeast U.S. than most models, I think the [More]
- 6:00 am Friday, May 18th, 2018 by Kirk Mellish
Rainfall the past two days has been highly variable, ranging from just a TRACE to 1.5 inches on average, with an isolated 4.6 inch total.
We will continue stuck in this soupy tropical air mass the next 5-10 days so no major change. Each day will be a little different in who gets the most sun and who gets the most rain or the strongest thunderstorm and who stays dry.
Due to the lack of an organized focusing mechanism that can be identified well in advance, the random nature of pop ups means there is no scientific basis to determine more than [More]
- 4:10 pm Wednesday, May 16th, 2018 by Kirk Mellish
Following the morning rain the atmosphere around Atlanta has stabilized so there’s much less rain with peaks of sun. Showers and an isolated thundershower will redevelop to end the day then diminish overnight.
As I pointed out on the radio the other day, in tropical air masses the computer models have a well known bias of over exaggerating the rain threat and amounts. This leads those web pages and phone APPS and other things you look at with cute weather symbols showing endless days of rain and lightning symbols and dire warnings of flooding. And yet much of Tuesday was dry [More]
- 8:22 am Tuesday, May 1st, 2018 by Kirk Mellish
We forecasters usually give just a single number for the high and low temperature forecast, and the precipitation chance, wind speed, precipitation amount etc.
In reality meteorologists are aware that there is in fact a range of possible outcomes for these forecast parameters each day, much like the forecast hurricane “cone of uncertainty”.
And like with the cone of uncertainty, that range of uncertainty grows with time. So it’s usually a small range on day one and usually a large one at days 7-10-15.
There are various ways to show this uncertainty range on charts using model ENSEMBLE temperature output from numerical weather [More]
- 5:43 am Thursday, April 26th, 2018 by Kirk Mellish
Reports are that Lake Lanier levels are in the best shape since 2016 at this time of year thanks to a wet couple weeks. More rain is expected today.
There is a risk of a strong storm this afternoon, maybe an isolated severe thunderstorm.
However, as of this morning the risk is just marginal, a level 1 on a scale of 1-5.
It’s possible new data later today could cause the risk to go up so stay tuned:
My detailed local forecast on the radio all day.
MID-DAY SURFACE WEATHER CHART THURSDAY:
24 HOUR ESTIMATED RAINFALL:
What follows is weather about as nice [More]
- 7:38 am Tuesday, April 17th, 2018 by Kirk Mellish
Many things go into if there will be thunderstorms or how widespread they will be and how strong they will be.
There are different types of thunderstorms. I won’t go over all that now but have covered that in past blogs and will no doubt do so at some point in the future.
This is a simplified explanation of what goes into SEVERE THUNDERSTORM and particularly TORNADO potential. A severe storm is defined as one that can cause damage through wind or hail. (lightning can and does do damage and kill, but all thunderstorms by definition have lightning even weak ones not [More]
- 12:31 pm Sunday, April 15th, 2018 by Kirk Mellish
The threat of severe weather has ended for Metro Atlanta and scattered showers and thundershowers will be ending, but temperatures will slowly fall this afternoon behind the cold front.
A touch of snow may even mix with rain overnight in the higher elevations of the Northeast Georgia mountains.
Clearing for Monday but temperatures will struggle to reach 60 with lows in the upper 30s to low 40s the next couple nights.
LATE SUNDAY SURFACE WEATHER MAP:
LATE SUNDAY NIGHT:
MONDAY SURFACE WEATHER CHART:
MONDAY AM LOW TEMPERATURES:
TUESDAY MORNING LOWS:
However, a quick rebound to highs in the 70s is due Tuesday into next Saturday, Wednesday may reach [More]
- 10:45 am Saturday, April 14th, 2018 by Kirk Mellish
As is typical of Spring “winter” storm systems this one will run the gamut from blizzard and ice storm North to flooding rain and some tornadoes South, a pattern that started yesterday and will continue through the weekend.
Most of us in Metro Atlanta stay dry during the daytime, but the chance of a shower or storm goes up before sunset, especially North and West suburbs.
The greatest risk of severe weather comes well after midnight through early Sunday morning. The risk level is currently a 1 on a scale of 1-5, (marginal) but COULD go up to level 2 in updates [More]